[lint] Use settings for additional hooks in exhaustive deps

Like in the diff below, we can read from the shared configuration to check exhaustive deps. I allow the classic additionalHooks configuration to override it so that this change is backwards compatible. --
[lint] Enable custom hooks configuration for useEffectEvent calling rules
2025-09-30 07:20:29 -04:00 · 2025-09-30 07:13:44 -04:00
1189 changed files with 16441 additions and 37418 deletions
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -331,7 +331,6 @@ module.exports = {
        'packages/react-server-dom-turbopack/**/*.js',
        'packages/react-server-dom-parcel/**/*.js',
        'packages/react-server-dom-fb/**/*.js',
-        'packages/react-server-dom-unbundled/**/*.js',
        'packages/react-test-renderer/**/*.js',
        'packages/react-debug-tools/**/*.js',
        'packages/react-devtools-extensions/**/*.js',
@@ -518,14 +517,6 @@ module.exports = {
        __IS_INTERNAL_VERSION__: 'readonly',
      },
    },
-    {
-      files: ['packages/react-devtools-*/**/*.js'],
-      excludedFiles: '**/__tests__/**/*.js',
-      plugins: ['eslint-plugin-react-hooks-published'],
-      rules: {
-        'react-hooks-published/rules-of-hooks': ERROR,
-      },
-    },
    {
      files: ['packages/eslint-plugin-react-hooks/src/**/*'],
      extends: ['plugin:@typescript-eslint/recommended'],
@@ -635,7 +626,6 @@ module.exports = {
    FocusOptions: 'readonly',
    OptionalEffectTiming: 'readonly',

-    __REACT_ROOT_PATH_TEST__: 'readonly',
    spyOnDev: 'readonly',
    spyOnDevAndProd: 'readonly',
    spyOnProd: 'readonly',
--- a/.github/ISSUE_TEMPLATE/compiler_bug_report.yml
+++ b/.github/ISSUE_TEMPLATE/compiler_bug_report.yml
@@ -11,7 +11,7 @@ body:
    options:
      - label: React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
      - label: babel-plugin-react-compiler (build issue installing or using the Babel plugin)
-      - label: eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
+      - label: eslint-plugin-react-compiler (build issue installing or using the eslint plugin)
      - label: react-compiler-healthcheck (build issue installing or using the healthcheck script)
 - type: input
  attributes:
--- a/.github/workflows/compiler_prereleases.yml
+++ b/.github/workflows/compiler_prereleases.yml
@@ -19,9 +19,6 @@ on:
      tag_version:
        required: false
        type: string
-      dry_run:
-        required: false
-        type: boolean
    secrets:
      NPM_TOKEN:
        required: true
@@ -58,13 +55,7 @@ jobs:
          key: compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/yarn.lock') }}
      - run: yarn install --frozen-lockfile
        if: steps.node_modules.outputs.cache-hit != 'true'
-      - if: inputs.dry_run == true
-        name: Publish packages to npm (dry run)
-        run: |
-          cp ./scripts/release/ci-npmrc ~/.npmrc
-          scripts/release/publish.js --frfr --debug --ci --versionName=${{ inputs.version_name }} --tag=${{ inputs.dist_tag }} ${{ inputs.tag_version && format('--tagVersion={0}', inputs.tag_version) || '' }}
-      - if: inputs.dry_run != true
-        name: Publish packages to npm
+      - name: Publish packages to npm
        run: |
          cp ./scripts/release/ci-npmrc ~/.npmrc
          scripts/release/publish.js --frfr --ci --versionName=${{ inputs.version_name }} --tag=${{ inputs.dist_tag }} ${{ inputs.tag_version && format('--tagVersion={0}', inputs.tag_version) || '' }}
--- a/.github/workflows/compiler_prereleases_manual.yml
+++ b/.github/workflows/compiler_prereleases_manual.yml
@@ -17,9 +17,6 @@ on:
      tag_version:
        required: false
        type: string
-      dry_run:
-        required: false
-        type: boolean

 permissions: {}

@@ -36,6 +33,5 @@ jobs:
      dist_tag: ${{ inputs.dist_tag }}
      version_name: ${{ inputs.version_name }}
      tag_version: ${{ inputs.tag_version }}
-      dry_run: ${{ inputs.dry_run }}
    secrets:
      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
--- a/.github/workflows/compiler_prereleases_nightly.yml
+++ b/.github/workflows/compiler_prereleases_nightly.yml
@@ -19,6 +19,5 @@ jobs:
      release_channel: experimental
      dist_tag: experimental
      version_name: '0.0.0'
-      dry_run: false
    secrets:
      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
--- a/.github/workflows/runtime_build_and_test.yml
+++ b/.github/workflows/runtime_build_and_test.yml
@@ -3,10 +3,6 @@ name: (Runtime) Build and Test
 on:
  push:
    branches: [main]
-    tags:
-      # To get CI for backport releases.
-      # This will duplicate CI for releases from main which is acceptable
-      - "v*"
  pull_request:
    paths-ignore:
      - compiler/**
@@ -45,7 +41,7 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
          lookup-only: true
      - uses: actions/setup-node@v4
        if: steps.node_modules.outputs.cache-hit != 'true'
@@ -59,8 +55,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          restore-keys: |
+            runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-node_modules-v6-
      - run: yarn install --frozen-lockfile
        if: steps.node_modules.outputs.cache-hit != 'true'
      - name: Save cache
@@ -69,7 +67,7 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}

  runtime_compiler_node_modules_cache:
    name: Cache Runtime, Compiler node_modules
@@ -84,7 +82,7 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
          lookup-only: true
      - uses: actions/setup-node@v4
        if: steps.node_modules.outputs.cache-hit != 'true'
@@ -100,8 +98,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          restore-keys: |
+            runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-and-compiler-node_modules-v6-
      - run: yarn install --frozen-lockfile
        if: steps.node_modules.outputs.cache-hit != 'true'
      - run: yarn --cwd compiler install --frozen-lockfile
@@ -112,7 +112,7 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}

  # ----- FLOW -----
  discover_flow_inline_configs:
@@ -154,8 +154,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          restore-keys: |
+            runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -182,8 +184,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          restore-keys: |
+            runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -212,7 +216,7 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -270,8 +274,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          restore-keys: |
+            runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-and-compiler-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -300,7 +306,7 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
      - name: Install runtime dependencies
        run: yarn install --frozen-lockfile
        if: steps.node_modules.outputs.cache-hit != 'true'
@@ -343,8 +349,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          restore-keys: |
+            runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-and-compiler-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -382,6 +390,9 @@ jobs:
          -r=experimental --env=development,
          -r=experimental --env=production,

+          # Dev Tools
+          --project=devtools -r=experimental,
+
          # TODO: Update test config to support www build tests
          # - "-r=www-classic --env=development --variant=false"
          # - "-r=www-classic --env=production --variant=false"
@@ -429,8 +440,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          restore-keys: |
+            runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-and-compiler-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -447,50 +460,6 @@ jobs:
        run: ls -R build
      - run: yarn test --build ${{ matrix.test_params }} --shard=${{ matrix.shard }} --ci

-  test_build_devtools:
-    name: yarn test-build (devtools)
-    needs: [build_and_lint, runtime_node_modules_cache]
-    strategy:
-      fail-fast: false
-      matrix:
-        shard:
-          - 1/5
-          - 2/5
-          - 3/5
-          - 4/5
-          - 5/5
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache/restore@v4
-        id: node_modules
-        with:
-          path: |
-            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
-      - name: Ensure clean build directory
-        run: rm -rf build
-      - run: yarn install --frozen-lockfile
-        if: steps.node_modules.outputs.cache-hit != 'true'
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - name: Display structure of build
-        run: ls -R build
-      - run: yarn test --build --project=devtools -r=experimental --shard=${{ matrix.shard }} --ci
-
  process_artifacts_combined:
    name: Process artifacts combined
    needs: [build_and_lint, runtime_node_modules_cache]
@@ -514,8 +483,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          restore-keys: |
+            runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -577,8 +548,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          restore-keys: |
+            runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -615,8 +588,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          restore-keys: |
+            runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -765,8 +740,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          restore-keys: |
+            runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
@@ -825,8 +802,10 @@ jobs:
        with:
          path: |
            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          restore-keys: |
+            runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-node_modules-v6-
      - name: Ensure clean build directory
        run: rm -rf build
      - run: yarn install --frozen-lockfile
--- a/.github/workflows/runtime_commit_artifacts.yml
+++ b/.github/workflows/runtime_commit_artifacts.yml
@@ -162,13 +162,10 @@ jobs:
          mv build/facebook-react-native/react-is/cjs/ $BASE_FOLDER/RKJSModules/vendor/react/react-is/
          mv build/facebook-react-native/react-test-renderer/cjs/ $BASE_FOLDER/RKJSModules/vendor/react/react-test-renderer/

-          # Delete the OSS renderers, these are sync'd to RN separately.
+          # Delete OSS renderer. OSS renderer is synced through internal script.
          RENDERER_FOLDER=$BASE_FOLDER/react-native-github/Libraries/Renderer/implementations/
          rm $RENDERER_FOLDER/ReactFabric-{dev,prod,profiling}.js
-          
-          # Delete the legacy renderer shim, this is not sync'd and will get deleted in the future.
-          SHIM_FOLDER=$BASE_FOLDER/react-native-github/Libraries/Renderer/shims/
-          rm $SHIM_FOLDER/ReactNative.js
+          rm $RENDERER_FOLDER/ReactNativeRenderer-{dev,prod,profiling}.js

          # Copy eslint-plugin-react-hooks
          # NOTE: This is different from www, here we include the full package
--- a/.github/workflows/runtime_prereleases.yml
+++ b/.github/workflows/runtime_prereleases.yml
@@ -82,6 +82,7 @@ jobs:
        run: |
          scripts/release/publish.js \
            --ci \
+            --skipTests \
            --tags=${{ inputs.dist_tag }} \
            --onlyPackages=${{ inputs.only_packages }} ${{ (inputs.dry && '') || '\'}}
            ${{ inputs.dry && '--dry' || '' }}
@@ -90,10 +91,11 @@ jobs:
        run: |
          scripts/release/publish.js \
            --ci \
+            --skipTests \
            --tags=${{ inputs.dist_tag }} \
            --skipPackages=${{ inputs.skip_packages }} ${{ (inputs.dry && '') || '\'}}
            ${{ inputs.dry && '--dry' || '' }}
-      - if: '${{ !inputs.skip_packages && !inputs.only_packages }}'
+      - if: '${{ !(inputs.skip_packages && inputs.only_packages) }}'
        name: 'Publish all packages'
        run: |
          scripts/release/publish.js \
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,88 +1,3 @@
-## 19.2.1 (Dec 3, 2025)
-
-### React Server Components
-
- Bring React Server Component fixes to Server Actions (@sebmarkbage [#35277](https://github.com/facebook/react/pull/35277))
-
-## 19.2.0 (October 1st, 2025)
-
-Below is a list of all new features, APIs, and bug fixes.
-
-Read the [React 19.2 release post](https://react.dev/blog/2025/10/01/react-19-2) for more information.
-
-### New React Features
-
- [`<Activity>`](https://react.dev/reference/react/Activity): A new API to hide and restore the UI and internal state of its children.
- [`useEffectEvent`](https://react.dev/reference/react/useEffectEvent) is a React Hook that lets you extract non-reactive logic into an [Effect Event](https://react.dev/learn/separating-events-from-effects#declaring-an-effect-event).
- [`cacheSignal`](https://react.dev/reference/react/cacheSignal) (for RSCs) lets your know when the `cache()` lifetime is over.
- [React Performance tracks](https://react.dev/reference/dev-tools/react-performance-tracks) appear on the Performance panel’s timeline in your browser developer tools
-
-### New React DOM Features
-
- Added resume APIs for partial pre-rendering with Web Streams:
-  - [`resume`](https://react.dev/reference/react-dom/server/resume): to resume a prerender to a stream.
-  - [`resumeAndPrerender`](https://react.dev/reference/react-dom/static/resumeAndPrerender): to resume a prerender to HTML.
- Added resume APIs for partial pre-rendering with Node Streams:
-  - [`resumeToPipeableStream`](https://react.dev/reference/react-dom/server/resumeToPipeableStream): to resume a prerender to a stream.
-  - [`resumeAndPrerenderToNodeStream`](https://react.dev/reference/react-dom/static/resumeAndPrerenderToNodeStream): to resume a prerender to HTML.
- Updated [`prerender`](https://react.dev/reference/react-dom/static/prerender) APIs to return a `postponed` state that can be passed to the `resume` APIs.
-
-### Notable changes
-
- React DOM now batches suspense boundary reveals, matching the behavior of client side rendering. This change is especially noticeable when animating the reveal of Suspense boundaries e.g. with the upcoming `<ViewTransition>` Component. React will batch as much reveals as possible before the first paint while trying to hit popular first-contentful paint metrics.
- Add Node Web Streams (`prerender`, `renderToReadableStream`) to server-side-rendering APIs for Node.js
- Use underscore instead of `:` IDs generated by useId
-
-### All Changes
-
-#### React
-
- `<Activity />` was developed over many years, starting before `ClassComponent.setState` (@acdlite @sebmarkbage and many others)
- Stringify context as "SomeContext" instead of "SomeContext.Provider" (@kassens [#33507](https://github.com/facebook/react/pull/33507))
- Include stack of cause of React instrumentation errors with `%o` placeholder (@eps1lon [#34198](https://github.com/facebook/react/pull/34198))
- Fix infinite `useDeferredValue` loop in popstate event (@acdlite [#32821](https://github.com/facebook/react/pull/32821))
- Fix a bug when an initial value was passed to `useDeferredValue` (@acdlite [#34376](https://github.com/facebook/react/pull/34376))
- Fix a crash when submitting forms with Client Actions (@sebmarkbage [#33055](https://github.com/facebook/react/pull/33055))
- Hide/unhide the content of dehydrated suspense boundaries if they resuspend (@sebmarkbage [#32900](https://github.com/facebook/react/pull/32900))
- Avoid stack overflow on wide trees during Hot Reload (@sophiebits [#34145](https://github.com/facebook/react/pull/34145))
- Improve Owner and Component stacks in various places (@sebmarkbage, @eps1lon: [#33629](https://github.com/facebook/react/pull/33629), [#33724](https://github.com/facebook/react/pull/33724), [#32735](https://github.com/facebook/react/pull/32735), [#33723](https://github.com/facebook/react/pull/33723))
- Add `cacheSignal` (@sebmarkbage [#33557](https://github.com/facebook/react/pull/33557))
-
-#### React DOM
-
- Block on Suspensey Fonts during reveal of server-side-rendered content (@sebmarkbage [#33342](https://github.com/facebook/react/pull/33342))
- Use underscore instead of `:` for IDs generated by `useId` (@sebmarkbage, @eps1lon: [#32001](https://github.com/facebook/react/pull/32001), [https://github.com/facebook/react/pull/33342](https://github.com/facebook/react/pull/33342)[#33099](https://github.com/facebook/react/pull/33099), [#33422](https://github.com/facebook/react/pull/33422))
- Stop warning when ARIA 1.3 attributes are used (@Abdul-Omira [#34264](https://github.com/facebook/react/pull/34264))
- Allow `nonce` to be used on hoistable styles (@Andarist [#32461](https://github.com/facebook/react/pull/32461))
- Warn for using a React owned node as a Container if it also has text content (@sebmarkbage [#32774](https://github.com/facebook/react/pull/32774))
- s/HTML/text for for error messages if text hydration mismatches (@rickhanlonii [#32763](https://github.com/facebook/react/pull/32763))
- Fix a bug with `React.use` inside `React.lazy`\-ed Component (@hi-ogawa [#33941](https://github.com/facebook/react/pull/33941))
- Enable the `progressiveChunkSize` option for server-side-rendering APIs (@sebmarkbage [#33027](https://github.com/facebook/react/pull/33027))
- Fix a bug with deeply nested Suspense inside Suspense fallback when server-side-rendering (@gnoff [#33467](https://github.com/facebook/react/pull/33467))
- Avoid hanging when suspending after aborting while rendering (@gnoff [#34192](https://github.com/facebook/react/pull/34192))
- Add Node Web Streams to server-side-rendering APIs for Node.js (@sebmarkbage [#33475](https://github.com/facebook/react/pull/33475))
-
-#### React Server Components
-
- Preload `<img>` and `<link>` using hints before they're rendered (@sebmarkbage [#34604](https://github.com/facebook/react/pull/34604))
- Log error if production elements are rendered during development (@eps1lon [#34189](https://github.com/facebook/react/pull/34189))
- Fix a bug when returning a Temporary reference (e.g. a Client Reference) from Server Functions (@sebmarkbage [#34084](https://github.com/facebook/react/pull/34084), @denk0403 [#33761](https://github.com/facebook/react/pull/33761))
- Pass line/column to `filterStackFrame` (@eps1lon [#33707](https://github.com/facebook/react/pull/33707))
- Support Async Modules in Turbopack Server References (@lubieowoce [#34531](https://github.com/facebook/react/pull/34531))
- Add support for .mjs file extension in Webpack (@jennyscript [#33028](https://github.com/facebook/react/pull/33028))
- Fix a wrong missing key warning (@unstubbable [#34350](https://github.com/facebook/react/pull/34350))
- Make console log resolve in predictable order (@sebmarkbage [#33665](https://github.com/facebook/react/pull/33665))
-
-#### React Reconciler
-
- [createContainer](https://github.com/facebook/react/blob/v19.2.0/packages/react-reconciler/src/ReactFiberReconciler.js#L255-L261) and [createHydrationContainer](https://github.com/facebook/react/blob/v19.2.0/packages/react-reconciler/src/ReactFiberReconciler.js#L305-L312) had their parameter order adjusted after `on*` handlers to account for upcoming experimental APIs
-
-## 19.1.2 (Dec 3, 2025)
-
-### React Server Components
-
- Bring React Server Component fixes to Server Actions (@sebmarkbage [#35277](https://github.com/facebook/react/pull/35277))
-
 ## 19.1.1 (July 28, 2025)

 ### React
@@ -135,12 +50,6 @@ An Owner Stack is a string representing the components that are directly respons
 * Exposed `registerServerReference` in client builds to handle server references in different environments. [#32534](https://github.com/facebook/react/pull/32534)
 * Added react-server-dom-parcel package which integrates Server Components with the [Parcel bundler](https://parceljs.org/) [#31725](https://github.com/facebook/react/pull/31725), [#32132](https://github.com/facebook/react/pull/32132), [#31799](https://github.com/facebook/react/pull/31799), [#32294](https://github.com/facebook/react/pull/32294), [#31741](https://github.com/facebook/react/pull/31741)

-## 19.0.1 (Dec 3, 2025)
-
-### React Server Components
-
- Bring React Server Component fixes to Server Actions (@sebmarkbage [#35277](https://github.com/facebook/react/pull/35277))
-
 ## 19.0.0 (December 5, 2024)

 Below is a list of all new features, APIs, deprecations, and breaking changes. Read [React 19 release post](https://react.dev/blog/2024/04/25/react-19) and [React 19 upgrade guide](https://react.dev/blog/2024/04/25/react-19-upgrade-guide) for more information.
--- a/ReactVersions.js
+++ b/ReactVersions.js
@@ -7,18 +7,18 @@
 //
 // The @latest channel uses the version as-is, e.g.:
 //
-//   19.3.0
+//   19.1.0
 //
 // The @canary channel appends additional information, with the scheme
 // <version>-<label>-<commit_sha>, e.g.:
 //
-//   19.3.0-canary-a1c2d3e4
+//   19.1.0-canary-a1c2d3e4
 //
 // The @experimental channel doesn't include a version, only a date and a sha, e.g.:
 //
 //   0.0.0-experimental-241c4467e-20200129

-const ReactVersion = '19.3.0';
+const ReactVersion = '19.2.0';

 // The label used by the @canary channel. Represents the upcoming release's
 // stability. Most of the time, this will be "canary", but we may temporarily
@@ -33,8 +33,8 @@ const canaryChannelLabel = 'canary';
 const rcNumber = 0;

 const stablePackages = {
-  'eslint-plugin-react-hooks': '7.1.0',
-  'jest-react': '0.18.0',
+  'eslint-plugin-react-hooks': '6.1.0',
+  'jest-react': '0.17.0',
  react: ReactVersion,
  'react-art': ReactVersion,
  'react-dom': ReactVersion,
@@ -42,12 +42,12 @@ const stablePackages = {
  'react-server-dom-turbopack': ReactVersion,
  'react-server-dom-parcel': ReactVersion,
  'react-is': ReactVersion,
-  'react-reconciler': '0.34.0',
-  'react-refresh': '0.19.0',
+  'react-reconciler': '0.33.0',
+  'react-refresh': '0.18.0',
  'react-test-renderer': ReactVersion,
-  'use-subscription': '1.13.0',
-  'use-sync-external-store': '1.7.0',
-  scheduler: '0.28.0',
+  'use-subscription': '1.12.0',
+  'use-sync-external-store': '1.6.0',
+  scheduler: '0.27.0',
 };

 // These packages do not exist in the @canary or @latest channel, only
--- a/compiler/.claude/settings.local.json
+++ b/compiler/.claude/settings.local.json
@@ -1,20 +0,0 @@
-{
-  "permissions": {
-    "allow": [
-      "Bash(node scripts/enable-feature-flag.js:*)",
-      "Bash(yarn snap:*)",
-      "Bash(for test in \"error.invalid-access-ref-during-render\" \"error.invalid-ref-in-callback-invoked-during-render\" \"error.invalid-impure-functions-in-render-via-render-helper\")",
-      "Bash(do)",
-      "Bash(echo:*)",
-      "Bash(done)",
-      "Bash(cat:*)",
-      "Bash(sl revert:*)",
-      "Bash(yarn workspace snap run build:*)",
-      "Bash(yarn tsc:*)",
-      "Bash(yarn snap:build)",
-      "Bash(timeout 30 yarn snap:*)"
-    ],
-    "deny": [],
-    "ask": []
-  }
-}
--- a/compiler/CLAUDE.md
+++ b/compiler/CLAUDE.md
@@ -1,245 +0,0 @@
-# React Compiler Knowledge Base
-
-This document contains knowledge about the React Compiler gathered during development sessions. It serves as a reference for understanding the codebase architecture and key concepts.
-
-## Project Structure
-
- `packages/babel-plugin-react-compiler/` - Main compiler package
-  - `src/HIR/` - High-level Intermediate Representation types and utilities
-  - `src/Inference/` - Effect inference passes (aliasing, mutation, etc.)
-  - `src/Validation/` - Validation passes that check for errors
-  - `src/Entrypoint/Pipeline.ts` - Main compilation pipeline with pass ordering
-  - `src/__tests__/fixtures/compiler/` - Test fixtures
-    - `error.*.js` - Fixtures that should produce compilation errors
-    - `*.expect.md` - Expected output for each fixture
-
-## Running Tests
-
-```bash
-# Run all tests
-yarn snap
-
-# Run specific test by pattern
-yarn snap -p <pattern>
-
-# Update fixture outputs
-yarn snap -u
-```
-
-## Version Control
-
-This repository uses Sapling (`sl`) for version control. Unlike git, Sapling does not require explicitly adding files to the staging area.
-
-```bash
-# Check status
-sl status
-
-# Commit all changes
-sl commit -m "Your commit message"
-
-# Commit with multi-line message using heredoc
-sl commit -m "$(cat <<'EOF'
-Summary line
-
-Detailed description here
-EOF
-)"
-```
-
-## Key Concepts
-
-### HIR (High-level Intermediate Representation)
-
-The compiler converts source code to HIR for analysis. Key types in `src/HIR/HIR.ts`:
-
- **HIRFunction** - A function being compiled
-  - `body.blocks` - Map of BasicBlocks
-  - `context` - Captured variables from outer scope
-  - `params` - Function parameters
-  - `returns` - The function's return place
-  - `aliasingEffects` - Effects that describe the function's behavior when called
-
- **Instruction** - A single operation
-  - `lvalue` - The place being assigned to
-  - `value` - The instruction kind (CallExpression, FunctionExpression, LoadLocal, etc.)
-  - `effects` - Array of AliasingEffects for this instruction
-
- **Terminal** - Block terminators (return, branch, etc.)
-  - `effects` - Array of AliasingEffects
-
- **Place** - A reference to a value
-  - `identifier.id` - Unique IdentifierId
-
- **Phi nodes** - Join points for values from different control flow paths
-  - Located at `block.phis`
-  - `phi.place` - The result place
-  - `phi.operands` - Map of predecessor block to source place
-
-### AliasingEffects System
-
-Effects describe data flow and operations. Defined in `src/Inference/AliasingEffects.ts`:
-
-**Data Flow Effects:**
- `Impure` - Marks a place as containing an impure value (e.g., Date.now() result, ref.current)
- `Capture a -> b` - Value from `a` is captured into `b` (mutable capture)
- `Alias a -> b` - `b` aliases `a`
- `ImmutableCapture a -> b` - Immutable capture (like Capture but read-only)
- `Assign a -> b` - Direct assignment
- `MaybeAlias a -> b` - Possible aliasing
- `CreateFrom a -> b` - Created from source
-
-**Mutation Effects:**
- `Mutate value` - Value is mutated
- `MutateTransitive value` - Value and transitive captures are mutated
- `MutateConditionally value` - May mutate
- `MutateTransitiveConditionally value` - May mutate transitively
-
-**Other Effects:**
- `Render place` - Place is used in render context (JSX props, component return)
- `Freeze place` - Place is frozen (made immutable)
- `Create place` - New value created
- `CreateFunction` - Function expression created, includes `captures` array
- `Apply` - Function application with receiver, function, args, and result
-
-### Hook Aliasing Signatures
-
-Located in `src/HIR/Globals.ts`, hooks can define custom aliasing signatures to control how data flows through them.
-
-**Structure:**
-```typescript
-aliasing: {
-  receiver: '@receiver',    // The hook function itself
-  params: ['@param0'],      // Named positional parameters
-  rest: '@rest',            // Rest parameters (or null)
-  returns: '@returns',      // Return value
-  temporaries: [],          // Temporary values during execution
-  effects: [                // Array of effects to apply when hook is called
-    {kind: 'Freeze', value: '@param0', reason: ValueReason.HookCaptured},
-    {kind: 'Assign', from: '@param0', into: '@returns'},
-  ],
-}
-```
-
-**Common patterns:**
-
-1. **RenderHookAliasing** (useState, useContext, useMemo, useCallback):
-   - Freezes arguments (`Freeze @rest`)
-   - Marks arguments as render-time (`Render @rest`)
-   - Creates frozen return value
-   - Aliases arguments to return
-
-2. **EffectHookAliasing** (useEffect, useLayoutEffect, useInsertionEffect):
-   - Freezes function and deps
-   - Creates internal effect object
-   - Captures function and deps into effect
-   - Returns undefined
-
-3. **Event handler hooks** (useEffectEvent):
-   - Freezes callback (`Freeze @fn`)
-   - Aliases input to return (`Assign @fn -> @returns`)
-   - NO Render effect (callback not called during render)
-
-**Example: useEffectEvent**
-```typescript
-const UseEffectEventHook = addHook(
-  DEFAULT_SHAPES,
-  {
-    positionalParams: [Effect.Freeze],  // Takes one positional param
-    restParam: null,
-    returnType: {kind: 'Function', ...},
-    calleeEffect: Effect.Read,
-    hookKind: 'useEffectEvent',
-    returnValueKind: ValueKind.Frozen,
-    aliasing: {
-      receiver: '@receiver',
-      params: ['@fn'],              // Name for the callback parameter
-      rest: null,
-      returns: '@returns',
-      temporaries: [],
-      effects: [
-        {kind: 'Freeze', value: '@fn', reason: ValueReason.HookCaptured},
-        {kind: 'Assign', from: '@fn', into: '@returns'},
-        // Note: NO Render effect - callback is not called during render
-      ],
-    },
-  },
-  BuiltInUseEffectEventId,
-);
-
-// Add as both names for compatibility
-['useEffectEvent', UseEffectEventHook],
-['experimental_useEffectEvent', UseEffectEventHook],
-```
-
-**Key insight:** If a hook is missing an `aliasing` config, it falls back to `DefaultNonmutatingHook` which includes a `Render` effect on all arguments. This can cause false positives for hooks like `useEffectEvent` whose callbacks are not called during render.
-
-### Effect Inference Pipeline
-
-Effects are populated by `InferMutationAliasingEffects` (runs before validation):
-
-1. For `Date.now()`, `Math.random()` etc. - adds `Impure` effect (controlled by `validateNoImpureFunctionsInRender` config)
-2. For `ref.current` access - adds `Impure` effect (controlled by `validateRefAccessDuringRender` config)
-3. For return terminals - adds `Alias` from return value to `fn.returns`
-4. For component/JSX returns - adds `Render` effect
-5. For function expressions - adds `CreateFunction` effect with captures
-
-### Validation: validateNoImpureValuesInRender
-
-Located at `src/Validation/ValidateNoImpureValuesInRender.ts`
-
-**Purpose:** Detect when impure values (refs, Date.now results, etc.) flow into render context.
-
-**Algorithm:**
-1. Track impure values in a Map<IdentifierId, ImpureEffect>
-2. Track functions with impure returns separately (they're not impure values themselves)
-3. Fixed-point iteration over all blocks:
-   - Process phi nodes (any impure operand makes result impure)
-   - Process instruction effects
-   - Process terminal effects
-   - Backwards propagation for mutated LoadLocal values
-4. Validate: check all Render effects against impure values
-
-**Key patterns:**
- `Impure` effect marks the target as impure
- `Capture/Alias/etc` propagates impurity from source to target
- `Apply` propagates impurity from args/receiver to result
- `CreateFunction` propagates impurity from captured values (but NOT from body effects)
- If a value has both `Render` and `Capture` in same instruction, only error on Render (don't cascade)
-
-**Tracking functions with impure returns:**
- Separate from the `impure` map (function values aren't impure, just their returns)
- Populated when analyzing FunctionExpression bodies
- Used when:
-  1. Calling the function - mark call result as impure
-  2. Capturing the function - mark target as impure (for object.foo = impureFunc cases)
-
-**Backwards propagation:**
- When `$x = LoadLocal y` and `$x` is mutated with impure content, mark `y` as impure
- This handles: `const arr = []; arr.push(impure); render(arr)`
-
-## Known Issues / Edge Cases
-
-### Function Outlining
-After `OutlineFunctions` pass, inner functions are replaced with `LoadGlobal(_temp)`. The validation runs BEFORE outlining, so it sees the original FunctionExpression. But be aware that test output shows post-outlining HIR.
-
-### SSA and LoadLocal
-In SSA form, each `LoadLocal` creates a new identifier. When a loaded value is mutated:
- `$x = LoadLocal y`
- `mutate($x, impure)`
- `$z = LoadLocal y` (different from $x!)
- `render($z)`
-
-The impurity in $x must propagate back to y, then forward to $z. This requires backwards propagation in the fixed-point loop.
-
-## Configuration Flags
-
-In `Environment.ts` / test directives:
- `validateNoImpureFunctionsInRender` - Enable impure function validation (Date.now, Math.random, etc.)
- `validateRefAccessDuringRender` - Enable ref access validation
-
-## Debugging Tips
-
-1. Run `yarn snap -p <fixture>` to see full HIR output with effects
-2. Look for `@aliasingEffects=` on FunctionExpressions
-3. Look for `Impure`, `Render`, `Capture` effects on instructions
-4. Check the pass ordering in Pipeline.ts to understand when effects are populated vs validated
--- a/compiler/apps/playground/.gitignore
+++ b/compiler/apps/playground/.gitignore
@@ -12,7 +12,6 @@
 # next.js
 /.next/
 /out/
-/next-env.d.ts

 # production
 /build
--- a/compiler/apps/playground/tests/e2e/page.spec.ts
+++ b/compiler/apps/playground/tests/e2e/page.spec.ts
@@ -23,8 +23,7 @@ function formatPrint(data: Array<string>): Promise<string> {

 async function expandConfigs(page: Page): Promise<void> {
  const expandButton = page.locator('[title="Expand config editor"]');
-  await expandButton.click();
-  await page.waitForSelector('.monaco-editor-config', {state: 'visible'});
+  expandButton.click();
 }

 const TEST_SOURCE = `export default function TestComponent({ x }) {
@@ -314,36 +313,6 @@ test('disableMemoizationForDebugging flag works as expected', async ({
  expect(output).toMatchSnapshot('disableMemoizationForDebugging-output.txt');
 });

-test('error is displayed when source has syntax error', async ({page}) => {
-  const syntaxErrorSource = `function TestComponent(props) {
-  const oops = props.
-  return (
-    <>{oops}</>
-  );
-}`;
-  const store: Store = {
-    source: syntaxErrorSource,
-    config: defaultConfig,
-    showInternals: false,
-  };
-  const hash = encodeStore(store);
-  await page.goto(`/#${hash}`);
-  await page.waitForFunction(isMonacoLoaded);
-  await expandConfigs(page);
-  await page.screenshot({
-    fullPage: true,
-    path: 'test-results/08-source-syntax-error.png',
-  });
-
-  const text =
-    (await page.locator('.monaco-editor-output').allInnerTexts()) ?? [];
-  const output = text.join('');
-
-  expect(output.replace(/\s+/g, ' ')).toContain(
-    'Expected identifier to be defined before being used',
-  );
-});
-
 TEST_CASE_INPUTS.forEach((t, idx) =>
  test(`playground compiles: ${t.name}`, async ({page}) => {
    const store: Store = {
--- a/compiler/apps/playground/components/AccordionWindow.tsx
+++ b/compiler/apps/playground/components/AccordionWindow.tsx
@@ -6,13 +6,7 @@
 */

 import {Resizable} from 're-resizable';
-import React, {
-  useId,
-  unstable_ViewTransition as ViewTransition,
-  unstable_addTransitionType as addTransitionType,
-  startTransition,
-} from 'react';
-import {EXPAND_ACCORDION_TRANSITION} from '../lib/transitionTypes';
+import React, {useCallback} from 'react';

 type TabsRecord = Map<string, React.ReactNode>;

@@ -24,21 +18,19 @@ export default function AccordionWindow(props: {
  changedPasses: Set<string>;
 }): React.ReactElement {
  return (
-    <div className="flex-1 min-w-[550px] sm:min-w-0">
-      <div className="flex flex-row h-full">
-        {Array.from(props.tabs.keys()).map(name => {
-          return (
-            <AccordionWindowItem
-              name={name}
-              key={name}
-              tabs={props.tabs}
-              tabsOpen={props.tabsOpen}
-              setTabsOpen={props.setTabsOpen}
-              hasChanged={props.changedPasses.has(name)}
-            />
-          );
-        })}
-      </div>
+    <div className="flex flex-row h-full">
+      {Array.from(props.tabs.keys()).map(name => {
+        return (
+          <AccordionWindowItem
+            name={name}
+            key={name}
+            tabs={props.tabs}
+            tabsOpen={props.tabsOpen}
+            setTabsOpen={props.setTabsOpen}
+            hasChanged={props.changedPasses.has(name)}
+          />
+        );
+      })}
    </div>
  );
 }
@@ -55,25 +47,18 @@ function AccordionWindowItem({
  tabsOpen: Set<string>;
  setTabsOpen: (newTab: Set<string>) => void;
  hasChanged: boolean;
-  isFailure: boolean;
 }): React.ReactElement {
-  const id = useId();
  const isShow = tabsOpen.has(name);

-  const transitionName = `accordion-window-item-${id}`;
-
-  const toggleTabs = (): void => {
-    startTransition(() => {
-      addTransitionType(EXPAND_ACCORDION_TRANSITION);
-      const nextState = new Set(tabsOpen);
-      if (nextState.has(name)) {
-        nextState.delete(name);
-      } else {
-        nextState.add(name);
-      }
-      setTabsOpen(nextState);
-    });
-  };
+  const toggleTabs = useCallback(() => {
+    const nextState = new Set(tabsOpen);
+    if (nextState.has(name)) {
+      nextState.delete(name);
+    } else {
+      nextState.add(name);
+    }
+    setTabsOpen(nextState);
+  }, [tabsOpen, name, setTabsOpen]);

  // Replace spaces with non-breaking spaces
  const displayName = name.replace(/ /g, '\u00A0');
@@ -81,45 +66,31 @@ function AccordionWindowItem({
  return (
    <div key={name} className="flex flex-row">
      {isShow ? (
-        <ViewTransition
-          name={transitionName}
-          update={{
-            [EXPAND_ACCORDION_TRANSITION]: 'expand-accordion',
-            default: 'none',
-          }}>
-          <Resizable className="border-r" minWidth={550} enable={{right: true}}>
-            <h2
-              title="Minimize tab"
-              aria-label="Minimize tab"
-              onClick={toggleTabs}
-              className={`p-4 duration-150 ease-in border-b cursor-pointer border-grey-200 ${
-                hasChanged ? 'font-bold' : 'font-light'
-              } text-secondary hover:text-link`}>
-              - {displayName}
-            </h2>
-            {tabs.get(name) ?? <div>No output for {name}</div>}
-          </Resizable>
-        </ViewTransition>
+        <Resizable className="border-r" minWidth={550} enable={{right: true}}>
+          <h2
+            title="Minimize tab"
+            aria-label="Minimize tab"
+            onClick={toggleTabs}
+            className={`p-4 duration-150 ease-in border-b cursor-pointer border-grey-200 ${
+              hasChanged ? 'font-bold' : 'font-light'
+            } text-secondary hover:text-link`}>
+            - {displayName}
+          </h2>
+          {tabs.get(name) ?? <div>No output for {name}</div>}
+        </Resizable>
      ) : (
-        <ViewTransition
-          name={transitionName}
-          update={{
-            [EXPAND_ACCORDION_TRANSITION]: 'expand-accordion',
-            default: 'none',
-          }}>
-          <div className="relative items-center h-full px-1 py-6 align-middle border-r border-grey-200">
-            <button
-              title={`Expand compiler tab: ${name}`}
-              aria-label={`Expand compiler tab: ${name}`}
-              style={{transform: 'rotate(90deg) translate(-50%)'}}
-              onClick={toggleTabs}
-              className={`flex-grow-0 w-5 transition-colors duration-150 ease-in ${
-                hasChanged ? 'font-bold' : 'font-light'
-              } text-secondary hover:text-link`}>
-              {displayName}
-            </button>
-          </div>
-        </ViewTransition>
+        <div className="relative items-center h-full px-1 py-6 align-middle border-r border-grey-200">
+          <button
+            title={`Expand compiler tab: ${name}`}
+            aria-label={`Expand compiler tab: ${name}`}
+            style={{transform: 'rotate(90deg) translate(-50%)'}}
+            onClick={toggleTabs}
+            className={`flex-grow-0 w-5 transition-colors duration-150 ease-in ${
+              hasChanged ? 'font-bold' : 'font-light'
+            } text-secondary hover:text-link`}>
+            {displayName}
+          </button>
+        </div>
      )}
    </div>
  );
--- a/compiler/apps/playground/components/Editor/ConfigEditor.tsx
+++ b/compiler/apps/playground/components/Editor/ConfigEditor.tsx
@@ -6,20 +6,15 @@
 */

 import MonacoEditor, {loader, type Monaco} from '@monaco-editor/react';
+import {PluginOptions} from 'babel-plugin-react-compiler';
 import type {editor} from 'monaco-editor';
 import * as monaco from 'monaco-editor';
-import React, {
-  useState,
-  useRef,
-  unstable_ViewTransition as ViewTransition,
-  unstable_addTransitionType as addTransitionType,
-  startTransition,
-} from 'react';
+import React, {useState, useRef} from 'react';
 import {Resizable} from 're-resizable';
 import {useStore, useStoreDispatch} from '../StoreContext';
-import {monacoConfigOptions} from './monacoOptions';
+import {monacoOptions} from './monacoOptions';
 import {IconChevron} from '../Icons/IconChevron';
-import {CONFIG_PANEL_TRANSITION} from '../../lib/transitionTypes';
+import prettyFormat from 'pretty-format';

 // @ts-expect-error - webpack asset/source loader handles .d.ts files as strings
 import compilerTypeDefs from 'babel-plugin-react-compiler/dist/index.d.ts';
@@ -27,56 +22,40 @@ import compilerTypeDefs from 'babel-plugin-react-compiler/dist/index.d.ts';
 loader.config({monaco});

 export default function ConfigEditor({
-  formattedAppliedConfig,
+  appliedOptions,
 }: {
-  formattedAppliedConfig: string;
+  appliedOptions: PluginOptions | null;
 }): React.ReactElement {
  const [isExpanded, setIsExpanded] = useState(false);

-  // TODO: Add back <Activity> after upgrading next.js
  return (
+    // TODO: Use <Activity> when it is compatible with Monaco: https://github.com/suren-atoyan/monaco-react/issues/753
    <>
      <div
        style={{
          display: isExpanded ? 'block' : 'none',
        }}>
-        {/* <Activity mode={isExpanded ? 'visible' : 'hidden'}> */}
        <ExpandedEditor
-          onToggle={() => {
-            startTransition(() => {
-              addTransitionType(CONFIG_PANEL_TRANSITION);
-              setIsExpanded(false);
-            });
-          }}
-          formattedAppliedConfig={formattedAppliedConfig}
+          onToggle={setIsExpanded}
+          appliedOptions={appliedOptions}
        />
      </div>
      <div
        style={{
          display: !isExpanded ? 'block' : 'none',
        }}>
-        {/* </Activity>
-        <Activity mode={isExpanded ? 'hidden' : 'visible'}></Activity> */}
-        <CollapsedEditor
-          onToggle={() => {
-            startTransition(() => {
-              addTransitionType(CONFIG_PANEL_TRANSITION);
-              setIsExpanded(true);
-            });
-          }}
-        />
+        <CollapsedEditor onToggle={setIsExpanded} />
      </div>
-      {/* </Activity> */}
    </>
  );
 }

 function ExpandedEditor({
  onToggle,
-  formattedAppliedConfig,
+  appliedOptions,
 }: {
  onToggle: (expanded: boolean) => void;
-  formattedAppliedConfig: string;
+  appliedOptions: PluginOptions | null;
 }): React.ReactElement {
  const store = useStore();
  const dispatchStore = useStoreDispatch();
@@ -124,80 +103,98 @@ function ExpandedEditor({
    });
  };

-  return (
-    <ViewTransition
-      update={{[CONFIG_PANEL_TRANSITION]: 'slide-in', default: 'none'}}>
-      {/* enter={{[CONFIG_PANEL_TRANSITION]: 'slide-in', default: 'none'}}
-      exit={{[CONFIG_PANEL_TRANSITION]: 'slide-out', default: 'none'}}> */}
-      <Resizable
-        minWidth={300}
-        maxWidth={600}
-        defaultSize={{width: 350}}
-        enable={{right: true, bottom: false}}>
-        <div className="bg-blue-10 relative h-full flex flex-col !h-[calc(100vh_-_3.5rem)] border border-gray-300">
-          <div
-            className="absolute w-8 h-16 bg-blue-10 rounded-r-full flex items-center justify-center z-[2] cursor-pointer border border-l-0 border-gray-300"
-            title="Minimize config editor"
-            onClick={onToggle}
-            style={{
-              top: '50%',
-              marginTop: '-32px',
-              right: '-32px',
-              borderTopLeftRadius: 0,
-              borderBottomLeftRadius: 0,
-            }}>
-            <IconChevron displayDirection="left" className="text-blue-50" />
-          </div>
+  const formattedAppliedOptions = appliedOptions
+    ? prettyFormat(appliedOptions, {
+        printFunctionName: false,
+        printBasicPrototype: false,
+      })
+    : 'Invalid configs';

-          <div className="flex-1 flex flex-col m-2 mb-2">
-            <div className="pb-2">
-              <h2 className="inline-block text-blue-50 py-1.5 px-1.5 xs:px-3 sm:px-4 text-sm">
-                Config Overrides
-              </h2>
-            </div>
-            <div className="flex-1 border border-gray-300">
-              <MonacoEditor
-                path={'config.ts'}
-                language={'typescript'}
-                value={store.config}
-                onMount={handleMount}
-                onChange={handleChange}
-                loading={''}
-                className="monaco-editor-config"
-                options={monacoConfigOptions}
-              />
-            </div>
+  return (
+    <Resizable
+      minWidth={300}
+      maxWidth={600}
+      defaultSize={{width: 350}}
+      enable={{right: true, bottom: false}}>
+      <div className="bg-blue-10 relative h-full flex flex-col !h-[calc(100vh_-_3.5rem)] border border-gray-300">
+        <div
+          className="absolute w-8 h-16 bg-blue-10 rounded-r-full flex items-center justify-center z-[2] cursor-pointer border border-l-0 border-gray-300"
+          title="Minimize config editor"
+          onClick={() => onToggle(false)}
+          style={{
+            top: '50%',
+            marginTop: '-32px',
+            right: '-32px',
+            borderTopLeftRadius: 0,
+            borderBottomLeftRadius: 0,
+          }}>
+          <IconChevron displayDirection="left" className="text-blue-50" />
+        </div>
+
+        <div className="flex-1 flex flex-col m-2 mb-2">
+          <div className="pb-2">
+            <h2 className="inline-block text-blue-50 py-1.5 px-1.5 xs:px-3 sm:px-4 text-sm">
+              Config Overrides
+            </h2>
          </div>
-          <div className="flex-1 flex flex-col m-2">
-            <div className="pb-2">
-              <h2 className="inline-block text-blue-50 py-1.5 px-1.5 xs:px-3 sm:px-4 text-sm">
-                Applied Configs
-              </h2>
-            </div>
-            <div className="flex-1 border border-gray-300">
-              <MonacoEditor
-                path={'applied-config.js'}
-                language={'javascript'}
-                value={formattedAppliedConfig}
-                loading={''}
-                className="monaco-editor-applied-config"
-                options={{
-                  ...monacoConfigOptions,
-                  readOnly: true,
-                }}
-              />
-            </div>
+          <div className="flex-1 rounded-lg overflow-hidden border border-gray-300">
+            <MonacoEditor
+              path={'config.ts'}
+              language={'typescript'}
+              value={store.config}
+              onMount={handleMount}
+              onChange={handleChange}
+              loading={''}
+              className="monaco-editor-config"
+              options={{
+                ...monacoOptions,
+                lineNumbers: 'off',
+                renderLineHighlight: 'none',
+                overviewRulerBorder: false,
+                overviewRulerLanes: 0,
+                fontSize: 12,
+                scrollBeyondLastLine: false,
+                glyphMargin: false,
+              }}
+            />
          </div>
        </div>
-      </Resizable>
-    </ViewTransition>
+        <div className="flex-1 flex flex-col m-2">
+          <div className="pb-2">
+            <h2 className="inline-block text-blue-50 py-1.5 px-1.5 xs:px-3 sm:px-4 text-sm">
+              Applied Configs
+            </h2>
+          </div>
+          <div className="flex-1 rounded-lg overflow-hidden border border-gray-300">
+            <MonacoEditor
+              path={'applied-config.js'}
+              language={'javascript'}
+              value={formattedAppliedOptions}
+              loading={''}
+              className="monaco-editor-applied-config"
+              options={{
+                ...monacoOptions,
+                lineNumbers: 'off',
+                renderLineHighlight: 'none',
+                overviewRulerBorder: false,
+                overviewRulerLanes: 0,
+                fontSize: 12,
+                scrollBeyondLastLine: false,
+                readOnly: true,
+                glyphMargin: false,
+              }}
+            />
+          </div>
+        </div>
+      </div>
+    </Resizable>
  );
 }

 function CollapsedEditor({
  onToggle,
 }: {
-  onToggle: () => void;
+  onToggle: (expanded: boolean) => void;
 }): React.ReactElement {
  return (
    <div
@@ -206,7 +203,7 @@ function CollapsedEditor({
      <div
        className="absolute w-10 h-16 bg-blue-10 hover:translate-x-2 transition-transform rounded-r-full flex items-center justify-center z-[2] cursor-pointer border border-gray-300"
        title="Expand config editor"
-        onClick={onToggle}
+        onClick={() => onToggle(true)}
        style={{
          top: '50%',
          marginTop: '-32px',
--- a/compiler/apps/playground/components/Editor/EditorImpl.tsx
+++ b/compiler/apps/playground/components/Editor/EditorImpl.tsx
@@ -5,17 +5,312 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {
+import {parse as babelParse, ParseResult} from '@babel/parser';
+import * as HermesParser from 'hermes-parser';
+import * as t from '@babel/types';
+import BabelPluginReactCompiler, {
+  CompilerError,
  CompilerErrorDetail,
  CompilerDiagnostic,
+  Effect,
+  ErrorCategory,
+  parseConfigPragmaForTests,
+  ValueKind,
+  type Hook,
+  PluginOptions,
+  CompilerPipelineValue,
+  parsePluginOptions,
+  printReactiveFunctionWithOutlined,
+  printFunctionWithOutlined,
+  type LoggerEvent,
 } from 'babel-plugin-react-compiler';
-import {useDeferredValue, useMemo, useState} from 'react';
+import {useDeferredValue, useMemo} from 'react';
 import {useStore} from '../StoreContext';
 import ConfigEditor from './ConfigEditor';
 import Input from './Input';
-import {CompilerOutput, default as Output} from './Output';
-import {compile} from '../../lib/compilation';
-import prettyFormat from 'pretty-format';
+import {
+  CompilerOutput,
+  CompilerTransformOutput,
+  default as Output,
+  PrintedCompilerPipelineValue,
+} from './Output';
+import {transformFromAstSync} from '@babel/core';
+
+function parseInput(
+  input: string,
+  language: 'flow' | 'typescript',
+): ParseResult<t.File> {
+  // Extract the first line to quickly check for custom test directives
+  if (language === 'flow') {
+    return HermesParser.parse(input, {
+      babel: true,
+      flow: 'all',
+      sourceType: 'module',
+      enableExperimentalComponentSyntax: true,
+    });
+  } else {
+    return babelParse(input, {
+      plugins: ['typescript', 'jsx'],
+      sourceType: 'module',
+    }) as ParseResult<t.File>;
+  }
+}
+
+function invokeCompiler(
+  source: string,
+  language: 'flow' | 'typescript',
+  options: PluginOptions,
+): CompilerTransformOutput {
+  const ast = parseInput(source, language);
+  let result = transformFromAstSync(ast, source, {
+    filename: '_playgroundFile.js',
+    highlightCode: false,
+    retainLines: true,
+    plugins: [[BabelPluginReactCompiler, options]],
+    ast: true,
+    sourceType: 'module',
+    configFile: false,
+    sourceMaps: true,
+    babelrc: false,
+  });
+  if (result?.ast == null || result?.code == null || result?.map == null) {
+    throw new Error('Expected successful compilation');
+  }
+  return {
+    code: result.code,
+    sourceMaps: result.map,
+    language,
+  };
+}
+
+const COMMON_HOOKS: Array<[string, Hook]> = [
+  [
+    'useFragment',
+    {
+      valueKind: ValueKind.Frozen,
+      effectKind: Effect.Freeze,
+      noAlias: true,
+      transitiveMixedData: true,
+    },
+  ],
+  [
+    'usePaginationFragment',
+    {
+      valueKind: ValueKind.Frozen,
+      effectKind: Effect.Freeze,
+      noAlias: true,
+      transitiveMixedData: true,
+    },
+  ],
+  [
+    'useRefetchableFragment',
+    {
+      valueKind: ValueKind.Frozen,
+      effectKind: Effect.Freeze,
+      noAlias: true,
+      transitiveMixedData: true,
+    },
+  ],
+  [
+    'useLazyLoadQuery',
+    {
+      valueKind: ValueKind.Frozen,
+      effectKind: Effect.Freeze,
+      noAlias: true,
+      transitiveMixedData: true,
+    },
+  ],
+  [
+    'usePreloadedQuery',
+    {
+      valueKind: ValueKind.Frozen,
+      effectKind: Effect.Freeze,
+      noAlias: true,
+      transitiveMixedData: true,
+    },
+  ],
+];
+
+function parseOptions(
+  source: string,
+  mode: 'compiler' | 'linter',
+  configOverrides: string,
+): PluginOptions {
+  // Extract the first line to quickly check for custom test directives
+  const pragma = source.substring(0, source.indexOf('\n'));
+
+  const parsedPragmaOptions = parseConfigPragmaForTests(pragma, {
+    compilationMode: 'infer',
+    environment:
+      mode === 'linter'
+        ? {
+            // enabled in compiler
+            validateRefAccessDuringRender: false,
+            // enabled in linter
+            validateNoSetStateInRender: true,
+            validateNoSetStateInEffects: true,
+            validateNoJSXInTryStatements: true,
+            validateNoImpureFunctionsInRender: true,
+            validateStaticComponents: true,
+            validateNoFreezingKnownMutableFunctions: true,
+            validateNoVoidUseMemo: true,
+          }
+        : {
+            /* use defaults for compiler mode */
+          },
+  });
+
+  // Parse config overrides from config editor
+  let configOverrideOptions: any = {};
+  const configMatch = configOverrides.match(/^\s*import.*?\n\n\((.*)\)/s);
+  if (configOverrides.trim()) {
+    if (configMatch && configMatch[1]) {
+      const configString = configMatch[1].replace(/satisfies.*$/, '').trim();
+      configOverrideOptions = new Function(`return (${configString})`)();
+    } else {
+      throw new Error('Invalid override format');
+    }
+  }
+
+  const opts: PluginOptions = parsePluginOptions({
+    ...parsedPragmaOptions,
+    ...configOverrideOptions,
+    environment: {
+      ...parsedPragmaOptions.environment,
+      ...configOverrideOptions.environment,
+      customHooks: new Map([...COMMON_HOOKS]),
+    },
+  });
+
+  return opts;
+}
+
+function compile(
+  source: string,
+  mode: 'compiler' | 'linter',
+  configOverrides: string,
+): [CompilerOutput, 'flow' | 'typescript', PluginOptions | null] {
+  const results = new Map<string, Array<PrintedCompilerPipelineValue>>();
+  const error = new CompilerError();
+  const otherErrors: Array<CompilerErrorDetail | CompilerDiagnostic> = [];
+  const upsert: (result: PrintedCompilerPipelineValue) => void = result => {
+    const entry = results.get(result.name);
+    if (Array.isArray(entry)) {
+      entry.push(result);
+    } else {
+      results.set(result.name, [result]);
+    }
+  };
+  let language: 'flow' | 'typescript';
+  if (source.match(/\@flow/)) {
+    language = 'flow';
+  } else {
+    language = 'typescript';
+  }
+  let transformOutput;
+
+  let baseOpts: PluginOptions | null = null;
+  try {
+    baseOpts = parseOptions(source, mode, configOverrides);
+  } catch (err) {
+    error.details.push(
+      new CompilerErrorDetail({
+        category: ErrorCategory.Config,
+        reason: `Unexpected failure when transforming configs! \n${err}`,
+        loc: null,
+        suggestions: null,
+      }),
+    );
+  }
+  if (baseOpts) {
+    try {
+      const logIR = (result: CompilerPipelineValue): void => {
+        switch (result.kind) {
+          case 'ast': {
+            break;
+          }
+          case 'hir': {
+            upsert({
+              kind: 'hir',
+              fnName: result.value.id,
+              name: result.name,
+              value: printFunctionWithOutlined(result.value),
+            });
+            break;
+          }
+          case 'reactive': {
+            upsert({
+              kind: 'reactive',
+              fnName: result.value.id,
+              name: result.name,
+              value: printReactiveFunctionWithOutlined(result.value),
+            });
+            break;
+          }
+          case 'debug': {
+            upsert({
+              kind: 'debug',
+              fnName: null,
+              name: result.name,
+              value: result.value,
+            });
+            break;
+          }
+          default: {
+            const _: never = result;
+            throw new Error(`Unhandled result ${result}`);
+          }
+        }
+      };
+      // Add logger options to the parsed options
+      const opts = {
+        ...baseOpts,
+        logger: {
+          debugLogIRs: logIR,
+          logEvent: (_filename: string | null, event: LoggerEvent): void => {
+            if (event.kind === 'CompileError') {
+              otherErrors.push(event.detail);
+            }
+          },
+        },
+      };
+      transformOutput = invokeCompiler(source, language, opts);
+    } catch (err) {
+      /**
+       * error might be an invariant violation or other runtime error
+       * (i.e. object shape that is not CompilerError)
+       */
+      if (err instanceof CompilerError && err.details.length > 0) {
+        error.merge(err);
+      } else {
+        /**
+         * Handle unexpected failures by logging (to get a stack trace)
+         * and reporting
+         */
+        error.details.push(
+          new CompilerErrorDetail({
+            category: ErrorCategory.Invariant,
+            reason: `Unexpected failure when transforming input! \n${err}`,
+            loc: null,
+            suggestions: null,
+          }),
+        );
+      }
+    }
+  }
+  // Only include logger errors if there weren't other errors
+  if (!error.hasErrors() && otherErrors.length !== 0) {
+    otherErrors.forEach(e => error.details.push(e));
+  }
+  if (error.hasErrors()) {
+    return [{kind: 'err', results, error}, language, baseOpts];
+  }
+  return [
+    {kind: 'ok', results, transformOutput, errors: error.details},
+    language,
+    baseOpts,
+  ];
+}

 export default function Editor(): JSX.Element {
  const store = useStore();
@@ -28,7 +323,6 @@ export default function Editor(): JSX.Element {
    () => compile(deferredStore.source, 'linter', deferredStore.config),
    [deferredStore.source, deferredStore.config],
  );
-  const [formattedAppliedConfig, setFormattedAppliedConfig] = useState('');

  let mergedOutput: CompilerOutput;
  let errors: Array<CompilerErrorDetail | CompilerDiagnostic>;
@@ -42,26 +336,19 @@ export default function Editor(): JSX.Element {
    mergedOutput = compilerOutput;
    errors = compilerOutput.error.details;
  }
-
-  if (appliedOptions) {
-    const formatted = prettyFormat(appliedOptions, {
-      printFunctionName: false,
-      printBasicPrototype: false,
-    });
-    if (formatted !== formattedAppliedConfig) {
-      setFormattedAppliedConfig(formatted);
-    }
-  }
-
  return (
    <>
      <div className="relative flex top-14">
        <div className="flex-shrink-0">
-          <ConfigEditor formattedAppliedConfig={formattedAppliedConfig} />
+          <ConfigEditor appliedOptions={appliedOptions} />
        </div>
        <div className="flex flex-1 min-w-0">
-          <Input language={language} errors={errors} />
-          <Output store={deferredStore} compilerOutput={mergedOutput} />
+          <div className="flex-1 min-w-[550px] sm:min-w-0">
+            <Input language={language} errors={errors} />
+          </div>
+          <div className="flex-1 min-w-[550px] sm:min-w-0">
+            <Output store={deferredStore} compilerOutput={mergedOutput} />
+          </div>
        </div>
      </div>
    </>
--- a/compiler/apps/playground/components/Editor/Input.tsx
+++ b/compiler/apps/playground/components/Editor/Input.tsx
@@ -13,17 +13,11 @@ import {
 import invariant from 'invariant';
 import type {editor} from 'monaco-editor';
 import * as monaco from 'monaco-editor';
-import {
-  useEffect,
-  useState,
-  unstable_ViewTransition as ViewTransition,
-} from 'react';
+import {useEffect, useState} from 'react';
 import {renderReactCompilerMarkers} from '../../lib/reactCompilerMonacoDiagnostics';
 import {useStore, useStoreDispatch} from '../StoreContext';
 import TabbedWindow from '../TabbedWindow';
 import {monacoOptions} from './monacoOptions';
-import {CONFIG_PANEL_TRANSITION} from '../../lib/transitionTypes';
-
 // @ts-expect-error TODO: Make TS recognize .d.ts files, in addition to loading them with webpack.
 import React$Types from '../../node_modules/@types/react/index.d.ts';

@@ -161,13 +155,9 @@ export default function Input({errors, language}: Props): JSX.Element {
  const [activeTab, setActiveTab] = useState('Input');

  return (
-    <ViewTransition
-      update={{
-        [CONFIG_PANEL_TRANSITION]: 'container',
-        default: 'none',
-      }}>
-      <div className="flex-1 min-w-[550px] sm:min-w-0">
-        <div className="flex flex-col h-full !h-[calc(100vh_-_3.5rem)] border-r border-gray-200">
+    <div className="relative flex flex-col flex-none border-r border-gray-200">
+      <div className="!h-[calc(100vh_-_3.5rem)]">
+        <div className="flex flex-col h-full">
          <TabbedWindow
            tabs={tabs}
            activeTab={activeTab}
@@ -175,6 +165,6 @@ export default function Input({errors, language}: Props): JSX.Element {
          />
        </div>
      </div>
-    </ViewTransition>
+    </div>
  );
 }
--- a/compiler/apps/playground/components/Editor/Output.tsx
+++ b/compiler/apps/playground/components/Editor/Output.tsx
@@ -20,25 +20,11 @@ import parserBabel from 'prettier/plugins/babel';
 import * as prettierPluginEstree from 'prettier/plugins/estree';
 import * as prettier from 'prettier/standalone';
 import {type Store} from '../../lib/stores';
-import {
-  memo,
-  ReactNode,
-  use,
-  useState,
-  Suspense,
-  unstable_ViewTransition as ViewTransition,
-  unstable_addTransitionType as addTransitionType,
-  startTransition,
-} from 'react';
+import {memo, ReactNode, use, useState, Suspense} from 'react';
 import AccordionWindow from '../AccordionWindow';
 import TabbedWindow from '../TabbedWindow';
 import {monacoOptions} from './monacoOptions';
 import {BabelFileResult} from '@babel/core';
-import {
-  CONFIG_PANEL_TRANSITION,
-  TOGGLE_INTERNALS_TRANSITION,
-  EXPAND_ACCORDION_TRANSITION,
-} from '../../lib/transitionTypes';
 import {LRUCache} from 'lru-cache';

 const MemoizedOutput = memo(Output);
@@ -271,19 +257,11 @@ function OutputContent({store, compilerOutput}: Props): JSX.Element {
  const [previousOutputKind, setPreviousOutputKind] = useState(
    compilerOutput.kind,
  );
-  const isFailure = compilerOutput.kind !== 'ok';
-
  if (compilerOutput.kind !== previousOutputKind) {
    setPreviousOutputKind(compilerOutput.kind);
-    if (isFailure) {
-      startTransition(() => {
-        addTransitionType(EXPAND_ACCORDION_TRANSITION);
-        setTabsOpen(prev => new Set(prev).add('Output'));
-        setActiveTab('Output');
-      });
-    }
+    setTabsOpen(new Set(['Output']));
+    setActiveTab('Output');
  }
-
  const changedPasses: Set<string> = new Set(['Output', 'HIR']); // Initial and final passes should always be bold
  let lastResult: string = '';
  for (const [passName, results] of compilerOutput.results) {
@@ -302,36 +280,22 @@ function OutputContent({store, compilerOutput}: Props): JSX.Element {

  if (!store.showInternals) {
    return (
-      <ViewTransition
-        update={{
-          [CONFIG_PANEL_TRANSITION]: 'container',
-          [TOGGLE_INTERNALS_TRANSITION]: '',
-          default: 'none',
-        }}>
-        <TabbedWindow
-          tabs={tabs}
-          activeTab={activeTab}
-          onTabChange={setActiveTab}
-        />
-      </ViewTransition>
+      <TabbedWindow
+        tabs={tabs}
+        activeTab={activeTab}
+        onTabChange={setActiveTab}
+      />
    );
  }

  return (
-    <ViewTransition
-      update={{
-        [CONFIG_PANEL_TRANSITION]: 'accordion-container',
-        [TOGGLE_INTERNALS_TRANSITION]: '',
-        default: 'none',
-      }}>
-      <AccordionWindow
-        defaultTab={store.showInternals ? 'HIR' : 'Output'}
-        setTabsOpen={setTabsOpen}
-        tabsOpen={tabsOpen}
-        tabs={tabs}
-        changedPasses={changedPasses}
-      />
-    </ViewTransition>
+    <AccordionWindow
+      defaultTab={store.showInternals ? 'HIR' : 'Output'}
+      setTabsOpen={setTabsOpen}
+      tabsOpen={tabsOpen}
+      tabs={tabs}
+      changedPasses={changedPasses}
+    />
  );
 }

@@ -386,18 +350,12 @@ function TextTabContent({
          loading={''}
          options={{
            ...monacoOptions,
-            scrollbar: {
-              vertical: 'hidden',
-            },
-            dimension: {
-              width: 0,
-              height: 0,
-            },
            readOnly: true,
            lineNumbers: 'off',
            glyphMargin: false,
            // Undocumented see https://github.com/Microsoft/vscode/issues/30795#issuecomment-410998882
-            overviewRulerLanes: 0,
+            lineDecorationsWidth: 0,
+            lineNumbersMinChars: 0,
          }}
        />
      ) : (
--- a/compiler/apps/playground/components/Editor/monacoOptions.ts
+++ b/compiler/apps/playground/components/Editor/monacoOptions.ts
@@ -32,14 +32,3 @@ export const monacoOptions: Partial<EditorProps['options']> = {

  tabSize: 2,
 };
-
-export const monacoConfigOptions: Partial<EditorProps['options']> = {
-  ...monacoOptions,
-  lineNumbers: 'off',
-  renderLineHighlight: 'none',
-  overviewRulerBorder: false,
-  overviewRulerLanes: 0,
-  fontSize: 12,
-  scrollBeyondLastLine: false,
-  glyphMargin: false,
-};
--- a/compiler/apps/playground/components/Header.tsx
+++ b/compiler/apps/playground/components/Header.tsx
@@ -10,16 +10,11 @@ import {CheckIcon} from '@heroicons/react/solid';
 import clsx from 'clsx';
 import Link from 'next/link';
 import {useSnackbar} from 'notistack';
-import {
-  useState,
-  startTransition,
-  unstable_addTransitionType as addTransitionType,
-} from 'react';
+import {useState} from 'react';
 import {defaultStore} from '../lib/defaultStore';
 import {IconGitHub} from './Icons/IconGitHub';
 import Logo from './Logo';
 import {useStore, useStoreDispatch} from './StoreContext';
-import {TOGGLE_INTERNALS_TRANSITION} from '../lib/transitionTypes';

 export default function Header(): JSX.Element {
  const [showCheck, setShowCheck] = useState(false);
@@ -67,12 +62,7 @@ export default function Header(): JSX.Element {
            <input
              type="checkbox"
              checked={store.showInternals}
-              onChange={() =>
-                startTransition(() => {
-                  addTransitionType(TOGGLE_INTERNALS_TRANSITION);
-                  dispatchStore({type: 'toggleInternals'});
-                })
-              }
+              onChange={() => dispatchStore({type: 'toggleInternals'})}
              className="absolute opacity-0 cursor-pointer h-full w-full m-0"
            />
            <span
--- a/compiler/apps/playground/components/TabbedWindow.tsx
+++ b/compiler/apps/playground/components/TabbedWindow.tsx
@@ -4,14 +4,8 @@
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
-import React, {
-  startTransition,
-  useId,
-  unstable_ViewTransition as ViewTransition,
-  unstable_addTransitionType as addTransitionType,
-} from 'react';
+import React from 'react';
 import clsx from 'clsx';
-import {TOGGLE_TAB_TRANSITION} from '../lib/transitionTypes';

 export default function TabbedWindow({
  tabs,
@@ -22,59 +16,27 @@ export default function TabbedWindow({
  activeTab: string;
  onTabChange: (tab: string) => void;
 }): React.ReactElement {
-  const id = useId();
-  const transitionName = `tab-highlight-${id}`;
-
-  const handleTabChange = (tab: string): void => {
-    startTransition(() => {
-      addTransitionType(TOGGLE_TAB_TRANSITION);
-      onTabChange(tab);
-    });
-  };
-
  return (
-    <div className="flex-1 min-w-[550px] sm:min-w-0">
-      <div className="flex flex-col h-full max-w-full">
-        <div className="flex p-2 flex-shrink-0">
-          {Array.from(tabs.keys()).map(tab => {
-            const isActive = activeTab === tab;
-            return (
-              <button
-                key={tab}
-                onClick={() => handleTabChange(tab)}
-                className={clsx(
-                  'transition-transform py-1.5 px-1.5 xs:px-3 sm:px-4 rounded-full text-sm relative',
-                  isActive ? 'text-link' : 'hover:bg-primary/5',
-                )}>
-                {isActive && (
-                  <ViewTransition
-                    name={transitionName}
-                    enter={{default: 'none'}}
-                    exit={{default: 'none'}}
-                    share={{
-                      [TOGGLE_TAB_TRANSITION]: 'tab-highlight',
-                      default: 'none',
-                    }}
-                    update={{default: 'none'}}>
-                    <div className="absolute inset-0 bg-highlight rounded-full" />
-                  </ViewTransition>
-                )}
-                <ViewTransition
-                  enter={{default: 'none'}}
-                  exit={{default: 'none'}}
-                  update={{
-                    [TOGGLE_TAB_TRANSITION]: 'tab-text',
-                    default: 'none',
-                  }}>
-                  <span className="relative z-1">{tab}</span>
-                </ViewTransition>
-              </button>
-            );
-          })}
-        </div>
-        <div className="flex-1 overflow-hidden w-full h-full">
-          {tabs.get(activeTab)}
-        </div>
+    <div className="flex flex-col h-full max-w-full">
+      <div className="flex p-2 flex-shrink-0">
+        {Array.from(tabs.keys()).map(tab => {
+          const isActive = activeTab === tab;
+          return (
+            <button
+              key={tab}
+              onClick={() => onTabChange(tab)}
+              className={clsx(
+                'active:scale-95 transition-transform py-1.5 px-1.5 xs:px-3 sm:px-4 rounded-full text-sm',
+                !isActive && 'hover:bg-primary/5',
+                isActive && 'bg-highlight text-link',
+              )}>
+              {tab}
+            </button>
+          );
+        })}
+      </div>
+      <div className="flex-1 overflow-hidden w-full h-full">
+        {tabs.get(activeTab)}
      </div>
    </div>
  );
--- a/compiler/apps/playground/lib/compilation.ts
+++ b/compiler/apps/playground/lib/compilation.ts
@@ -1,308 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {parse as babelParse, ParseResult} from '@babel/parser';
-import * as HermesParser from 'hermes-parser';
-import * as t from '@babel/types';
-import BabelPluginReactCompiler, {
-  CompilerError,
-  CompilerErrorDetail,
-  CompilerDiagnostic,
-  Effect,
-  ErrorCategory,
-  parseConfigPragmaForTests,
-  ValueKind,
-  type Hook,
-  PluginOptions,
-  CompilerPipelineValue,
-  parsePluginOptions,
-  printReactiveFunctionWithOutlined,
-  printFunctionWithOutlined,
-  type LoggerEvent,
-} from 'babel-plugin-react-compiler';
-import {transformFromAstSync} from '@babel/core';
-import type {
-  CompilerOutput,
-  CompilerTransformOutput,
-  PrintedCompilerPipelineValue,
-} from '../components/Editor/Output';
-
-function parseInput(
-  input: string,
-  language: 'flow' | 'typescript',
-): ParseResult<t.File> {
-  // Extract the first line to quickly check for custom test directives
-  if (language === 'flow') {
-    return HermesParser.parse(input, {
-      babel: true,
-      flow: 'all',
-      sourceType: 'module',
-      enableExperimentalComponentSyntax: true,
-    });
-  } else {
-    return babelParse(input, {
-      plugins: ['typescript', 'jsx'],
-      sourceType: 'module',
-    }) as ParseResult<t.File>;
-  }
-}
-
-function invokeCompiler(
-  source: string,
-  language: 'flow' | 'typescript',
-  options: PluginOptions,
-): CompilerTransformOutput {
-  const ast = parseInput(source, language);
-  let result = transformFromAstSync(ast, source, {
-    filename: '_playgroundFile.js',
-    highlightCode: false,
-    retainLines: true,
-    plugins: [[BabelPluginReactCompiler, options]],
-    ast: true,
-    sourceType: 'module',
-    configFile: false,
-    sourceMaps: true,
-    babelrc: false,
-  });
-  if (result?.ast == null || result?.code == null || result?.map == null) {
-    throw new Error('Expected successful compilation');
-  }
-  return {
-    code: result.code,
-    sourceMaps: result.map,
-    language,
-  };
-}
-
-const COMMON_HOOKS: Array<[string, Hook]> = [
-  [
-    'useFragment',
-    {
-      valueKind: ValueKind.Frozen,
-      effectKind: Effect.Freeze,
-      noAlias: true,
-      transitiveMixedData: true,
-    },
-  ],
-  [
-    'usePaginationFragment',
-    {
-      valueKind: ValueKind.Frozen,
-      effectKind: Effect.Freeze,
-      noAlias: true,
-      transitiveMixedData: true,
-    },
-  ],
-  [
-    'useRefetchableFragment',
-    {
-      valueKind: ValueKind.Frozen,
-      effectKind: Effect.Freeze,
-      noAlias: true,
-      transitiveMixedData: true,
-    },
-  ],
-  [
-    'useLazyLoadQuery',
-    {
-      valueKind: ValueKind.Frozen,
-      effectKind: Effect.Freeze,
-      noAlias: true,
-      transitiveMixedData: true,
-    },
-  ],
-  [
-    'usePreloadedQuery',
-    {
-      valueKind: ValueKind.Frozen,
-      effectKind: Effect.Freeze,
-      noAlias: true,
-      transitiveMixedData: true,
-    },
-  ],
-];
-
-function parseOptions(
-  source: string,
-  mode: 'compiler' | 'linter',
-  configOverrides: string,
-): PluginOptions {
-  // Extract the first line to quickly check for custom test directives
-  const pragma = source.substring(0, source.indexOf('\n'));
-
-  const parsedPragmaOptions = parseConfigPragmaForTests(pragma, {
-    compilationMode: 'infer',
-    environment:
-      mode === 'linter'
-        ? {
-            // enabled in compiler
-            validateRefAccessDuringRender: false,
-            // enabled in linter
-            validateNoSetStateInRender: true,
-            validateNoSetStateInEffects: true,
-            validateNoJSXInTryStatements: true,
-            validateNoImpureFunctionsInRender: true,
-            validateStaticComponents: true,
-            validateNoFreezingKnownMutableFunctions: true,
-            validateNoVoidUseMemo: true,
-          }
-        : {
-            /* use defaults for compiler mode */
-          },
-  });
-
-  // Parse config overrides from config editor
-  let configOverrideOptions: any = {};
-  const configMatch = configOverrides.match(/^\s*import.*?\n\n\((.*)\)/s);
-  if (configOverrides.trim()) {
-    if (configMatch && configMatch[1]) {
-      const configString = configMatch[1].replace(/satisfies.*$/, '').trim();
-      configOverrideOptions = new Function(`return (${configString})`)();
-    } else {
-      throw new Error('Invalid override format');
-    }
-  }
-
-  const opts: PluginOptions = parsePluginOptions({
-    ...parsedPragmaOptions,
-    ...configOverrideOptions,
-    environment: {
-      ...parsedPragmaOptions.environment,
-      ...configOverrideOptions.environment,
-      customHooks: new Map([...COMMON_HOOKS]),
-    },
-  });
-
-  return opts;
-}
-
-export function compile(
-  source: string,
-  mode: 'compiler' | 'linter',
-  configOverrides: string,
-): [CompilerOutput, 'flow' | 'typescript', PluginOptions | null] {
-  const results = new Map<string, Array<PrintedCompilerPipelineValue>>();
-  const error = new CompilerError();
-  const otherErrors: Array<CompilerErrorDetail | CompilerDiagnostic> = [];
-  const upsert: (result: PrintedCompilerPipelineValue) => void = result => {
-    const entry = results.get(result.name);
-    if (Array.isArray(entry)) {
-      entry.push(result);
-    } else {
-      results.set(result.name, [result]);
-    }
-  };
-  let language: 'flow' | 'typescript';
-  if (source.match(/\@flow/)) {
-    language = 'flow';
-  } else {
-    language = 'typescript';
-  }
-  let transformOutput;
-
-  let baseOpts: PluginOptions | null = null;
-  try {
-    baseOpts = parseOptions(source, mode, configOverrides);
-  } catch (err) {
-    error.details.push(
-      new CompilerErrorDetail({
-        category: ErrorCategory.Config,
-        reason: `Unexpected failure when transforming configs! \n${err}`,
-        loc: null,
-        suggestions: null,
-      }),
-    );
-  }
-  if (baseOpts) {
-    try {
-      const logIR = (result: CompilerPipelineValue): void => {
-        switch (result.kind) {
-          case 'ast': {
-            break;
-          }
-          case 'hir': {
-            upsert({
-              kind: 'hir',
-              fnName: result.value.id,
-              name: result.name,
-              value: printFunctionWithOutlined(result.value),
-            });
-            break;
-          }
-          case 'reactive': {
-            upsert({
-              kind: 'reactive',
-              fnName: result.value.id,
-              name: result.name,
-              value: printReactiveFunctionWithOutlined(result.value),
-            });
-            break;
-          }
-          case 'debug': {
-            upsert({
-              kind: 'debug',
-              fnName: null,
-              name: result.name,
-              value: result.value,
-            });
-            break;
-          }
-          default: {
-            const _: never = result;
-            throw new Error(`Unhandled result ${result}`);
-          }
-        }
-      };
-      // Add logger options to the parsed options
-      const opts = {
-        ...baseOpts,
-        logger: {
-          debugLogIRs: logIR,
-          logEvent: (_filename: string | null, event: LoggerEvent): void => {
-            if (event.kind === 'CompileError') {
-              otherErrors.push(event.detail);
-            }
-          },
-        },
-      };
-      transformOutput = invokeCompiler(source, language, opts);
-    } catch (err) {
-      /**
-       * error might be an invariant violation or other runtime error
-       * (i.e. object shape that is not CompilerError)
-       */
-      if (err instanceof CompilerError && err.details.length > 0) {
-        error.merge(err);
-      } else {
-        /**
-         * Handle unexpected failures by logging (to get a stack trace)
-         * and reporting
-         */
-        error.details.push(
-          new CompilerErrorDetail({
-            category: ErrorCategory.Invariant,
-            reason: `Unexpected failure when transforming input! \n${err}`,
-            loc: null,
-            suggestions: null,
-          }),
-        );
-      }
-    }
-  }
-  // Only include logger errors if there weren't other errors
-  if (!error.hasErrors() && otherErrors.length !== 0) {
-    otherErrors.forEach(e => error.details.push(e));
-  }
-  if (error.hasErrors() || !transformOutput) {
-    return [{kind: 'err', results, error}, language, baseOpts];
-  }
-  return [
-    {kind: 'ok', results, transformOutput, errors: error.details},
-    language,
-    baseOpts,
-  ];
-}
--- a/compiler/apps/playground/lib/transitionTypes.ts
+++ b/compiler/apps/playground/lib/transitionTypes.ts
@@ -1,11 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-export const CONFIG_PANEL_TRANSITION = 'config-panel';
-export const TOGGLE_TAB_TRANSITION = 'toggle-tab';
-export const TOGGLE_INTERNALS_TRANSITION = 'toggle-internals';
-export const EXPAND_ACCORDION_TRANSITION = 'open-accordion';
--- a/compiler/apps/playground/next-env.d.ts
+++ b/compiler/apps/playground/next-env.d.ts
@@ -0,0 +1,6 @@
+/// <reference types="next" />
+/// <reference types="next/image-types/global" />
+import "./.next/types/routes.d.ts";
+
+// NOTE: This file should not be edited
+// see https://nextjs.org/docs/app/api-reference/config/typescript for more information.
--- a/compiler/apps/playground/next.config.js
+++ b/compiler/apps/playground/next.config.js
@@ -11,7 +11,6 @@ const path = require('path');
 const nextConfig = {
  experimental: {
    reactCompiler: true,
-    viewTransition: true,
  },
  reactStrictMode: true,
  webpack: (config, options) => {
--- a/compiler/apps/playground/package.json
+++ b/compiler/apps/playground/package.json
@@ -26,8 +26,8 @@
    "@babel/traverse": "^7.18.9",
    "@babel/types": "7.26.3",
    "@heroicons/react": "^1.0.6",
-    "@monaco-editor/react": "^4.8.0-rc.2",
-    "@playwright/test": "^1.56.1",
+    "@monaco-editor/react": "^4.4.6",
+    "@playwright/test": "^1.51.1",
    "@use-gesture/react": "^10.2.22",
    "hermes-eslint": "^0.25.0",
    "hermes-parser": "^0.25.0",
@@ -35,18 +35,18 @@
    "lru-cache": "^11.2.2",
    "lz-string": "^1.5.0",
    "monaco-editor": "^0.52.0",
-    "next": "15.5.9",
+    "next": "15.6.0-canary.7",
    "notistack": "^3.0.0-alpha.7",
    "prettier": "^3.3.3",
    "pretty-format": "^29.3.1",
    "re-resizable": "^6.9.16",
-    "react": "19.2.3",
-    "react-dom": "19.2.3"
+    "react": "19.1.1",
+    "react-dom": "19.1.1"
  },
  "devDependencies": {
    "@types/node": "18.11.9",
-    "@types/react": "19.2",
-    "@types/react-dom": "19.2",
+    "@types/react": "19.1.13",
+    "@types/react-dom": "19.1.9",
    "autoprefixer": "^10.4.13",
    "clsx": "^1.2.1",
    "concurrently": "^7.4.0",
@@ -58,7 +58,7 @@
    "wait-on": "^7.2.0"
  },
  "resolutions": {
-    "@types/react": "19.2",
-    "@types/react-dom": "19.2"
+    "@types/react": "19.1.12",
+    "@types/react-dom": "19.1.9"
  }
 }
--- a/compiler/apps/playground/styles/globals.css
+++ b/compiler/apps/playground/styles/globals.css
@@ -69,75 +69,3 @@
    scrollbar-width: none; /* Firefox */
  }
 }
-
-::view-transition-old(.slide-in) {
-  animation-name: slideOutLeft;
-}
-::view-transition-new(.slide-in) {
-  animation-name: slideInLeft;
-}
-::view-transition-group(.slide-in) {
-  z-index: 1;
-}
-::view-transition-old(.slide-out) {
-  animation-name: slideOutLeft;
-}
-::view-transition-new(.slide-out) {
-  animation-name: slideInLeft;
-}
-::view-transition-group(.slide-out) {
-  z-index: 1;
-}
-
-@keyframes slideOutLeft {
-  from {
-    transform: translateX(0);
-  }
-  to {
-    transform: translateX(-100%);
-  }
-}
-@keyframes slideInLeft {
-  from {
-    transform: translateX(-100%);
-  }
-  to {
-    transform: translateX(0);
-  }
-}
-
-::view-transition-old(.container),
-::view-transition-new(.container) {
-  height: 100%;
-}
-
-::view-transition-old(.accordion-container),
-::view-transition-new(.accordion-container) {
-  height: 100%;
-  object-fit: none;
-  object-position: left;
-}
-
-::view-transition-old(.tab-highlight),
-::view-transition-new(.tab-highlight) {
-  height: 100%;
-}
-::view-transition-group(.tab-text) {
-	z-index: 1;
-}
-
-::view-transition-old(.expand-accordion),
-::view-transition-new(.expand-accordion) {
-  width: auto;
-}
-::view-transition-group(.expand-accordion) {
-  overflow: clip;
-}
-
-/**
- * For some reason, the original Monaco editor is still visible to the
- * left of the DiffEditor. This is a workaround for better visual clarity.
- */
-.monaco-diff-editor .editor.original{
-  visibility: hidden !important;
-}
--- a/compiler/apps/playground/tsconfig.json
+++ b/compiler/apps/playground/tsconfig.json
@@ -19,7 +19,7 @@
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
-    "jsx": "preserve",
+    "jsx": "react-jsx",
    "incremental": true,
    "plugins": [
      {
--- a/compiler/apps/playground/yarn.lock
+++ b/compiler/apps/playground/yarn.lock
@@ -701,24 +701,24 @@
    "@jridgewell/resolve-uri" "^3.1.0"
    "@jridgewell/sourcemap-codec" "^1.4.14"

-"@monaco-editor/loader@^1.6.1":
-  version "1.6.1"
-  resolved "https://registry.npmjs.org/@monaco-editor/loader/-/loader-1.6.1.tgz#c99177d87765abf10de31a0086084e714acfbc0f"
-  integrity sha512-w3tEnj9HYEC73wtjdpR089AqkUPskFRcdkxsiSFt3SoUc3OHpmu+leP94CXBm4mHfefmhsdfI0ZQu6qJ0wgtPg==
+"@monaco-editor/loader@^1.4.0":
+  version "1.4.0"
+  resolved "https://registry.yarnpkg.com/@monaco-editor/loader/-/loader-1.4.0.tgz#f08227057331ec890fa1e903912a5b711a2ad558"
+  integrity sha512-00ioBig0x642hytVspPl7DbQyaSWRaolYie/UFNjoTdvoKPzo6xrXLhTk9ixgIKcLH5b5vDOjVNiGyY+uDCUlg==
  dependencies:
    state-local "^1.0.6"

-"@monaco-editor/react@^4.8.0-rc.2":
-  version "4.8.0-rc.2"
-  resolved "https://registry.npmjs.org/@monaco-editor/react/-/react-4.8.0-rc.2.tgz#e9acf652e23e9f640671a69875f496dde7f098aa"
-  integrity sha512-RzFHKBCnRA4RnozaG/EPhKsbkhX5wcApSa5MElR/AD2ojxhMY+QP+G8aJpxALCnIwKs6L0dec5MJ0nAjMUEqnA==
+"@monaco-editor/react@^4.4.6":
+  version "4.6.0"
+  resolved "https://registry.yarnpkg.com/@monaco-editor/react/-/react-4.6.0.tgz#bcc68671e358a21c3814566b865a54b191e24119"
+  integrity sha512-RFkU9/i7cN2bsq/iTkurMWOEErmYcY6JiQI3Jn+WeR/FGISH8JbHERjpS9oRuSOPvDMJI0Z8nJeKkbOs9sBYQw==
  dependencies:
-    "@monaco-editor/loader" "^1.6.1"
+    "@monaco-editor/loader" "^1.4.0"

-"@next/env@15.5.9":
-  version "15.5.9"
-  resolved "https://registry.yarnpkg.com/@next/env/-/env-15.5.9.tgz#53c2c34dc17cd87b61f70c6cc211e303123b2ab8"
-  integrity sha512-4GlTZ+EJM7WaW2HEZcyU317tIQDjkQIyENDLxYJfSWlfqguN+dHkZgyQTV/7ykvobU7yEH5gKvreNrH4B6QgIg==
+"@next/env@15.6.0-canary.7":
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/@next/env/-/env-15.6.0-canary.7.tgz#cdbf2967a9437ef09eef755e203f315acc4d8d8f"
+  integrity sha512-LNZ7Yd3Cl9rKvjYdeJmszf2HmSDP76SQmfafKep2Ux16ZXKoN5OjwVHFTltKNdsB3vt2t+XJzLP2rhw5lBoFBA==

 "@next/eslint-plugin-next@15.5.2":
  version "15.5.2"
@@ -727,45 +727,45 @@
  dependencies:
    fast-glob "3.3.1"

-"@next/swc-darwin-arm64@15.5.7":
-  version "15.5.7"
-  resolved "https://registry.yarnpkg.com/@next/swc-darwin-arm64/-/swc-darwin-arm64-15.5.7.tgz#f0c9ccfec2cd87cbd4b241ce4c779a7017aed958"
-  integrity sha512-IZwtxCEpI91HVU/rAUOOobWSZv4P2DeTtNaCdHqLcTJU4wdNXgAySvKa/qJCgR5m6KI8UsKDXtO2B31jcaw1Yw==
+"@next/swc-darwin-arm64@15.6.0-canary.7":
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/@next/swc-darwin-arm64/-/swc-darwin-arm64-15.6.0-canary.7.tgz#628cd34ce9120000f1cb5b08963426431174fc57"
+  integrity sha512-POsBrxhrR3qvqXV+JZ6ZoBc8gJf8rhYe+OedceI1piPVqtJYOJa3EB4eaqcc+kMsllKRrH/goNlhLwtyhE+0Qg==

-"@next/swc-darwin-x64@15.5.7":
-  version "15.5.7"
-  resolved "https://registry.yarnpkg.com/@next/swc-darwin-x64/-/swc-darwin-x64-15.5.7.tgz#18009e9fcffc5c0687cc9db24182ddeac56280d9"
-  integrity sha512-UP6CaDBcqaCBuiq/gfCEJw7sPEoX1aIjZHnBWN9v9qYHQdMKvCKcAVs4OX1vIjeE+tC5EIuwDTVIoXpUes29lg==
+"@next/swc-darwin-x64@15.6.0-canary.7":
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/@next/swc-darwin-x64/-/swc-darwin-x64-15.6.0-canary.7.tgz#37d4ebab14da74a2f8028daf6d76aab410153e06"
+  integrity sha512-lmk9ysBuSiPlAJZTCo/3O4mXNFosg6EDIf4GrmynIwCG2as6/KxzyD1WqFp56Exp8eFDjP7SFapD10sV43vCsA==

-"@next/swc-linux-arm64-gnu@15.5.7":
-  version "15.5.7"
-  resolved "https://registry.yarnpkg.com/@next/swc-linux-arm64-gnu/-/swc-linux-arm64-gnu-15.5.7.tgz#fe7c7e08264cf522d4e524299f6d3e63d68d579a"
-  integrity sha512-NCslw3GrNIw7OgmRBxHtdWFQYhexoUCq+0oS2ccjyYLtcn1SzGzeM54jpTFonIMUjNbHmpKpziXnpxhSWLcmBA==
+"@next/swc-linux-arm64-gnu@15.6.0-canary.7":
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/@next/swc-linux-arm64-gnu/-/swc-linux-arm64-gnu-15.6.0-canary.7.tgz#ce700cc0e0d24763136838223105a524b36694fa"
+  integrity sha512-why8k6d0SBm3AKoOD5S7ir3g+BF34l9oFKIoZrLaZaKBvNGpFcjc7Ovc2TunNMeaMJzv9k1dHYSap0EI5oSuzg==

-"@next/swc-linux-arm64-musl@15.5.7":
-  version "15.5.7"
-  resolved "https://registry.yarnpkg.com/@next/swc-linux-arm64-musl/-/swc-linux-arm64-musl-15.5.7.tgz#94228fe293475ec34a5a54284e1056876f43a3cf"
-  integrity sha512-nfymt+SE5cvtTrG9u1wdoxBr9bVB7mtKTcj0ltRn6gkP/2Nu1zM5ei8rwP9qKQP0Y//umK+TtkKgNtfboBxRrw==
+"@next/swc-linux-arm64-musl@15.6.0-canary.7":
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/@next/swc-linux-arm64-musl/-/swc-linux-arm64-musl-15.6.0-canary.7.tgz#c791b8e15bf2c338b4cc0387fe7afb3ef83ecfcf"
+  integrity sha512-HzvTRsKvYj32Va4YuJN3n3xOxvk+6QwB63d/EsgmdkeA/vrqciUAmJDYpuzZEvRc3Yp2nyPq8KZxtHAr6ISZ2Q==

-"@next/swc-linux-x64-gnu@15.5.7":
-  version "15.5.7"
-  resolved "https://registry.yarnpkg.com/@next/swc-linux-x64-gnu/-/swc-linux-x64-gnu-15.5.7.tgz#078c71201dfe7fcfb8fa6dc92aae6c94bc011cdc"
-  integrity sha512-hvXcZvCaaEbCZcVzcY7E1uXN9xWZfFvkNHwbe/n4OkRhFWrs1J1QV+4U1BN06tXLdaS4DazEGXwgqnu/VMcmqw==
+"@next/swc-linux-x64-gnu@15.6.0-canary.7":
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/@next/swc-linux-x64-gnu/-/swc-linux-x64-gnu-15.6.0-canary.7.tgz#c01c3a3d8e71660c49298dd053d078379b6b5919"
+  integrity sha512-6yRFrg2qWXOqa+1BI53J9EmHWFzKg9U2r+5R7n7BFUp8PH5SC92WBsmYTnh/RkvAYvdupiVzMervwwswCs6kFg==

-"@next/swc-linux-x64-musl@15.5.7":
-  version "15.5.7"
-  resolved "https://registry.yarnpkg.com/@next/swc-linux-x64-musl/-/swc-linux-x64-musl-15.5.7.tgz#72947f5357f9226292353e0bb775643da3c7a182"
-  integrity sha512-4IUO539b8FmF0odY6/SqANJdgwn1xs1GkPO5doZugwZ3ETF6JUdckk7RGmsfSf7ws8Qb2YB5It33mvNL/0acqA==
+"@next/swc-linux-x64-musl@15.6.0-canary.7":
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/@next/swc-linux-x64-musl/-/swc-linux-x64-musl-15.6.0-canary.7.tgz#3f4b39faef4a5f88b13e4c726b008ddc9717f819"
+  integrity sha512-O/JjvOvNK/Wao/OIQaA6evDkxkmFFQgJ1/hI1dVk6/PAeKmW2/Q+6Dodh97eAkOwedS1ZdQl2mojf87TzLvzdQ==

-"@next/swc-win32-arm64-msvc@15.5.7":
-  version "15.5.7"
-  resolved "https://registry.yarnpkg.com/@next/swc-win32-arm64-msvc/-/swc-win32-arm64-msvc-15.5.7.tgz#397b912cd51c6a80e32b9c0507ecd82514353941"
-  integrity sha512-CpJVTkYI3ZajQkC5vajM7/ApKJUOlm6uP4BknM3XKvJ7VXAvCqSjSLmM0LKdYzn6nBJVSjdclx8nYJSa3xlTgQ==
+"@next/swc-win32-arm64-msvc@15.6.0-canary.7":
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/@next/swc-win32-arm64-msvc/-/swc-win32-arm64-msvc-15.6.0-canary.7.tgz#9bc5da0907b7ce67eedda02a6d56a09d9a539ccf"
+  integrity sha512-p9DvrDgnePofZCtiWVY7qZtwXxiOGJlAyy2LoGPYSGOUDhjbTG8j6XMUFXpV9UwpH+l7st522psO1BVzbpT8IQ==

-"@next/swc-win32-x64-msvc@15.5.7":
-  version "15.5.7"
-  resolved "https://registry.yarnpkg.com/@next/swc-win32-x64-msvc/-/swc-win32-x64-msvc-15.5.7.tgz#e02b543d9dc6c1631d4ac239cb1177245dfedfe4"
-  integrity sha512-gMzgBX164I6DN+9/PGA+9dQiwmTkE4TloBNx8Kv9UiGARsr9Nba7IpcBRA1iTV9vwlYnrE3Uy6I7Aj6qLjQuqw==
+"@next/swc-win32-x64-msvc@15.6.0-canary.7":
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/@next/swc-win32-x64-msvc/-/swc-win32-x64-msvc-15.6.0-canary.7.tgz#5b271c591ccbe67d5fa966dd22db86c547414fd1"
+  integrity sha512-f1ywT3xWu4StWKA1mZRyGfelu/h+W0OEEyBxQNXzXyYa0VGZb9LyCNb5cYoNKBm0Bw18Hp1PVe0bHuusemGCcw==

 "@nodelib/fs.scandir@2.1.5":
  version "2.1.5"
@@ -798,12 +798,12 @@
  resolved "https://registry.yarnpkg.com/@pkgjs/parseargs/-/parseargs-0.11.0.tgz#a77ea742fab25775145434eb1d2328cf5013ac33"
  integrity sha512-+1VkjdD0QBLPodGrJUeqarH8VAIvQODIbwh9XpP5Syisf7YoQgsJKPNFoqqLQlu+VQ/tVSshMR6loPMn8U+dPg==

-"@playwright/test@^1.56.1":
-  version "1.56.1"
-  resolved "https://registry.yarnpkg.com/@playwright/test/-/test-1.56.1.tgz#6e3bf3d0c90c5cf94bf64bdb56fd15a805c8bd3f"
-  integrity sha512-vSMYtL/zOcFpvJCW71Q/OEGQb7KYBPAdKh35WNSkaZA75JlAO8ED8UN6GUNTm3drWomcbcqRPFqQbLae8yBTdg==
+"@playwright/test@^1.51.1":
+  version "1.51.1"
+  resolved "https://registry.yarnpkg.com/@playwright/test/-/test-1.51.1.tgz#75357d513221a7be0baad75f01e966baf9c41a2e"
+  integrity sha512-nM+kEaTSAoVlXmMPH10017vn3FSiFqr/bh4fKg9vmAdMfd9SDqRZNvPSiAHADc/itWak+qPvMPZQOPwCBW7k7Q==
  dependencies:
-    playwright "1.56.1"
+    playwright "1.51.1"

 "@rtsao/scc@^1.1.0":
  version "1.1.0"
@@ -854,15 +854,22 @@
  resolved "https://registry.yarnpkg.com/@types/node/-/node-18.11.9.tgz#02d013de7058cea16d36168ef2fc653464cfbad4"
  integrity sha512-CRpX21/kGdzjOpFsZSkcrXMGIBWMGNIHXXBVFSH+ggkftxg+XYP20TESbh+zFvFj3EQOl5byk0HTRn1IL6hbqg==

-"@types/react-dom@19.2":
-  version "19.2.2"
-  resolved "https://registry.npmjs.org/@types/react-dom/-/react-dom-19.2.2.tgz#a4cc874797b7ddc9cb180ef0d5dc23f596fc2332"
-  integrity sha512-9KQPoO6mZCi7jcIStSnlOWn2nEF3mNmyr3rIAsGnAbQKYbRLyqmeSc39EVgtxXVia+LMT8j3knZLAZAh+xLmrw==
+"@types/react-dom@19.1.9":
+  version "19.1.9"
+  resolved "https://registry.yarnpkg.com/@types/react-dom/-/react-dom-19.1.9.tgz#5ab695fce1e804184767932365ae6569c11b4b4b"
+  integrity sha512-qXRuZaOsAdXKFyOhRBg6Lqqc0yay13vN7KrIg4L7N4aaHN68ma9OK3NE1BoDFgFOTfM7zg+3/8+2n8rLUH3OKQ==

-"@types/react@19.2":
-  version "19.2.2"
-  resolved "https://registry.npmjs.org/@types/react/-/react-19.2.2.tgz#ba123a75d4c2a51158697160a4ea2ff70aa6bf36"
-  integrity sha512-6mDvHUFSjyT2B2yeNx2nUgMxh9LtOWvkhIU3uePn2I2oyNymUAX1NIsdgviM4CH+JSrp2D2hsMvJOkxY+0wNRA==
+"@types/react@19.1.12":
+  version "19.1.12"
+  resolved "https://registry.yarnpkg.com/@types/react/-/react-19.1.12.tgz#7bfaa76aabbb0b4fe0493c21a3a7a93d33e8937b"
+  integrity sha512-cMoR+FoAf/Jyq6+Df2/Z41jISvGZZ2eTlnsaJRptmZ76Caldwy1odD4xTr/gNV9VLj0AWgg/nmkevIyUfIIq5w==
+  dependencies:
+    csstype "^3.0.2"
+
+"@types/react@19.1.13":
+  version "19.1.13"
+  resolved "https://registry.yarnpkg.com/@types/react/-/react-19.1.13.tgz#fc650ffa680d739a25a530f5d7ebe00cdd771883"
+  integrity sha512-hHkbU/eoO3EG5/MZkuFSKmYqPbSVk5byPFa3e7y/8TybHiLMACgI8seVYlicwk7H5K/rI2px9xrQp/C+AUDTiQ==
  dependencies:
    csstype "^3.0.2"

@@ -3204,25 +3211,25 @@ natural-compare@^1.4.0:
  resolved "https://registry.yarnpkg.com/natural-compare/-/natural-compare-1.4.0.tgz#4abebfeed7541f2c27acfb29bdbbd15c8d5ba4f7"
  integrity sha512-OWND8ei3VtNC9h7V60qff3SVobHr996CTwgxubgyQYEpg290h9J0buyECNNJexkFm5sOajh5G116RYA1c8ZMSw==

-next@15.5.9:
-  version "15.5.9"
-  resolved "https://registry.yarnpkg.com/next/-/next-15.5.9.tgz#1b80d05865cc27e710fb4dcfc6fd9e726ed12ad4"
-  integrity sha512-agNLK89seZEtC5zUHwtut0+tNrc0Xw4FT/Dg+B/VLEo9pAcS9rtTKpek3V6kVcVwsB2YlqMaHdfZL4eLEVYuCg==
+next@15.6.0-canary.7:
+  version "15.6.0-canary.7"
+  resolved "https://registry.yarnpkg.com/next/-/next-15.6.0-canary.7.tgz#bfc2ac3c9a78e23d550c303d18247a263e6b5bc1"
+  integrity sha512-4ukX2mxat9wWT6E0Gw/3TOR9ULV1q399E42F86cwsPSFgTWa04ABhcTqO0r9J/QR1YWPR8WEgh9qUzmWA/1yEw==
  dependencies:
-    "@next/env" "15.5.9"
+    "@next/env" "15.6.0-canary.7"
    "@swc/helpers" "0.5.15"
    caniuse-lite "^1.0.30001579"
    postcss "8.4.31"
    styled-jsx "5.1.6"
  optionalDependencies:
-    "@next/swc-darwin-arm64" "15.5.7"
-    "@next/swc-darwin-x64" "15.5.7"
-    "@next/swc-linux-arm64-gnu" "15.5.7"
-    "@next/swc-linux-arm64-musl" "15.5.7"
-    "@next/swc-linux-x64-gnu" "15.5.7"
-    "@next/swc-linux-x64-musl" "15.5.7"
-    "@next/swc-win32-arm64-msvc" "15.5.7"
-    "@next/swc-win32-x64-msvc" "15.5.7"
+    "@next/swc-darwin-arm64" "15.6.0-canary.7"
+    "@next/swc-darwin-x64" "15.6.0-canary.7"
+    "@next/swc-linux-arm64-gnu" "15.6.0-canary.7"
+    "@next/swc-linux-arm64-musl" "15.6.0-canary.7"
+    "@next/swc-linux-x64-gnu" "15.6.0-canary.7"
+    "@next/swc-linux-x64-musl" "15.6.0-canary.7"
+    "@next/swc-win32-arm64-msvc" "15.6.0-canary.7"
+    "@next/swc-win32-x64-msvc" "15.6.0-canary.7"
    sharp "^0.34.3"

 node-releases@^2.0.18:
@@ -3453,17 +3460,17 @@ pirates@^4.0.1:
  resolved "https://registry.yarnpkg.com/pirates/-/pirates-4.0.6.tgz#3018ae32ecfcff6c29ba2267cbf21166ac1f36b9"
  integrity sha512-saLsH7WeYYPiD25LDuLRRY/i+6HaPYr6G1OUlN39otzkSTxKnubR9RTxS3/Kk50s1g2JTgFwWQDQyplC5/SHZg==

-playwright-core@1.56.1:
-  version "1.56.1"
-  resolved "https://registry.yarnpkg.com/playwright-core/-/playwright-core-1.56.1.tgz#24a66481e5cd33a045632230aa2c4f0cb6b1db3d"
-  integrity sha512-hutraynyn31F+Bifme+Ps9Vq59hKuUCz7H1kDOcBs+2oGguKkWTU50bBWrtz34OUWmIwpBTWDxaRPXrIXkgvmQ==
+playwright-core@1.51.1:
+  version "1.51.1"
+  resolved "https://registry.yarnpkg.com/playwright-core/-/playwright-core-1.51.1.tgz#d57f0393e02416f32a47cf82b27533656a8acce1"
+  integrity sha512-/crRMj8+j/Nq5s8QcvegseuyeZPxpQCZb6HNk3Sos3BlZyAknRjoyJPFWkpNn8v0+P3WiwqFF8P+zQo4eqiNuw==

-playwright@1.56.1:
-  version "1.56.1"
-  resolved "https://registry.yarnpkg.com/playwright/-/playwright-1.56.1.tgz#62e3b99ddebed0d475e5936a152c88e68be55fbf"
-  integrity sha512-aFi5B0WovBHTEvpM3DzXTUaeN6eN0qWnTkKx4NQaH4Wvcmc153PdaY2UBdSYKaGYw+UyWXSVyxDUg5DoPEttjw==
+playwright@1.51.1:
+  version "1.51.1"
+  resolved "https://registry.yarnpkg.com/playwright/-/playwright-1.51.1.tgz#ae1467ee318083968ad28d6990db59f47a55390f"
+  integrity sha512-kkx+MB2KQRkyxjYPc3a0wLZZoDczmppyGJIvQ43l+aZihkaVvmu/21kiyaHeHjiFxjxNNFnUncKmcGIyOojsaw==
  dependencies:
-    playwright-core "1.56.1"
+    playwright-core "1.51.1"
  optionalDependencies:
    fsevents "2.3.2"

@@ -3582,12 +3589,12 @@ re-resizable@^6.9.16:
  resolved "https://registry.yarnpkg.com/re-resizable/-/re-resizable-6.10.0.tgz#d684a096ab438f1a93f59ad3a580a206b0ce31ee"
  integrity sha512-hysSK0xmA5nz24HBVztlk4yCqCLCvS32E6ZpWxVKop9x3tqCa4yAj1++facrmkOf62JsJHjmjABdKxXofYioCw==

-react-dom@19.2.3:
-  version "19.2.3"
-  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-19.2.3.tgz#f0b61d7e5c4a86773889fcc1853af3ed5f215b17"
-  integrity sha512-yELu4WmLPw5Mr/lmeEpox5rw3RETacE++JgHqQzd2dg+YbJuat3jH4ingc+WPZhxaoFzdv9y33G+F7Nl5O0GBg==
+react-dom@19.1.1:
+  version "19.1.1"
+  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-19.1.1.tgz#2daa9ff7f3ae384aeb30e76d5ee38c046dc89893"
+  integrity sha512-Dlq/5LAZgF0Gaz6yiqZCf6VCcZs1ghAJyrsu84Q/GT0gV+mCxbfmKNoGRKBYMJ8IEdGPqu49YWXD02GCknEDkw==
  dependencies:
-    scheduler "^0.27.0"
+    scheduler "^0.26.0"

 react-is@^16.13.1:
  version "16.13.1"
@@ -3599,10 +3606,10 @@ react-is@^18.0.0:
  resolved "https://registry.yarnpkg.com/react-is/-/react-is-18.3.1.tgz#e83557dc12eae63a99e003a46388b1dcbb44db7e"
  integrity sha512-/LLMVyas0ljjAtoYiPqYiL8VWXzUUdThrmU5+n20DZv+a+ClRoevUzw5JxU+Ieh5/c87ytoTBV9G1FiKfNJdmg==

-react@19.2.3:
-  version "19.2.3"
-  resolved "https://registry.yarnpkg.com/react/-/react-19.2.3.tgz#d83e5e8e7a258cf6b4fe28640515f99b87cd19b8"
-  integrity sha512-Ku/hhYbVjOQnXDZFv2+RibmLFGwFdeeKHFcOTlrt7xplBnya5OGn/hIRDsqDiSUcfORsDC7MPxwork8jBwsIWA==
+react@19.1.1:
+  version "19.1.1"
+  resolved "https://registry.yarnpkg.com/react/-/react-19.1.1.tgz#06d9149ec5e083a67f9a1e39ce97b06a03b644af"
+  integrity sha512-w8nqGImo45dmMIfljjMwOGtbmC/mk4CMYhWIicdSflH91J9TyCyczcPFXJzrZ/ZXcgGRFeP6BU0BEJTw6tZdfQ==

 read-cache@^1.0.0:
  version "1.0.0"
@@ -3778,10 +3785,10 @@ safe-regex-test@^1.1.0:
    es-errors "^1.3.0"
    is-regex "^1.2.1"

-scheduler@^0.27.0:
-  version "0.27.0"
-  resolved "https://registry.npmjs.org/scheduler/-/scheduler-0.27.0.tgz#0c4ef82d67d1e5c1e359e8fc76d3a87f045fe5bd"
-  integrity sha512-eNv+WrVbKu1f3vbYJT/xtiF5syA5HPIMtf9IgY/nKg0sWqzAUEvqY/xm7OcZc/qafLx/iO9FgOmeSAp4v5ti/Q==
+scheduler@^0.26.0:
+  version "0.26.0"
+  resolved "https://registry.yarnpkg.com/scheduler/-/scheduler-0.26.0.tgz#4ce8a8c2a2095f13ea11bf9a445be50c555d6337"
+  integrity sha512-NlHwttCI/l5gCPR3D1nNXtWABUmBwvZpEQiD4IXSbIDq8BzLIK/7Ir5gTFSGZDUu37K5cMNp0hFtzO38sC7gWA==

 semver@^6.3.1:
  version "6.3.1"
--- a/compiler/packages/babel-plugin-react-compiler/package.json
+++ b/compiler/packages/babel-plugin-react-compiler/package.json
@@ -52,8 +52,8 @@
    "react-dom": "0.0.0-experimental-4beb1fd8-20241118",
    "ts-jest": "^29.1.1",
    "ts-node": "^10.9.2",
-    "zod": "^3.25.0 || ^4.0.0",
-    "zod-validation-error": "^3.5.0 || ^4.0.0"
+    "zod": "^3.22.4",
+    "zod-validation-error": "^2.1.0"
  },
  "resolutions": {
    "./**/@babel/parser": "7.7.4",
--- a/compiler/packages/babel-plugin-react-compiler/src/CompilerError.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/CompilerError.ts
@@ -12,28 +12,6 @@ import {Err, Ok, Result} from './Utils/Result';
 import {assertExhaustive} from './Utils/utils';
 import invariant from 'invariant';

-// Number of context lines to display above the source of an error
-const CODEFRAME_LINES_ABOVE = 2;
-// Number of context lines to display below the source of an error
-const CODEFRAME_LINES_BELOW = 3;
-/*
- * Max number of lines for the _source_ of an error, before we abbreviate
- * the display of the source portion
- */
-const CODEFRAME_MAX_LINES = 10;
-/*
- * When the error source exceeds the above threshold, how many lines of
- * the source should be displayed? We show:
- * - CODEFRAME_LINES_ABOVE context lines
- * - CODEFRAME_ABBREVIATED_SOURCE_LINES of the error
- * - '...' ellipsis
- * - CODEFRAME_ABBREVIATED_SOURCE_LINES of the error
- * - CODEFRAME_LINES_BELOW context lines
- *
- * This value must be at least 2 or else we'll cut off important parts of the error message
- */
-const CODEFRAME_ABBREVIATED_SOURCE_LINES = 5;
-
 export enum ErrorSeverity {
  /**
   * An actionable error that the developer can fix. For example, product code errors should be
@@ -132,12 +110,6 @@ export class CompilerDiagnostic {
    return new CompilerDiagnostic({...options, details: []});
  }

-  clone(): CompilerDiagnostic {
-    const cloned = CompilerDiagnostic.create({...this.options});
-    cloned.options.details = [...this.options.details];
-    return cloned;
-  }
-
  get reason(): CompilerDiagnosticOptions['reason'] {
    return this.options.reason;
  }
@@ -310,30 +282,6 @@ export class CompilerError extends Error {
  disabledDetails: Array<CompilerErrorDetail | CompilerDiagnostic> = [];
  printedMessage: string | null = null;

-  static simpleInvariant(
-    condition: unknown,
-    options: {
-      reason: CompilerDiagnosticOptions['reason'];
-      description?: CompilerDiagnosticOptions['description'];
-      loc: SourceLocation;
-    },
-  ): asserts condition {
-    if (!condition) {
-      const errors = new CompilerError();
-      errors.pushDiagnostic(
-        CompilerDiagnostic.create({
-          reason: options.reason,
-          description: options.description ?? null,
-          category: ErrorCategory.Invariant,
-        }).withDetails({
-          kind: 'error',
-          loc: options.loc,
-          message: options.reason,
-        }),
-      );
-      throw errors;
-    }
-  }
  static invariant(
    condition: unknown,
    options: Omit<CompilerDiagnosticOptions, 'category'>,
@@ -548,7 +496,7 @@ function printCodeFrame(
  loc: t.SourceLocation,
  message: string,
 ): string {
-  const printed = codeFrameColumns(
+  return codeFrameColumns(
    source,
    {
      start: {
@@ -562,25 +510,8 @@ function printCodeFrame(
    },
    {
      message,
-      linesAbove: CODEFRAME_LINES_ABOVE,
-      linesBelow: CODEFRAME_LINES_BELOW,
    },
  );
-  const lines = printed.split(/\r?\n/);
-  if (loc.end.line - loc.start.line < CODEFRAME_MAX_LINES) {
-    return printed;
-  }
-  const pipeIndex = lines[0].indexOf('|');
-  return [
-    ...lines.slice(
-      0,
-      CODEFRAME_LINES_ABOVE + CODEFRAME_ABBREVIATED_SOURCE_LINES,
-    ),
-    ' '.repeat(pipeIndex) + '…',
-    ...lines.slice(
-      -(CODEFRAME_LINES_BELOW + CODEFRAME_ABBREVIATED_SOURCE_LINES),
-    ),
-  ].join('\n');
 }

 function printErrorSummary(category: ErrorCategory, message: string): string {
@@ -605,10 +536,7 @@ function printErrorSummary(category: ErrorCategory, message: string): string {
    case ErrorCategory.StaticComponents:
    case ErrorCategory.Suppression:
    case ErrorCategory.Syntax:
-    case ErrorCategory.UseMemo:
-    case ErrorCategory.VoidUseMemo:
-    case ErrorCategory.MemoDependencies:
-    case ErrorCategory.EffectExhaustiveDependencies: {
+    case ErrorCategory.UseMemo: {
      heading = 'Error';
      break;
    }
@@ -654,10 +582,6 @@ export enum ErrorCategory {
   * Checking for valid usage of manual memoization
   */
  UseMemo = 'UseMemo',
-  /**
-   * Checking that useMemos always return a value
-   */
-  VoidUseMemo = 'VoidUseMemo',
  /**
   * Checking for higher order functions acting as factories for components/hooks
   */
@@ -666,10 +590,6 @@ export enum ErrorCategory {
   * Checks that manual memoization is preserved
   */
  PreserveManualMemo = 'PreserveManualMemo',
-  /**
-   * Checks for exhaustive useMemo/useCallback dependencies without extraneous values
-   */
-  MemoDependencies = 'MemoDependencies',
  /**
   * Checks for known incompatible libraries
   */
@@ -690,10 +610,6 @@ export enum ErrorCategory {
   * Checks for memoized effect deps
   */
  EffectDependencies = 'EffectDependencies',
-  /**
-   * Checks for exhaustive and extraneous effect dependencies
-   */
-  EffectExhaustiveDependencies = 'EffectExhaustiveDependencies',
  /**
   * Checks for no setState in effect bodies
   */
@@ -753,21 +669,6 @@ export enum ErrorCategory {
  FBT = 'FBT',
 }

-export enum LintRulePreset {
-  /**
-   * Rules that are stable and included in the `recommended` preset.
-   */
-  Recommended = 'recommended',
-  /**
-   * Rules that are more experimental and only included in the `recommended-latest` preset.
-   */
-  RecommendedLatest = 'recommended-latest',
-  /**
-   * Rules that are disabled.
-   */
-  Off = 'off',
-}
-
 export type LintRule = {
  // Stores the category the rule corresponds to, used to filter errors when reporting
  category: ErrorCategory;
@@ -788,14 +689,15 @@ export type LintRule = {
  description: string;

  /**
-   * Configures the preset in which the rule is enabled. If 'off', the rule will not be included in
-   * any preset.
+   * If true, this rule will automatically appear in the default, "recommended" ESLint
+   * rule set. Otherwise it will be part of an `allRules` export that developers can
+   * use to opt-in to showing output of all possible rules.
   *
   * NOTE: not all validations are enabled by default! Setting this flag only affects
   * whether a given rule is part of the recommended set. The corresponding validation
   * also should be enabled by default if you want the error to actually show up!
   */
-  preset: LintRulePreset;
+  recommended: boolean;
 };

 const RULE_NAME_PATTERN = /^[a-z]+(-[a-z]+)*$/;
@@ -818,7 +720,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'automatic-effect-dependencies',
        description:
          'Verifies that automatic effect dependencies are compiled if opted-in',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.CapitalizedCalls: {
@@ -828,7 +730,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'capitalized-calls',
        description:
          'Validates against calling capitalized functions/methods instead of using JSX',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.Config: {
@@ -837,7 +739,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        severity: ErrorSeverity.Error,
        name: 'config',
        description: 'Validates the compiler configuration options',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.EffectDependencies: {
@@ -846,17 +748,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        severity: ErrorSeverity.Error,
        name: 'memoized-effect-dependencies',
        description: 'Validates that effect dependencies are memoized',
-        preset: LintRulePreset.Off,
-      };
-    }
-    case ErrorCategory.EffectExhaustiveDependencies: {
-      return {
-        category,
-        severity: ErrorSeverity.Error,
-        name: 'exhaustive-effect-dependencies',
-        description:
-          'Validates that effect dependencies are exhaustive and without extraneous values',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.EffectDerivationsOfState: {
@@ -866,7 +758,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'no-deriving-state-in-effects',
        description:
          'Validates against deriving values from state in an effect',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.EffectSetState: {
@@ -875,10 +767,8 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        severity: ErrorSeverity.Error,
        name: 'set-state-in-effect',
        description:
-          'Validates against calling setState synchronously in an effect. ' +
-          'This can indicate non-local derived data, a derived event pattern, or ' +
-          'improper external data synchronization.',
-        preset: LintRulePreset.Recommended,
+          'Validates against calling setState synchronously in an effect, which can lead to re-renders that degrade performance',
+        recommended: true,
      };
    }
    case ErrorCategory.ErrorBoundaries: {
@@ -888,7 +778,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'error-boundaries',
        description:
          'Validates usage of error boundaries instead of try/catch for errors in child components',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.Factories: {
@@ -899,7 +789,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        description:
          'Validates against higher order functions defining nested components or hooks. ' +
          'Components and hooks should be defined at the module level',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.FBT: {
@@ -908,7 +798,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        severity: ErrorSeverity.Error,
        name: 'fbt',
        description: 'Validates usage of fbt',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.Fire: {
@@ -917,7 +807,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        severity: ErrorSeverity.Error,
        name: 'fire',
        description: 'Validates usage of `fire`',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.Gating: {
@@ -927,7 +817,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'gating',
        description:
          'Validates configuration of [gating mode](https://react.dev/reference/react-compiler/gating)',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.Globals: {
@@ -938,7 +828,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        description:
          'Validates against assignment/mutation of globals during render, part of ensuring that ' +
          '[side effects must render outside of render](https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.Hooks: {
@@ -952,7 +842,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
         * We need to dedeupe these (moving the remaining bits into the compiler) and then enable
         * this rule.
         */
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.Immutability: {
@@ -962,7 +852,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'immutability',
        description:
          'Validates against mutating props, state, and other values that [are immutable](https://react.dev/reference/rules/components-and-hooks-must-be-pure#props-and-state-are-immutable)',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.Invariant: {
@@ -971,7 +861,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        severity: ErrorSeverity.Error,
        name: 'invariant',
        description: 'Internal invariants',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.PreserveManualMemo: {
@@ -983,7 +873,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
          'Validates that existing manual memoized is preserved by the compiler. ' +
          'React Compiler will only compile components and hooks if its inference ' +
          '[matches or exceeds the existing manual memoization](https://react.dev/learn/react-compiler/introduction#what-should-i-do-about-usememo-usecallback-and-reactmemo)',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.Purity: {
@@ -993,7 +883,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'purity',
        description:
          'Validates that [components/hooks are pure](https://react.dev/reference/rules/components-and-hooks-must-be-pure) by checking that they do not call known-impure functions',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.Refs: {
@@ -1003,7 +893,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'refs',
        description:
          'Validates correct usage of refs, not reading/writing during render. See the "pitfalls" section in [`useRef()` usage](https://react.dev/reference/react/useRef#usage)',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.RenderSetState: {
@@ -1013,7 +903,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'set-state-in-render',
        description:
          'Validates against setting state during render, which can trigger additional renders and potential infinite render loops',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.StaticComponents: {
@@ -1023,7 +913,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'static-components',
        description:
          'Validates that components are static, not recreated every render. Components that are recreated dynamically can reset state and trigger excessive re-rendering',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.Suppression: {
@@ -1032,7 +922,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        severity: ErrorSeverity.Error,
        name: 'rule-suppression',
        description: 'Validates against suppression of other rules',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.Syntax: {
@@ -1041,7 +931,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        severity: ErrorSeverity.Error,
        name: 'syntax',
        description: 'Validates against invalid syntax',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.Todo: {
@@ -1050,7 +940,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        severity: ErrorSeverity.Hint,
        name: 'todo',
        description: 'Unimplemented features',
-        preset: LintRulePreset.Off,
+        recommended: false,
      };
    }
    case ErrorCategory.UnsupportedSyntax: {
@@ -1060,7 +950,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'unsupported-syntax',
        description:
          'Validates against syntax that we do not plan to support in React Compiler',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    case ErrorCategory.UseMemo: {
@@ -1070,35 +960,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'use-memo',
        description:
          'Validates usage of the useMemo() hook against common mistakes. See [`useMemo()` docs](https://react.dev/reference/react/useMemo) for more information.',
-        preset: LintRulePreset.Recommended,
-      };
-    }
-    case ErrorCategory.VoidUseMemo: {
-      return {
-        category,
-        severity: ErrorSeverity.Error,
-        name: 'void-use-memo',
-        description:
-          'Validates that useMemos always return a value and that the result of the useMemo is used by the component/hook. See [`useMemo()` docs](https://react.dev/reference/react/useMemo) for more information.',
-        preset: LintRulePreset.RecommendedLatest,
-      };
-    }
-    case ErrorCategory.MemoDependencies: {
-      return {
-        category,
-        severity: ErrorSeverity.Error,
-        name: 'memo-dependencies',
-        description:
-          'Validates that useMemo() and useCallback() specify comprehensive dependencies without extraneous values. See [`useMemo()` docs](https://react.dev/reference/react/useMemo) for more information.',
-        /**
-         * TODO: the "MemoDependencies" rule largely reimplements the "exhaustive-deps" non-compiler rule,
-         * allowing the compiler to ensure it does not regress change behavior due to different dependencies.
-         * We previously relied on the source having ESLint suppressions for any exhaustive-deps violations,
-         * but it's more reliable to verify it within the compiler.
-         *
-         * Long-term we should de-duplicate these implementations.
-         */
-        preset: LintRulePreset.Off,
+        recommended: true,
      };
    }
    case ErrorCategory.IncompatibleLibrary: {
@@ -1108,7 +970,7 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
        name: 'incompatible-library',
        description:
          'Validates against usage of libraries which are incompatible with memoization (manual or automatic)',
-        preset: LintRulePreset.Recommended,
+        recommended: true,
      };
    }
    default: {
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Options.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Options.ts
@@ -6,7 +6,7 @@
 */

 import * as t from '@babel/types';
-import {z} from 'zod/v4';
+import {z} from 'zod';
 import {
  CompilerDiagnostic,
  CompilerError,
@@ -20,7 +20,7 @@ import {
  tryParseExternalFunction,
 } from '../HIR/Environment';
 import {hasOwnProperty} from '../Utils/utils';
-import {fromZodError} from 'zod-validation-error/v4';
+import {fromZodError} from 'zod-validation-error';
 import {CompilerPipelineValue} from './Pipeline';

 const PanicThresholdOptionsSchema = z.enum([
@@ -102,25 +102,14 @@ export type PluginOptions = Partial<{

  panicThreshold: PanicThresholdOptions;

-  /**
-   * @deprecated
-   *
+  /*
   * When enabled, Forget will continue statically analyzing and linting code, but skip over codegen
   * passes.
   *
-   * NOTE: ignored if `outputMode` is specified
-   *
   * Defaults to false
   */
  noEmit: boolean;

-  /**
-   * If specified, overrides `noEmit` and controls the output mode of the compiler.
-   *
-   * Defaults to null
-   */
-  outputMode: CompilerOutputMode | null;
-
  /*
   * Determines the strategy for determining which functions to compile. Note that regardless of
   * which mode is enabled, a component can be opted out by adding the string literal
@@ -223,19 +212,6 @@ const CompilationModeSchema = z.enum([

 export type CompilationMode = z.infer<typeof CompilationModeSchema>;

-const CompilerOutputModeSchema = z.enum([
-  // Build optimized for SSR, with client features removed
-  'ssr',
-  // Build optimized for the client, with auto memoization
-  'client',
-  // Build optimized for the client without auto memo
-  'client-no-memo',
-  // Lint mode, the output is unused but validations should run
-  'lint',
-]);
-
-export type CompilerOutputMode = z.infer<typeof CompilerOutputModeSchema>;
-
 /**
 * Represents 'events' that may occur during compilation. Events are only
 * recorded when a logger is set (through the config).
@@ -317,7 +293,6 @@ export const defaultOptions: ParsedPluginOptions = {
  logger: null,
  gating: null,
  noEmit: false,
-  outputMode: null,
  dynamicGating: null,
  eslintSuppressionRules: null,
  flowSuppressions: true,
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
@@ -8,7 +8,7 @@
 import {NodePath} from '@babel/traverse';
 import * as t from '@babel/types';
 import prettyFormat from 'pretty-format';
-import {CompilerOutputMode, Logger, ProgramContext} from '.';
+import {Logger, ProgramContext} from '.';
 import {
  HIRFunction,
  ReactiveFunction,
@@ -24,6 +24,7 @@ import {
  pruneUnusedLabelsHIR,
 } from '../HIR';
 import {
+  CompilerMode,
  Environment,
  EnvironmentConfig,
  ReactFunctionType,
@@ -96,17 +97,13 @@ import {propagateScopeDependenciesHIR} from '../HIR/PropagateScopeDependenciesHI
 import {outlineJSX} from '../Optimization/OutlineJsx';
 import {optimizePropsMethodCalls} from '../Optimization/OptimizePropsMethodCalls';
 import {transformFire} from '../Transform';
+import {validateNoImpureFunctionsInRender} from '../Validation/ValidateNoImpureFunctionsInRender';
 import {validateStaticComponents} from '../Validation/ValidateStaticComponents';
 import {validateNoFreezingKnownMutableFunctions} from '../Validation/ValidateNoFreezingKnownMutableFunctions';
 import {inferMutationAliasingEffects} from '../Inference/InferMutationAliasingEffects';
 import {inferMutationAliasingRanges} from '../Inference/InferMutationAliasingRanges';
 import {validateNoDerivedComputationsInEffects} from '../Validation/ValidateNoDerivedComputationsInEffects';
-import {validateNoDerivedComputationsInEffects_exp} from '../Validation/ValidateNoDerivedComputationsInEffects_exp';
 import {nameAnonymousFunctions} from '../Transform/NameAnonymousFunctions';
-import {optimizeForSSR} from '../Optimization/OptimizeForSSR';
-import {validateExhaustiveDependencies} from '../Validation/ValidateExhaustiveDependencies';
-import {validateSourceLocations} from '../Validation/ValidateSourceLocations';
-import {validateNoImpureValuesInRender} from '../Validation/ValidateNoImpureValuesInRender';

 export type CompilerPipelineValue =
  | {kind: 'ast'; name: string; value: CodegenFunction}
@@ -120,7 +117,7 @@ function run(
  >,
  config: EnvironmentConfig,
  fnType: ReactFunctionType,
-  mode: CompilerOutputMode,
+  mode: CompilerMode,
  programContext: ProgramContext,
  logger: Logger | null,
  filename: string | null,
@@ -170,7 +167,7 @@ function runWithEnvironment(
  validateUseMemo(hir).unwrap();

  if (
-    env.enableDropManualMemoization &&
+    env.isInferredMemoEnabled &&
    !env.config.enablePreserveExistingManualUseMemo &&
    !env.config.disableMemoizationForDebugging &&
    !env.config.enableChangeDetectionForDebugging
@@ -206,7 +203,7 @@ function runWithEnvironment(
  inferTypes(hir);
  log({kind: 'hir', name: 'InferTypes', value: hir});

-  if (env.enableValidations) {
+  if (env.isInferredMemoEnabled) {
    if (env.config.validateHooksUsage) {
      validateHooksUsage(hir).unwrap();
    }
@@ -232,17 +229,12 @@ function runWithEnvironment(

  const mutabilityAliasingErrors = inferMutationAliasingEffects(hir);
  log({kind: 'hir', name: 'InferMutationAliasingEffects', value: hir});
-  if (env.enableValidations) {
+  if (env.isInferredMemoEnabled) {
    if (mutabilityAliasingErrors.isErr()) {
      throw mutabilityAliasingErrors.unwrapErr();
    }
  }

-  if (env.outputMode === 'ssr') {
-    optimizeForSSR(hir);
-    log({kind: 'hir', name: 'OptimizeForSSR', value: hir});
-  }
-
  // Note: Has to come after infer reference effects because "dead" code may still affect inference
  deadCodeElimination(hir);
  log({kind: 'hir', name: 'DeadCodeElimination', value: hir});
@@ -259,48 +251,40 @@ function runWithEnvironment(
    isFunctionExpression: false,
  });
  log({kind: 'hir', name: 'InferMutationAliasingRanges', value: hir});
-  if (env.enableValidations) {
+  if (env.isInferredMemoEnabled) {
    if (mutabilityAliasingRangeErrors.isErr()) {
      throw mutabilityAliasingRangeErrors.unwrapErr();
    }
    validateLocalsNotReassignedAfterRender(hir);
  }

-  if (env.enableValidations) {
+  if (env.isInferredMemoEnabled) {
    if (env.config.assertValidMutableRanges) {
      assertValidMutableRanges(hir);
    }

+    if (env.config.validateRefAccessDuringRender) {
+      validateNoRefAccessInRender(hir).unwrap();
+    }
+
    if (env.config.validateNoSetStateInRender) {
      validateNoSetStateInRender(hir).unwrap();
    }

-    if (
-      env.config.validateNoDerivedComputationsInEffects_exp &&
-      env.outputMode === 'lint'
-    ) {
-      env.logErrors(validateNoDerivedComputationsInEffects_exp(hir));
-    } else if (env.config.validateNoDerivedComputationsInEffects) {
+    if (env.config.validateNoDerivedComputationsInEffects) {
      validateNoDerivedComputationsInEffects(hir);
    }

-    if (env.config.validateNoSetStateInEffects && env.outputMode === 'lint') {
+    if (env.config.validateNoSetStateInEffects) {
      env.logErrors(validateNoSetStateInEffects(hir, env));
    }

-    if (env.config.validateNoJSXInTryStatements && env.outputMode === 'lint') {
+    if (env.config.validateNoJSXInTryStatements) {
      env.logErrors(validateNoJSXInTryStatement(hir));
    }

-    if (
-      env.config.validateNoImpureFunctionsInRender ||
-      env.config.validateRefAccessDuringRender
-    ) {
-      validateNoImpureValuesInRender(hir).unwrap();
-    }
-
-    if (env.config.validateRefAccessDuringRender) {
-      validateNoRefAccessInRender(hir).unwrap();
+    if (env.config.validateNoImpureFunctionsInRender) {
+      validateNoImpureFunctionsInRender(hir).unwrap();
    }

    validateNoFreezingKnownMutableFunctions(hir).unwrap();
@@ -309,16 +293,6 @@ function runWithEnvironment(
  inferReactivePlaces(hir);
  log({kind: 'hir', name: 'InferReactivePlaces', value: hir});

-  if (env.enableValidations) {
-    if (
-      env.config.validateExhaustiveMemoizationDependencies ||
-      env.config.validateExhaustiveEffectDependencies
-    ) {
-      // NOTE: this relies on reactivity inference running first
-      validateExhaustiveDependencies(hir).unwrap();
-    }
-  }
-
  rewriteInstructionKindsBasedOnReassignment(hir);
  log({
    kind: 'hir',
@@ -326,15 +300,11 @@ function runWithEnvironment(
    value: hir,
  });

-  if (
-    env.enableValidations &&
-    env.config.validateStaticComponents &&
-    env.outputMode === 'lint'
-  ) {
-    env.logErrors(validateStaticComponents(hir));
-  }
+  if (env.isInferredMemoEnabled) {
+    if (env.config.validateStaticComponents) {
+      env.logErrors(validateStaticComponents(hir));
+    }

-  if (env.enableMemoization) {
    /**
     * Only create reactive scopes (which directly map to generated memo blocks)
     * if inferred memoization is enabled. This makes all later passes which
@@ -584,10 +554,6 @@ function runWithEnvironment(
    log({kind: 'ast', name: 'Codegen (outlined)', value: outlined.fn});
  }

-  if (env.config.validateSourceLocations) {
-    validateSourceLocations(func, ast).unwrap();
-  }
-
  /**
   * This flag should be only set for unit / fixture tests to check
   * that Forget correctly handles unexpected errors (e.g. exceptions
@@ -606,7 +572,7 @@ export function compileFn(
  >,
  config: EnvironmentConfig,
  fnType: ReactFunctionType,
-  mode: CompilerOutputMode,
+  mode: CompilerMode,
  programContext: ProgramContext,
  logger: Logger | null,
  filename: string | null,
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Program.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Program.ts
@@ -24,7 +24,6 @@ import {
  validateRestrictedImports,
 } from './Imports';
 import {
-  CompilerOutputMode,
  CompilerReactTarget,
  ParsedPluginOptions,
  PluginOptions,
@@ -400,15 +399,7 @@ export function compileProgram(
   */
  const suppressions = findProgramSuppressions(
    pass.comments,
-    /*
-     * If the compiler is validating hooks rules and exhaustive memo dependencies, we don't need to check
-     * for React ESLint suppressions
-     */
-    pass.opts.environment.validateExhaustiveMemoizationDependencies &&
-      pass.opts.environment.validateHooksUsage
-      ? null
-      : (pass.opts.eslintSuppressionRules ?? DEFAULT_ESLINT_SUPPRESSIONS),
-    // Always bail on Flow suppressions
+    pass.opts.eslintSuppressionRules ?? DEFAULT_ESLINT_SUPPRESSIONS,
    pass.opts.flowSuppressions,
  );

@@ -430,17 +421,9 @@ export function compileProgram(
  );
  const compiledFns: Array<CompileResult> = [];

-  // outputMode takes precedence if specified
-  const outputMode: CompilerOutputMode =
-    pass.opts.outputMode ?? (pass.opts.noEmit ? 'lint' : 'client');
  while (queue.length !== 0) {
    const current = queue.shift()!;
-    const compiled = processFn(
-      current.fn,
-      current.fnType,
-      programContext,
-      outputMode,
-    );
+    const compiled = processFn(current.fn, current.fnType, programContext);

    if (compiled != null) {
      for (const outlined of compiled.outlined) {
@@ -598,7 +581,6 @@ function processFn(
  fn: BabelFn,
  fnType: ReactFunctionType,
  programContext: ProgramContext,
-  outputMode: CompilerOutputMode,
 ): null | CodegenFunction {
  let directives: {
    optIn: t.Directive | null;
@@ -634,27 +616,18 @@ function processFn(
  }

  let compiledFn: CodegenFunction;
-  const compileResult = tryCompileFunction(
-    fn,
-    fnType,
-    programContext,
-    outputMode,
-  );
+  const compileResult = tryCompileFunction(fn, fnType, programContext);
  if (compileResult.kind === 'error') {
    if (directives.optOut != null) {
      logError(compileResult.error, programContext, fn.node.loc ?? null);
    } else {
      handleError(compileResult.error, programContext, fn.node.loc ?? null);
    }
-    if (outputMode === 'client') {
-      const retryResult = retryCompileFunction(fn, fnType, programContext);
-      if (retryResult == null) {
-        return null;
-      }
-      compiledFn = retryResult;
-    } else {
+    const retryResult = retryCompileFunction(fn, fnType, programContext);
+    if (retryResult == null) {
      return null;
    }
+    compiledFn = retryResult;
  } else {
    compiledFn = compileResult.compiledFn;
  }
@@ -690,7 +663,7 @@ function processFn(

  if (programContext.hasModuleScopeOptOut) {
    return null;
-  } else if (programContext.opts.outputMode === 'lint') {
+  } else if (programContext.opts.noEmit) {
    /**
     * inferEffectDependencies + noEmit is currently only used for linting. In
     * this mode, add source locations for where the compiler *can* infer effect
@@ -720,7 +693,6 @@ function tryCompileFunction(
  fn: BabelFn,
  fnType: ReactFunctionType,
  programContext: ProgramContext,
-  outputMode: CompilerOutputMode,
 ):
  | {kind: 'compile'; compiledFn: CodegenFunction}
  | {kind: 'error'; error: unknown} {
@@ -747,7 +719,7 @@ function tryCompileFunction(
        fn,
        programContext.opts.environment,
        fnType,
-        outputMode,
+        'all_features',
        programContext,
        programContext.opts.logger,
        programContext.filename,
@@ -785,7 +757,7 @@ function retryCompileFunction(
      fn,
      environment,
      fnType,
-      'client-no-memo',
+      'no_inferred_memo',
      programContext,
      programContext.opts.logger,
      programContext.filename,
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Suppression.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Suppression.ts
@@ -78,7 +78,7 @@ export function filterSuppressionsThatAffectFunction(

 export function findProgramSuppressions(
  programComments: Array<t.Comment>,
-  ruleNames: Array<string> | null,
+  ruleNames: Array<string>,
  flowSuppressions: boolean,
 ): Array<SuppressionRange> {
  const suppressionRanges: Array<SuppressionRange> = [];
@@ -89,7 +89,7 @@ export function findProgramSuppressions(
  let disableNextLinePattern: RegExp | null = null;
  let disablePattern: RegExp | null = null;
  let enablePattern: RegExp | null = null;
-  if (ruleNames != null && ruleNames.length !== 0) {
+  if (ruleNames.length !== 0) {
    const rulePattern = `(${ruleNames.join('|')})`;
    disableNextLinePattern = new RegExp(
      `eslint-disable-next-line ${rulePattern}`,
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
@@ -1568,6 +1568,20 @@ function lowerObjectPropertyKey(
      name: key.node.value,
    };
  } else if (property.node.computed && key.isExpression()) {
+    if (!key.isIdentifier() && !key.isMemberExpression()) {
+      /*
+       * NOTE: allowing complex key expressions can trigger a bug where a mutation is made conditional
+       * see fixture
+       * error.object-expression-computed-key-modified-during-after-construction.js
+       */
+      builder.errors.push({
+        reason: `(BuildHIR::lowerExpression) Expected Identifier, got ${key.type} key in ObjectExpression`,
+        category: ErrorCategory.Todo,
+        loc: key.node.loc ?? null,
+        suggestions: null,
+      });
+      return null;
+    }
    const place = lowerExpressionToTemporary(builder, key);
    return {
      kind: 'computed',
@@ -4026,7 +4040,6 @@ function lowerAssignment(
          pattern: {
            kind: 'ArrayPattern',
            items,
-            loc: lvalue.node.loc ?? GeneratedSource,
          },
        },
        value,
@@ -4204,7 +4217,6 @@ function lowerAssignment(
          pattern: {
            kind: 'ObjectPattern',
            properties,
-            loc: lvalue.node.loc ?? GeneratedSource,
          },
        },
        value,
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/CollectHoistablePropertyLoads.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/CollectHoistablePropertyLoads.ts
@@ -454,32 +454,6 @@ function collectNonNullsInBlocks(
            assumedNonNullObjects.add(entry);
          }
        }
-      } else if (
-        fn.env.config.enablePreserveExistingMemoizationGuarantees &&
-        instr.value.kind === 'StartMemoize' &&
-        instr.value.deps != null
-      ) {
-        for (const dep of instr.value.deps) {
-          if (dep.root.kind === 'NamedLocal') {
-            if (
-              !isImmutableAtInstr(dep.root.value.identifier, instr.id, context)
-            ) {
-              continue;
-            }
-            for (let i = 0; i < dep.path.length; i++) {
-              const pathEntry = dep.path[i]!;
-              if (pathEntry.optional) {
-                break;
-              }
-              const depNode = context.registry.getOrCreateProperty({
-                identifier: dep.root.value.identifier,
-                path: dep.path.slice(0, i),
-                reactive: dep.root.value.reactive,
-              });
-              assumedNonNullObjects.add(depNode);
-            }
-          }
-        }
      }
    }

--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts
@@ -6,10 +6,10 @@
 */

 import * as t from '@babel/types';
-import {ZodError, z} from 'zod/v4';
-import {fromZodError} from 'zod-validation-error/v4';
+import {ZodError, z} from 'zod';
+import {fromZodError} from 'zod-validation-error';
 import {CompilerError} from '../CompilerError';
-import {CompilerOutputMode, Logger, ProgramContext} from '../Entrypoint';
+import {Logger, ProgramContext} from '../Entrypoint';
 import {Err, Ok, Result} from '../Utils/Result';
 import {
  DEFAULT_GLOBALS,
@@ -51,7 +51,6 @@ import {Scope as BabelScope, NodePath} from '@babel/traverse';
 import {TypeSchema} from './TypeSchema';
 import {FlowTypeEnv} from '../Flood/Types';
 import {defaultModuleTypeProvider} from './DefaultModuleTypeProvider';
-import {assertExhaustive} from '../Utils/utils';

 export const ReactElementSymbolSchema = z.object({
  elementSymbol: z.union([
@@ -84,11 +83,21 @@ export type ExternalFunction = z.infer<typeof ExternalFunctionSchema>;
 export const USE_FIRE_FUNCTION_NAME = 'useFire';
 export const EMIT_FREEZE_GLOBAL_GATING = '__DEV__';

-export const MacroSchema = z.string();
+export const MacroMethodSchema = z.union([
+  z.object({type: z.literal('wildcard')}),
+  z.object({type: z.literal('name'), name: z.string()}),
+]);
+
+// Would like to change this to drop the string option, but breaks compatibility with existing configs
+export const MacroSchema = z.union([
+  z.string(),
+  z.tuple([z.string(), z.array(MacroMethodSchema)]),
+]);

 export type CompilerMode = 'all_features' | 'no_inferred_memo';

 export type Macro = z.infer<typeof MacroSchema>;
+export type MacroMethod = z.infer<typeof MacroMethodSchema>;

 const HookSchema = z.object({
  /*
@@ -150,7 +159,7 @@ export const EnvironmentConfigSchema = z.object({
   * A function that, given the name of a module, can optionally return a description
   * of that module's type signature.
   */
-  moduleTypeProvider: z.nullable(z.any()).default(null),
+  moduleTypeProvider: z.nullable(z.function().args(z.string())).default(null),

  /**
   * A list of functions which the application compiles as macros, where
@@ -201,7 +210,7 @@ export const EnvironmentConfigSchema = z.object({
   * that if a useEffect or useCallback references a function value, that function value will be
   * considered frozen, and in turn all of its referenced variables will be considered frozen as well.
   */
-  enablePreserveExistingMemoizationGuarantees: z.boolean().default(true),
+  enablePreserveExistingMemoizationGuarantees: z.boolean().default(false),

  /**
   * Validates that all useMemo/useCallback values are also memoized by Forget. This mode can be
@@ -218,23 +227,6 @@ export const EnvironmentConfigSchema = z.object({
   */
  validatePreserveExistingMemoizationGuarantees: z.boolean().default(true),

-  /**
-   * Validate that dependencies supplied to manual memoization calls are exhaustive.
-   */
-  validateExhaustiveMemoizationDependencies: z.boolean().default(true),
-
-  /**
-   * Validate that dependencies supplied to effect hooks are exhaustive.
-   * Can be:
-   * - 'off': No validation (default)
-   * - 'all': Validate and report both missing and extra dependencies
-   * - 'missing-only': Only report missing dependencies
-   * - 'extra-only': Only report extra/unnecessary dependencies
-   */
-  validateExhaustiveEffectDependencies: z
-    .enum(['off', 'all', 'missing-only', 'extra-only'])
-    .default('off'),
-
  /**
   * When this is true, rather than pruning existing manual memoization but ensuring or validating
   * that the memoized values remain memoized, the compiler will simply not prune existing calls to
@@ -257,7 +249,7 @@ export const EnvironmentConfigSchema = z.object({
   * Allows specifying a function that can populate HIR with type information from
   * Flow
   */
-  flowTypeProvider: z.nullable(z.any()).default(null),
+  flowTypeProvider: z.nullable(z.function().args(z.string())).default(null),

  /**
   * Enables inference of optional dependency chains. Without this flag
@@ -330,12 +322,6 @@ export const EnvironmentConfigSchema = z.object({
   */
  validateNoSetStateInRender: z.boolean().default(true),

-  /**
-   * When enabled, changes the behavior of validateNoSetStateInRender to recommend
-   * using useKeyedState instead of the manual pattern for resetting state.
-   */
-  enableUseKeyedState: z.boolean().default(false),
-
  /**
   * Validates that setState is not called synchronously within an effect (useEffect and friends).
   * Scheduling a setState (with an event listener, subscription, etc) is valid.
@@ -348,12 +334,6 @@ export const EnvironmentConfigSchema = z.object({
   */
  validateNoDerivedComputationsInEffects: z.boolean().default(false),

-  /**
-   * Experimental: Validates that effects are not used to calculate derived data which could instead be computed
-   * during render. Generates a custom error message for each type of violation.
-   */
-  validateNoDerivedComputationsInEffects_exp: z.boolean().default(false),
-
  /**
   * Validates against creating JSX within a try block and recommends using an error boundary
   * instead.
@@ -388,13 +368,6 @@ export const EnvironmentConfigSchema = z.object({
  validateNoCapitalizedCalls: z.nullable(z.array(z.string())).default(null),
  validateBlocklistedImports: z.nullable(z.array(z.string())).default(null),

-  /**
-   * Validates that AST nodes generated during codegen have proper source locations.
-   * This is useful for debugging issues with source maps and Istanbul coverage.
-   * When enabled, the compiler will error if important source locations are missing in the generated AST.
-   */
-  validateSourceLocations: z.boolean().default(false),
-
  /**
   * Validate against impure functions called during render
   */
@@ -686,7 +659,7 @@ export const EnvironmentConfigSchema = z.object({
   * Invalid:
   *   useMemo(() => { ... }, [...]);
   */
-  validateNoVoidUseMemo: z.boolean().default(true),
+  validateNoVoidUseMemo: z.boolean().default(false),

  /**
   * Validates that Components/Hooks are always defined at module level. This prevents scope
@@ -696,35 +669,11 @@ export const EnvironmentConfigSchema = z.object({
  validateNoDynamicallyCreatedComponentsOrHooks: z.boolean().default(false),

  /**
-   * When enabled, allows setState calls in effects based on valid patterns involving refs:
-   * - Allow setState where the value being set is derived from a ref. This is useful where
-   *   state needs to take into account layer information, and a layout effect reads layout
-   *   data from a ref and sets state.
-   * - Allow conditionally calling setState after manually comparing previous/new values
-   *   for changes via a ref. Relying on effect deps is insufficient for non-primitive values,
-   *   so a ref is generally required to manually track previous values and compare prev/next
-   *   for meaningful changes before setting state.
+   * When enabled, allows setState calls in effects when the value being set is
+   * derived from a ref. This is useful for patterns where initial layout measurements
+   * from refs need to be stored in state during mount.
   */
  enableAllowSetStateFromRefsInEffects: z.boolean().default(true),
-
-  /**
-   * When enabled, provides verbose error messages for setState calls within effects,
-   * presenting multiple possible fixes to the user/agent since we cannot statically
-   * determine which specific use-case applies:
-   * 1. Non-local derived data - requires restructuring state ownership
-   * 2. Derived event pattern - detecting when a prop changes
-   * 3. Force update / external sync - should use useSyncExternalStore
-   */
-  enableVerboseNoSetStateInEffect: z.boolean().default(false),
-
-  /**
-   * Enables inference of event handler types for JSX props on built-in DOM elements.
-   * When enabled, functions passed to event handler props (props starting with "on")
-   * on primitive JSX tags are inferred to have the BuiltinEventHandlerId type, which
-   * allows ref access within those functions since DOM event handlers are guaranteed
-   * by React to only execute in response to events, not during render.
-   */
-  enableInferEventHandlers: z.boolean().default(false),
 });

 export type EnvironmentConfig = z.infer<typeof EnvironmentConfigSchema>;
@@ -764,7 +713,7 @@ export class Environment {
  code: string | null;
  config: EnvironmentConfig;
  fnType: ReactFunctionType;
-  outputMode: CompilerOutputMode;
+  compilerMode: CompilerMode;
  programContext: ProgramContext;
  hasFireRewrite: boolean;
  hasInferredEffect: boolean;
@@ -779,7 +728,7 @@ export class Environment {
  constructor(
    scope: BabelScope,
    fnType: ReactFunctionType,
-    outputMode: CompilerOutputMode,
+    compilerMode: CompilerMode,
    config: EnvironmentConfig,
    contextIdentifiers: Set<t.Identifier>,
    parentFunction: NodePath<t.Function>, // the outermost function being compiled
@@ -790,7 +739,7 @@ export class Environment {
  ) {
    this.#scope = scope;
    this.fnType = fnType;
-    this.outputMode = outputMode;
+    this.compilerMode = compilerMode;
    this.config = config;
    this.filename = filename;
    this.code = code;
@@ -886,65 +835,8 @@ export class Environment {
    return this.#flowTypeEnvironment;
  }

-  get enableDropManualMemoization(): boolean {
-    switch (this.outputMode) {
-      case 'lint': {
-        // linting drops to be more compatible with compiler analysis
-        return true;
-      }
-      case 'client':
-      case 'ssr': {
-        return true;
-      }
-      case 'client-no-memo': {
-        return false;
-      }
-      default: {
-        assertExhaustive(
-          this.outputMode,
-          `Unexpected output mode '${this.outputMode}'`,
-        );
-      }
-    }
-  }
-
-  get enableMemoization(): boolean {
-    switch (this.outputMode) {
-      case 'client':
-      case 'lint': {
-        // linting also enables memoization so that we can check if manual memoization is preserved
-        return true;
-      }
-      case 'ssr':
-      case 'client-no-memo': {
-        return false;
-      }
-      default: {
-        assertExhaustive(
-          this.outputMode,
-          `Unexpected output mode '${this.outputMode}'`,
-        );
-      }
-    }
-  }
-
-  get enableValidations(): boolean {
-    switch (this.outputMode) {
-      case 'client':
-      case 'lint':
-      case 'ssr': {
-        return true;
-      }
-      case 'client-no-memo': {
-        return false;
-      }
-      default: {
-        assertExhaustive(
-          this.outputMode,
-          `Unexpected output mode '${this.outputMode}'`,
-        );
-      }
-    }
+  get isInferredMemoEnabled(): boolean {
+    return this.compilerMode !== 'no_inferred_memo';
  }

  get nextIdentifierId(): IdentifierId {
@@ -1014,12 +906,6 @@ export class Environment {
      if (moduleTypeProvider == null) {
        return null;
      }
-      if (typeof moduleTypeProvider !== 'function') {
-        CompilerError.throwInvalidConfig({
-          reason: `Expected a function for \`moduleTypeProvider\``,
-          loc,
-        });
-      }
      const unparsedModuleConfig = moduleTypeProvider(moduleName);
      if (unparsedModuleConfig != null) {
        const parsedModuleConfig = TypeSchema.safeParse(unparsedModuleConfig);
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/Globals.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/Globals.ts
@@ -23,14 +23,13 @@ import {
  BuiltInUseInsertionEffectHookId,
  BuiltInUseLayoutEffectHookId,
  BuiltInUseOperatorId,
-  BuiltInUseOptimisticId,
  BuiltInUseReducerId,
  BuiltInUseRefId,
  BuiltInUseStateId,
  BuiltInUseTransitionId,
  BuiltInWeakMapId,
  BuiltInWeakSetId,
-  BuiltInEffectEventId,
+  BuiltinEffectEventId,
  ReanimatedSharedValueId,
  ShapeRegistry,
  addFunction,
@@ -38,7 +37,7 @@ import {
  addObject,
 } from './ObjectShape';
 import {BuiltInType, ObjectType, PolyType} from './Types';
-import {AliasingSignatureConfig, TypeConfig} from './TypeSchema';
+import {TypeConfig} from './TypeSchema';
 import {assertExhaustive} from '../Utils/utils';
 import {isHookName} from './Environment';
 import {CompilerError, SourceLocation} from '..';
@@ -626,136 +625,11 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
  // TODO: rest of Global objects
 ];

-const RenderHookAliasing: (
-  reason: ValueReason,
-) => AliasingSignatureConfig = reason => ({
-  receiver: '@receiver',
-  params: [],
-  rest: '@rest',
-  returns: '@returns',
-  temporaries: [],
-  effects: [
-    // Freeze the arguments
-    {
-      kind: 'Freeze',
-      value: '@rest',
-      reason: ValueReason.HookCaptured,
-    },
-    // Render the arguments
-    {
-      kind: 'Render',
-      place: '@rest',
-    },
-    // Returns a frozen value
-    {
-      kind: 'Create',
-      into: '@returns',
-      value: ValueKind.Frozen,
-      reason,
-    },
-    // May alias any arguments into the return
-    {
-      kind: 'Alias',
-      from: '@rest',
-      into: '@returns',
-    },
-  ],
-});
-
-const EffectHookAliasing: AliasingSignatureConfig = {
-  receiver: '@receiver',
-  params: ['@fn', '@deps'],
-  rest: '@rest',
-  returns: '@returns',
-  temporaries: ['@effect'],
-  effects: [
-    // Freezes the function and deps
-    {
-      kind: 'Freeze',
-      value: '@rest',
-      reason: ValueReason.Effect,
-    },
-    {
-      kind: 'Freeze',
-      value: '@fn',
-      reason: ValueReason.Effect,
-    },
-    {
-      kind: 'Freeze',
-      value: '@deps',
-      reason: ValueReason.Effect,
-    },
-    // Deps are accessed during render
-    {
-      kind: 'Render',
-      place: '@deps',
-    },
-    // Internally creates an effect object that captures the function and deps
-    {
-      kind: 'Create',
-      into: '@effect',
-      value: ValueKind.Frozen,
-      reason: ValueReason.KnownReturnSignature,
-    },
-    // The effect stores the function and dependencies
-    {
-      kind: 'Capture',
-      from: '@rest',
-      into: '@effect',
-    },
-    {
-      kind: 'Capture',
-      from: '@fn',
-      into: '@effect',
-    },
-    // Returns undefined
-    {
-      kind: 'Create',
-      into: '@returns',
-      value: ValueKind.Primitive,
-      reason: ValueReason.KnownReturnSignature,
-    },
-  ],
-};
-
 /*
 * TODO(mofeiZ): We currently only store rest param effects for hooks.
 * now that FeatureFlag `enableTreatHooksAsFunctions` is removed we can
 * use positional params too (?)
 */
-const useEffectEvent = addHook(
-  DEFAULT_SHAPES,
-  {
-    positionalParams: [],
-    restParam: Effect.Freeze,
-    returnType: {
-      kind: 'Function',
-      return: {kind: 'Poly'},
-      shapeId: BuiltInEffectEventId,
-      isConstructor: false,
-    },
-    calleeEffect: Effect.Read,
-    hookKind: 'useEffectEvent',
-    // Frozen because it should not mutate any locally-bound values
-    returnValueKind: ValueKind.Frozen,
-    aliasing: {
-      receiver: '@receiver',
-      params: ['@value'],
-      rest: null,
-      returns: '@return',
-      temporaries: [],
-      effects: [
-        {kind: 'Assign', from: '@value', into: '@return'},
-        {
-          kind: 'Freeze',
-          value: '@value',
-          reason: ValueReason.HookCaptured,
-        },
-      ],
-    },
-  },
-  BuiltInUseEffectEventId,
-);
 const REACT_APIS: Array<[string, BuiltInType]> = [
  [
    'useContext',
@@ -769,7 +643,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
        hookKind: 'useContext',
        returnValueKind: ValueKind.Frozen,
        returnValueReason: ValueReason.Context,
-        aliasing: RenderHookAliasing(ValueReason.Context),
      },
      BuiltInUseContextHookId,
    ),
@@ -784,7 +657,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
      hookKind: 'useState',
      returnValueKind: ValueKind.Frozen,
      returnValueReason: ValueReason.State,
-      aliasing: RenderHookAliasing(ValueReason.State),
    }),
  ],
  [
@@ -797,7 +669,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
      hookKind: 'useActionState',
      returnValueKind: ValueKind.Frozen,
      returnValueReason: ValueReason.State,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
    }),
  ],
  [
@@ -810,7 +681,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
      hookKind: 'useReducer',
      returnValueKind: ValueKind.Frozen,
      returnValueReason: ValueReason.ReducerState,
-      aliasing: RenderHookAliasing(ValueReason.ReducerState),
    }),
  ],
  [
@@ -822,22 +692,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
      calleeEffect: Effect.Read,
      hookKind: 'useRef',
      returnValueKind: ValueKind.Mutable,
-      aliasing: {
-        receiver: '@receiver',
-        params: [],
-        rest: '@rest',
-        returns: '@return',
-        temporaries: [],
-        effects: [
-          {
-            kind: 'Create',
-            into: '@return',
-            value: ValueKind.Mutable,
-            reason: ValueReason.KnownReturnSignature,
-          },
-          {kind: 'Capture', from: '@rest', into: '@return'},
-        ],
-      },
    }),
  ],
  [
@@ -860,7 +714,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
      calleeEffect: Effect.Read,
      hookKind: 'useMemo',
      returnValueKind: ValueKind.Frozen,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
    }),
  ],
  [
@@ -868,16 +721,10 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
    addHook(DEFAULT_SHAPES, {
      positionalParams: [],
      restParam: Effect.Freeze,
-      returnType: {
-        kind: 'Function',
-        isConstructor: false,
-        return: {kind: 'Poly'},
-        shapeId: null,
-      },
+      returnType: {kind: 'Poly'},
      calleeEffect: Effect.Read,
      hookKind: 'useCallback',
      returnValueKind: ValueKind.Frozen,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
    }),
  ],
  [
@@ -891,7 +738,41 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
        calleeEffect: Effect.Read,
        hookKind: 'useEffect',
        returnValueKind: ValueKind.Frozen,
-        aliasing: EffectHookAliasing,
+        aliasing: {
+          receiver: '@receiver',
+          params: [],
+          rest: '@rest',
+          returns: '@returns',
+          temporaries: ['@effect'],
+          effects: [
+            // Freezes the function and deps
+            {
+              kind: 'Freeze',
+              value: '@rest',
+              reason: ValueReason.Effect,
+            },
+            // Internally creates an effect object that captures the function and deps
+            {
+              kind: 'Create',
+              into: '@effect',
+              value: ValueKind.Frozen,
+              reason: ValueReason.KnownReturnSignature,
+            },
+            // The effect stores the function and dependencies
+            {
+              kind: 'Capture',
+              from: '@rest',
+              into: '@effect',
+            },
+            // Returns undefined
+            {
+              kind: 'Create',
+              into: '@returns',
+              value: ValueKind.Primitive,
+              reason: ValueReason.KnownReturnSignature,
+            },
+          ],
+        },
      },
      BuiltInUseEffectHookId,
    ),
@@ -907,7 +788,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
        calleeEffect: Effect.Read,
        hookKind: 'useLayoutEffect',
        returnValueKind: ValueKind.Frozen,
-        aliasing: EffectHookAliasing,
      },
      BuiltInUseLayoutEffectHookId,
    ),
@@ -923,7 +803,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
        calleeEffect: Effect.Read,
        hookKind: 'useInsertionEffect',
        returnValueKind: ValueKind.Frozen,
-        aliasing: EffectHookAliasing,
      },
      BuiltInUseInsertionEffectHookId,
    ),
@@ -937,20 +816,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
      calleeEffect: Effect.Read,
      hookKind: 'useTransition',
      returnValueKind: ValueKind.Frozen,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
-    }),
-  ],
-  [
-    'useOptimistic',
-    addHook(DEFAULT_SHAPES, {
-      positionalParams: [],
-      restParam: Effect.Freeze,
-      returnType: {kind: 'Object', shapeId: BuiltInUseOptimisticId},
-      calleeEffect: Effect.Read,
-      hookKind: 'useOptimistic',
-      returnValueKind: ValueKind.Frozen,
-      returnValueReason: ValueReason.State,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
    }),
  ],
  [
@@ -964,7 +829,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
        returnType: {kind: 'Poly'},
        calleeEffect: Effect.Read,
        returnValueKind: ValueKind.Frozen,
-        aliasing: RenderHookAliasing(ValueReason.HookCaptured),
      },
      BuiltInUseOperatorId,
    ),
@@ -989,8 +853,27 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
      BuiltInFireId,
    ),
  ],
-  ['useEffectEvent', useEffectEvent],
-  ['experimental_useEffectEvent', useEffectEvent],
+  [
+    'useEffectEvent',
+    addHook(
+      DEFAULT_SHAPES,
+      {
+        positionalParams: [],
+        restParam: Effect.Freeze,
+        returnType: {
+          kind: 'Function',
+          return: {kind: 'Poly'},
+          shapeId: BuiltinEffectEventId,
+          isConstructor: false,
+        },
+        calleeEffect: Effect.Read,
+        hookKind: 'useEffectEvent',
+        // Frozen because it should not mutate any locally-bound values
+        returnValueKind: ValueKind.Frozen,
+      },
+      BuiltInUseEffectEventId,
+    ),
+  ],
  ['AUTODEPS', addObject(DEFAULT_SHAPES, BuiltInAutodepsId, [])],
 ];

--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts
@@ -16,7 +16,7 @@ import {assertExhaustive} from '../Utils/utils';
 import {Environment, ReactFunctionType} from './Environment';
 import type {HookKind} from './ObjectShape';
 import {Type, makeType} from './Types';
-import {z} from 'zod/v4';
+import {z} from 'zod';
 import type {AliasingEffect} from '../Inference/AliasingEffects';
 import {isReservedWord} from '../Utils/Keyword';
 import {Err, Ok, Result} from '../Utils/Result';
@@ -694,13 +694,11 @@ export type SpreadPattern = {
 export type ArrayPattern = {
  kind: 'ArrayPattern';
  items: Array<Place | SpreadPattern | Hole>;
-  loc: SourceLocation;
 };

 export type ObjectPattern = {
  kind: 'ObjectPattern';
  properties: Array<ObjectProperty | SpreadPattern>;
-  loc: SourceLocation;
 };

 export type ObjectPropertyKey =
@@ -805,11 +803,9 @@ export type ManualMemoDependency = {
    | {
        kind: 'NamedLocal';
        value: Place;
-        constant: boolean;
      }
    | {kind: 'Global'; identifierName: string};
  path: DependencyPath;
-  loc: SourceLocation;
 };

 export type StartMemoize = {
@@ -821,11 +817,6 @@ export type StartMemoize = {
   * (e.g. useMemo without a second arg)
   */
  deps: Array<ManualMemoDependency> | null;
-  /**
-   * The source location of the dependencies argument. Used for
-   * emitting diagnostics with a suggested replacement
-   */
-  depsLoc: SourceLocation | null;
  loc: SourceLocation;
 };
 export type FinishMemoize = {
@@ -1689,28 +1680,6 @@ export function areEqualPaths(a: DependencyPath, b: DependencyPath): boolean {
    )
  );
 }
-export function isSubPath(
-  subpath: DependencyPath,
-  path: DependencyPath,
-): boolean {
-  return (
-    subpath.length <= path.length &&
-    subpath.every(
-      (item, ix) =>
-        item.property === path[ix].property &&
-        item.optional === path[ix].optional,
-    )
-  );
-}
-export function isSubPathIgnoringOptionals(
-  subpath: DependencyPath,
-  path: DependencyPath,
-): boolean {
-  return (
-    subpath.length <= path.length &&
-    subpath.every((item, ix) => item.property === path[ix].property)
-  );
-}

 export function getPlaceScope(
  id: InstructionId,
@@ -1854,10 +1823,6 @@ export function isPrimitiveType(id: Identifier): boolean {
  return id.type.kind === 'Primitive';
 }

-export function isPlainObjectType(id: Identifier): boolean {
-  return id.type.kind === 'Object' && id.type.shapeId === 'BuiltInObject';
-}
-
 export function isArrayType(id: Identifier): boolean {
  return id.type.kind === 'Object' && id.type.shapeId === 'BuiltInArray';
 }
@@ -1879,15 +1844,7 @@ export function isRefValueType(id: Identifier): boolean {
 }

 export function isUseRefType(id: Identifier): boolean {
-  return isUseRefType_(id.type);
-}
-
-export function isUseRefType_(type: Type): boolean {
-  return (
-    (type.kind === 'Object' && type.shapeId === 'BuiltInUseRefId') ||
-    (type.kind === 'Phi' &&
-      type.operands.some(operand => isUseRefType_(operand)))
-  );
+  return id.type.kind === 'Object' && id.type.shapeId === 'BuiltInUseRefId';
 }

 export function isUseStateType(id: Identifier): boolean {
@@ -1898,13 +1855,6 @@ export function isJsxType(type: Type): boolean {
  return type.kind === 'Object' && type.shapeId === 'BuiltInJsx';
 }

-export function isJsxOrJsxUnionType(type: Type): boolean {
-  return (
-    (type.kind === 'Object' && type.shapeId === 'BuiltInJsx') ||
-    (type.kind === 'Phi' && type.operands.some(op => isJsxOrJsxUnionType(op)))
-  );
-}
-
 export function isRefOrRefValue(id: Identifier): boolean {
  return isUseRefType(id) || isRefValueType(id);
 }
@@ -1937,18 +1887,6 @@ export function isStartTransitionType(id: Identifier): boolean {
  );
 }

-export function isUseOptimisticType(id: Identifier): boolean {
-  return (
-    id.type.kind === 'Object' && id.type.shapeId === 'BuiltInUseOptimistic'
-  );
-}
-
-export function isSetOptimisticType(id: Identifier): boolean {
-  return (
-    id.type.kind === 'Function' && id.type.shapeId === 'BuiltInSetOptimistic'
-  );
-}
-
 export function isSetActionStateType(id: Identifier): boolean {
  return (
    id.type.kind === 'Function' && id.type.shapeId === 'BuiltInSetActionState'
@@ -1982,8 +1920,7 @@ export function isStableType(id: Identifier): boolean {
    isSetActionStateType(id) ||
    isDispatcherType(id) ||
    isUseRefType(id) ||
-    isStartTransitionType(id) ||
-    isSetOptimisticType(id)
+    isStartTransitionType(id)
  );
 }

@@ -1994,9 +1931,8 @@ export function isStableTypeContainer(id: Identifier): boolean {
  }
  return (
    isUseStateType(id) || // setState
-    isUseActionStateType(id) || // setActionState
+    type_.shapeId === 'BuiltInUseActionState' || // setActionState
    isUseReducerType(id) || // dispatcher
-    isUseOptimisticType(id) || // setOptimistic
    type_.shapeId === 'BuiltInUseTransition' // startTransition
  );
 }
@@ -2016,7 +1952,6 @@ export function evaluatesToStableTypeOrContainer(
      case 'useActionState':
      case 'useRef':
      case 'useTransition':
-      case 'useOptimistic':
        return true;
    }
  }
@@ -2040,11 +1975,6 @@ export function isUseInsertionEffectHookType(id: Identifier): boolean {
    id.type.shapeId === 'BuiltInUseInsertionEffectHook'
  );
 }
-export function isUseEffectEventType(id: Identifier): boolean {
-  return (
-    id.type.kind === 'Function' && id.type.shapeId === 'BuiltInUseEffectEvent'
-  );
-}

 export function isUseContextHookType(id: Identifier): boolean {
  return (
@@ -2073,23 +2003,4 @@ export function getHookKindForType(
  return null;
 }

-export function areEqualSourceLocations(
-  loc1: SourceLocation,
-  loc2: SourceLocation,
-): boolean {
-  if (typeof loc1 === 'symbol' || typeof loc2 === 'symbol') {
-    return false;
-  }
-  return (
-    loc1.filename === loc2.filename &&
-    loc1.identifierName === loc2.identifierName &&
-    loc1.start.line === loc2.start.line &&
-    loc1.start.column === loc2.start.column &&
-    loc1.start.index === loc2.start.index &&
-    loc1.end.line === loc2.end.line &&
-    loc1.end.column === loc2.end.column &&
-    loc1.end.index === loc2.end.index
-  );
-}
-
 export * from './Types';
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/HIRBuilder.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/HIRBuilder.ts
@@ -988,7 +988,7 @@ export function createTemporaryPlace(
    identifier: makeTemporaryIdentifier(env.nextIdentifierId, loc),
    reactive: false,
    effect: Effect.Unknown,
-    loc,
+    loc: GeneratedSource,
  };
 }

--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/ObjectShape.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/ObjectShape.ts
@@ -5,7 +5,7 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {CompilerError, ErrorCategory} from '../CompilerError';
+import {CompilerError} from '../CompilerError';
 import {AliasingEffect, AliasingSignature} from '../Inference/AliasingEffects';
 import {assertExhaustive} from '../Utils/utils';
 import {
@@ -190,22 +190,14 @@ function parseAliasingSignatureConfig(
          };
        }
        case 'Impure': {
-          const into = lookup(effect.into);
-          return {
-            kind: 'Impure',
-            into,
-            category: ErrorCategory.Purity,
-            description: effect.description,
-            reason: effect.reason,
-            sourceMessage: effect.sourceMessage,
-            usageMessage: effect.usageMessage,
-          };
-        }
-        case 'Render': {
          const place = lookup(effect.place);
          return {
-            kind: 'Render',
+            kind: 'Impure',
            place,
+            error: CompilerError.throwTodo({
+              reason: 'Support impure effect declarations',
+              loc: GeneratedSource,
+            }),
          };
        }
        case 'Apply': {
@@ -312,7 +304,6 @@ export type HookKind =
  | 'useTransition'
  | 'useImperativeHandle'
  | 'useEffectEvent'
-  | 'useOptimistic'
  | 'Custom';

 /*
@@ -408,15 +399,12 @@ export const BuiltInUseReducerId = 'BuiltInUseReducer';
 export const BuiltInDispatchId = 'BuiltInDispatch';
 export const BuiltInUseContextHookId = 'BuiltInUseContextHook';
 export const BuiltInUseTransitionId = 'BuiltInUseTransition';
-export const BuiltInUseOptimisticId = 'BuiltInUseOptimistic';
-export const BuiltInSetOptimisticId = 'BuiltInSetOptimistic';
 export const BuiltInStartTransitionId = 'BuiltInStartTransition';
 export const BuiltInFireId = 'BuiltInFire';
 export const BuiltInFireFunctionId = 'BuiltInFireFunction';
 export const BuiltInUseEffectEventId = 'BuiltInUseEffectEvent';
-export const BuiltInEffectEventId = 'BuiltInEffectEventFunction';
+export const BuiltinEffectEventId = 'BuiltInEffectEventFunction';
 export const BuiltInAutodepsId = 'BuiltInAutoDepsId';
-export const BuiltInEventHandlerId = 'BuiltInEventHandlerId';

 // See getReanimatedModuleType() in Globals.ts — this is part of supporting Reanimated's ref-like types
 export const ReanimatedSharedValueId = 'ReanimatedSharedValueId';
@@ -1197,25 +1185,6 @@ addObject(BUILTIN_SHAPES, BuiltInUseTransitionId, [
  ],
 ]);

-addObject(BUILTIN_SHAPES, BuiltInUseOptimisticId, [
-  ['0', {kind: 'Poly'}],
-  [
-    '1',
-    addFunction(
-      BUILTIN_SHAPES,
-      [],
-      {
-        positionalParams: [],
-        restParam: Effect.Freeze,
-        returnType: PRIMITIVE_TYPE,
-        calleeEffect: Effect.Read,
-        returnValueKind: ValueKind.Primitive,
-      },
-      BuiltInSetOptimisticId,
-    ),
-  ],
-]);
-
 addObject(BUILTIN_SHAPES, BuiltInUseActionStateId, [
  ['0', {kind: 'Poly'}],
  [
@@ -1274,20 +1243,7 @@ addFunction(
    calleeEffect: Effect.ConditionallyMutate,
    returnValueKind: ValueKind.Mutable,
  },
-  BuiltInEffectEventId,
-);
-
-addFunction(
-  BUILTIN_SHAPES,
-  [],
-  {
-    positionalParams: [],
-    restParam: Effect.ConditionallyMutate,
-    returnType: {kind: 'Poly'},
-    calleeEffect: Effect.ConditionallyMutate,
-    returnValueKind: ValueKind.Mutable,
-  },
-  BuiltInEventHandlerId,
+  BuiltinEffectEventId,
 );

 /**
@@ -1521,11 +1477,6 @@ export const DefaultNonmutatingHook = addHook(
          value: '@rest',
          reason: ValueReason.HookCaptured,
        },
-        // Render the arguments
-        {
-          kind: 'Render',
-          place: '@rest',
-        },
        // Returns a frozen value
        {
          kind: 'Create',
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/PrintHIR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/PrintHIR.ts
@@ -983,15 +983,15 @@ export function printAliasingEffect(effect: AliasingEffect): string {
          return `...${printPlaceForAliasEffect(arg.place)}`;
        })
        .join(', ');
-      // let signature = '';
-      // if (effect.signature != null) {
-      //   if (effect.signature.aliasing != null) {
-      //     signature = printAliasingSignature(effect.signature.aliasing);
-      //   } else {
-      //     signature = JSON.stringify(effect.signature, null, 2);
-      //   }
-      // }
-      return `Apply ${printPlaceForAliasEffect(effect.into)} = ${receiverCallee}(${args})`;
+      let signature = '';
+      if (effect.signature != null) {
+        if (effect.signature.aliasing != null) {
+          signature = printAliasingSignature(effect.signature.aliasing);
+        } else {
+          signature = JSON.stringify(effect.signature, null, 2);
+        }
+      }
+      return `Apply ${printPlaceForAliasEffect(effect.into)} = ${receiverCallee}(${args})${signature != '' ? '\n     ' : ''}${signature}`;
    }
    case 'Freeze': {
      return `Freeze ${printPlaceForAliasEffect(effect.value)} ${effect.reason}`;
@@ -1009,7 +1009,7 @@ export function printAliasingEffect(effect: AliasingEffect): string {
      return `MutateGlobal ${printPlaceForAliasEffect(effect.place)} reason=${JSON.stringify(effect.error.reason)}`;
    }
    case 'Impure': {
-      return `Impure ${printPlaceForAliasEffect(effect.into)} reason=${effect.reason} description=${effect.description}`;
+      return `Impure ${printPlaceForAliasEffect(effect.place)} reason=${JSON.stringify(effect.error.reason)}`;
    }
    case 'Render': {
      return `Render ${printPlaceForAliasEffect(effect.place)}`;
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/TypeSchema.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/TypeSchema.ts
@@ -6,7 +6,7 @@
 */

 import {isValidIdentifier} from '@babel/types';
-import {z} from 'zod/v4';
+import {z} from 'zod';
 import {Effect, ValueKind} from '..';
 import {
  EffectSchema,
@@ -185,29 +185,11 @@ export const ApplyEffectSchema: z.ZodType<ApplyEffectConfig> = z.object({

 export type ImpureEffectConfig = {
  kind: 'Impure';
-  into: string;
-  reason: string;
-  description: string;
-  sourceMessage: string;
-  usageMessage: string;
+  place: string;
 };

 export const ImpureEffectSchema: z.ZodType<ImpureEffectConfig> = z.object({
  kind: z.literal('Impure'),
-  into: LifetimeIdSchema,
-  reason: z.string(),
-  description: z.string(),
-  sourceMessage: z.string(),
-  usageMessage: z.string(),
-});
-
-export type RenderEffectConfig = {
-  kind: 'Render';
-  place: string;
-};
-
-export const RenderEffectSchema: z.ZodType<RenderEffectConfig> = z.object({
-  kind: z.literal('Render'),
  place: LifetimeIdSchema,
 });

@@ -222,8 +204,7 @@ export type AliasingEffectConfig =
  | ImpureEffectConfig
  | MutateEffectConfig
  | MutateTransitiveConditionallyConfig
-  | ApplyEffectConfig
-  | RenderEffectConfig;
+  | ApplyEffectConfig;

 export const AliasingEffectSchema: z.ZodType<AliasingEffectConfig> = z.union([
  FreezeEffectSchema,
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/visitors.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/visitors.ts
@@ -11,7 +11,6 @@ import {
  BasicBlock,
  BlockId,
  Instruction,
-  InstructionKind,
  InstructionValue,
  makeInstructionId,
  Pattern,
@@ -33,32 +32,6 @@ export function* eachInstructionLValue(
  yield* eachInstructionValueLValue(instr.value);
 }

-export function* eachInstructionLValueWithKind(
-  instr: ReactiveInstruction,
-): Iterable<[Place, InstructionKind]> {
-  switch (instr.value.kind) {
-    case 'DeclareContext':
-    case 'StoreContext':
-    case 'DeclareLocal':
-    case 'StoreLocal': {
-      yield [instr.value.lvalue.place, instr.value.lvalue.kind];
-      break;
-    }
-    case 'Destructure': {
-      const kind = instr.value.lvalue.kind;
-      for (const place of eachPatternOperand(instr.value.lvalue.pattern)) {
-        yield [place, kind];
-      }
-      break;
-    }
-    case 'PostfixUpdate':
-    case 'PrefixUpdate': {
-      yield [instr.value.lvalue, InstructionKind.Reassign];
-      break;
-    }
-  }
-}
-
 export function* eachInstructionValueLValue(
  value: ReactiveValue,
 ): Iterable<Place> {
--- a/compiler/packages/babel-plugin-react-compiler/src/Inference/AliasingEffects.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Inference/AliasingEffects.ts
@@ -5,7 +5,7 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {CompilerDiagnostic, ErrorCategory} from '../CompilerError';
+import {CompilerDiagnostic} from '../CompilerError';
 import {
  FunctionExpression,
  GeneratedSource,
@@ -162,15 +162,7 @@ export type AliasingEffect =
  /**
   * Indicates a side-effect that is not safe during render
   */
-  | {
-      kind: 'Impure';
-      into: Place;
-      category: ErrorCategory;
-      reason: string;
-      description: string;
-      usageMessage: string;
-      sourceMessage: string;
-    }
+  | {kind: 'Impure'; place: Place; error: CompilerDiagnostic}
  /**
   * Indicates that a given place is accessed during render. Used to distingush
   * hook arguments that are known to be called immediately vs those used for
@@ -230,14 +222,6 @@ export function hashEffect(effect: AliasingEffect): string {
      return [effect.kind, effect.value.identifier.id, effect.reason].join(':');
    }
    case 'Impure':
-      return [
-        effect.kind,
-        effect.into.identifier.id,
-        effect.reason,
-        effect.description,
-        effect.usageMessage,
-        effect.sourceMessage,
-      ].join(':');
    case 'Render': {
      return [effect.kind, effect.place.identifier.id].join(':');
    }
--- a/compiler/packages/babel-plugin-react-compiler/src/Inference/ControlDominators.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Inference/ControlDominators.ts
@@ -1,114 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {BlockId, computePostDominatorTree, HIRFunction, Place} from '../HIR';
-import {PostDominator} from '../HIR/Dominator';
-
-export type ControlDominators = (id: BlockId) => Place | null;
-
-/**
- * Returns an object that lazily calculates whether particular blocks are controlled
- * by values of interest. Which values matter are up to the caller.
- */
-export function createControlDominators(
-  fn: HIRFunction,
-  isControlVariable: (place: Place) => boolean,
-): ControlDominators {
-  const postDominators = computePostDominatorTree(fn, {
-    includeThrowsAsExitNode: false,
-  });
-  const postDominatorFrontierCache = new Map<BlockId, Set<BlockId>>();
-
-  function isControlledBlock(id: BlockId): Place | null {
-    let controlBlocks = postDominatorFrontierCache.get(id);
-    if (controlBlocks === undefined) {
-      controlBlocks = postDominatorFrontier(fn, postDominators, id);
-      postDominatorFrontierCache.set(id, controlBlocks);
-    }
-    for (const blockId of controlBlocks) {
-      const controlBlock = fn.body.blocks.get(blockId)!;
-      switch (controlBlock.terminal.kind) {
-        case 'if':
-        case 'branch': {
-          if (isControlVariable(controlBlock.terminal.test)) {
-            return controlBlock.terminal.test;
-          }
-          break;
-        }
-        case 'switch': {
-          if (isControlVariable(controlBlock.terminal.test)) {
-            return controlBlock.terminal.test;
-          }
-          for (const case_ of controlBlock.terminal.cases) {
-            if (case_.test !== null && isControlVariable(case_.test)) {
-              return case_.test;
-            }
-          }
-          break;
-        }
-      }
-    }
-    return null;
-  }
-
-  return isControlledBlock;
-}
-
-/*
- * Computes the post-dominator frontier of @param block. These are immediate successors of nodes that
- * post-dominate @param targetId and from which execution may not reach @param block. Intuitively, these
- * are the earliest blocks from which execution branches such that it may or may not reach the target block.
- */
-function postDominatorFrontier(
-  fn: HIRFunction,
-  postDominators: PostDominator<BlockId>,
-  targetId: BlockId,
-): Set<BlockId> {
-  const visited = new Set<BlockId>();
-  const frontier = new Set<BlockId>();
-  const targetPostDominators = postDominatorsOf(fn, postDominators, targetId);
-  for (const blockId of [...targetPostDominators, targetId]) {
-    if (visited.has(blockId)) {
-      continue;
-    }
-    visited.add(blockId);
-    const block = fn.body.blocks.get(blockId)!;
-    for (const pred of block.preds) {
-      if (!targetPostDominators.has(pred)) {
-        // The predecessor does not always reach this block, we found an item on the frontier!
-        frontier.add(pred);
-      }
-    }
-  }
-  return frontier;
-}
-
-function postDominatorsOf(
-  fn: HIRFunction,
-  postDominators: PostDominator<BlockId>,
-  targetId: BlockId,
-): Set<BlockId> {
-  const result = new Set<BlockId>();
-  const visited = new Set<BlockId>();
-  const queue = [targetId];
-  while (queue.length) {
-    const currentId = queue.shift()!;
-    if (visited.has(currentId)) {
-      continue;
-    }
-    visited.add(currentId);
-    const current = fn.body.blocks.get(currentId)!;
-    for (const pred of current.preds) {
-      const predPostDominator = postDominators.get(pred) ?? pred;
-      if (predPostDominator === targetId || result.has(predPostDominator)) {
-        result.add(pred);
-      }
-      queue.push(pred);
-    }
-  }
-  return result;
-}
--- a/compiler/packages/babel-plugin-react-compiler/src/Inference/DropManualMemoization.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Inference/DropManualMemoization.ts
@@ -42,7 +42,7 @@ type IdentifierSidemap = {
  functions: Map<IdentifierId, TInstruction<FunctionExpression>>;
  manualMemos: Map<IdentifierId, ManualMemoCallee>;
  react: Set<IdentifierId>;
-  maybeDepsLists: Map<IdentifierId, {loc: SourceLocation; deps: Array<Place>}>;
+  maybeDepsLists: Map<IdentifierId, Array<Place>>;
  maybeDeps: Map<IdentifierId, ManualMemoDependency>;
  optionals: Set<IdentifierId>;
 };
@@ -65,7 +65,6 @@ export function collectMaybeMemoDependencies(
          identifierName: value.binding.name,
        },
        path: [],
-        loc: value.loc,
      };
    }
    case 'PropertyLoad': {
@@ -75,7 +74,6 @@ export function collectMaybeMemoDependencies(
          root: object.root,
          // TODO: determine if the access is optional
          path: [...object.path, {property: value.property, optional}],
-          loc: value.loc,
        };
      }
      break;
@@ -94,10 +92,8 @@ export function collectMaybeMemoDependencies(
          root: {
            kind: 'NamedLocal',
            value: {...value.place},
-            constant: false,
          },
          path: [],
-          loc: value.place.loc,
        };
      }
      break;
@@ -163,10 +159,10 @@ function collectTemporaries(
    }
    case 'ArrayExpression': {
      if (value.elements.every(e => e.kind === 'Identifier')) {
-        sidemap.maybeDepsLists.set(instr.lvalue.identifier.id, {
-          loc: value.loc,
-          deps: value.elements as Array<Place>,
-        });
+        sidemap.maybeDepsLists.set(
+          instr.lvalue.identifier.id,
+          value.elements as Array<Place>,
+        );
      }
      break;
    }
@@ -186,7 +182,6 @@ function makeManualMemoizationMarkers(
  fnExpr: Place,
  env: Environment,
  depsList: Array<ManualMemoDependency> | null,
-  depsLoc: SourceLocation | null,
  memoDecl: Place,
  manualMemoId: number,
 ): [TInstruction<StartMemoize>, TInstruction<FinishMemoize>] {
@@ -202,7 +197,6 @@ function makeManualMemoizationMarkers(
         * as dependencies
         */
        deps: depsList,
-        depsLoc,
        loc: fnExpr.loc,
      },
      effects: null,
@@ -293,85 +287,86 @@ function extractManualMemoizationArgs(
  sidemap: IdentifierSidemap,
  errors: CompilerError,
 ): {
-  fnPlace: Place;
+  fnPlace: Place | null;
  depsList: Array<ManualMemoDependency> | null;
-  depsLoc: SourceLocation | null;
-} | null {
+} {
  const [fnPlace, depsListPlace] = instr.value.args as Array<
    Place | SpreadPattern | undefined
  >;
-  if (fnPlace == null || fnPlace.kind !== 'Identifier') {
+  if (fnPlace == null) {
    errors.pushDiagnostic(
      CompilerDiagnostic.create({
        category: ErrorCategory.UseMemo,
        reason: `Expected a callback function to be passed to ${kind}`,
-        description:
-          kind === 'useCallback'
-            ? 'The first argument to useCallback() must be a function to cache'
-            : 'The first argument to useMemo() must be a function that calculates a result to cache',
+        description: `Expected a callback function to be passed to ${kind}`,
        suggestions: null,
      }).withDetails({
        kind: 'error',
        loc: instr.value.loc,
-        message:
-          kind === 'useCallback'
-            ? `Expected a callback function`
-            : `Expected a memoization function`,
+        message: `Expected a callback function to be passed to ${kind}`,
      }),
    );
-    return null;
+    return {fnPlace: null, depsList: null};
  }
-  if (depsListPlace == null) {
-    return {
-      fnPlace,
-      depsList: null,
-      depsLoc: null,
-    };
-  }
-  const maybeDepsList =
-    depsListPlace.kind === 'Identifier'
-      ? sidemap.maybeDepsLists.get(depsListPlace.identifier.id)
-      : null;
-  if (maybeDepsList == null) {
+  if (fnPlace.kind === 'Spread' || depsListPlace?.kind === 'Spread') {
    errors.pushDiagnostic(
      CompilerDiagnostic.create({
        category: ErrorCategory.UseMemo,
-        reason: `Expected the dependency list for ${kind} to be an array literal`,
-        description: `Expected the dependency list for ${kind} to be an array literal`,
+        reason: `Unexpected spread argument to ${kind}`,
+        description: `Unexpected spread argument to ${kind}`,
        suggestions: null,
      }).withDetails({
        kind: 'error',
-        loc:
-          depsListPlace?.kind === 'Identifier' ? depsListPlace.loc : instr.loc,
-        message: `Expected the dependency list for ${kind} to be an array literal`,
+        loc: instr.value.loc,
+        message: `Unexpected spread argument to ${kind}`,
      }),
    );
-    return null;
+    return {fnPlace: null, depsList: null};
  }
-  const depsList: Array<ManualMemoDependency> = [];
-  for (const dep of maybeDepsList.deps) {
-    const maybeDep = sidemap.maybeDeps.get(dep.identifier.id);
-    if (maybeDep == null) {
+  let depsList: Array<ManualMemoDependency> | null = null;
+  if (depsListPlace != null) {
+    const maybeDepsList = sidemap.maybeDepsLists.get(
+      depsListPlace.identifier.id,
+    );
+    if (maybeDepsList == null) {
      errors.pushDiagnostic(
        CompilerDiagnostic.create({
          category: ErrorCategory.UseMemo,
-          reason: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
-          description: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
+          reason: `Expected the dependency list for ${kind} to be an array literal`,
+          description: `Expected the dependency list for ${kind} to be an array literal`,
          suggestions: null,
        }).withDetails({
          kind: 'error',
-          loc: dep.loc,
-          message: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
+          loc: depsListPlace.loc,
+          message: `Expected the dependency list for ${kind} to be an array literal`,
        }),
      );
-    } else {
-      depsList.push(maybeDep);
+      return {fnPlace, depsList: null};
+    }
+    depsList = [];
+    for (const dep of maybeDepsList) {
+      const maybeDep = sidemap.maybeDeps.get(dep.identifier.id);
+      if (maybeDep == null) {
+        errors.pushDiagnostic(
+          CompilerDiagnostic.create({
+            category: ErrorCategory.UseMemo,
+            reason: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
+            description: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
+            suggestions: null,
+          }).withDetails({
+            kind: 'error',
+            loc: dep.loc,
+            message: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
+          }),
+        );
+      } else {
+        depsList.push(maybeDep);
+      }
    }
  }
  return {
    fnPlace,
    depsList,
-    depsLoc: maybeDepsList.loc,
  };
 }

@@ -432,17 +427,50 @@ export function dropManualMemoization(

        const manualMemo = sidemap.manualMemos.get(id);
        if (manualMemo != null) {
-          const memoDetails = extractManualMemoizationArgs(
+          const {fnPlace, depsList} = extractManualMemoizationArgs(
            instr as TInstruction<CallExpression> | TInstruction<MethodCall>,
            manualMemo.kind,
            sidemap,
            errors,
          );

-          if (memoDetails == null) {
+          if (fnPlace == null) {
            continue;
          }
-          const {fnPlace, depsList, depsLoc} = memoDetails;
+
+          /**
+           * Bailout on void return useMemos. This is an anti-pattern where code might be using
+           * useMemo like useEffect: running arbirtary side-effects synced to changes in specific
+           * values.
+           */
+          if (
+            func.env.config.validateNoVoidUseMemo &&
+            manualMemo.kind === 'useMemo'
+          ) {
+            const funcToCheck = sidemap.functions.get(
+              fnPlace.identifier.id,
+            )?.value;
+            if (funcToCheck !== undefined && funcToCheck.loweredFunc.func) {
+              if (!hasNonVoidReturn(funcToCheck.loweredFunc.func)) {
+                errors.pushDiagnostic(
+                  CompilerDiagnostic.create({
+                    category: ErrorCategory.UseMemo,
+                    reason: 'useMemo() callbacks must return a value',
+                    description: `This ${
+                      manualMemo.loadInstr.value.kind === 'PropertyLoad'
+                        ? 'React.useMemo'
+                        : 'useMemo'
+                    } callback doesn't return a value. useMemo is for computing and caching values, not for arbitrary side effects`,
+                    suggestions: null,
+                  }).withDetails({
+                    kind: 'error',
+                    loc: instr.value.loc,
+                    message: 'useMemo() callbacks must return a value',
+                  }),
+                );
+              }
+            }
+          }

          instr.value = getManualMemoizationReplacement(
            fnPlace,
@@ -493,7 +521,6 @@ export function dropManualMemoization(
              fnPlace,
              func.env,
              depsList,
-              depsLoc,
              memoDecl,
              nextManualMemoId++,
            );
@@ -602,3 +629,17 @@ function findOptionalPlaces(fn: HIRFunction): Set<IdentifierId> {
  }
  return optionals;
 }
+
+function hasNonVoidReturn(func: HIRFunction): boolean {
+  for (const [, block] of func.body.blocks) {
+    if (block.terminal.kind === 'return') {
+      if (
+        block.terminal.returnVariant === 'Explicit' ||
+        block.terminal.returnVariant === 'Implicit'
+      ) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
--- a/compiler/packages/babel-plugin-react-compiler/src/Inference/InferMutationAliasingEffects.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Inference/InferMutationAliasingEffects.ts
@@ -19,7 +19,6 @@ import {
  Environment,
  FunctionExpression,
  GeneratedSource,
-  getHookKind,
  HIRFunction,
  Hole,
  IdentifierId,
@@ -27,13 +26,11 @@ import {
  InstructionKind,
  InstructionValue,
  isArrayType,
-  isJsxOrJsxUnionType,
+  isJsxType,
  isMapType,
-  isMutableEffect,
  isPrimitiveType,
  isRefOrRefValue,
  isSetType,
-  isUseRefType,
  makeIdentifierId,
  Phi,
  Place,
@@ -72,7 +69,6 @@ import {
  MutationReason,
 } from './AliasingEffects';
 import {ErrorCategory} from '../CompilerError';
-import {REF_ERROR_DESCRIPTION} from '../Validation/ValidateNoRefAccessInRender';

 const DEBUG = false;

@@ -202,7 +198,6 @@ export function inferMutationAliasingEffects(
    isFunctionExpression,
    fn,
    hoistedContextDeclarations,
-    findNonMutatedDestructureSpreads(fn),
  );

  let iterationCount = 0;
@@ -292,18 +287,15 @@ class Context {
  isFuctionExpression: boolean;
  fn: HIRFunction;
  hoistedContextDeclarations: Map<DeclarationId, Place | null>;
-  nonMutatingSpreads: Set<IdentifierId>;

  constructor(
    isFunctionExpression: boolean,
    fn: HIRFunction,
    hoistedContextDeclarations: Map<DeclarationId, Place | null>,
-    nonMutatingSpreads: Set<IdentifierId>,
  ) {
    this.isFuctionExpression = isFunctionExpression;
    this.fn = fn;
    this.hoistedContextDeclarations = hoistedContextDeclarations;
-    this.nonMutatingSpreads = nonMutatingSpreads;
  }

  cacheApplySignature(
@@ -330,161 +322,6 @@ class Context {
  }
 }

-/**
- * Finds objects created via ObjectPattern spread destructuring
- * (`const {x, ...spread} = ...`) where a) the rvalue is known frozen and
- * b) the spread value cannot possibly be directly mutated. The idea is that
- * for this set of values, we can treat the spread object as frozen.
- *
- * The primary use case for this is props spreading:
- *
- * ```
- * function Component({prop, ...otherProps}) {
- *   const transformedProp = transform(prop, otherProps.foo);
- *   // pass `otherProps` down:
- *   return <Foo {...otherProps} prop={transformedProp} />;
- * }
- * ```
- *
- * Here we know that since `otherProps` cannot be mutated, we don't have to treat
- * it as mutable: `otherProps.foo` only reads a value that must be frozen, so it
- * can be treated as frozen too.
- */
-function findNonMutatedDestructureSpreads(fn: HIRFunction): Set<IdentifierId> {
-  const knownFrozen = new Set<IdentifierId>();
-  if (fn.fnType === 'Component') {
-    const [props] = fn.params;
-    if (props != null && props.kind === 'Identifier') {
-      knownFrozen.add(props.identifier.id);
-    }
-  } else {
-    for (const param of fn.params) {
-      if (param.kind === 'Identifier') {
-        knownFrozen.add(param.identifier.id);
-      }
-    }
-  }
-
-  // Map of temporaries to identifiers for spread objects
-  const candidateNonMutatingSpreads = new Map<IdentifierId, IdentifierId>();
-  for (const block of fn.body.blocks.values()) {
-    if (candidateNonMutatingSpreads.size !== 0) {
-      for (const phi of block.phis) {
-        for (const operand of phi.operands.values()) {
-          const spread = candidateNonMutatingSpreads.get(operand.identifier.id);
-          if (spread != null) {
-            candidateNonMutatingSpreads.delete(spread);
-          }
-        }
-      }
-    }
-    for (const instr of block.instructions) {
-      const {lvalue, value} = instr;
-      switch (value.kind) {
-        case 'Destructure': {
-          if (
-            !knownFrozen.has(value.value.identifier.id) ||
-            !(
-              value.lvalue.kind === InstructionKind.Let ||
-              value.lvalue.kind === InstructionKind.Const
-            ) ||
-            value.lvalue.pattern.kind !== 'ObjectPattern'
-          ) {
-            continue;
-          }
-          for (const item of value.lvalue.pattern.properties) {
-            if (item.kind !== 'Spread') {
-              continue;
-            }
-            candidateNonMutatingSpreads.set(
-              item.place.identifier.id,
-              item.place.identifier.id,
-            );
-          }
-          break;
-        }
-        case 'LoadLocal': {
-          const spread = candidateNonMutatingSpreads.get(
-            value.place.identifier.id,
-          );
-          if (spread != null) {
-            candidateNonMutatingSpreads.set(lvalue.identifier.id, spread);
-          }
-          break;
-        }
-        case 'StoreLocal': {
-          const spread = candidateNonMutatingSpreads.get(
-            value.value.identifier.id,
-          );
-          if (spread != null) {
-            candidateNonMutatingSpreads.set(lvalue.identifier.id, spread);
-            candidateNonMutatingSpreads.set(
-              value.lvalue.place.identifier.id,
-              spread,
-            );
-          }
-          break;
-        }
-        case 'JsxFragment':
-        case 'JsxExpression': {
-          // Passing objects created with spread to jsx can't mutate them
-          break;
-        }
-        case 'PropertyLoad': {
-          // Properties must be frozen since the original value was frozen
-          break;
-        }
-        case 'CallExpression':
-        case 'MethodCall': {
-          const callee =
-            value.kind === 'CallExpression' ? value.callee : value.property;
-          if (getHookKind(fn.env, callee.identifier) != null) {
-            // Hook calls have frozen arguments, and non-ref returns are frozen
-            if (!isRefOrRefValue(lvalue.identifier)) {
-              knownFrozen.add(lvalue.identifier.id);
-            }
-          } else {
-            // Non-hook calls check their operands, since they are potentially mutable
-            if (candidateNonMutatingSpreads.size !== 0) {
-              // Otherwise any reference to the spread object itself may mutate
-              for (const operand of eachInstructionValueOperand(value)) {
-                const spread = candidateNonMutatingSpreads.get(
-                  operand.identifier.id,
-                );
-                if (spread != null) {
-                  candidateNonMutatingSpreads.delete(spread);
-                }
-              }
-            }
-          }
-          break;
-        }
-        default: {
-          if (candidateNonMutatingSpreads.size !== 0) {
-            // Otherwise any reference to the spread object itself may mutate
-            for (const operand of eachInstructionValueOperand(value)) {
-              const spread = candidateNonMutatingSpreads.get(
-                operand.identifier.id,
-              );
-              if (spread != null) {
-                candidateNonMutatingSpreads.delete(spread);
-              }
-            }
-          }
-        }
-      }
-    }
-  }
-
-  const nonMutatingSpreads = new Set<IdentifierId>();
-  for (const [key, value] of candidateNonMutatingSpreads) {
-    if (key === value) {
-      nonMutatingSpreads.add(key);
-    }
-  }
-  return nonMutatingSpreads;
-}
-
 function inferParam(
  param: Place | SpreadPattern,
  initialState: InferenceState,
@@ -572,32 +409,14 @@ function inferBlock(
      terminal.effects = effects.length !== 0 ? effects : null;
    }
  } else if (terminal.kind === 'return') {
-    terminal.effects = [
-      context.internEffect({
-        kind: 'Alias',
-        from: terminal.value,
-        into: context.fn.returns,
-      }),
-    ];
    if (!context.isFuctionExpression) {
-      terminal.effects.push(
+      terminal.effects = [
        context.internEffect({
          kind: 'Freeze',
          value: terminal.value,
          reason: ValueReason.JsxCaptured,
        }),
-      );
-    }
-    if (
-      context.fn.fnType === 'Component' ||
-      isJsxOrJsxUnionType(context.fn.returns.identifier.type)
-    ) {
-      terminal.effects.push(
-        context.internEffect({
-          kind: 'Render',
-          place: terminal.value,
-        }),
-      );
+      ];
    }
  }
 }
@@ -770,7 +589,17 @@ function applyEffect(
      break;
    }
    case 'ImmutableCapture': {
-      effects.push(effect);
+      const kind = state.kind(effect.from).kind;
+      switch (kind) {
+        case ValueKind.Global:
+        case ValueKind.Primitive: {
+          // no-op: we don't need to track data flow for copy types
+          break;
+        }
+        default: {
+          effects.push(effect);
+        }
+      }
      break;
    }
    case 'CreateFrom': {
@@ -965,7 +794,6 @@ function applyEffect(
        case ValueKind.Primitive: {
          break;
        }
-        case ValueKind.MaybeFrozen:
        case ValueKind.Frozen: {
          sourceType = 'frozen';
          break;
@@ -1072,17 +900,6 @@ function applyEffect(
            reason: new Set(fromValue.reason),
          });
          state.define(effect.into, value);
-          applyEffect(
-            context,
-            state,
-            {
-              kind: 'ImmutableCapture',
-              from: effect.from,
-              into: effect.into,
-            },
-            initialized,
-            effects,
-          );
          break;
        }
        default: {
@@ -1094,8 +911,6 @@ function applyEffect(
      break;
    }
    case 'Apply': {
-      effects.push(effect);
-
      const functionValues = state.values(effect.function);
      if (
        functionValues.length === 1 &&
@@ -1990,11 +1805,6 @@ function computeSignatureForInstruction(
          value: ValueKind.Primitive,
          reason: ValueReason.Other,
        });
-        effects.push({
-          kind: 'ImmutableCapture',
-          from: value.object,
-          into: lvalue,
-        });
      } else {
        effects.push({
          kind: 'CreateFrom',
@@ -2002,20 +1812,6 @@ function computeSignatureForInstruction(
          into: lvalue,
        });
      }
-      if (
-        env.config.validateRefAccessDuringRender &&
-        isUseRefType(value.object.identifier)
-      ) {
-        effects.push({
-          kind: 'Impure',
-          into: lvalue,
-          category: ErrorCategory.Refs,
-          reason: `Cannot access ref value during render`,
-          description: REF_ERROR_DESCRIPTION,
-          sourceMessage: `Ref is initially accessed`,
-          usageMessage: `Ref value is used during render`,
-        });
-      }
      break;
    }
    case 'PropertyStore':
@@ -2180,15 +1976,6 @@ function computeSignatureForInstruction(
          into: lvalue,
        });
      }
-      if (value.children != null) {
-        // Children are typically called during render, not used as an event/effect callback
-        for (const child of value.children) {
-          effects.push({
-            kind: 'Render',
-            place: child,
-          });
-        }
-      }
      if (value.kind === 'JsxExpression') {
        if (value.tag.kind === 'Identifier') {
          // Tags are render function, by definition they're called during render
@@ -2197,17 +1984,29 @@ function computeSignatureForInstruction(
            place: value.tag,
          });
        }
-        for (const prop of value.props) {
-          const place =
-            prop.kind === 'JsxAttribute' ? prop.place : prop.argument;
-          if (isUseRefType(place.identifier)) {
-            continue;
-          }
-          if (place.identifier.type.kind !== 'Function') {
-            // Functions are checked independently
+        if (value.children != null) {
+          // Children are typically called during render, not used as an event/effect callback
+          for (const child of value.children) {
            effects.push({
              kind: 'Render',
-              place,
+              place: child,
+            });
+          }
+        }
+        for (const prop of value.props) {
+          if (
+            prop.kind === 'JsxAttribute' &&
+            prop.place.identifier.type.kind === 'Function' &&
+            (isJsxType(prop.place.identifier.type.return) ||
+              (prop.place.identifier.type.return.kind === 'Phi' &&
+                prop.place.identifier.type.return.operands.some(operand =>
+                  isJsxType(operand),
+                )))
+          ) {
+            // Any props which return jsx are assumed to be called during render
+            effects.push({
+              kind: 'Render',
+              place: prop.place,
            });
          }
        }
@@ -2243,11 +2042,6 @@ function computeSignatureForInstruction(
            value: ValueKind.Primitive,
            reason: ValueReason.Other,
          });
-          effects.push({
-            kind: 'ImmutableCapture',
-            from: value.value,
-            into: place,
-          });
        } else if (patternItem.kind === 'Identifier') {
          effects.push({
            kind: 'CreateFrom',
@@ -2260,9 +2054,7 @@ function computeSignatureForInstruction(
            kind: 'Create',
            into: place,
            reason: ValueReason.Other,
-            value: context.nonMutatingSpreads.has(place.identifier.id)
-              ? ValueKind.Frozen
-              : ValueKind.Mutable,
+            value: ValueKind.Mutable,
          });
          effects.push({
            kind: 'Capture',
@@ -2429,46 +2221,15 @@ function computeSignatureForInstruction(
      });
      break;
    }
-    case 'BinaryExpression': {
-      effects.push({
-        kind: 'Create',
-        into: lvalue,
-        value: ValueKind.Primitive,
-        reason: ValueReason.Other,
-      });
-      effects.push({
-        kind: 'ImmutableCapture',
-        into: lvalue,
-        from: value.left,
-      });
-      effects.push({
-        kind: 'ImmutableCapture',
-        into: lvalue,
-        from: value.right,
-      });
-      break;
-    }
-    case 'UnaryExpression': {
-      effects.push({
-        kind: 'Create',
-        into: lvalue,
-        value: ValueKind.Primitive,
-        reason: ValueReason.Other,
-      });
-      effects.push({
-        kind: 'ImmutableCapture',
-        into: lvalue,
-        from: value.value,
-      });
-      break;
-    }
    case 'TaggedTemplateExpression':
+    case 'BinaryExpression':
    case 'Debugger':
    case 'JSXText':
    case 'MetaProperty':
    case 'Primitive':
    case 'RegExpLiteral':
    case 'TemplateLiteral':
+    case 'UnaryExpression':
    case 'UnsupportedNode': {
      effects.push({
        kind: 'Create',
@@ -2499,7 +2260,7 @@ function computeEffectsForLegacySignature(
  lvalue: Place,
  receiver: Place,
  args: Array<Place | SpreadPattern | Hole>,
-  _loc: SourceLocation,
+  loc: SourceLocation,
 ): Array<AliasingEffect> {
  const returnValueReason = signature.returnValueReason ?? ValueReason.Other;
  const effects: Array<AliasingEffect> = [];
@@ -2512,21 +2273,23 @@ function computeEffectsForLegacySignature(
  if (signature.impure && state.env.config.validateNoImpureFunctionsInRender) {
    effects.push({
      kind: 'Impure',
-      into: lvalue,
-      category: ErrorCategory.Purity,
-      reason: 'Cannot access impure value during render',
-      description:
-        'Calling an impure function can produce unstable results that update ' +
-        'unpredictably when the component happens to re-render. ' +
-        '(https://react.dev/reference/rules/components-and-hooks-must-be-pure#components-and-hooks-must-be-idempotent)',
-      sourceMessage:
-        signature.canonicalName != null
-          ? `\`${signature.canonicalName}\` is an impure function.`
-          : 'This function is impure',
-      usageMessage: 'Cannot access impure value during render',
+      place: receiver,
+      error: CompilerDiagnostic.create({
+        category: ErrorCategory.Purity,
+        reason: 'Cannot call impure function during render',
+        description:
+          (signature.canonicalName != null
+            ? `\`${signature.canonicalName}\` is an impure function. `
+            : '') +
+          'Calling an impure function can produce unstable results that update unpredictably when the component happens to re-render. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#components-and-hooks-must-be-idempotent)',
+      }).withDetails({
+        kind: 'error',
+        loc,
+        message: 'Cannot call impure function',
+      }),
    });
  }
-  if (signature.knownIncompatible != null && state.env.enableValidations) {
+  if (signature.knownIncompatible != null && state.env.isInferredMemoEnabled) {
    const errors = new CompilerError();
    errors.pushDiagnostic(
      CompilerDiagnostic.create({
@@ -2822,23 +2585,7 @@ function computeEffectsForSignature(
        }
        break;
      }
-      case 'Impure': {
-        if (env.config.validateNoImpureFunctionsInRender) {
-          const values = substitutions.get(effect.into.identifier.id) ?? [];
-          for (const value of values) {
-            effects.push({
-              kind: effect.kind,
-              into: value,
-              category: effect.category,
-              reason: effect.reason,
-              description: effect.description,
-              sourceMessage: effect.sourceMessage,
-              usageMessage: effect.usageMessage,
-            });
-          }
-        }
-        break;
-      }
+      case 'Impure':
      case 'MutateFrozen':
      case 'MutateGlobal': {
        const values = substitutions.get(effect.place.identifier.id) ?? [];
--- a/compiler/packages/babel-plugin-react-compiler/src/Inference/InferMutationAliasingRanges.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Inference/InferMutationAliasingRanges.ts
@@ -19,8 +19,6 @@ import {
  ValueReason,
  Place,
  isPrimitiveType,
-  isUseRefType,
-  isJsxOrJsxUnionType,
 } from '../HIR/HIR';
 import {
  eachInstructionLValue,
@@ -30,9 +28,6 @@ import {
 import {assertExhaustive, getOrInsertWith} from '../Utils/utils';
 import {Err, Ok, Result} from '../Utils/Result';
 import {AliasingEffect, MutationReason} from './AliasingEffects';
-import {printIdentifier, printType} from '../HIR/PrintHIR';
-
-const DEBUG = false;

 /**
 * This pass builds an abstract model of the heap and interprets the effects of the
@@ -109,6 +104,7 @@ export function inferMutationAliasingRanges(
    reason: MutationReason | null;
  }> = [];
  const renders: Array<{index: number; place: Place}> = [];
+
  let index = 0;

  const errors = new CompilerError();
@@ -201,12 +197,14 @@ export function inferMutationAliasingRanges(
          });
        } else if (
          effect.kind === 'MutateFrozen' ||
-          effect.kind === 'MutateGlobal'
+          effect.kind === 'MutateGlobal' ||
+          effect.kind === 'Impure'
        ) {
          errors.pushDiagnostic(effect.error);
          functionEffects.push(effect);
        } else if (effect.kind === 'Render') {
          renders.push({index: index++, place: effect.place});
+          functionEffects.push(effect);
        }
      }
    }
@@ -216,6 +214,10 @@ export function inferMutationAliasingRanges(
        state.assign(index, from, into);
      }
    }
+    if (block.terminal.kind === 'return') {
+      state.assign(index++, block.terminal.value, fn.returns);
+    }
+
    if (
      (block.terminal.kind === 'maybe-throw' ||
        block.terminal.kind === 'return') &&
@@ -225,31 +227,23 @@ export function inferMutationAliasingRanges(
        if (effect.kind === 'Alias') {
          state.assign(index++, effect.from, effect.into);
        } else {
-          CompilerError.invariant(
-            effect.kind === 'Freeze' || effect.kind === 'Render',
-            {
-              reason: `Unexpected '${effect.kind}' effect for MaybeThrow terminal`,
-              description: null,
-              details: [
-                {
-                  kind: 'error',
-                  loc: block.terminal.loc,
-                  message: null,
-                },
-              ],
-            },
-          );
+          CompilerError.invariant(effect.kind === 'Freeze', {
+            reason: `Unexpected '${effect.kind}' effect for MaybeThrow terminal`,
+            description: null,
+            details: [
+              {
+                kind: 'error',
+                loc: block.terminal.loc,
+                message: null,
+              },
+            ],
+          });
        }
      }
    }
  }

  for (const mutation of mutations) {
-    if (DEBUG) {
-      console.log(
-        `[${mutation.index}] mutate ${printIdentifier(mutation.place.identifier)}`,
-      );
-    }
    state.mutate(
      mutation.index,
      mutation.place.identifier,
@@ -261,16 +255,8 @@ export function inferMutationAliasingRanges(
      errors,
    );
  }
-  if (DEBUG) {
-    console.log(state.debug());
-  }
  for (const render of renders) {
-    if (DEBUG) {
-      console.log(
-        `[${render.index}] render ${printIdentifier(render.place.identifier)}`,
-      );
-    }
-    state.render(render.index, render.place, errors);
+    state.render(render.index, render.place.identifier, errors);
  }
  for (const param of [...fn.context, ...fn.params]) {
    const place = param.kind === 'Identifier' ? param : param.place;
@@ -397,7 +383,17 @@ export function inferMutationAliasingRanges(
            break;
          }
          case 'Apply': {
-            break;
+            CompilerError.invariant(false, {
+              reason: `[AnalyzeFunctions] Expected Apply effects to be replaced with more precise effects`,
+              description: null,
+              details: [
+                {
+                  kind: 'error',
+                  loc: effect.function.loc,
+                  message: null,
+                },
+              ],
+            });
          }
          case 'MutateTransitive':
          case 'MutateConditionally':
@@ -519,13 +515,6 @@ export function inferMutationAliasingRanges(
  const ignoredErrors = new CompilerError();
  for (const param of [...fn.params, ...fn.context, fn.returns]) {
    const place = param.kind === 'Identifier' ? param : param.place;
-    const node = state.nodes.get(place.identifier);
-    if (node != null && node.render != null) {
-      functionEffects.push({
-        kind: 'Render',
-        place: place,
-      });
-    }
    tracked.push(place);
  }
  for (const into of tracked) {
@@ -579,12 +568,7 @@ export function inferMutationAliasingRanges(
    }
  }

-  if (
-    errors.hasAnyErrors() &&
-    (fn.fnType === 'Component' ||
-      isJsxOrJsxUnionType(fn.returns.identifier.type) ||
-      !isFunctionExpression)
-  ) {
+  if (errors.hasAnyErrors() && !isFunctionExpression) {
    return Err(errors);
  }
  return Ok(functionEffects);
@@ -593,6 +577,7 @@ export function inferMutationAliasingRanges(
 function appendFunctionErrors(errors: CompilerError, fn: HIRFunction): void {
  for (const effect of fn.aliasingEffects ?? []) {
    switch (effect.kind) {
+      case 'Impure':
      case 'MutateFrozen':
      case 'MutateGlobal': {
        errors.pushDiagnostic(effect.error);
@@ -627,74 +612,10 @@ type Node = {
    | {kind: 'Object'}
    | {kind: 'Phi'}
    | {kind: 'Function'; function: HIRFunction};
-  render: Place | null;
 };
-
-function _printNode(node: Node): string {
-  const out: Array<string> = [];
-  debugNode(out, node);
-  return out.join('\n');
-}
-function debugNode(out: Array<string>, node: Node): void {
-  out.push(
-    printIdentifier(node.id) +
-      printType(node.id.type) +
-      ` lastMutated=[${node.lastMutated}]`,
-  );
-  if (node.transitive != null) {
-    out.push(`  transitive=${node.transitive.kind}`);
-  }
-  if (node.local != null) {
-    out.push(`  local=${node.local.kind}`);
-  }
-  if (node.mutationReason != null) {
-    out.push(`  mutationReason=${node.mutationReason?.kind}`);
-  }
-  const edges: Array<{
-    index: number;
-    direction: '<=' | '=>';
-    kind: string;
-    id: Identifier;
-  }> = [];
-  for (const [alias, index] of node.createdFrom) {
-    edges.push({index, direction: '<=', kind: 'createFrom', id: alias});
-  }
-  for (const [alias, index] of node.aliases) {
-    edges.push({index, direction: '<=', kind: 'alias', id: alias});
-  }
-  for (const [alias, index] of node.maybeAliases) {
-    edges.push({index, direction: '<=', kind: 'alias?', id: alias});
-  }
-  for (const [alias, index] of node.captures) {
-    edges.push({index, direction: '<=', kind: 'capture', id: alias});
-  }
-  for (const edge of node.edges) {
-    edges.push({
-      index: edge.index,
-      direction: '=>',
-      kind: edge.kind,
-      id: edge.node,
-    });
-  }
-  edges.sort((a, b) => a.index - b.index);
-  for (const edge of edges) {
-    out.push(
-      `  [${edge.index}] ${edge.direction} ${edge.kind} ${printIdentifier(edge.id)}`,
-    );
-  }
-}
-
 class AliasingState {
  nodes: Map<Identifier, Node> = new Map();

-  debug(): string {
-    const items: Array<string> = [];
-    for (const [_id, node] of this.nodes) {
-      debugNode(items, node);
-    }
-    return items.join('\n');
-  }
-
  create(place: Place, value: Node['value']): void {
    this.nodes.set(place.identifier, {
      id: place.identifier,
@@ -708,7 +629,6 @@ class AliasingState {
      lastMutated: 0,
      mutationReason: null,
      value,
-      render: null,
    });
  }

@@ -761,9 +681,9 @@ class AliasingState {
    }
  }

-  render(index: number, start: Place, errors: CompilerError): void {
+  render(index: number, start: Identifier, errors: CompilerError): void {
    const seen = new Set<Identifier>();
-    const queue: Array<Identifier> = [start.identifier];
+    const queue: Array<Identifier> = [start];
    while (queue.length !== 0) {
      const current = queue.pop()!;
      if (seen.has(current)) {
@@ -771,34 +691,11 @@ class AliasingState {
      }
      seen.add(current);
      const node = this.nodes.get(current);
-      if (node == null || isUseRefType(node.id)) {
-        if (DEBUG) {
-          console.log(`  render ${printIdentifier(current)}: skip mutated/ref`);
-        }
+      if (node == null || node.transitive != null || node.local != null) {
        continue;
      }
-      if (
-        node.local == null &&
-        node.transitive == null &&
-        node.value.kind === 'Function'
-      ) {
-        const returns = node.value.function.returns;
-        if (
-          isJsxType(returns.identifier.type) ||
-          (returns.identifier.type.kind === 'Phi' &&
-            returns.identifier.type.operands.some(operand =>
-              isJsxType(operand),
-            ))
-        ) {
-          appendFunctionErrors(errors, node.value.function);
-        }
-        if (DEBUG) {
-          console.log(`  render ${printIdentifier(current)}: skip function`);
-        }
-        continue;
-      }
-      if (node.render == null) {
-        node.render = start;
+      if (node.value.kind === 'Function') {
+        appendFunctionErrors(errors, node.value.function);
      }
      for (const [alias, when] of node.createdFrom) {
        if (when >= index) {
@@ -812,12 +709,6 @@ class AliasingState {
        }
        queue.push(alias);
      }
-      for (const [alias, when] of node.maybeAliases) {
-        if (when >= index) {
-          continue;
-        }
-        queue.push(alias);
-      }
      for (const [capture, when] of node.captures) {
        if (when >= index) {
          continue;
--- a/compiler/packages/babel-plugin-react-compiler/src/Inference/InferReactivePlaces.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Inference/InferReactivePlaces.ts
@@ -7,6 +7,7 @@

 import {CompilerError} from '..';
 import {
+  BlockId,
  Effect,
  Environment,
  HIRFunction,
@@ -14,12 +15,14 @@ import {
  IdentifierId,
  Instruction,
  Place,
+  computePostDominatorTree,
  evaluatesToStableTypeOrContainer,
  getHookKind,
  isStableType,
  isStableTypeContainer,
  isUseOperator,
 } from '../HIR';
+import {PostDominator} from '../HIR/Dominator';
 import {
  eachInstructionLValue,
  eachInstructionOperand,
@@ -32,7 +35,6 @@ import {
 } from '../ReactiveScopes/InferReactiveScopeVariables';
 import DisjointSet from '../Utils/DisjointSet';
 import {assertExhaustive} from '../Utils/utils';
-import {createControlDominators} from './ControlDominators';

 /**
 * Side map to track and propagate sources of stability (i.e. hook calls such as
@@ -210,9 +212,45 @@ export function inferReactivePlaces(fn: HIRFunction): void {
    reactiveIdentifiers.markReactive(place);
  }

-  const isReactiveControlledBlock = createControlDominators(fn, place =>
-    reactiveIdentifiers.isReactive(place),
-  );
+  const postDominators = computePostDominatorTree(fn, {
+    includeThrowsAsExitNode: false,
+  });
+  const postDominatorFrontierCache = new Map<BlockId, Set<BlockId>>();
+
+  function isReactiveControlledBlock(id: BlockId): boolean {
+    let controlBlocks = postDominatorFrontierCache.get(id);
+    if (controlBlocks === undefined) {
+      controlBlocks = postDominatorFrontier(fn, postDominators, id);
+      postDominatorFrontierCache.set(id, controlBlocks);
+    }
+    for (const blockId of controlBlocks) {
+      const controlBlock = fn.body.blocks.get(blockId)!;
+      switch (controlBlock.terminal.kind) {
+        case 'if':
+        case 'branch': {
+          if (reactiveIdentifiers.isReactive(controlBlock.terminal.test)) {
+            return true;
+          }
+          break;
+        }
+        case 'switch': {
+          if (reactiveIdentifiers.isReactive(controlBlock.terminal.test)) {
+            return true;
+          }
+          for (const case_ of controlBlock.terminal.cases) {
+            if (
+              case_.test !== null &&
+              reactiveIdentifiers.isReactive(case_.test)
+            ) {
+              return true;
+            }
+          }
+          break;
+        }
+      }
+    }
+    return false;
+  }

  do {
    for (const [, block] of fn.body.blocks) {
@@ -373,6 +411,61 @@ export function inferReactivePlaces(fn: HIRFunction): void {
  propagateReactivityToInnerFunctions(fn, true);
 }

+/*
+ * Computes the post-dominator frontier of @param block. These are immediate successors of nodes that
+ * post-dominate @param targetId and from which execution may not reach @param block. Intuitively, these
+ * are the earliest blocks from which execution branches such that it may or may not reach the target block.
+ */
+function postDominatorFrontier(
+  fn: HIRFunction,
+  postDominators: PostDominator<BlockId>,
+  targetId: BlockId,
+): Set<BlockId> {
+  const visited = new Set<BlockId>();
+  const frontier = new Set<BlockId>();
+  const targetPostDominators = postDominatorsOf(fn, postDominators, targetId);
+  for (const blockId of [...targetPostDominators, targetId]) {
+    if (visited.has(blockId)) {
+      continue;
+    }
+    visited.add(blockId);
+    const block = fn.body.blocks.get(blockId)!;
+    for (const pred of block.preds) {
+      if (!targetPostDominators.has(pred)) {
+        // The predecessor does not always reach this block, we found an item on the frontier!
+        frontier.add(pred);
+      }
+    }
+  }
+  return frontier;
+}
+
+function postDominatorsOf(
+  fn: HIRFunction,
+  postDominators: PostDominator<BlockId>,
+  targetId: BlockId,
+): Set<BlockId> {
+  const result = new Set<BlockId>();
+  const visited = new Set<BlockId>();
+  const queue = [targetId];
+  while (queue.length) {
+    const currentId = queue.shift()!;
+    if (visited.has(currentId)) {
+      continue;
+    }
+    visited.add(currentId);
+    const current = fn.body.blocks.get(currentId)!;
+    for (const pred of current.preds) {
+      const predPostDominator = postDominators.get(pred) ?? pred;
+      if (predPostDominator === targetId || result.has(predPostDominator)) {
+        result.add(pred);
+      }
+      queue.push(pred);
+    }
+  }
+  return result;
+}
+
 class ReactivityMap {
  hasChanges: boolean = false;
  reactive: Set<IdentifierId> = new Set();
--- a/compiler/packages/babel-plugin-react-compiler/src/Optimization/ConstantPropagation.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Optimization/ConstantPropagation.ts
@@ -609,19 +609,6 @@ function evaluateInstruction(
      constantPropagationImpl(value.loweredFunc.func, constants);
      return null;
    }
-    case 'StartMemoize': {
-      if (value.deps != null) {
-        for (const dep of value.deps) {
-          if (dep.root.kind === 'NamedLocal') {
-            const placeValue = read(constants, dep.root.value);
-            if (placeValue != null && placeValue.kind === 'Primitive') {
-              dep.root.constant = true;
-            }
-          }
-        }
-      }
-      return null;
-    }
    default: {
      // TODO: handle more cases
      return null;
--- a/compiler/packages/babel-plugin-react-compiler/src/Optimization/DeadCodeElimination.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Optimization/DeadCodeElimination.ts
@@ -7,8 +7,6 @@

 import {
  BlockId,
-  Environment,
-  getHookKind,
  HIRFunction,
  Identifier,
  IdentifierId,
@@ -70,14 +68,9 @@ export function deadCodeElimination(fn: HIRFunction): void {
 }

 class State {
-  env: Environment;
  named: Set<string> = new Set();
  identifiers: Set<IdentifierId> = new Set();

-  constructor(env: Environment) {
-    this.env = env;
-  }
-
  // Mark the identifier as being referenced (not dead code)
  reference(identifier: Identifier): void {
    this.identifiers.add(identifier.id);
@@ -119,7 +112,7 @@ function findReferencedIdentifiers(fn: HIRFunction): State {
  const hasLoop = hasBackEdge(fn);
  const reversedBlocks = [...fn.body.blocks.values()].reverse();

-  const state = new State(fn.env);
+  const state = new State();
  let size = state.count;
  do {
    size = state.count;
@@ -317,27 +310,12 @@ function pruneableValue(value: InstructionValue, state: State): boolean {
      // explicitly retain debugger statements to not break debugging workflows
      return false;
    }
-    case 'CallExpression':
-    case 'MethodCall': {
-      if (state.env.outputMode === 'ssr') {
-        const calleee =
-          value.kind === 'CallExpression' ? value.callee : value.property;
-        const hookKind = getHookKind(state.env, calleee.identifier);
-        switch (hookKind) {
-          case 'useState':
-          case 'useReducer':
-          case 'useRef': {
-            // unused refs can be removed
-            return true;
-          }
-        }
-      }
-      return false;
-    }
    case 'Await':
+    case 'CallExpression':
    case 'ComputedDelete':
    case 'ComputedStore':
    case 'PropertyDelete':
+    case 'MethodCall':
    case 'PropertyStore':
    case 'StoreGlobal': {
      /*
--- a/compiler/packages/babel-plugin-react-compiler/src/Optimization/OptimizeForSSR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Optimization/OptimizeForSSR.ts
@@ -1,269 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {CompilerError} from '..';
-import {
-  CallExpression,
-  getHookKind,
-  HIRFunction,
-  IdentifierId,
-  InstructionValue,
-  isArrayType,
-  isPlainObjectType,
-  isPrimitiveType,
-  isSetStateType,
-  isStartTransitionType,
-  LoadLocal,
-  StoreLocal,
-} from '../HIR';
-import {
-  eachInstructionValueOperand,
-  eachTerminalOperand,
-} from '../HIR/visitors';
-import {retainWhere} from '../Utils/utils';
-
-/**
- * Optimizes the code for running specifically in an SSR environment. This optimization
- * asssumes that setState will not be called during render during initial mount, which
- * allows inlining useState/useReducer.
- *
- * Optimizations:
- * - Inline useState/useReducer
- * - Remove effects
- * - Remove refs where known to be unused during render (eg directly passed to a dom node)
- * - Remove event handlers
- *
- * Note that an earlier pass already inlines useMemo/useCallback
- */
-export function optimizeForSSR(fn: HIRFunction): void {
-  const inlinedState = new Map<IdentifierId, InstructionValue>();
-  /**
-   * First pass identifies useState/useReducer which can be safely inlined. Any use
-   * of the hook return other than destructuring (with a specific pattern) prevents
-   * inlining.
-   *
-   * Supported cases:
-   * - `const [state, ] = useState( <primitive-array-or-object> )`
-   * - `const [state, ] = useReducer(..., <value>)`
-   * - `const [state, ] = useReducer[..., <value>, <init>]`
-   */
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const {value} = instr;
-      switch (value.kind) {
-        case 'Destructure': {
-          if (
-            inlinedState.has(value.value.identifier.id) &&
-            value.lvalue.pattern.kind === 'ArrayPattern' &&
-            value.lvalue.pattern.items.length >= 1 &&
-            value.lvalue.pattern.items[0].kind === 'Identifier'
-          ) {
-            // Allow destructuring of inlined states
-            continue;
-          }
-          break;
-        }
-        case 'MethodCall':
-        case 'CallExpression': {
-          const calleee =
-            value.kind === 'CallExpression' ? value.callee : value.property;
-          const hookKind = getHookKind(fn.env, calleee.identifier);
-          switch (hookKind) {
-            case 'useReducer': {
-              if (
-                value.args.length === 2 &&
-                value.args[1].kind === 'Identifier'
-              ) {
-                const arg = value.args[1];
-                const replace: LoadLocal = {
-                  kind: 'LoadLocal',
-                  place: arg,
-                  loc: arg.loc,
-                };
-                inlinedState.set(instr.lvalue.identifier.id, replace);
-              } else if (
-                value.args.length === 3 &&
-                value.args[1].kind === 'Identifier' &&
-                value.args[2].kind === 'Identifier'
-              ) {
-                const arg = value.args[1];
-                const initializer = value.args[2];
-                const replace: CallExpression = {
-                  kind: 'CallExpression',
-                  callee: initializer,
-                  args: [arg],
-                  loc: value.loc,
-                };
-                inlinedState.set(instr.lvalue.identifier.id, replace);
-              }
-              break;
-            }
-            case 'useState': {
-              if (
-                value.args.length === 1 &&
-                value.args[0].kind === 'Identifier'
-              ) {
-                const arg = value.args[0];
-                if (
-                  isPrimitiveType(arg.identifier) ||
-                  isPlainObjectType(arg.identifier) ||
-                  isArrayType(arg.identifier)
-                ) {
-                  const replace: LoadLocal = {
-                    kind: 'LoadLocal',
-                    place: arg,
-                    loc: arg.loc,
-                  };
-                  inlinedState.set(instr.lvalue.identifier.id, replace);
-                }
-              }
-              break;
-            }
-          }
-        }
-      }
-      // Any use of useState/useReducer return besides destructuring prevents inlining
-      if (inlinedState.size !== 0) {
-        for (const operand of eachInstructionValueOperand(value)) {
-          inlinedState.delete(operand.identifier.id);
-        }
-      }
-    }
-    if (inlinedState.size !== 0) {
-      for (const operand of eachTerminalOperand(block.terminal)) {
-        inlinedState.delete(operand.identifier.id);
-      }
-    }
-  }
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const {value} = instr;
-      switch (value.kind) {
-        case 'FunctionExpression': {
-          if (hasKnownNonRenderCall(value.loweredFunc.func)) {
-            instr.value = {
-              kind: 'Primitive',
-              value: undefined,
-              loc: value.loc,
-            };
-          }
-          break;
-        }
-        case 'JsxExpression': {
-          if (
-            value.tag.kind === 'BuiltinTag' &&
-            value.tag.name.indexOf('-') === -1
-          ) {
-            const tag = value.tag.name;
-            retainWhere(value.props, prop => {
-              return (
-                prop.kind === 'JsxSpreadAttribute' ||
-                (!isKnownEventHandler(tag, prop.name) && prop.name !== 'ref')
-              );
-            });
-          }
-          break;
-        }
-        case 'Destructure': {
-          if (inlinedState.has(value.value.identifier.id)) {
-            // Canonical check is part of determining if state can inline, this is for TS
-            CompilerError.invariant(
-              value.lvalue.pattern.kind === 'ArrayPattern' &&
-                value.lvalue.pattern.items.length >= 1 &&
-                value.lvalue.pattern.items[0].kind === 'Identifier',
-              {
-                reason:
-                  'Expected a valid destructuring pattern for inlined state',
-                description: null,
-                details: [
-                  {
-                    kind: 'error',
-                    message: 'Expected a valid destructuring pattern',
-                    loc: value.loc,
-                  },
-                ],
-              },
-            );
-            const store: StoreLocal = {
-              kind: 'StoreLocal',
-              loc: value.loc,
-              type: null,
-              lvalue: {
-                kind: value.lvalue.kind,
-                place: value.lvalue.pattern.items[0],
-              },
-              value: value.value,
-            };
-            instr.value = store;
-          }
-          break;
-        }
-        case 'MethodCall':
-        case 'CallExpression': {
-          const calleee =
-            value.kind === 'CallExpression' ? value.callee : value.property;
-          const hookKind = getHookKind(fn.env, calleee.identifier);
-          switch (hookKind) {
-            case 'useEffectEvent': {
-              if (
-                value.args.length === 1 &&
-                value.args[0].kind === 'Identifier'
-              ) {
-                const load: LoadLocal = {
-                  kind: 'LoadLocal',
-                  place: value.args[0],
-                  loc: value.loc,
-                };
-                instr.value = load;
-              }
-              break;
-            }
-            case 'useEffect':
-            case 'useLayoutEffect':
-            case 'useInsertionEffect': {
-              // Drop effects
-              instr.value = {
-                kind: 'Primitive',
-                value: undefined,
-                loc: value.loc,
-              };
-              break;
-            }
-            case 'useReducer':
-            case 'useState': {
-              const replace = inlinedState.get(instr.lvalue.identifier.id);
-              if (replace != null) {
-                instr.value = replace;
-              }
-              break;
-            }
-          }
-        }
-      }
-    }
-  }
-}
-
-function hasKnownNonRenderCall(fn: HIRFunction): boolean {
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      if (
-        instr.value.kind === 'CallExpression' &&
-        (isSetStateType(instr.value.callee.identifier) ||
-          isStartTransitionType(instr.value.callee.identifier))
-      ) {
-        return true;
-      }
-    }
-  }
-  return false;
-}
-
-const EVENT_HANDLER_PATTERN = /^on[A-Z]/;
-function isKnownEventHandler(_tag: string, prop: string): boolean {
-  return EVENT_HANDLER_PATTERN.test(prop);
-}
--- a/compiler/packages/babel-plugin-react-compiler/src/Optimization/OutlineJsx.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Optimization/OutlineJsx.ts
@@ -515,7 +515,6 @@ function emitDestructureProps(
        pattern: {
          kind: 'ObjectPattern',
          properties,
-          loc: GeneratedSource,
        },
        kind: InstructionKind.Let,
      },
--- a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/CodegenReactiveFunction.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/CodegenReactiveFunction.ts
@@ -159,7 +159,7 @@ export function codegenFunction(
  const compiled = compileResult.unwrap();

  const hookGuard = fn.env.config.enableEmitHookGuards;
-  if (hookGuard != null && fn.env.outputMode === 'client') {
+  if (hookGuard != null && fn.env.isInferredMemoEnabled) {
    compiled.body = t.blockStatement([
      createHookGuard(
        hookGuard,
@@ -259,7 +259,7 @@ export function codegenFunction(
  if (
    emitInstrumentForget != null &&
    fn.id != null &&
-    fn.env.outputMode === 'client'
+    fn.env.isInferredMemoEnabled
  ) {
    /*
     * Technically, this is a conditional hook call. However, we expect
@@ -591,10 +591,7 @@ function codegenBlockNoReset(
 }

 function wrapCacheDep(cx: Context, value: t.Expression): t.Expression {
-  if (
-    cx.env.config.enableEmitFreeze != null &&
-    cx.env.outputMode === 'client'
-  ) {
+  if (cx.env.config.enableEmitFreeze != null && cx.env.isInferredMemoEnabled) {
    const emitFreezeIdentifier = cx.env.programContext.addImportSpecifier(
      cx.env.config.enableEmitFreeze,
    ).name;
@@ -702,7 +699,7 @@ function codegenReactiveScope(
    outputComments.push(name.name);
    if (!cx.hasDeclared(identifier)) {
      statements.push(
-        t.variableDeclaration('let', [createVariableDeclarator(name, null)]),
+        t.variableDeclaration('let', [t.variableDeclarator(name)]),
      );
    }
    cacheLoads.push({name, index, value: wrapCacheDep(cx, name)});
@@ -1362,6 +1359,8 @@ function codegenInstructionNullable(
      value = null;
    } else {
      lvalue = instr.value.lvalue.pattern;
+      let hasReassign = false;
+      let hasDeclaration = false;
      for (const place of eachPatternOperand(lvalue)) {
        if (
          kind !== InstructionKind.Reassign &&
@@ -1369,6 +1368,26 @@ function codegenInstructionNullable(
        ) {
          cx.temp.set(place.identifier.declarationId, null);
        }
+        const isDeclared = cx.hasDeclared(place.identifier);
+        hasReassign ||= isDeclared;
+        hasDeclaration ||= !isDeclared;
+      }
+      if (hasReassign && hasDeclaration) {
+        CompilerError.invariant(false, {
+          reason:
+            'Encountered a destructuring operation where some identifiers are already declared (reassignments) but others are not (declarations)',
+          description: null,
+          details: [
+            {
+              kind: 'error',
+              loc: instr.loc,
+              message: null,
+            },
+          ],
+          suggestions: null,
+        });
+      } else if (hasReassign) {
+        kind = InstructionKind.Reassign;
      }
      value = codegenPlaceToExpression(cx, instr.value.value);
    }
@@ -1387,7 +1406,7 @@ function codegenInstructionNullable(
          suggestions: null,
        });
        return createVariableDeclaration(instr.loc, 'const', [
-          createVariableDeclarator(codegenLValue(cx, lvalue), value),
+          t.variableDeclarator(codegenLValue(cx, lvalue), value),
        ]);
      }
      case InstructionKind.Function: {
@@ -1451,7 +1470,7 @@ function codegenInstructionNullable(
          suggestions: null,
        });
        return createVariableDeclaration(instr.loc, 'let', [
-          createVariableDeclarator(codegenLValue(cx, lvalue), value),
+          t.variableDeclarator(codegenLValue(cx, lvalue), value),
        ]);
      }
      case InstructionKind.Reassign: {
@@ -1691,9 +1710,6 @@ function withLoc<T extends (...args: Array<any>) => t.Node>(
  };
 }

-const createIdentifier = withLoc(t.identifier);
-const createArrayPattern = withLoc(t.arrayPattern);
-const createObjectPattern = withLoc(t.objectPattern);
 const createBinaryExpression = withLoc(t.binaryExpression);
 const createExpressionStatement = withLoc(t.expressionStatement);
 const _createLabelledStatement = withLoc(t.labeledStatement);
@@ -1725,31 +1741,6 @@ const createTryStatement = withLoc(t.tryStatement);
 const createBreakStatement = withLoc(t.breakStatement);
 const createContinueStatement = withLoc(t.continueStatement);

-function createVariableDeclarator(
-  id: t.LVal,
-  init?: t.Expression | null,
-): t.VariableDeclarator {
-  const node = t.variableDeclarator(id, init);
-
-  /*
-   * The variable declarator location is not preserved in HIR, however, we can use the
-   * start location of the id and the end location of the init to recreate the
-   * exact original variable declarator location.
-   *
-   * Or if init is null, we likely have a declaration without an initializer, so we can use the id.loc.end as the end location.
-   */
-  if (id.loc && (init === null || init?.loc)) {
-    node.loc = {
-      start: id.loc.start,
-      end: init?.loc?.end ?? id.loc.end,
-      filename: id.loc.filename,
-      identifierName: undefined,
-    };
-  }
-
-  return node;
-}
-
 function createHookGuard(
  guard: ExternalFunction,
  context: ProgramContext,
@@ -1803,7 +1794,7 @@ function createCallExpression(
  }

  const hookGuard = env.config.enableEmitHookGuards;
-  if (hookGuard != null && isHook && env.outputMode === 'client') {
+  if (hookGuard != null && isHook && env.isInferredMemoEnabled) {
    const iife = t.functionExpression(
      null,
      [],
@@ -1857,7 +1848,7 @@ function codegenInstruction(
      );
    } else {
      return createVariableDeclaration(instr.loc, 'const', [
-        createVariableDeclarator(
+        t.variableDeclarator(
          convertIdentifier(instr.lvalue.identifier),
          expressionValue,
        ),
@@ -2784,7 +2775,7 @@ function codegenArrayPattern(
 ): t.ArrayPattern {
  const hasHoles = !pattern.items.every(e => e.kind !== 'Hole');
  if (hasHoles) {
-    const result = createArrayPattern(pattern.loc, []);
+    const result = t.arrayPattern([]);
    /*
     * Older versions of babel have a validation bug fixed by
     * https://github.com/babel/babel/pull/10917
@@ -2805,8 +2796,7 @@ function codegenArrayPattern(
    }
    return result;
  } else {
-    return createArrayPattern(
-      pattern.loc,
+    return t.arrayPattern(
      pattern.items.map(item => {
        if (item.kind === 'Hole') {
          return null;
@@ -2826,8 +2816,7 @@ function codegenLValue(
      return codegenArrayPattern(cx, pattern);
    }
    case 'ObjectPattern': {
-      return createObjectPattern(
-        pattern.loc,
+      return t.objectPattern(
        pattern.properties.map(property => {
          if (property.kind === 'ObjectProperty') {
            const key = codegenObjectPropertyKey(cx, property.key);
@@ -2946,7 +2935,7 @@ function convertIdentifier(identifier: Identifier): t.Identifier {
      suggestions: null,
    },
  );
-  return createIdentifier(identifier.loc, identifier.name.value);
+  return t.identifier(identifier.name.value);
 }

 function compareScopeDependency(
--- a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/ExtractScopeDeclarationsFromDestructuring.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/ExtractScopeDeclarationsFromDestructuring.ts
@@ -19,11 +19,7 @@ import {
  promoteTemporary,
 } from '../HIR';
 import {clonePlaceToTemporary} from '../HIR/HIRBuilder';
-import {
-  eachInstructionLValueWithKind,
-  eachPatternOperand,
-  mapPatternOperands,
-} from '../HIR/visitors';
+import {eachPatternOperand, mapPatternOperands} from '../HIR/visitors';
 import {
  ReactiveFunctionTransform,
  Transformed,
@@ -117,9 +113,6 @@ class Visitor extends ReactiveFunctionTransform<State> {
  ): Transformed<ReactiveStatement> {
    this.visitInstruction(instruction, state);

-    let instructionsToProcess: Array<ReactiveInstruction> = [instruction];
-    let result: Transformed<ReactiveStatement> = {kind: 'keep'};
-
    if (instruction.value.kind === 'Destructure') {
      const transformed = transformDestructuring(
        state,
@@ -127,8 +120,7 @@ class Visitor extends ReactiveFunctionTransform<State> {
        instruction.value,
      );
      if (transformed) {
-        instructionsToProcess = transformed;
-        result = {
+        return {
          kind: 'replace-many',
          value: transformed.map(instruction => ({
            kind: 'instruction',
@@ -137,17 +129,7 @@ class Visitor extends ReactiveFunctionTransform<State> {
        };
      }
    }
-
-    // Update state.declared with declarations from the instruction(s)
-    for (const instr of instructionsToProcess) {
-      for (const [place, kind] of eachInstructionLValueWithKind(instr)) {
-        if (kind !== InstructionKind.Reassign) {
-          state.declared.add(place.identifier.declarationId);
-        }
-      }
-    }
-
-    return result;
+    return {kind: 'keep'};
  }
 }

@@ -162,13 +144,10 @@ function transformDestructuring(
    const isDeclared = state.declared.has(place.identifier.declarationId);
    if (isDeclared) {
      reassigned.add(place.identifier.id);
-    } else {
-      hasDeclaration = true;
    }
+    hasDeclaration ||= !isDeclared;
  }
-  if (!hasDeclaration) {
-    // all reassignments
-    destructure.lvalue.kind = InstructionKind.Reassign;
+  if (reassigned.size === 0 || !hasDeclaration) {
    return null;
  }
  /*
--- a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/InferReactiveScopeVariables.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/InferReactiveScopeVariables.ts
@@ -389,6 +389,14 @@ export function findDisjointMutableValues(
             */
            operand.identifier.mutableRange.start > 0
          ) {
+            if (
+              instr.value.kind === 'FunctionExpression' ||
+              instr.value.kind === 'ObjectMethod'
+            ) {
+              if (operand.identifier.type.kind === 'Primitive') {
+                continue;
+              }
+            }
            operands.push(operand.identifier);
          }
        }
--- a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/MemoizeFbtAndMacroOperandsInSameScope.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/MemoizeFbtAndMacroOperandsInSameScope.ts
@@ -8,41 +8,13 @@
 import {
  HIRFunction,
  IdentifierId,
-  InstructionValue,
  makeInstructionId,
  MutableRange,
  Place,
-  ReactiveScope,
+  ReactiveValue,
 } from '../HIR';
-import {Macro} from '../HIR/Environment';
-import {eachInstructionValueOperand} from '../HIR/visitors';
-
-/**
- * Whether a macro requires its arguments to be transitively inlined (eg fbt)
- * or just avoid having the top-level values be converted to variables (eg fbt.param)
- */
-enum InlineLevel {
-  Transitive = 'Transitive',
-  Shallow = 'Shallow',
-}
-type MacroDefinition = {
-  level: InlineLevel;
-  properties: Map<string, MacroDefinition> | null;
-};
-
-const SHALLOW_MACRO: MacroDefinition = {
-  level: InlineLevel.Shallow,
-  properties: null,
-};
-const TRANSITIVE_MACRO: MacroDefinition = {
-  level: InlineLevel.Transitive,
-  properties: null,
-};
-const FBT_MACRO: MacroDefinition = {
-  level: InlineLevel.Transitive,
-  properties: new Map([['*', SHALLOW_MACRO]]),
-};
-FBT_MACRO.properties!.set('enum', FBT_MACRO);
+import {Macro, MacroMethod} from '../HIR/Environment';
+import {eachReactiveValueOperand} from './visitors';

 /**
 * This pass supports the `fbt` translation system (https://facebook.github.io/fbt/)
@@ -67,210 +39,230 @@ FBT_MACRO.properties!.set('enum', FBT_MACRO);
 * ## User-defined macro-like function
 *
 * Users can also specify their own functions to be treated similarly to fbt via the
- * `customMacros` environment configuration. By default, user-supplied custom macros
- * have their arguments transitively inlined.
+ * `customMacros` environment configuration.
 */
 export function memoizeFbtAndMacroOperandsInSameScope(
  fn: HIRFunction,
 ): Set<IdentifierId> {
-  const macroKinds = new Map<Macro, MacroDefinition>([
-    ...Array.from(FBT_TAGS.entries()),
-    ...(fn.env.config.customMacros ?? []).map(
-      name => [name, TRANSITIVE_MACRO] as [Macro, MacroDefinition],
-    ),
+  const fbtMacroTags = new Set<Macro>([
+    ...Array.from(FBT_TAGS).map((tag): Macro => [tag, []]),
+    ...(fn.env.config.customMacros ?? []),
  ]);
-  /**
-   * Forward data-flow analysis to identify all macro tags, including
-   * things like `fbt.foo.bar(...)`
-   */
-  const macroTags = populateMacroTags(fn, macroKinds);
-
-  /**
-   * Reverse data-flow analysis to merge arguments to macro *invocations*
-   * based on the kind of the macro
-   */
-  const macroValues = mergeMacroArguments(fn, macroTags, macroKinds);
-
-  return macroValues;
+  const fbtValues: Set<IdentifierId> = new Set();
+  const macroMethods = new Map<IdentifierId, Array<Array<MacroMethod>>>();
+  while (true) {
+    let vsize = fbtValues.size;
+    let msize = macroMethods.size;
+    visit(fn, fbtMacroTags, fbtValues, macroMethods);
+    if (vsize === fbtValues.size && msize === macroMethods.size) {
+      break;
+    }
+  }
+  return fbtValues;
 }

-const FBT_TAGS: Map<string, MacroDefinition> = new Map([
-  ['fbt', FBT_MACRO],
-  ['fbt:param', SHALLOW_MACRO],
-  ['fbt:enum', FBT_MACRO],
-  ['fbt:plural', SHALLOW_MACRO],
-  ['fbs', FBT_MACRO],
-  ['fbs:param', SHALLOW_MACRO],
-  ['fbs:enum', FBT_MACRO],
-  ['fbs:plural', SHALLOW_MACRO],
+export const FBT_TAGS: Set<string> = new Set([
+  'fbt',
+  'fbt:param',
+  'fbs',
+  'fbs:param',
 ]);
 export const SINGLE_CHILD_FBT_TAGS: Set<string> = new Set([
  'fbt:param',
  'fbs:param',
 ]);

-function populateMacroTags(
+function visit(
  fn: HIRFunction,
-  macroKinds: Map<Macro, MacroDefinition>,
-): Map<IdentifierId, MacroDefinition> {
-  const macroTags = new Map<IdentifierId, MacroDefinition>();
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const {lvalue, value} = instr;
-      switch (value.kind) {
-        case 'Primitive': {
-          if (typeof value.value === 'string') {
-            const macroDefinition = macroKinds.get(value.value);
-            if (macroDefinition != null) {
-              /*
-               * We don't distinguish between tag names and strings, so record
-               * all `fbt` string literals in case they are used as a jsx tag.
-               */
-              macroTags.set(lvalue.identifier.id, macroDefinition);
+  fbtMacroTags: Set<Macro>,
+  fbtValues: Set<IdentifierId>,
+  macroMethods: Map<IdentifierId, Array<Array<MacroMethod>>>,
+): void {
+  for (const [, block] of fn.body.blocks) {
+    for (const instruction of block.instructions) {
+      const {lvalue, value} = instruction;
+      if (lvalue === null) {
+        continue;
+      }
+      if (
+        value.kind === 'Primitive' &&
+        typeof value.value === 'string' &&
+        matchesExactTag(value.value, fbtMacroTags)
+      ) {
+        /*
+         * We don't distinguish between tag names and strings, so record
+         * all `fbt` string literals in case they are used as a jsx tag.
+         */
+        fbtValues.add(lvalue.identifier.id);
+      } else if (
+        value.kind === 'LoadGlobal' &&
+        matchesExactTag(value.binding.name, fbtMacroTags)
+      ) {
+        // Record references to `fbt` as a global
+        fbtValues.add(lvalue.identifier.id);
+      } else if (
+        value.kind === 'LoadGlobal' &&
+        matchTagRoot(value.binding.name, fbtMacroTags) !== null
+      ) {
+        const methods = matchTagRoot(value.binding.name, fbtMacroTags)!;
+        macroMethods.set(lvalue.identifier.id, methods);
+      } else if (
+        value.kind === 'PropertyLoad' &&
+        macroMethods.has(value.object.identifier.id)
+      ) {
+        const methods = macroMethods.get(value.object.identifier.id)!;
+        const newMethods = [];
+        for (const method of methods) {
+          if (
+            method.length > 0 &&
+            (method[0].type === 'wildcard' ||
+              (method[0].type === 'name' && method[0].name === value.property))
+          ) {
+            if (method.length > 1) {
+              newMethods.push(method.slice(1));
+            } else {
+              fbtValues.add(lvalue.identifier.id);
            }
          }
-          break;
        }
-        case 'LoadGlobal': {
-          let macroDefinition = macroKinds.get(value.binding.name);
-          if (macroDefinition != null) {
-            macroTags.set(lvalue.identifier.id, macroDefinition);
-          }
-          break;
+        if (newMethods.length > 0) {
+          macroMethods.set(lvalue.identifier.id, newMethods);
        }
-        case 'PropertyLoad': {
-          if (typeof value.property === 'string') {
-            const macroDefinition = macroTags.get(value.object.identifier.id);
-            if (macroDefinition != null) {
-              const propertyDefinition =
-                macroDefinition.properties != null
-                  ? (macroDefinition.properties.get(value.property) ??
-                    macroDefinition.properties.get('*'))
-                  : null;
-              const propertyMacro = propertyDefinition ?? macroDefinition;
-              macroTags.set(lvalue.identifier.id, propertyMacro);
-            }
+      } else if (isFbtCallExpression(fbtValues, value)) {
+        const fbtScope = lvalue.identifier.scope;
+        if (fbtScope === null) {
+          continue;
+        }
+
+        /*
+         * if the JSX element's tag was `fbt`, mark all its operands
+         * to ensure that they end up in the same scope as the jsx element
+         * itself.
+         */
+        for (const operand of eachReactiveValueOperand(value)) {
+          operand.identifier.scope = fbtScope;
+
+          // Expand the jsx element's range to account for its operands
+          expandFbtScopeRange(fbtScope.range, operand.identifier.mutableRange);
+          fbtValues.add(operand.identifier.id);
+        }
+      } else if (
+        isFbtJsxExpression(fbtMacroTags, fbtValues, value) ||
+        isFbtJsxChild(fbtValues, lvalue, value)
+      ) {
+        const fbtScope = lvalue.identifier.scope;
+        if (fbtScope === null) {
+          continue;
+        }
+
+        /*
+         * if the JSX element's tag was `fbt`, mark all its operands
+         * to ensure that they end up in the same scope as the jsx element
+         * itself.
+         */
+        for (const operand of eachReactiveValueOperand(value)) {
+          operand.identifier.scope = fbtScope;
+
+          // Expand the jsx element's range to account for its operands
+          expandFbtScopeRange(fbtScope.range, operand.identifier.mutableRange);
+
+          /*
+           * NOTE: we add the operands as fbt values so that they are also
+           * grouped with this expression
+           */
+          fbtValues.add(operand.identifier.id);
+        }
+      } else if (fbtValues.has(lvalue.identifier.id)) {
+        const fbtScope = lvalue.identifier.scope;
+        if (fbtScope === null) {
+          return;
+        }
+
+        for (const operand of eachReactiveValueOperand(value)) {
+          if (
+            operand.identifier.name !== null &&
+            operand.identifier.name.kind === 'named'
+          ) {
+            /*
+             * named identifiers were already locals, we only have to force temporaries
+             * into the same scope
+             */
+            continue;
          }
-          break;
+          operand.identifier.scope = fbtScope;
+
+          // Expand the jsx element's range to account for its operands
+          expandFbtScopeRange(fbtScope.range, operand.identifier.mutableRange);
        }
      }
    }
  }
-  return macroTags;
 }

-function mergeMacroArguments(
-  fn: HIRFunction,
-  macroTags: Map<IdentifierId, MacroDefinition>,
-  macroKinds: Map<Macro, MacroDefinition>,
-): Set<IdentifierId> {
-  const macroValues = new Set<IdentifierId>(macroTags.keys());
-  for (const block of Array.from(fn.body.blocks.values()).reverse()) {
-    for (let i = block.instructions.length - 1; i >= 0; i--) {
-      const instr = block.instructions[i]!;
-      const {lvalue, value} = instr;
-      switch (value.kind) {
-        case 'DeclareContext':
-        case 'DeclareLocal':
-        case 'Destructure':
-        case 'LoadContext':
-        case 'LoadLocal':
-        case 'PostfixUpdate':
-        case 'PrefixUpdate':
-        case 'StoreContext':
-        case 'StoreLocal': {
-          // Instructions that never need to be merged
-          break;
-        }
-        case 'CallExpression':
-        case 'MethodCall': {
-          const scope = lvalue.identifier.scope;
-          if (scope == null) {
-            continue;
-          }
-          const callee =
-            value.kind === 'CallExpression' ? value.callee : value.property;
-          const macroDefinition =
-            macroTags.get(callee.identifier.id) ??
-            macroTags.get(lvalue.identifier.id);
-          if (macroDefinition != null) {
-            visitOperands(
-              macroDefinition,
-              scope,
-              lvalue,
-              value,
-              macroValues,
-              macroTags,
-            );
-          }
-          break;
-        }
-        case 'JsxExpression': {
-          const scope = lvalue.identifier.scope;
-          if (scope == null) {
-            continue;
-          }
-          let macroDefinition;
-          if (value.tag.kind === 'Identifier') {
-            macroDefinition = macroTags.get(value.tag.identifier.id);
-          } else {
-            macroDefinition = macroKinds.get(value.tag.name);
-          }
-          macroDefinition ??= macroTags.get(lvalue.identifier.id);
-          if (macroDefinition != null) {
-            visitOperands(
-              macroDefinition,
-              scope,
-              lvalue,
-              value,
-              macroValues,
-              macroTags,
-            );
-          }
-          break;
-        }
-        default: {
-          const scope = lvalue.identifier.scope;
-          if (scope == null) {
-            continue;
-          }
-          const macroDefinition = macroTags.get(lvalue.identifier.id);
-          if (macroDefinition != null) {
-            visitOperands(
-              macroDefinition,
-              scope,
-              lvalue,
-              value,
-              macroValues,
-              macroTags,
-            );
-          }
-          break;
-        }
-      }
+function matchesExactTag(s: string, tags: Set<Macro>): boolean {
+  return Array.from(tags).some(macro =>
+    typeof macro === 'string'
+      ? s === macro
+      : macro[1].length === 0 && macro[0] === s,
+  );
+}
+
+function matchTagRoot(
+  s: string,
+  tags: Set<Macro>,
+): Array<Array<MacroMethod>> | null {
+  const methods: Array<Array<MacroMethod>> = [];
+  for (const macro of tags) {
+    if (typeof macro === 'string') {
+      continue;
    }
-    for (const phi of block.phis) {
-      const scope = phi.place.identifier.scope;
-      if (scope == null) {
-        continue;
-      }
-      const macroDefinition = macroTags.get(phi.place.identifier.id);
-      if (
-        macroDefinition == null ||
-        macroDefinition.level === InlineLevel.Shallow
-      ) {
-        continue;
-      }
-      macroValues.add(phi.place.identifier.id);
-      for (const operand of phi.operands.values()) {
-        operand.identifier.scope = scope;
-        expandFbtScopeRange(scope.range, operand.identifier.mutableRange);
-        macroTags.set(operand.identifier.id, macroDefinition);
-        macroValues.add(operand.identifier.id);
-      }
+    const [tag, rest] = macro;
+    if (tag === s && rest.length > 0) {
+      methods.push(rest);
    }
  }
-  return macroValues;
+  if (methods.length > 0) {
+    return methods;
+  } else {
+    return null;
+  }
+}
+
+function isFbtCallExpression(
+  fbtValues: Set<IdentifierId>,
+  value: ReactiveValue,
+): boolean {
+  return (
+    (value.kind === 'CallExpression' &&
+      fbtValues.has(value.callee.identifier.id)) ||
+    (value.kind === 'MethodCall' && fbtValues.has(value.property.identifier.id))
+  );
+}
+
+function isFbtJsxExpression(
+  fbtMacroTags: Set<Macro>,
+  fbtValues: Set<IdentifierId>,
+  value: ReactiveValue,
+): boolean {
+  return (
+    value.kind === 'JsxExpression' &&
+    ((value.tag.kind === 'Identifier' &&
+      fbtValues.has(value.tag.identifier.id)) ||
+      (value.tag.kind === 'BuiltinTag' &&
+        matchesExactTag(value.tag.name, fbtMacroTags)))
+  );
+}
+
+function isFbtJsxChild(
+  fbtValues: Set<IdentifierId>,
+  lvalue: Place | null,
+  value: ReactiveValue,
+): boolean {
+  return (
+    (value.kind === 'JsxExpression' || value.kind === 'JsxFragment') &&
+    lvalue !== null &&
+    fbtValues.has(lvalue.identifier.id)
+  );
 }

 function expandFbtScopeRange(
@@ -283,22 +275,3 @@ function expandFbtScopeRange(
    );
  }
 }
-
-function visitOperands(
-  macroDefinition: MacroDefinition,
-  scope: ReactiveScope,
-  lvalue: Place,
-  value: InstructionValue,
-  macroValues: Set<IdentifierId>,
-  macroTags: Map<IdentifierId, MacroDefinition>,
-): void {
-  macroValues.add(lvalue.identifier.id);
-  for (const operand of eachInstructionValueOperand(value)) {
-    if (macroDefinition.level === InlineLevel.Transitive) {
-      operand.identifier.scope = scope;
-      expandFbtScopeRange(scope.range, operand.identifier.mutableRange);
-      macroTags.set(operand.identifier.id, macroDefinition);
-    }
-    macroValues.add(operand.identifier.id);
-  }
-}
--- a/compiler/packages/babel-plugin-react-compiler/src/TypeInference/InferTypes.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/TypeInference/InferTypes.ts
@@ -25,7 +25,6 @@ import {
 } from '../HIR/HIR';
 import {
  BuiltInArrayId,
-  BuiltInEventHandlerId,
  BuiltInFunctionId,
  BuiltInJsxId,
  BuiltInMixedReadonlyId,
@@ -394,7 +393,7 @@ function* generateInstructionTypes(
              shapeId: BuiltInArrayId,
            });
          } else {
-            continue;
+            break;
          }
        }
      } else {
@@ -472,41 +471,6 @@ function* generateInstructionTypes(
          }
        }
      }
-      if (env.config.enableInferEventHandlers) {
-        if (
-          value.kind === 'JsxExpression' &&
-          value.tag.kind === 'BuiltinTag' &&
-          !value.tag.name.includes('-')
-        ) {
-          /*
-           * Infer event handler types for built-in DOM elements.
-           * Props starting with "on" (e.g., onClick, onSubmit) on primitive tags
-           * are inferred as event handlers. This allows functions with ref access
-           * to be passed to these props, since DOM event handlers are guaranteed
-           * by React to only execute in response to events, never during render.
-           *
-           * We exclude tags with hyphens to avoid web components (custom elements),
-           * which are required by the HTML spec to contain a hyphen. Web components
-           * may call event handler props during their lifecycle methods (e.g.,
-           * connectedCallback), which would be unsafe for ref access.
-           */
-          for (const prop of value.props) {
-            if (
-              prop.kind === 'JsxAttribute' &&
-              prop.name.startsWith('on') &&
-              prop.name.length > 2 &&
-              prop.name[2] === prop.name[2].toUpperCase()
-            ) {
-              yield equation(prop.place.identifier.type, {
-                kind: 'Function',
-                shapeId: BuiltInEventHandlerId,
-                return: makeType(),
-                isConstructor: false,
-              });
-            }
-          }
-        }
-      }
      yield equation(left, {kind: 'Object', shapeId: BuiltInJsxId});
      break;
    }
--- a/compiler/packages/babel-plugin-react-compiler/src/Utils/TestUtils.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Utils/TestUtils.ts
@@ -5,7 +5,7 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {fromZodError} from 'zod-validation-error/v4';
+import {fromZodError} from 'zod-validation-error';
 import {CompilerError} from '../CompilerError';
 import {
  CompilationMode,
@@ -135,7 +135,16 @@ function parseConfigPragmaEnvironmentForTest(
    } else if (val) {
      const parsedVal = tryParseTestPragmaValue(val).unwrap();
      if (key === 'customMacros' && typeof parsedVal === 'string') {
-        maybeConfig[key] = [parsedVal.split('.')[0]];
+        const valSplit = parsedVal.split('.');
+        const props = [];
+        for (const elt of valSplit.slice(1)) {
+          if (elt === '*') {
+            props.push({type: 'wildcard'});
+          } else if (elt.length > 0) {
+            props.push({type: 'name', name: elt});
+          }
+        }
+        maybeConfig[key] = [[valSplit[0], props]];
        continue;
      }
      maybeConfig[key] = parsedVal;
--- a/compiler/packages/babel-plugin-react-compiler/src/Utils/utils.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Utils/utils.ts
@@ -167,14 +167,6 @@ export function Set_filter<T>(
  return result;
 }

-export function Set_subtract<T>(
-  source: ReadonlySet<T>,
-  other: Iterable<T>,
-): Set<T> {
-  const otherSet = other instanceof Set ? other : new Set(other);
-  return Set_filter(source, item => !otherSet.has(item));
-}
-
 export function hasNode<T>(
  input: NodePath<T | null | undefined>,
 ): input is NodePath<NonNullable<T>> {
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateExhaustiveDependencies.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateExhaustiveDependencies.ts
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoDerivedComputationsInEffects_exp.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoDerivedComputationsInEffects_exp.ts
@@ -1,862 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {Result} from '../Utils/Result';
-import {CompilerDiagnostic, CompilerError, Effect} from '..';
-import {ErrorCategory} from '../CompilerError';
-import {
-  BlockId,
-  FunctionExpression,
-  HIRFunction,
-  IdentifierId,
-  isSetStateType,
-  isUseEffectHookType,
-  Place,
-  CallExpression,
-  Instruction,
-  isUseStateType,
-  BasicBlock,
-  isUseRefType,
-  SourceLocation,
-  ArrayExpression,
-} from '../HIR';
-import {eachInstructionLValue, eachInstructionOperand} from '../HIR/visitors';
-import {isMutable} from '../ReactiveScopes/InferReactiveScopeVariables';
-import {assertExhaustive} from '../Utils/utils';
-
-type TypeOfValue = 'ignored' | 'fromProps' | 'fromState' | 'fromPropsAndState';
-
-type DerivationMetadata = {
-  typeOfValue: TypeOfValue;
-  place: Place;
-  sourcesIds: Set<IdentifierId>;
-  isStateSource: boolean;
-};
-
-type EffectMetadata = {
-  effect: HIRFunction;
-  dependencies: ArrayExpression;
-};
-
-type ValidationContext = {
-  readonly functions: Map<IdentifierId, FunctionExpression>;
-  readonly candidateDependencies: Map<IdentifierId, ArrayExpression>;
-  readonly errors: CompilerError;
-  readonly derivationCache: DerivationCache;
-  readonly effectsCache: Map<IdentifierId, EffectMetadata>;
-  readonly setStateLoads: Map<IdentifierId, IdentifierId | null>;
-  readonly setStateUsages: Map<IdentifierId, Set<SourceLocation>>;
-};
-
-const MAX_FIXPOINT_ITERATIONS = 100;
-
-class DerivationCache {
-  hasChanges: boolean = false;
-  cache: Map<IdentifierId, DerivationMetadata> = new Map();
-  private previousCache: Map<IdentifierId, DerivationMetadata> | null = null;
-
-  takeSnapshot(): void {
-    this.previousCache = new Map();
-    for (const [key, value] of this.cache.entries()) {
-      this.previousCache.set(key, {
-        place: value.place,
-        sourcesIds: new Set(value.sourcesIds),
-        typeOfValue: value.typeOfValue,
-        isStateSource: value.isStateSource,
-      });
-    }
-  }
-
-  checkForChanges(): void {
-    if (this.previousCache === null) {
-      this.hasChanges = true;
-      return;
-    }
-
-    for (const [key, value] of this.cache.entries()) {
-      const previousValue = this.previousCache.get(key);
-      if (
-        previousValue === undefined ||
-        !this.isDerivationEqual(previousValue, value)
-      ) {
-        this.hasChanges = true;
-        return;
-      }
-    }
-
-    if (this.cache.size !== this.previousCache.size) {
-      this.hasChanges = true;
-      return;
-    }
-
-    this.hasChanges = false;
-  }
-
-  snapshot(): boolean {
-    const hasChanges = this.hasChanges;
-    this.hasChanges = false;
-    return hasChanges;
-  }
-
-  addDerivationEntry(
-    derivedVar: Place,
-    sourcesIds: Set<IdentifierId>,
-    typeOfValue: TypeOfValue,
-    isStateSource: boolean,
-  ): void {
-    let finalIsSource = isStateSource;
-    if (!finalIsSource) {
-      for (const sourceId of sourcesIds) {
-        const sourceMetadata = this.cache.get(sourceId);
-        if (
-          sourceMetadata?.isStateSource &&
-          sourceMetadata.place.identifier.name?.kind !== 'named'
-        ) {
-          finalIsSource = true;
-          break;
-        }
-      }
-    }
-
-    this.cache.set(derivedVar.identifier.id, {
-      place: derivedVar,
-      sourcesIds: sourcesIds,
-      typeOfValue: typeOfValue ?? 'ignored',
-      isStateSource: finalIsSource,
-    });
-  }
-
-  private isDerivationEqual(
-    a: DerivationMetadata,
-    b: DerivationMetadata,
-  ): boolean {
-    if (a.typeOfValue !== b.typeOfValue) {
-      return false;
-    }
-    if (a.sourcesIds.size !== b.sourcesIds.size) {
-      return false;
-    }
-    for (const id of a.sourcesIds) {
-      if (!b.sourcesIds.has(id)) {
-        return false;
-      }
-    }
-    return true;
-  }
-}
-
-function isNamedIdentifier(place: Place): place is Place & {
-  identifier: {name: NonNullable<Place['identifier']['name']>};
-} {
-  return (
-    place.identifier.name !== null && place.identifier.name.kind === 'named'
-  );
-}
-
-/**
- * Validates that useEffect is not used for derived computations which could/should
- * be performed in render.
- *
- * See https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state
- *
- * Example:
- *
- * ```
- * // 🔴 Avoid: redundant state and unnecessary Effect
- * const [fullName, setFullName] = useState('');
- * useEffect(() => {
- *   setFullName(firstName + ' ' + lastName);
- * }, [firstName, lastName]);
- * ```
- *
- * Instead use:
- *
- * ```
- * // ✅ Good: calculated during rendering
- * const fullName = firstName + ' ' + lastName;
- * ```
- */
-export function validateNoDerivedComputationsInEffects_exp(
-  fn: HIRFunction,
-): Result<void, CompilerError> {
-  const functions: Map<IdentifierId, FunctionExpression> = new Map();
-  const candidateDependencies: Map<IdentifierId, ArrayExpression> = new Map();
-  const derivationCache = new DerivationCache();
-  const errors = new CompilerError();
-  const effectsCache: Map<IdentifierId, EffectMetadata> = new Map();
-
-  const setStateLoads: Map<IdentifierId, IdentifierId> = new Map();
-  const setStateUsages: Map<IdentifierId, Set<SourceLocation>> = new Map();
-
-  const context: ValidationContext = {
-    functions,
-    candidateDependencies,
-    errors,
-    derivationCache,
-    effectsCache,
-    setStateLoads,
-    setStateUsages,
-  };
-
-  if (fn.fnType === 'Hook') {
-    for (const param of fn.params) {
-      if (param.kind === 'Identifier') {
-        context.derivationCache.cache.set(param.identifier.id, {
-          place: param,
-          sourcesIds: new Set(),
-          typeOfValue: 'fromProps',
-          isStateSource: true,
-        });
-      }
-    }
-  } else if (fn.fnType === 'Component') {
-    const props = fn.params[0];
-    if (props != null && props.kind === 'Identifier') {
-      context.derivationCache.cache.set(props.identifier.id, {
-        place: props,
-        sourcesIds: new Set(),
-        typeOfValue: 'fromProps',
-        isStateSource: true,
-      });
-    }
-  }
-
-  let isFirstPass = true;
-  let iterationCount = 0;
-  do {
-    context.derivationCache.takeSnapshot();
-
-    for (const block of fn.body.blocks.values()) {
-      recordPhiDerivations(block, context);
-      for (const instr of block.instructions) {
-        recordInstructionDerivations(instr, context, isFirstPass);
-      }
-    }
-
-    context.derivationCache.checkForChanges();
-    isFirstPass = false;
-    iterationCount++;
-    CompilerError.invariant(iterationCount < MAX_FIXPOINT_ITERATIONS, {
-      reason:
-        '[ValidateNoDerivedComputationsInEffects] Fixpoint iteration failed to converge.',
-      description: `Fixpoint iteration exceeded ${MAX_FIXPOINT_ITERATIONS} iterations while tracking derivations. This suggests a cyclic dependency in the derivation cache.`,
-      details: [
-        {
-          kind: 'error',
-          loc: fn.loc,
-          message: `Exceeded ${MAX_FIXPOINT_ITERATIONS} iterations in ValidateNoDerivedComputationsInEffects`,
-        },
-      ],
-    });
-  } while (context.derivationCache.snapshot());
-
-  for (const [, effect] of effectsCache) {
-    validateEffect(effect.effect, effect.dependencies, context);
-  }
-
-  return errors.asResult();
-}
-
-function recordPhiDerivations(
-  block: BasicBlock,
-  context: ValidationContext,
-): void {
-  for (const phi of block.phis) {
-    let typeOfValue: TypeOfValue = 'ignored';
-    let sourcesIds: Set<IdentifierId> = new Set();
-    for (const operand of phi.operands.values()) {
-      const operandMetadata = context.derivationCache.cache.get(
-        operand.identifier.id,
-      );
-
-      if (operandMetadata === undefined) {
-        continue;
-      }
-
-      typeOfValue = joinValue(typeOfValue, operandMetadata.typeOfValue);
-      sourcesIds.add(operand.identifier.id);
-    }
-
-    if (typeOfValue !== 'ignored') {
-      context.derivationCache.addDerivationEntry(
-        phi.place,
-        sourcesIds,
-        typeOfValue,
-        false,
-      );
-    }
-  }
-}
-
-function joinValue(
-  lvalueType: TypeOfValue,
-  valueType: TypeOfValue,
-): TypeOfValue {
-  if (lvalueType === 'ignored') return valueType;
-  if (valueType === 'ignored') return lvalueType;
-  if (lvalueType === valueType) return lvalueType;
-  return 'fromPropsAndState';
-}
-
-function getRootSetState(
-  key: IdentifierId,
-  loads: Map<IdentifierId, IdentifierId | null>,
-  visited: Set<IdentifierId> = new Set(),
-): IdentifierId | null {
-  if (visited.has(key)) {
-    return null;
-  }
-  visited.add(key);
-
-  const parentId = loads.get(key);
-
-  if (parentId === undefined) {
-    return null;
-  }
-
-  if (parentId === null) {
-    return key;
-  }
-
-  return getRootSetState(parentId, loads, visited);
-}
-
-function maybeRecordSetState(
-  instr: Instruction,
-  loads: Map<IdentifierId, IdentifierId | null>,
-  usages: Map<IdentifierId, Set<SourceLocation>>,
-): void {
-  for (const operand of eachInstructionLValue(instr)) {
-    if (
-      instr.value.kind === 'LoadLocal' &&
-      loads.has(instr.value.place.identifier.id)
-    ) {
-      loads.set(operand.identifier.id, instr.value.place.identifier.id);
-    } else {
-      if (isSetStateType(operand.identifier)) {
-        // this is a root setState
-        loads.set(operand.identifier.id, null);
-      }
-    }
-
-    const rootSetState = getRootSetState(operand.identifier.id, loads);
-    if (rootSetState !== null && usages.get(rootSetState) === undefined) {
-      usages.set(rootSetState, new Set([operand.loc]));
-    }
-  }
-}
-
-function recordInstructionDerivations(
-  instr: Instruction,
-  context: ValidationContext,
-  isFirstPass: boolean,
-): void {
-  maybeRecordSetState(instr, context.setStateLoads, context.setStateUsages);
-
-  let typeOfValue: TypeOfValue = 'ignored';
-  let isSource: boolean = false;
-  const sources: Set<IdentifierId> = new Set();
-  const {lvalue, value} = instr;
-  if (value.kind === 'FunctionExpression') {
-    context.functions.set(lvalue.identifier.id, value);
-    for (const [, block] of value.loweredFunc.func.body.blocks) {
-      recordPhiDerivations(block, context);
-      for (const instr of block.instructions) {
-        recordInstructionDerivations(instr, context, isFirstPass);
-      }
-    }
-  } else if (value.kind === 'CallExpression' || value.kind === 'MethodCall') {
-    const callee =
-      value.kind === 'CallExpression' ? value.callee : value.property;
-    if (
-      isUseEffectHookType(callee.identifier) &&
-      value.args.length === 2 &&
-      value.args[0].kind === 'Identifier' &&
-      value.args[1].kind === 'Identifier'
-    ) {
-      const effectFunction = context.functions.get(value.args[0].identifier.id);
-      const deps = context.candidateDependencies.get(
-        value.args[1].identifier.id,
-      );
-      if (effectFunction != null && deps != null) {
-        context.effectsCache.set(value.args[0].identifier.id, {
-          effect: effectFunction.loweredFunc.func,
-          dependencies: deps,
-        });
-      }
-    } else if (isUseStateType(lvalue.identifier)) {
-      typeOfValue = 'fromState';
-      context.derivationCache.addDerivationEntry(
-        lvalue,
-        new Set(),
-        typeOfValue,
-        true,
-      );
-      return;
-    }
-  } else if (value.kind === 'ArrayExpression') {
-    context.candidateDependencies.set(lvalue.identifier.id, value);
-  }
-
-  for (const operand of eachInstructionOperand(instr)) {
-    if (context.setStateLoads.has(operand.identifier.id)) {
-      const rootSetStateId = getRootSetState(
-        operand.identifier.id,
-        context.setStateLoads,
-      );
-      if (rootSetStateId !== null) {
-        context.setStateUsages.get(rootSetStateId)?.add(operand.loc);
-      }
-    }
-
-    const operandMetadata = context.derivationCache.cache.get(
-      operand.identifier.id,
-    );
-
-    if (operandMetadata === undefined) {
-      continue;
-    }
-
-    typeOfValue = joinValue(typeOfValue, operandMetadata.typeOfValue);
-    sources.add(operand.identifier.id);
-  }
-
-  if (typeOfValue === 'ignored') {
-    return;
-  }
-
-  for (const lvalue of eachInstructionLValue(instr)) {
-    context.derivationCache.addDerivationEntry(
-      lvalue,
-      sources,
-      typeOfValue,
-      isSource,
-    );
-  }
-
-  if (value.kind === 'FunctionExpression') {
-    /*
-     * We don't want to record effect mutations of FunctionExpressions the mutations will happen in the
-     * function body and we will record them there.
-     */
-    return;
-  }
-
-  for (const operand of eachInstructionOperand(instr)) {
-    switch (operand.effect) {
-      case Effect.Capture:
-      case Effect.Store:
-      case Effect.ConditionallyMutate:
-      case Effect.ConditionallyMutateIterator:
-      case Effect.Mutate: {
-        if (isMutable(instr, operand)) {
-          if (context.derivationCache.cache.has(operand.identifier.id)) {
-            const operandMetadata = context.derivationCache.cache.get(
-              operand.identifier.id,
-            );
-
-            if (operandMetadata !== undefined) {
-              operandMetadata.typeOfValue = joinValue(
-                typeOfValue,
-                operandMetadata.typeOfValue,
-              );
-            }
-          } else {
-            context.derivationCache.addDerivationEntry(
-              operand,
-              sources,
-              typeOfValue,
-              false,
-            );
-          }
-        }
-        break;
-      }
-      case Effect.Freeze:
-      case Effect.Read: {
-        // no-op
-        break;
-      }
-      case Effect.Unknown: {
-        CompilerError.invariant(false, {
-          reason: 'Unexpected unknown effect',
-          description: null,
-          details: [
-            {
-              kind: 'error',
-              loc: operand.loc,
-              message: 'Unexpected unknown effect',
-            },
-          ],
-        });
-      }
-      default: {
-        assertExhaustive(
-          operand.effect,
-          `Unexpected effect kind \`${operand.effect}\``,
-        );
-      }
-    }
-  }
-}
-
-type TreeNode = {
-  name: string;
-  typeOfValue: TypeOfValue;
-  isSource: boolean;
-  children: Array<TreeNode>;
-};
-
-function buildTreeNode(
-  sourceId: IdentifierId,
-  context: ValidationContext,
-  visited: Set<string> = new Set(),
-): Array<TreeNode> {
-  const sourceMetadata = context.derivationCache.cache.get(sourceId);
-  if (!sourceMetadata) {
-    return [];
-  }
-
-  if (sourceMetadata.isStateSource && isNamedIdentifier(sourceMetadata.place)) {
-    return [
-      {
-        name: sourceMetadata.place.identifier.name.value,
-        typeOfValue: sourceMetadata.typeOfValue,
-        isSource: sourceMetadata.isStateSource,
-        children: [],
-      },
-    ];
-  }
-
-  const children: Array<TreeNode> = [];
-
-  const namedSiblings: Set<string> = new Set();
-  for (const childId of sourceMetadata.sourcesIds) {
-    CompilerError.invariant(childId !== sourceId, {
-      reason:
-        'Unexpected self-reference: a value should not have itself as a source',
-      description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: sourceMetadata.place.loc,
-          message: null,
-        },
-      ],
-    });
-
-    const childNodes = buildTreeNode(
-      childId,
-      context,
-      new Set([
-        ...visited,
-        ...(isNamedIdentifier(sourceMetadata.place)
-          ? [sourceMetadata.place.identifier.name.value]
-          : []),
-      ]),
-    );
-    if (childNodes) {
-      for (const childNode of childNodes) {
-        if (!namedSiblings.has(childNode.name)) {
-          children.push(childNode);
-          namedSiblings.add(childNode.name);
-        }
-      }
-    }
-  }
-
-  if (
-    isNamedIdentifier(sourceMetadata.place) &&
-    !visited.has(sourceMetadata.place.identifier.name.value)
-  ) {
-    return [
-      {
-        name: sourceMetadata.place.identifier.name.value,
-        typeOfValue: sourceMetadata.typeOfValue,
-        isSource: sourceMetadata.isStateSource,
-        children: children,
-      },
-    ];
-  }
-
-  return children;
-}
-
-function renderTree(
-  node: TreeNode,
-  indent: string = '',
-  isLast: boolean = true,
-  propsSet: Set<string>,
-  stateSet: Set<string>,
-): string {
-  const prefix = indent + (isLast ? '└── ' : '├── ');
-  const childIndent = indent + (isLast ? '    ' : '│   ');
-
-  let result = `${prefix}${node.name}`;
-
-  if (node.isSource) {
-    let typeLabel: string;
-    if (node.typeOfValue === 'fromProps') {
-      propsSet.add(node.name);
-      typeLabel = 'Prop';
-    } else if (node.typeOfValue === 'fromState') {
-      stateSet.add(node.name);
-      typeLabel = 'State';
-    } else {
-      propsSet.add(node.name);
-      stateSet.add(node.name);
-      typeLabel = 'Prop and State';
-    }
-    result += ` (${typeLabel})`;
-  }
-
-  if (node.children.length > 0) {
-    result += '\n';
-    node.children.forEach((child, index) => {
-      const isLastChild = index === node.children.length - 1;
-      result += renderTree(child, childIndent, isLastChild, propsSet, stateSet);
-      if (index < node.children.length - 1) {
-        result += '\n';
-      }
-    });
-  }
-
-  return result;
-}
-
-function getFnLocalDeps(
-  fn: FunctionExpression | undefined,
-): Set<IdentifierId> | undefined {
-  if (!fn) {
-    return undefined;
-  }
-
-  const deps: Set<IdentifierId> = new Set();
-
-  for (const [, block] of fn.loweredFunc.func.body.blocks) {
-    for (const instr of block.instructions) {
-      if (instr.value.kind === 'LoadLocal') {
-        deps.add(instr.value.place.identifier.id);
-      }
-    }
-  }
-
-  return deps;
-}
-
-function validateEffect(
-  effectFunction: HIRFunction,
-  dependencies: ArrayExpression,
-  context: ValidationContext,
-): void {
-  const seenBlocks: Set<BlockId> = new Set();
-
-  const effectDerivedSetStateCalls: Array<{
-    value: CallExpression;
-    id: IdentifierId;
-    sourceIds: Set<IdentifierId>;
-    typeOfValue: TypeOfValue;
-  }> = [];
-
-  const effectSetStateUsages: Map<
-    IdentifierId,
-    Set<SourceLocation>
-  > = new Map();
-
-  // Consider setStates in the effect's dependency array as being part of effectSetStateUsages
-  for (const dep of dependencies.elements) {
-    if (dep.kind === 'Identifier') {
-      const root = getRootSetState(dep.identifier.id, context.setStateLoads);
-      if (root !== null) {
-        effectSetStateUsages.set(root, new Set([dep.loc]));
-      }
-    }
-  }
-
-  let cleanUpFunctionDeps: Set<IdentifierId> | undefined;
-
-  const globals: Set<IdentifierId> = new Set();
-  for (const block of effectFunction.body.blocks.values()) {
-    /*
-     * if the block is in an effect and is of type return then its an effect's cleanup function
-     * if the cleanup function depends on a value from which effect-set state is derived then
-     * we can't validate
-     */
-    if (
-      block.terminal.kind === 'return' &&
-      block.terminal.returnVariant === 'Explicit'
-    ) {
-      cleanUpFunctionDeps = getFnLocalDeps(
-        context.functions.get(block.terminal.value.identifier.id),
-      );
-    }
-    for (const pred of block.preds) {
-      if (!seenBlocks.has(pred)) {
-        // skip if block has a back edge
-        return;
-      }
-    }
-
-    for (const instr of block.instructions) {
-      // Early return if any instruction is deriving a value from a ref
-      if (isUseRefType(instr.lvalue.identifier)) {
-        return;
-      }
-
-      maybeRecordSetState(instr, context.setStateLoads, effectSetStateUsages);
-
-      for (const operand of eachInstructionOperand(instr)) {
-        if (context.setStateLoads.has(operand.identifier.id)) {
-          const rootSetStateId = getRootSetState(
-            operand.identifier.id,
-            context.setStateLoads,
-          );
-          if (rootSetStateId !== null) {
-            effectSetStateUsages.get(rootSetStateId)?.add(operand.loc);
-          }
-        }
-      }
-
-      if (
-        instr.value.kind === 'CallExpression' &&
-        isSetStateType(instr.value.callee.identifier) &&
-        instr.value.args.length === 1 &&
-        instr.value.args[0].kind === 'Identifier'
-      ) {
-        const calleeMetadata = context.derivationCache.cache.get(
-          instr.value.callee.identifier.id,
-        );
-
-        /*
-         * If the setState comes from a source other than local state skip
-         * since the fix is not to calculate in render
-         */
-        if (calleeMetadata?.typeOfValue != 'fromState') {
-          continue;
-        }
-
-        const argMetadata = context.derivationCache.cache.get(
-          instr.value.args[0].identifier.id,
-        );
-
-        if (argMetadata !== undefined) {
-          effectDerivedSetStateCalls.push({
-            value: instr.value,
-            id: instr.value.callee.identifier.id,
-            sourceIds: argMetadata.sourcesIds,
-            typeOfValue: argMetadata.typeOfValue,
-          });
-        }
-      } else if (instr.value.kind === 'CallExpression') {
-        const calleeMetadata = context.derivationCache.cache.get(
-          instr.value.callee.identifier.id,
-        );
-
-        if (
-          calleeMetadata !== undefined &&
-          (calleeMetadata.typeOfValue === 'fromProps' ||
-            calleeMetadata.typeOfValue === 'fromPropsAndState')
-        ) {
-          // If the callee is a prop we can't confidently say that it should be derived in render
-          return;
-        }
-
-        if (globals.has(instr.value.callee.identifier.id)) {
-          // If the callee is a global we can't confidently say that it should be derived in render
-          return;
-        }
-      } else if (instr.value.kind === 'LoadGlobal') {
-        globals.add(instr.lvalue.identifier.id);
-        for (const operand of eachInstructionOperand(instr)) {
-          globals.add(operand.identifier.id);
-        }
-      }
-    }
-    seenBlocks.add(block.id);
-  }
-
-  for (const derivedSetStateCall of effectDerivedSetStateCalls) {
-    const rootSetStateCall = getRootSetState(
-      derivedSetStateCall.id,
-      context.setStateLoads,
-    );
-
-    if (
-      rootSetStateCall !== null &&
-      effectSetStateUsages.has(rootSetStateCall) &&
-      context.setStateUsages.has(rootSetStateCall) &&
-      effectSetStateUsages.get(rootSetStateCall)!.size ===
-        context.setStateUsages.get(rootSetStateCall)!.size - 1
-    ) {
-      const propsSet = new Set<string>();
-      const stateSet = new Set<string>();
-
-      const rootNodesMap = new Map<string, TreeNode>();
-      for (const id of derivedSetStateCall.sourceIds) {
-        const nodes = buildTreeNode(id, context);
-        for (const node of nodes) {
-          if (!rootNodesMap.has(node.name)) {
-            rootNodesMap.set(node.name, node);
-          }
-        }
-      }
-      const rootNodes = Array.from(rootNodesMap.values());
-
-      const trees = rootNodes.map((node, index) =>
-        renderTree(
-          node,
-          '',
-          index === rootNodes.length - 1,
-          propsSet,
-          stateSet,
-        ),
-      );
-
-      for (const dep of derivedSetStateCall.sourceIds) {
-        if (cleanUpFunctionDeps !== undefined && cleanUpFunctionDeps.has(dep)) {
-          return;
-        }
-      }
-
-      const propsArr = Array.from(propsSet);
-      const stateArr = Array.from(stateSet);
-
-      let rootSources = '';
-      if (propsArr.length > 0) {
-        rootSources += `Props: [${propsArr.join(', ')}]`;
-      }
-      if (stateArr.length > 0) {
-        if (rootSources) rootSources += '\n';
-        rootSources += `State: [${stateArr.join(', ')}]`;
-      }
-
-      const description = `Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user
-
-This setState call is setting a derived value that depends on the following reactive sources:
-
-${rootSources}
-
-Data Flow Tree:
-${trees.join('\n')}
-
-See: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state`;
-
-      context.errors.pushDiagnostic(
-        CompilerDiagnostic.create({
-          description: description,
-          category: ErrorCategory.EffectDerivationsOfState,
-          reason:
-            'You might not need an effect. Derive values in render, not effects.',
-        }).withDetails({
-          kind: 'error',
-          loc: derivedSetStateCall.value.callee.loc,
-          message: 'This should be computed during render, not in an effect',
-        }),
-      );
-    }
-  }
-}
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoImpureFunctionsInRender.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoImpureFunctionsInRender.ts
@@ -0,0 +1,59 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {CompilerDiagnostic, CompilerError} from '..';
+import {ErrorCategory} from '../CompilerError';
+import {HIRFunction} from '../HIR';
+import {getFunctionCallSignature} from '../Inference/InferMutationAliasingEffects';
+import {Result} from '../Utils/Result';
+
+/**
+ * Checks that known-impure functions are not called during render. Examples of invalid functions to
+ * call during render are `Math.random()` and `Date.now()`. Users may extend this set of
+ * impure functions via a module type provider and specifying functions with `impure: true`.
+ *
+ * TODO: add best-effort analysis of functions which are called during render. We have variations of
+ * this in several of our validation passes and should unify those analyses into a reusable helper
+ * and use it here.
+ */
+export function validateNoImpureFunctionsInRender(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
+  const errors = new CompilerError();
+  for (const [, block] of fn.body.blocks) {
+    for (const instr of block.instructions) {
+      const value = instr.value;
+      if (value.kind === 'MethodCall' || value.kind == 'CallExpression') {
+        const callee =
+          value.kind === 'MethodCall' ? value.property : value.callee;
+        const signature = getFunctionCallSignature(
+          fn.env,
+          callee.identifier.type,
+        );
+        if (signature != null && signature.impure === true) {
+          errors.pushDiagnostic(
+            CompilerDiagnostic.create({
+              category: ErrorCategory.Purity,
+              reason: 'Cannot call impure function during render',
+              description:
+                (signature.canonicalName != null
+                  ? `\`${signature.canonicalName}\` is an impure function. `
+                  : '') +
+                'Calling an impure function can produce unstable results that update unpredictably when the component happens to re-render. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#components-and-hooks-must-be-idempotent)',
+              suggestions: null,
+            }).withDetails({
+              kind: 'error',
+              loc: callee.loc,
+              message: 'Cannot call impure function',
+            }),
+          );
+        }
+      }
+    }
+  }
+  return errors.asResult();
+}
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoImpureValuesInRender.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoImpureValuesInRender.ts
@@ -1,387 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {CompilerDiagnostic, CompilerError, Effect} from '..';
-import {
-  areEqualSourceLocations,
-  HIRFunction,
-  IdentifierId,
-  InstructionId,
-  isJsxType,
-  isUseRefType,
-} from '../HIR';
-import {AliasingEffect, hashEffect} from '../Inference/AliasingEffects';
-import {createControlDominators} from '../Inference/ControlDominators';
-import {isMutable} from '../ReactiveScopes/InferReactiveScopeVariables';
-import {Err, Ok, Result} from '../Utils/Result';
-import {getOrInsertWith} from '../Utils/utils';
-import {printFunction} from '../HIR/PrintHIR';
-
-type ImpureEffect = Extract<AliasingEffect, {kind: 'Impure'}>;
-type RenderEffect = Extract<AliasingEffect, {kind: 'Render'}>;
-type FunctionCache = Map<HIRFunction, Map<string, ImpuritySignature>>;
-type ImpuritySignature = {
-  effects: Map<IdentifierId, ImpureEffect>;
-  error: CompilerError;
-  returns: IdentifierId;
-};
-
-export function validateNoImpureValuesInRender(
-  fn: HIRFunction,
-): Result<void, CompilerError> {
-  const impure = new Map<IdentifierId, ImpureEffect>();
-  const impureFunctions = new Map<IdentifierId, ImpuritySignature>();
-  const result = inferImpureValues(fn, impure, impureFunctions, new Map());
-
-  if (result.error.hasAnyErrors()) {
-    return Err(result.error);
-  }
-  return Ok(undefined);
-}
-
-function inferFunctionExpressionMemo(
-  fn: HIRFunction,
-  impure: Map<IdentifierId, ImpureEffect>,
-  impureFunctions: Map<IdentifierId, ImpuritySignature>,
-  cache: FunctionCache,
-): ImpuritySignature {
-  const key = fn.context
-    .map(
-      place =>
-        `${place.identifier.id}:${impure.has(place.identifier.id)}:${Array.from(
-          impureFunctions.get(place.identifier.id)?.effects ?? new Map(),
-        )
-          .map(([id, effect]) => `${id}=>${effect.into.identifier.id}`)
-          .join(',')}`,
-    )
-    .join(',');
-  return getOrInsertWith(
-    getOrInsertWith(cache, fn, () => new Map()),
-    key,
-    () => inferImpureValues(fn, impure, impureFunctions, cache),
-  );
-}
-
-function processEffects(
-  id: InstructionId,
-  effects: Array<AliasingEffect>,
-  impure: Map<IdentifierId, ImpureEffect>,
-  impureFunctions: Map<IdentifierId, ImpuritySignature>,
-  cache: FunctionCache,
-): boolean {
-  let hasChanges = false;
-  const rendered: Set<IdentifierId> = new Set();
-  for (const effect of effects) {
-    if (effect.kind === 'Render') {
-      rendered.add(effect.place.identifier.id);
-    }
-  }
-  for (const effect of effects) {
-    switch (effect.kind) {
-      case 'Alias':
-      case 'Assign':
-      case 'Capture':
-      case 'CreateFrom':
-      case 'ImmutableCapture': {
-        const sourceEffect = impure.get(effect.from.identifier.id);
-        if (
-          sourceEffect != null &&
-          !impure.has(effect.into.identifier.id) &&
-          !rendered.has(effect.from.identifier.id) &&
-          !isUseRefType(effect.into.identifier) &&
-          !isJsxType(effect.into.identifier.type)
-        ) {
-          // console.log(
-          //   `${effect.kind} $${effect.into.identifier.id} <= $${effect.from.identifier.id} ($${sourceEffect.into.identifier.id} forward)`,
-          // );
-          impure.set(effect.into.identifier.id, sourceEffect);
-          hasChanges = true;
-        }
-        if (
-          sourceEffect == null &&
-          (effect.kind === 'Assign' || effect.kind === 'Capture') &&
-          !impure.has(effect.from.identifier.id) &&
-          !rendered.has(effect.from.identifier.id) &&
-          !isUseRefType(effect.from.identifier) &&
-          isMutable({id}, effect.into)
-        ) {
-          const destinationEffect = impure.get(effect.into.identifier.id);
-          if (destinationEffect != null) {
-            // console.log(
-            //   `${effect.kind} $${effect.into.identifier.id} => $${effect.from.identifier.id} ($${destinationEffect.into.identifier.id} backward)`,
-            // );
-            impure.set(effect.from.identifier.id, destinationEffect);
-            hasChanges = true;
-          }
-        }
-        if (
-          (effect.kind === 'Alias' ||
-            effect.kind === 'Assign' ||
-            effect.kind === 'ImmutableCapture') &&
-          !rendered.has(effect.into.identifier.id) &&
-          !isJsxType(effect.into.identifier.type)
-        ) {
-          const functionEffect = impureFunctions.get(effect.from.identifier.id);
-          if (
-            functionEffect != null &&
-            !impureFunctions.has(effect.into.identifier.id)
-            // ||
-            //   !areEqualFunctionSignatures(
-            //     impureFunctions.get(effect.into.identifier.id)!.effects,
-            //     functionEffect.effects,
-            //   )
-          ) {
-            // console.log(
-            //   `${effect.kind} $${effect.into.identifier.id} <= $${effect.from.identifier.id} (function)`,
-            // );
-            impureFunctions.set(effect.into.identifier.id, functionEffect);
-            hasChanges = true;
-          }
-        }
-        break;
-      }
-      case 'Impure': {
-        if (!impure.has(effect.into.identifier.id)) {
-          // console.log(`Impure $${effect.into.identifier.id}`);
-          impure.set(effect.into.identifier.id, effect);
-          hasChanges = true;
-        }
-        break;
-      }
-      case 'Render': {
-        break;
-      }
-      case 'CreateFunction': {
-        const result = inferFunctionExpressionMemo(
-          effect.function.loweredFunc.func,
-          impure,
-          impureFunctions,
-          cache,
-        );
-        if (result.error.hasAnyErrors()) {
-          break;
-        }
-        const previousResult = impureFunctions.get(effect.into.identifier.id);
-        if (
-          previousResult == null ||
-          !areEqualFunctionSignatures(result.effects, previousResult.effects)
-        ) {
-          // console.log(`Function $${effect.into.identifier.id}`);
-          impureFunctions.set(effect.into.identifier.id, result);
-          hasChanges = true;
-        }
-        break;
-      }
-      case 'Apply': {
-        const functionSignature = impureFunctions.get(
-          effect.function.identifier.id,
-        );
-        if (functionSignature != null) {
-          for (const [id, functionEffect] of functionSignature.effects) {
-            if (!impure.has(id)) {
-              impure.set(id, functionEffect);
-              hasChanges = true;
-            }
-            if (
-              id === functionSignature.returns &&
-              !impure.has(effect.into.identifier.id)
-            ) {
-              impure.set(effect.into.identifier.id, functionEffect);
-              hasChanges = true;
-            }
-          }
-        }
-        break;
-      }
-      case 'MaybeAlias':
-      case 'Create':
-      case 'Freeze':
-      case 'Mutate':
-      case 'MutateConditionally':
-      case 'MutateFrozen':
-      case 'MutateGlobal':
-      case 'MutateTransitive':
-      case 'MutateTransitiveConditionally': {
-        break;
-      }
-    }
-  }
-  return hasChanges;
-}
-
-function inferImpureValues(
-  fn: HIRFunction,
-  impure: Map<IdentifierId, ImpureEffect>,
-  impureFunctions: Map<IdentifierId, ImpuritySignature>,
-  cache: FunctionCache,
-): ImpuritySignature {
-  const getBlockControl = createControlDominators(fn, place => {
-    return impure.has(place.identifier.id);
-  });
-
-  let hasChanges = false;
-  let iterations = 0;
-  do {
-    hasChanges = false;
-
-    if (iterations++ > 100) {
-      throw new Error('too many iterations');
-    }
-
-    for (const block of fn.body.blocks.values()) {
-      const controlPlace = getBlockControl(block.id);
-      const controlImpureEffect =
-        controlPlace != null ? impure.get(controlPlace.identifier.id) : null;
-
-      for (const phi of block.phis) {
-        if (impure.has(phi.place.identifier.id)) {
-          // Already marked impure on a previous pass
-          continue;
-        }
-        let impureEffect = null;
-        for (const [, operand] of phi.operands) {
-          const operandEffect = impure.get(operand.identifier.id);
-          if (operandEffect != null) {
-            impureEffect = operandEffect;
-            break;
-          }
-        }
-        if (impureEffect != null) {
-          impure.set(phi.place.identifier.id, impureEffect);
-          hasChanges = true;
-        } else {
-          for (const [pred] of phi.operands) {
-            const predControl = getBlockControl(pred);
-            if (predControl != null) {
-              const predEffect = impure.get(predControl.identifier.id);
-              if (predEffect != null) {
-                impure.set(phi.place.identifier.id, predEffect);
-                hasChanges = true;
-                break;
-              }
-            }
-          }
-        }
-      }
-
-      for (const instr of block.instructions) {
-        const _impure = new Set(impure.keys());
-        hasChanges =
-          processEffects(
-            instr.id,
-            instr.effects ?? [],
-            impure,
-            impureFunctions,
-            cache,
-          ) || hasChanges;
-      }
-      if (block.terminal.kind === 'return' && block.terminal.effects != null) {
-        hasChanges =
-          processEffects(
-            block.terminal.id,
-            block.terminal.effects,
-            impure,
-            impureFunctions,
-            cache,
-          ) || hasChanges;
-      }
-    }
-  } while (hasChanges);
-
-  fn.env.logger?.debugLogIRs?.({
-    kind: 'debug',
-    name: 'ValidateNoImpureValuesInRender',
-    value: JSON.stringify(Array.from(impure.keys()).sort(), null, 2),
-  });
-  fn.env.logger?.debugLogIRs?.({
-    kind: 'debug',
-    name: 'ValidateNoImpureValuesInRender (function)',
-    value: JSON.stringify(Array.from(impureFunctions.keys()).sort(), null, 2),
-  });
-
-  const error = new CompilerError();
-  function validateRenderEffect(effect: RenderEffect): void {
-    let impureEffect = impure.get(effect.place.identifier.id);
-    if (impureEffect == null) {
-      const functionSignature = impureFunctions.get(effect.place.identifier.id);
-      impureEffect = functionSignature?.effects.get(functionSignature.returns);
-    }
-    if (impureEffect == null) {
-      return;
-    }
-    const diagnostic = CompilerDiagnostic.create({
-      category: impureEffect.category,
-      reason: impureEffect.reason,
-      description: impureEffect.description,
-    }).withDetails({
-      kind: 'error',
-      loc: effect.place.loc,
-      message: impureEffect.usageMessage,
-    });
-    if (!areEqualSourceLocations(effect.place.loc, impureEffect.into.loc)) {
-      diagnostic.withDetails({
-        kind: 'error',
-        loc: impureEffect.into.loc,
-        message: impureEffect.sourceMessage,
-      });
-    }
-    error.pushDiagnostic(diagnostic);
-  }
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const value = instr.value;
-      if (
-        value.kind === 'FunctionExpression' ||
-        value.kind === 'ObjectMethod'
-      ) {
-        const result = inferFunctionExpressionMemo(
-          value.loweredFunc.func,
-          impure,
-          impureFunctions,
-          cache,
-        );
-        if (result.error.hasAnyErrors()) {
-          error.merge(result.error);
-        }
-      }
-      for (const effect of instr.effects ?? []) {
-        if (effect.kind === 'Render') {
-          validateRenderEffect(effect);
-        }
-      }
-    }
-    if (block.terminal.kind === 'return' && block.terminal.effects != null) {
-      for (const effect of block.terminal.effects) {
-        if (effect.kind === 'Render') {
-          validateRenderEffect(effect);
-        }
-      }
-    }
-  }
-  const impureEffects: Map<IdentifierId, ImpureEffect> = new Map();
-  for (const param of [...fn.context, ...fn.params, fn.returns]) {
-    const place = param.kind === 'Identifier' ? param : param.place;
-    const impureEffect = impure.get(place.identifier.id);
-    if (impureEffect != null) {
-      impureEffects.set(place.identifier.id, impureEffect);
-    }
-  }
-  return {effects: impureEffects, error, returns: fn.returns.identifier.id};
-}
-
-function areEqualFunctionSignatures(
-  sig1: Map<IdentifierId, ImpureEffect>,
-  sig2: Map<IdentifierId, ImpureEffect>,
-): boolean {
-  return (
-    sig1.size === sig2.size &&
-    Array.from(sig1).every(
-      ([id, effect]) =>
-        sig2.has(id) && hashEffect(effect) === hashEffect(sig2.get(id)!),
-    )
-  );
-}
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoRefAccessInRender.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoRefAccessInRender.md
@@ -1,137 +0,0 @@
-# ValidateNoRefAccessInRender
-
-This document summarizes the design and key learnings for the ref mutation validation pass.
-
-## Purpose
-
-Validates that a function does not mutate a ref value during render. This ensures React components follow the rules of React by not writing to `ref.current` during the render phase.
-
-## Key Concepts
-
-### Ref vs RefValue
-
- **Ref**: The ref object itself (e.g., `useRef()` return value). Has type `React.RefObject<T>`.
- **RefValue**: The `.current` property of a ref. This is the mutable value that should not be accessed during render.
-
-The validation tracks both using a `RefInfo` type with a `refId` that correlates refs with their `.current` values.
-
-### What Constitutes a Mutation
-
-A mutation is any `PropertyStore` or `ComputedStore` instruction where:
-1. The target object is a known ref (tracked in the `refs` map)
-2. OR the target object has a ref type (`isUseRefType`)
-
-### Allowed Patterns
-
-1. **Event handlers and effect callbacks**: Functions that are not called at the top level during render can mutate refs freely.
-
-2. **Null-guard initialization**: The pattern `if (ref.current == null) { ref.current = value; }` is allowed because it's a common lazy initialization pattern that only runs once.
-
-## Algorithm: Single Forward Data-Flow Pass
-
-The validation uses a single forward pass over all blocks:
-
-### Phase 1: Track Refs
- Initialize refs from function params and context (captured variables)
- Process phi nodes to propagate ref info through control flow joins
- Track refs through LoadLocal, StoreLocal, PropertyLoad operations
-
-### Phase 2: Detect Null Guards
- Track nullable values (null literals, undefined)
- Track binary comparisons of `ref.current` to null (`==`, `===`, `!=`, `!==`)
- Mark blocks as "safe" for specific refs when inside null-guard branches
- Propagate safety through control flow until fallthrough
-
-### Phase 3: Validate Mutations
- For PropertyStore/ComputedStore on refs:
-  - If inside a null-guard for this ref: allow (but track for duplicate detection)
-  - If at top level: error immediately
-  - If in nested function: track for later (error if function is called)
-
-### Phase 4: Track Ref-Mutating Functions
- When a FunctionExpression mutates a ref, track it in `refMutatingFunctions`
- When such a function is called at top level, report the error at the mutation site
-
-## Key Data Structures
-
-```typescript
-// Correlates refs with their .current values
-type RefInfo = {
-  kind: 'Ref' | 'RefValue';
-  refId: number;
-};
-
-// Tracks null-guard conditions
-type GuardInfo = {
-  refId: number;
-  isEquality: boolean; // true for ==, ===; false for !=, !==
-};
-
-// Information about a mutation (for error reporting)
-type MutationInfo = {
-  loc: SourceLocation;
-  isCurrentProperty: boolean;
-};
-```
-
-## Error Reporting
-
-### Error Location
-
-Errors highlight the **entire instruction** (e.g., `ref.current = value`), not just the ref identifier. This is achieved by using `instr.loc` instead of `value.object.loc`.
-
-### Duplicate Initialization
-
-When a ref is initialized more than once inside a null-guard:
-1. Primary error: Points to the second initialization
-2. Secondary error: Points to the first initialization with "Ref was first initialized here"
-
-### Transitive Mutations
-
-When a function that mutates refs is called during render:
- The error points to the mutation site inside the function
- Not the call site (the call site is what triggers the check)
-
-## Edge Cases and Patterns
-
-### Unary NOT on Guards
-
-The `!` operator inverts guard polarity:
-```javascript
-if (!ref.current) { ... }  // Same as: if (ref.current == null)
-```
-
-### Nested Functions
-
-Functions defined during render but not called are allowed to mutate refs:
-```javascript
-// OK - onClick is not called during render
-const onClick = () => { ref.current = value; };
-return <button onClick={onClick} />;
-```
-
-### Props with Ref Type
-
-Refs can come from props. The validation handles `props.ref` by checking type information.
-
-## Limitations / Known Gaps
-
-The following patterns are NOT currently validated by this pass:
-
-1. **Impure values in render**: `Date.now()`, `Math.random()` flowing into render context (handled by `ValidateNoImpureValuesInRender`)
-
-2. **useState/useReducer callbacks**: These hooks call their initializer functions during render, so ref access inside them should error. This requires special hook semantics.
-
-3. **Ref reads during render**: This pass focuses on mutations. Ref reads are handled separately.
-
-## Testing
-
-Test fixtures use naming conventions:
- `error.*.ts` - Fixtures expected to produce compilation errors
- Regular names - Fixtures expected to compile successfully
-
-Run tests with:
-```bash
-yarn snap -p <pattern> --nodebug    # Run specific tests
-yarn snap -p <pattern> --nodebug -u # Update expected output
-```
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoRefAccessInRender.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoRefAccessInRender.ts
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoSetStateInEffects.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoSetStateInEffects.ts
@@ -16,23 +16,18 @@ import {
  IdentifierId,
  isSetStateType,
  isUseEffectHookType,
-  isUseEffectEventType,
  isUseInsertionEffectHookType,
  isUseLayoutEffectHookType,
  isUseRefType,
  isRefValueType,
  Place,
-  Effect,
-  BlockId,
 } from '../HIR';
 import {
  eachInstructionLValue,
  eachInstructionValueOperand,
 } from '../HIR/visitors';
-import {createControlDominators} from '../Inference/ControlDominators';
-import {isMutable} from '../ReactiveScopes/InferReactiveScopeVariables';
 import {Result} from '../Utils/Result';
-import {assertExhaustive, Iterable_some} from '../Utils/utils';
+import {Iterable_some} from '../Utils/utils';

 /**
 * Validates against calling setState in the body of an effect (useEffect and friends),
@@ -99,20 +94,7 @@ export function validateNoSetStateInEffects(
            instr.value.kind === 'MethodCall'
              ? instr.value.receiver
              : instr.value.callee;
-
-          if (isUseEffectEventType(callee.identifier)) {
-            const arg = instr.value.args[0];
-            if (arg !== undefined && arg.kind === 'Identifier') {
-              const setState = setStateFunctions.get(arg.identifier.id);
-              if (setState !== undefined) {
-                /**
-                 * This effect event function calls setState synchonously,
-                 * treat it as a setState function for transitive tracking
-                 */
-                setStateFunctions.set(instr.lvalue.identifier.id, setState);
-              }
-            }
-          } else if (
+          if (
            isUseEffectHookType(callee.identifier) ||
            isUseLayoutEffectHookType(callee.identifier) ||
            isUseInsertionEffectHookType(callee.identifier)
@@ -121,58 +103,26 @@ export function validateNoSetStateInEffects(
            if (arg !== undefined && arg.kind === 'Identifier') {
              const setState = setStateFunctions.get(arg.identifier.id);
              if (setState !== undefined) {
-                const enableVerbose =
-                  env.config.enableVerboseNoSetStateInEffect;
-                if (enableVerbose) {
-                  errors.pushDiagnostic(
-                    CompilerDiagnostic.create({
-                      category: ErrorCategory.EffectSetState,
-                      reason:
-                        'Calling setState synchronously within an effect can trigger cascading renders',
-                      description:
-                        'Effects are intended to synchronize state between React and external systems. ' +
-                        'Calling setState synchronously causes cascading renders that hurt performance.\n\n' +
-                        'This pattern may indicate one of several issues:\n\n' +
-                        '**1. Non-local derived data**: If the value being set could be computed from props/state ' +
-                        'but requires data from a parent component, consider restructuring state ownership so the ' +
-                        'derivation can happen during render in the component that owns the relevant state.\n\n' +
-                        "**2. Derived event pattern**: If you're detecting when a prop changes (e.g., `isPlaying` " +
-                        'transitioning from false to true), this often indicates the parent should provide an event ' +
-                        'callback (like `onPlay`) instead of just the current state. Request access to the original event.\n\n' +
-                        "**3. Force update / external sync**: If you're forcing a re-render to sync with an external " +
-                        'data source (mutable values outside React), use `useSyncExternalStore` to properly subscribe ' +
-                        'to external state changes.\n\n' +
-                        'See: https://react.dev/learn/you-might-not-need-an-effect',
-                      suggestions: null,
-                    }).withDetails({
-                      kind: 'error',
-                      loc: setState.loc,
-                      message:
-                        'Avoid calling setState() directly within an effect',
-                    }),
-                  );
-                } else {
-                  errors.pushDiagnostic(
-                    CompilerDiagnostic.create({
-                      category: ErrorCategory.EffectSetState,
-                      reason:
-                        'Calling setState synchronously within an effect can trigger cascading renders',
-                      description:
-                        'Effects are intended to synchronize state between React and external systems such as manually updating the DOM, state management libraries, or other platform APIs. ' +
-                        'In general, the body of an effect should do one or both of the following:\n' +
-                        '* Update external systems with the latest state from React.\n' +
-                        '* Subscribe for updates from some external system, calling setState in a callback function when external state changes.\n\n' +
-                        'Calling setState synchronously within an effect body causes cascading renders that can hurt performance, and is not recommended. ' +
-                        '(https://react.dev/learn/you-might-not-need-an-effect)',
-                      suggestions: null,
-                    }).withDetails({
-                      kind: 'error',
-                      loc: setState.loc,
-                      message:
-                        'Avoid calling setState() directly within an effect',
-                    }),
-                  );
-                }
+                errors.pushDiagnostic(
+                  CompilerDiagnostic.create({
+                    category: ErrorCategory.EffectSetState,
+                    reason:
+                      'Calling setState synchronously within an effect can trigger cascading renders',
+                    description:
+                      'Effects are intended to synchronize state between React and external systems such as manually updating the DOM, state management libraries, or other platform APIs. ' +
+                      'In general, the body of an effect should do one or both of the following:\n' +
+                      '* Update external systems with the latest state from React.\n' +
+                      '* Subscribe for updates from some external system, calling setState in a callback function when external state changes.\n\n' +
+                      'Calling setState synchronously within an effect body causes cascading renders that can hurt performance, and is not recommended. ' +
+                      '(https://react.dev/learn/you-might-not-need-an-effect)',
+                    suggestions: null,
+                  }).withDetails({
+                    kind: 'error',
+                    loc: setState.loc,
+                    message:
+                      'Avoid calling setState() directly within an effect',
+                  }),
+                );
              }
            }
          }
@@ -190,8 +140,6 @@ function getSetStateCall(
  setStateFunctions: Map<IdentifierId, Place>,
  env: Environment,
 ): Place | null {
-  const enableAllowSetStateFromRefsInEffects =
-    env.config.enableAllowSetStateFromRefsInEffects;
  const refDerivedValues: Set<IdentifierId> = new Set();

  const isDerivedFromRef = (place: Place): boolean => {
@@ -202,38 +150,9 @@ function getSetStateCall(
    );
  };

-  const isRefControlledBlock: (id: BlockId) => Place | null =
-    enableAllowSetStateFromRefsInEffects
-      ? createControlDominators(fn, place => isDerivedFromRef(place))
-      : (): Place | null => null;
-
  for (const [, block] of fn.body.blocks) {
-    if (enableAllowSetStateFromRefsInEffects) {
-      for (const phi of block.phis) {
-        if (isDerivedFromRef(phi.place)) {
-          continue;
-        }
-        let isPhiDerivedFromRef = false;
-        for (const [, operand] of phi.operands) {
-          if (isDerivedFromRef(operand)) {
-            isPhiDerivedFromRef = true;
-            break;
-          }
-        }
-        if (isPhiDerivedFromRef) {
-          refDerivedValues.add(phi.place.identifier.id);
-        } else {
-          for (const [pred] of phi.operands) {
-            if (isRefControlledBlock(pred) != null) {
-              refDerivedValues.add(phi.place.identifier.id);
-              break;
-            }
-          }
-        }
-      }
-    }
    for (const instr of block.instructions) {
-      if (enableAllowSetStateFromRefsInEffects) {
+      if (env.config.enableAllowSetStateFromRefsInEffects) {
        const hasRefOperand = Iterable_some(
          eachInstructionValueOperand(instr.value),
          isDerivedFromRef,
@@ -243,46 +162,6 @@ function getSetStateCall(
          for (const lvalue of eachInstructionLValue(instr)) {
            refDerivedValues.add(lvalue.identifier.id);
          }
-          // Ref-derived values can also propagate through mutation
-          for (const operand of eachInstructionValueOperand(instr.value)) {
-            switch (operand.effect) {
-              case Effect.Capture:
-              case Effect.Store:
-              case Effect.ConditionallyMutate:
-              case Effect.ConditionallyMutateIterator:
-              case Effect.Mutate: {
-                if (isMutable(instr, operand)) {
-                  refDerivedValues.add(operand.identifier.id);
-                }
-                break;
-              }
-              case Effect.Freeze:
-              case Effect.Read: {
-                // no-op
-                break;
-              }
-              case Effect.Unknown: {
-                CompilerError.invariant(false, {
-                  reason: 'Unexpected unknown effect',
-                  description: null,
-                  details: [
-                    {
-                      kind: 'error',
-                      loc: operand.loc,
-                      message: null,
-                    },
-                  ],
-                  suggestions: null,
-                });
-              }
-              default: {
-                assertExhaustive(
-                  operand.effect,
-                  `Unexpected effect kind \`${operand.effect}\``,
-                );
-              }
-            }
-          }
        }

        if (
@@ -324,7 +203,7 @@ function getSetStateCall(
            isSetStateType(callee.identifier) ||
            setStateFunctions.has(callee.identifier.id)
          ) {
-            if (enableAllowSetStateFromRefsInEffects) {
+            if (env.config.enableAllowSetStateFromRefsInEffects) {
              const arg = instr.value.args.at(0);
              if (
                arg !== undefined &&
@@ -337,8 +216,6 @@ function getSetStateCall(
                 * be needed when initial layout measurements from refs need to be stored in state.
                 */
                return null;
-              } else if (isRefControlledBlock(block.id) != null) {
-                continue;
              }
            }
            /*
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoSetStateInRender.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoSetStateInRender.ts
@@ -155,40 +155,20 @@ function validateNoSetStateInRenderImpl(
                }),
              );
            } else if (unconditionalBlocks.has(block.id)) {
-              const enableUseKeyedState = fn.env.config.enableUseKeyedState;
-              if (enableUseKeyedState) {
-                errors.pushDiagnostic(
-                  CompilerDiagnostic.create({
-                    category: ErrorCategory.RenderSetState,
-                    reason: 'Cannot call setState during render',
-                    description:
-                      'Calling setState during render may trigger an infinite loop.\n' +
-                      '* To reset state when other state/props change, use `const [state, setState] = useKeyedState(initialState, key)` to reset `state` when `key` changes.\n' +
-                      '* To derive data from other state/props, compute the derived data during render without using state',
-                    suggestions: null,
-                  }).withDetails({
-                    kind: 'error',
-                    loc: callee.loc,
-                    message: 'Found setState() in render',
-                  }),
-                );
-              } else {
-                errors.pushDiagnostic(
-                  CompilerDiagnostic.create({
-                    category: ErrorCategory.RenderSetState,
-                    reason: 'Cannot call setState during render',
-                    description:
-                      'Calling setState during render may trigger an infinite loop.\n' +
-                      '* To reset state when other state/props change, store the previous value in state and update conditionally: https://react.dev/reference/react/useState#storing-information-from-previous-renders\n' +
-                      '* To derive data from other state/props, compute the derived data during render without using state',
-                    suggestions: null,
-                  }).withDetails({
-                    kind: 'error',
-                    loc: callee.loc,
-                    message: 'Found setState() in render',
-                  }),
-                );
-              }
+              errors.pushDiagnostic(
+                CompilerDiagnostic.create({
+                  category: ErrorCategory.RenderSetState,
+                  reason:
+                    'Calling setState during render may trigger an infinite loop',
+                  description:
+                    'Calling setState during render will trigger another render, and can lead to infinite loops. (https://react.dev/reference/react/useState)',
+                  suggestions: null,
+                }).withDetails({
+                  kind: 'error',
+                  loc: callee.loc,
+                  message: 'Found setState() in render',
+                }),
+              );
            }
          }
          break;
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidatePreservedManualMemoization.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidatePreservedManualMemoization.ts
@@ -242,7 +242,6 @@ function validateInferredDep(
    normalizedDep = {
      root: maybeNormalizedRoot.root,
      path: [...maybeNormalizedRoot.path, ...dep.path],
-      loc: maybeNormalizedRoot.loc,
    };
  } else {
    CompilerError.invariant(dep.identifier.name?.kind === 'named', {
@@ -268,10 +267,8 @@ function validateInferredDep(
          effect: Effect.Read,
          reactive: false,
        },
-        constant: false,
      },
      path: [...dep.path],
-      loc: GeneratedSource,
    };
  }
  for (const decl of declsWithinMemoBlock) {
@@ -382,10 +379,8 @@ class Visitor extends ReactiveFunctionVisitor<VisitorState> {
                root: {
                  kind: 'NamedLocal',
                  value: storeTarget,
-                  constant: false,
                },
                path: [],
-                loc: storeTarget.loc,
              });
            }
          }
@@ -413,10 +408,8 @@ class Visitor extends ReactiveFunctionVisitor<VisitorState> {
        root: {
          kind: 'NamedLocal',
          value: {...lvalue},
-          constant: false,
        },
        path: [],
-        loc: lvalue.loc,
      });
    }
  }
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateSourceLocations.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateSourceLocations.ts
@@ -1,296 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {NodePath} from '@babel/traverse';
-import * as t from '@babel/types';
-import {CompilerDiagnostic, CompilerError, ErrorCategory} from '..';
-import {CodegenFunction} from '../ReactiveScopes';
-import {Result} from '../Utils/Result';
-
-/**
- * IMPORTANT: This validation is only intended for use in unit tests.
- * It is not intended for use in production.
- *
- * This validation is used to ensure that the generated AST has proper source locations
- * for "important" original nodes.
- *
- * There's one big gotcha with this validation: it only works if the "important" original nodes
- * are not optimized away by the compiler.
- *
- * When that scenario happens, we should just update the fixture to not include a node that has no
- * corresponding node in the generated AST due to being completely removed during compilation.
- */
-
-/**
- * Some common node types that are important for coverage tracking.
- * Based on istanbul-lib-instrument + some other common nodes we expect to be present in the generated AST.
- *
- * Note: For VariableDeclaration, VariableDeclarator, and Identifier, we enforce stricter validation
- * that requires both the source location AND node type to match in the generated AST. This ensures
- * that variable declarations maintain their structural integrity through compilation.
- */
-const IMPORTANT_INSTRUMENTED_TYPES = new Set([
-  'ArrowFunctionExpression',
-  'AssignmentPattern',
-  'ObjectMethod',
-  'ExpressionStatement',
-  'BreakStatement',
-  'ContinueStatement',
-  'ReturnStatement',
-  'ThrowStatement',
-  'TryStatement',
-  'VariableDeclarator',
-  'IfStatement',
-  'ForStatement',
-  'ForInStatement',
-  'ForOfStatement',
-  'WhileStatement',
-  'DoWhileStatement',
-  'SwitchStatement',
-  'SwitchCase',
-  'WithStatement',
-  'FunctionDeclaration',
-  'FunctionExpression',
-  'LabeledStatement',
-  'ConditionalExpression',
-  'LogicalExpression',
-
-  /**
-   * Note: these aren't important for coverage tracking,
-   * but we still want to track them to ensure we aren't regressing them when
-   * we fix the source location tracking for other nodes.
-   */
-  'VariableDeclaration',
-  'Identifier',
-]);
-
-/**
- * Check if a node is a manual memoization call that the compiler optimizes away.
- * These include useMemo and useCallback calls, which are intentionally removed
- * by the DropManualMemoization pass.
- */
-function isManualMemoization(node: t.Node): boolean {
-  // Check if this is a useMemo/useCallback call expression
-  if (t.isCallExpression(node)) {
-    const callee = node.callee;
-    if (t.isIdentifier(callee)) {
-      return callee.name === 'useMemo' || callee.name === 'useCallback';
-    }
-    if (
-      t.isMemberExpression(callee) &&
-      t.isIdentifier(callee.property) &&
-      t.isIdentifier(callee.object)
-    ) {
-      return (
-        callee.object.name === 'React' &&
-        (callee.property.name === 'useMemo' ||
-          callee.property.name === 'useCallback')
-      );
-    }
-  }
-
-  return false;
-}
-
-/**
- * Create a location key for comparison. We compare by line/column/source,
- * not by object identity.
- */
-function locationKey(loc: t.SourceLocation): string {
-  return `${loc.start.line}:${loc.start.column}-${loc.end.line}:${loc.end.column}`;
-}
-
-/**
- * Validates that important source locations from the original code are preserved
- * in the generated AST. This ensures that Istanbul coverage instrumentation can
- * properly map back to the original source code.
- *
- * The validator:
- * 1. Collects locations from "important" nodes in the original AST (those that
- *    Istanbul instruments for coverage tracking)
- * 2. Exempts known compiler optimizations (useMemo/useCallback removal)
- * 3. Verifies that all important locations appear somewhere in the generated AST
- *
- * Missing locations can cause Istanbul to fail to track coverage for certain
- * code paths, leading to inaccurate coverage reports.
- */
-export function validateSourceLocations(
-  func: NodePath<
-    t.FunctionDeclaration | t.ArrowFunctionExpression | t.FunctionExpression
-  >,
-  generatedAst: CodegenFunction,
-): Result<void, CompilerError> {
-  const errors = new CompilerError();
-
-  /*
-   * Step 1: Collect important locations from the original source
-   * Note: Multiple node types can share the same location (e.g. VariableDeclarator and Identifier)
-   */
-  const importantOriginalLocations = new Map<
-    string,
-    {loc: t.SourceLocation; nodeTypes: Set<string>}
-  >();
-
-  func.traverse({
-    enter(path) {
-      const node = path.node;
-
-      // Only track node types that Istanbul instruments
-      if (!IMPORTANT_INSTRUMENTED_TYPES.has(node.type)) {
-        return;
-      }
-
-      // Skip manual memoization that the compiler intentionally removes
-      if (isManualMemoization(node)) {
-        return;
-      }
-
-      // Collect the location if it exists
-      if (node.loc) {
-        const key = locationKey(node.loc);
-        const existing = importantOriginalLocations.get(key);
-        if (existing) {
-          existing.nodeTypes.add(node.type);
-        } else {
-          importantOriginalLocations.set(key, {
-            loc: node.loc,
-            nodeTypes: new Set([node.type]),
-          });
-        }
-      }
-    },
-  });
-
-  // Step 2: Collect all locations from the generated AST with their node types
-  const generatedLocations = new Map<string, Set<string>>();
-
-  function collectGeneratedLocations(node: t.Node): void {
-    if (node.loc) {
-      const key = locationKey(node.loc);
-      const nodeTypes = generatedLocations.get(key);
-      if (nodeTypes) {
-        nodeTypes.add(node.type);
-      } else {
-        generatedLocations.set(key, new Set([node.type]));
-      }
-    }
-
-    // Use Babel's VISITOR_KEYS to traverse only actual node properties
-    const keys = t.VISITOR_KEYS[node.type as keyof typeof t.VISITOR_KEYS];
-
-    if (!keys) {
-      return;
-    }
-
-    for (const key of keys) {
-      const value = (node as any)[key];
-
-      if (Array.isArray(value)) {
-        for (const item of value) {
-          if (t.isNode(item)) {
-            collectGeneratedLocations(item);
-          }
-        }
-      } else if (t.isNode(value)) {
-        collectGeneratedLocations(value);
-      }
-    }
-  }
-
-  // Collect from main function body
-  collectGeneratedLocations(generatedAst.body);
-
-  // Collect from outlined functions
-  for (const outlined of generatedAst.outlined) {
-    collectGeneratedLocations(outlined.fn.body);
-  }
-
-  /*
-   * Step 3: Validate that all important locations are preserved
-   * For certain node types, also validate that the node type matches
-   */
-  const strictNodeTypes = new Set([
-    'VariableDeclaration',
-    'VariableDeclarator',
-    'Identifier',
-  ]);
-
-  const reportMissingLocation = (
-    loc: t.SourceLocation,
-    nodeType: string,
-  ): void => {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        category: ErrorCategory.Todo,
-        reason: 'Important source location missing in generated code',
-        description:
-          `Source location for ${nodeType} is missing in the generated output. This can cause coverage instrumentation ` +
-          `to fail to track this code properly, resulting in inaccurate coverage reports.`,
-      }).withDetails({
-        kind: 'error',
-        loc,
-        message: null,
-      }),
-    );
-  };
-
-  const reportWrongNodeType = (
-    loc: t.SourceLocation,
-    expectedType: string,
-    actualTypes: Set<string>,
-  ): void => {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        category: ErrorCategory.Todo,
-        reason:
-          'Important source location has wrong node type in generated code',
-        description:
-          `Source location for ${expectedType} exists in the generated output but with wrong node type(s): ${Array.from(actualTypes).join(', ')}. ` +
-          `This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports.`,
-      }).withDetails({
-        kind: 'error',
-        loc,
-        message: null,
-      }),
-    );
-  };
-
-  for (const [key, {loc, nodeTypes}] of importantOriginalLocations) {
-    const generatedNodeTypes = generatedLocations.get(key);
-
-    if (!generatedNodeTypes) {
-      // Location is completely missing
-      reportMissingLocation(loc, Array.from(nodeTypes).join(', '));
-    } else {
-      // Location exists, check each node type
-      for (const nodeType of nodeTypes) {
-        if (
-          strictNodeTypes.has(nodeType) &&
-          !generatedNodeTypes.has(nodeType)
-        ) {
-          /*
-           * For strict node types, the specific node type must be present
-           * Check if any generated node type is also an important original node type
-           */
-          const hasValidNodeType = Array.from(generatedNodeTypes).some(
-            genType => nodeTypes.has(genType),
-          );
-
-          if (hasValidNodeType) {
-            // At least one generated node type is valid (also in original), so this is just missing
-            reportMissingLocation(loc, nodeType);
-          } else {
-            // None of the generated node types are in original - this is wrong node type
-            reportWrongNodeType(loc, nodeType, generatedNodeTypes);
-          }
-        }
-      }
-    }
-  }
-
-  return errors.asResult();
-}
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateUseMemo.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateUseMemo.ts
@@ -10,37 +10,16 @@ import {
  CompilerError,
  ErrorCategory,
 } from '../CompilerError';
-import {
-  FunctionExpression,
-  HIRFunction,
-  IdentifierId,
-  SourceLocation,
-} from '../HIR';
-import {
-  eachInstructionValueOperand,
-  eachTerminalOperand,
-} from '../HIR/visitors';
+import {FunctionExpression, HIRFunction, IdentifierId} from '../HIR';
 import {Result} from '../Utils/Result';

 export function validateUseMemo(fn: HIRFunction): Result<void, CompilerError> {
  const errors = new CompilerError();
-  const voidMemoErrors = new CompilerError();
  const useMemos = new Set<IdentifierId>();
  const react = new Set<IdentifierId>();
  const functions = new Map<IdentifierId, FunctionExpression>();
-  const unusedUseMemos = new Map<IdentifierId, SourceLocation>();
  for (const [, block] of fn.body.blocks) {
    for (const {lvalue, value} of block.instructions) {
-      if (unusedUseMemos.size !== 0) {
-        /**
-         * Most of the time useMemo results are referenced immediately. Don't bother
-         * scanning instruction operands for useMemos unless there is an as-yet-unused
-         * useMemo.
-         */
-        for (const operand of eachInstructionValueOperand(value)) {
-          unusedUseMemos.delete(operand.identifier.id);
-        }
-      }
      switch (value.kind) {
        case 'LoadGlobal': {
          if (value.binding.name === 'useMemo') {
@@ -66,8 +45,10 @@ export function validateUseMemo(fn: HIRFunction): Result<void, CompilerError> {
        case 'CallExpression': {
          // Is the function being called useMemo, with at least 1 argument?
          const callee =
-            value.kind === 'CallExpression' ? value.callee : value.property;
-          const isUseMemo = useMemos.has(callee.identifier.id);
+            value.kind === 'CallExpression'
+              ? value.callee.identifier.id
+              : value.property.identifier.id;
+          const isUseMemo = useMemos.has(callee);
          if (!isUseMemo || value.args.length === 0) {
            continue;
          }
@@ -123,106 +104,10 @@ export function validateUseMemo(fn: HIRFunction): Result<void, CompilerError> {
            );
          }

-          validateNoContextVariableAssignment(body.loweredFunc.func, errors);
-
-          if (fn.env.config.validateNoVoidUseMemo) {
-            if (!hasNonVoidReturn(body.loweredFunc.func)) {
-              voidMemoErrors.pushDiagnostic(
-                CompilerDiagnostic.create({
-                  category: ErrorCategory.VoidUseMemo,
-                  reason: 'useMemo() callbacks must return a value',
-                  description: `This useMemo() callback doesn't return a value. useMemo() is for computing and caching values, not for arbitrary side effects`,
-                  suggestions: null,
-                }).withDetails({
-                  kind: 'error',
-                  loc: body.loc,
-                  message: 'useMemo() callbacks must return a value',
-                }),
-              );
-            } else {
-              unusedUseMemos.set(lvalue.identifier.id, callee.loc);
-            }
-          }
          break;
        }
      }
    }
-    if (unusedUseMemos.size !== 0) {
-      for (const operand of eachTerminalOperand(block.terminal)) {
-        unusedUseMemos.delete(operand.identifier.id);
-      }
-    }
  }
-  if (unusedUseMemos.size !== 0) {
-    /**
-     * Basic check for unused memos, where the result of the call is never referenced. This runs
-     * before DCE so it's more of an AST-level check that something, _anything_, cares about the value.
-     *
-     * This is easy to defeat with e.g. `const _ = useMemo(...)` but it at least gives us something to teach.
-     * Even a DCE-based version could be bypassed with `noop(useMemo(...))`.
-     */
-    for (const loc of unusedUseMemos.values()) {
-      voidMemoErrors.pushDiagnostic(
-        CompilerDiagnostic.create({
-          category: ErrorCategory.VoidUseMemo,
-          reason: 'useMemo() result is unused',
-          description: `This useMemo() value is unused. useMemo() is for computing and caching values, not for arbitrary side effects`,
-          suggestions: null,
-        }).withDetails({
-          kind: 'error',
-          loc,
-          message: 'useMemo() result is unused',
-        }),
-      );
-    }
-  }
-  fn.env.logErrors(voidMemoErrors.asResult());
  return errors.asResult();
 }
-
-function validateNoContextVariableAssignment(
-  fn: HIRFunction,
-  errors: CompilerError,
-): void {
-  const context = new Set(fn.context.map(place => place.identifier.id));
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const value = instr.value;
-      switch (value.kind) {
-        case 'StoreContext': {
-          if (context.has(value.lvalue.place.identifier.id)) {
-            errors.pushDiagnostic(
-              CompilerDiagnostic.create({
-                category: ErrorCategory.UseMemo,
-                reason:
-                  'useMemo() callbacks may not reassign variables declared outside of the callback',
-                description:
-                  'useMemo() callbacks must be pure functions and cannot reassign variables defined outside of the callback function',
-                suggestions: null,
-              }).withDetails({
-                kind: 'error',
-                loc: value.lvalue.place.loc,
-                message: 'Cannot reassign variable',
-              }),
-            );
-          }
-          break;
-        }
-      }
-    }
-  }
-}
-
-function hasNonVoidReturn(func: HIRFunction): boolean {
-  for (const [, block] of func.body.blocks) {
-    if (block.terminal.kind === 'return') {
-      if (
-        block.terminal.returnVariant === 'Explicit' ||
-        block.terminal.returnVariant === 'Implicit'
-      ) {
-        return true;
-      }
-    }
-  }
-  return false;
-}
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/index.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/index.ts
@@ -12,5 +12,4 @@ export {validateNoCapitalizedCalls} from './ValidateNoCapitalizedCalls';
 export {validateNoRefAccessInRender} from './ValidateNoRefAccessInRender';
 export {validateNoSetStateInRender} from './ValidateNoSetStateInRender';
 export {validatePreservedManualMemoization} from './ValidatePreservedManualMemoization';
-export {validateSourceLocations} from './ValidateSourceLocations';
 export {validateUseMemo} from './ValidateUseMemo';
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/envConfig-test.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/envConfig-test.ts
@@ -20,7 +20,7 @@ describe('parseConfigPragma()', () => {
        validateHooksUsage: 1,
      } as any);
    }).toThrowErrorMatchingInlineSnapshot(
-      `"Error: Could not validate environment config. Update React Compiler config to fix the error. Validation error: Invalid input: expected boolean, received number at "validateHooksUsage"."`,
+      `"Error: Could not validate environment config. Update React Compiler config to fix the error. Validation error: Expected boolean, received number at "validateHooksUsage"."`,
    );
  });

@@ -38,7 +38,7 @@ describe('parseConfigPragma()', () => {
        ],
      } as any);
    }).toThrowErrorMatchingInlineSnapshot(
-      `"Error: Could not validate environment config. Update React Compiler config to fix the error. Validation error: AutodepsIndex must be > 0 at "inferEffectDependencies[0].autodepsIndex"."`,
+      `"Error: Could not validate environment config. Update React Compiler config to fix the error. Validation error: autodepsIndex must be > 0 at "inferEffectDependencies[0].autodepsIndex"."`,
    );
  });

--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/access-ref-in-render-mutate-object-with-ref-function.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/access-ref-in-render-mutate-object-with-ref-function.expect.md
@@ -1,51 +0,0 @@
-
-## Input
-
-```javascript
-import {useRef} from 'react';
-
-/**
- * Allowed: we don't have sufficient type information to be sure that
- * this accesses an impure value during render.
- */
-function Component() {
-  const ref = useRef(null);
-  const object = {};
-  object.foo = () => ref.current;
-  const refValue = object.foo();
-  return <div>{refValue}</div>;
-}
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime";
-import { useRef } from "react";
-
-/**
- * Allowed: we don't have sufficient type information to be sure that
- * this accesses an impure value during render.
- */
-function Component() {
-  const $ = _c(2);
-  const ref = useRef(null);
-  const object = {};
-  object.foo = () => ref.current;
-  const refValue = object.foo();
-  let t0;
-  if ($[0] !== refValue) {
-    t0 = <div>{refValue}</div>;
-    $[0] = refValue;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  return t0;
-}
-
-```
-      
-### Eval output
-(kind: exception) Fixture not implemented
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/alias-capture-in-method-receiver-and-mutate.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/alias-capture-in-method-receiver-and-mutate.expect.md
@@ -35,8 +35,10 @@ function Component() {
  let t0;
  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
    const a = makeObject_Primitives();
+
    const x = [];
    x.push(a);
+
    mutate(x);
    t0 = [x, a];
    $[0] = t0;
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/alias-capture-in-method-receiver.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/alias-capture-in-method-receiver.expect.md
@@ -33,6 +33,7 @@ function Component() {
  if ($[1] === Symbol.for("react.memo_cache_sentinel")) {
    const x = [];
    x.push(a);
+
    t1 = [x, a];
    $[1] = t1;
  } else {
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/aliased-nested-scope-fn-expr.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/aliased-nested-scope-fn-expr.expect.md
@@ -85,10 +85,14 @@ function Component(t0) {
  let t1;
  if ($[0] !== prop) {
    const obj = shallowCopy(prop);
+
    const aliasedObj = identity(obj);
+
    const getId = () => obj.id;
+
    mutate(aliasedObj);
    setPropertyByKey(aliasedObj, "id", prop.id + 1);
+
    t1 = <Stringify getId={getId} shouldInvokeFns={true} />;
    $[0] = prop;
    $[1] = t1;
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/aliased-nested-scope-truncated-dep.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/aliased-nested-scope-truncated-dep.expect.md
@@ -181,9 +181,12 @@ function Component(t0) {
  if ($[0] !== prop) {
    const obj = shallowCopy(prop);
    const aliasedObj = identity(obj);
+
    const id = [obj.id];
+
    mutate(aliasedObj);
    setPropertyByKey(aliasedObj, "id", prop.id + 1);
+
    t1 = <Stringify id={id} />;
    $[0] = prop;
    $[1] = t1;
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/align-scopes-within-nested-valueblock-in-array.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/align-scopes-within-nested-valueblock-in-array.expect.md
@@ -54,6 +54,7 @@ function Foo(t0) {
  let t1;
  if ($[0] !== cond1 || $[1] !== cond2) {
    const arr = makeArray({ a: 2 }, 2, []);
+
    t1 = cond1 ? (
      <>
        <div>{identity("foo")}</div>
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allocating-primitive-as-dep.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allocating-primitive-as-dep.expect.md
@@ -2,7 +2,6 @@
 ## Input

 ```javascript
-// @enablePreserveExistingMemoizationGuarantees:false
 // bar(props.b) is an allocating expression that produces a primitive, which means
 // that Forget should memoize it.
 // Correctness:
@@ -17,8 +16,7 @@ function AllocatingPrimitiveAsDep(props) {
 ## Code

 ```javascript
-import { c as _c } from "react/compiler-runtime"; // @enablePreserveExistingMemoizationGuarantees:false
-// bar(props.b) is an allocating expression that produces a primitive, which means
+import { c as _c } from "react/compiler-runtime"; // bar(props.b) is an allocating expression that produces a primitive, which means
 // that Forget should memoize it.
 // Correctness:
 //   - y depends on either bar(props.b) or bar(props.b) + 1
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allocating-primitive-as-dep.js
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allocating-primitive-as-dep.js
@@ -1,4 +1,3 @@
-// @enablePreserveExistingMemoizationGuarantees:false
 // bar(props.b) is an allocating expression that produces a primitive, which means
 // that Forget should memoize it.
 // Correctness:
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-assigning-ref-accessing-function-to-object-property-if-not-mutated.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-assigning-ref-accessing-function-to-object-property-if-not-mutated.expect.md
@@ -5,10 +5,6 @@
 import {useRef} from 'react';
 import {Stringify} from 'shared-runtime';

-/**
- * Allowed: we don't have sufficient type information to be sure that
- * this accesses an impure value during render.
- */
 function Component(props) {
  const ref = useRef(props.value);
  const object = {};
@@ -30,10 +26,6 @@ import { c as _c } from "react/compiler-runtime";
 import { useRef } from "react";
 import { Stringify } from "shared-runtime";

-/**
- * Allowed: we don't have sufficient type information to be sure that
- * this accesses an impure value during render.
- */
 function Component(props) {
  const $ = _c(1);
  const ref = useRef(props.value);
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-assigning-ref-accessing-function-to-object-property-if-not-mutated.js
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-assigning-ref-accessing-function-to-object-property-if-not-mutated.js
@@ -1,10 +1,6 @@
 import {useRef} from 'react';
 import {Stringify} from 'shared-runtime';

-/**
- * Allowed: we don't have sufficient type information to be sure that
- * this accesses an impure value during render.
- */
 function Component(props) {
  const ref = useRef(props.value);
  const object = {};
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-modify-global-in-callback-jsx.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-modify-global-in-callback-jsx.expect.md
@@ -2,7 +2,6 @@
 ## Input

 ```javascript
-// @enablePreserveExistingMemoizationGuarantees:false @validateExhaustiveMemoizationDependencies:false
 import {useMemo} from 'react';

 const someGlobal = {value: 0};
@@ -33,7 +32,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code

 ```javascript
-import { c as _c } from "react/compiler-runtime"; // @enablePreserveExistingMemoizationGuarantees:false @validateExhaustiveMemoizationDependencies:false
+import { c as _c } from "react/compiler-runtime";
 import { useMemo } from "react";

 const someGlobal = { value: 0 };
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-modify-global-in-callback-jsx.js
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-modify-global-in-callback-jsx.js
@@ -1,4 +1,3 @@
-// @enablePreserveExistingMemoizationGuarantees:false @validateExhaustiveMemoizationDependencies:false
 import {useMemo} from 'react';

 const someGlobal = {value: 0};
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-mutating-ref-in-callback-passed-to-jsx-indirect.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-mutating-ref-in-callback-passed-to-jsx-indirect.expect.md
@@ -49,6 +49,7 @@ function Component() {
        ref.current = "";
      }
    };
+
    t0 = () => {
      setRef();
    };
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-mutating-ref-property-in-callback-passed-to-jsx-indirect.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-mutating-ref-property-in-callback-passed-to-jsx-indirect.expect.md
@@ -49,6 +49,7 @@ function Component() {
        ref.current.value = "";
      }
    };
+
    t0 = () => {
      setRef();
    };
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-access-in-async-event-handler-wrapper.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-access-in-async-event-handler-wrapper.expect.md
@@ -1,148 +0,0 @@
-
-## Input
-
-```javascript
-// @enableInferEventHandlers
-import {useRef} from 'react';
-
-// Simulates react-hook-form's handleSubmit
-function handleSubmit<T>(callback: (data: T) => void | Promise<void>) {
-  return (event: any) => {
-    event.preventDefault();
-    callback({} as T);
-  };
-}
-
-// Simulates an upload function
-async function upload(file: any): Promise<{blob: {url: string}}> {
-  return {blob: {url: 'https://example.com/file.jpg'}};
-}
-
-interface SignatureRef {
-  toFile(): any;
-}
-
-function Component() {
-  const ref = useRef<SignatureRef>(null);
-
-  const onSubmit = async (value: any) => {
-    // This should be allowed: accessing ref.current in an async event handler
-    // that's wrapped and passed to onSubmit prop
-    let sigUrl: string;
-    if (value.hasSignature) {
-      const {blob} = await upload(ref.current?.toFile());
-      sigUrl = blob?.url || '';
-    } else {
-      sigUrl = value.signature;
-    }
-    console.log('Signature URL:', sigUrl);
-  };
-
-  return (
-    <form onSubmit={handleSubmit(onSubmit)}>
-      <input type="text" name="signature" />
-      <button type="submit">Submit</button>
-    </form>
-  );
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{}],
-};
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime"; // @enableInferEventHandlers
-import { useRef } from "react";
-
-// Simulates react-hook-form's handleSubmit
-function handleSubmit(callback) {
-  const $ = _c(2);
-  let t0;
-  if ($[0] !== callback) {
-    t0 = (event) => {
-      event.preventDefault();
-      callback({} as T);
-    };
-    $[0] = callback;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  return t0;
-}
-
-// Simulates an upload function
-async function upload(file) {
-  const $ = _c(1);
-  let t0;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t0 = { blob: { url: "https://example.com/file.jpg" } };
-    $[0] = t0;
-  } else {
-    t0 = $[0];
-  }
-  return t0;
-}
-
-interface SignatureRef {
-  toFile(): any;
-}
-
-function Component() {
-  const $ = _c(4);
-  const ref = useRef(null);
-
-  const onSubmit = async (value) => {
-    let sigUrl;
-    if (value.hasSignature) {
-      const { blob } = await upload(ref.current?.toFile());
-      sigUrl = blob?.url || "";
-    } else {
-      sigUrl = value.signature;
-    }
-
-    console.log("Signature URL:", sigUrl);
-  };
-
-  const t0 = handleSubmit(onSubmit);
-  let t1;
-  let t2;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t1 = <input type="text" name="signature" />;
-    t2 = <button type="submit">Submit</button>;
-    $[0] = t1;
-    $[1] = t2;
-  } else {
-    t1 = $[0];
-    t2 = $[1];
-  }
-  let t3;
-  if ($[2] !== t0) {
-    t3 = (
-      <form onSubmit={t0}>
-        {t1}
-        {t2}
-      </form>
-    );
-    $[2] = t0;
-    $[3] = t3;
-  } else {
-    t3 = $[3];
-  }
-  return t3;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{}],
-};
-
-```
-      
-### Eval output
-(kind: ok) <form><input type="text" name="signature"><button type="submit">Submit</button></form>
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-access-in-async-event-handler-wrapper.tsx
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-access-in-async-event-handler-wrapper.tsx
@@ -1,48 +0,0 @@
-// @enableInferEventHandlers
-import {useRef} from 'react';
-
-// Simulates react-hook-form's handleSubmit
-function handleSubmit<T>(callback: (data: T) => void | Promise<void>) {
-  return (event: any) => {
-    event.preventDefault();
-    callback({} as T);
-  };
-}
-
-// Simulates an upload function
-async function upload(file: any): Promise<{blob: {url: string}}> {
-  return {blob: {url: 'https://example.com/file.jpg'}};
-}
-
-interface SignatureRef {
-  toFile(): any;
-}
-
-function Component() {
-  const ref = useRef<SignatureRef>(null);
-
-  const onSubmit = async (value: any) => {
-    // This should be allowed: accessing ref.current in an async event handler
-    // that's wrapped and passed to onSubmit prop
-    let sigUrl: string;
-    if (value.hasSignature) {
-      const {blob} = await upload(ref.current?.toFile());
-      sigUrl = blob?.url || '';
-    } else {
-      sigUrl = value.signature;
-    }
-    console.log('Signature URL:', sigUrl);
-  };
-
-  return (
-    <form onSubmit={handleSubmit(onSubmit)}>
-      <input type="text" name="signature" />
-      <button type="submit">Submit</button>
-    </form>
-  );
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{}],
-};
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-access-in-event-handler-wrapper.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-access-in-event-handler-wrapper.expect.md
@@ -1,100 +0,0 @@
-
-## Input
-
-```javascript
-// @enableInferEventHandlers
-import {useRef} from 'react';
-
-// Simulates react-hook-form's handleSubmit or similar event handler wrappers
-function handleSubmit<T>(callback: (data: T) => void) {
-  return (event: any) => {
-    event.preventDefault();
-    callback({} as T);
-  };
-}
-
-function Component() {
-  const ref = useRef<HTMLInputElement>(null);
-
-  const onSubmit = (data: any) => {
-    // This should be allowed: accessing ref.current in an event handler
-    // that's wrapped by handleSubmit and passed to onSubmit prop
-    if (ref.current !== null) {
-      console.log(ref.current.value);
-    }
-  };
-
-  return (
-    <>
-      <input ref={ref} />
-      <form onSubmit={handleSubmit(onSubmit)}>
-        <button type="submit">Submit</button>
-      </form>
-    </>
-  );
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{}],
-};
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime"; // @enableInferEventHandlers
-import { useRef } from "react";
-
-// Simulates react-hook-form's handleSubmit or similar event handler wrappers
-function handleSubmit(callback) {
-  const $ = _c(2);
-  let t0;
-  if ($[0] !== callback) {
-    t0 = (event) => {
-      event.preventDefault();
-      callback({} as T);
-    };
-    $[0] = callback;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  return t0;
-}
-
-function Component() {
-  const $ = _c(1);
-  const ref = useRef(null);
-  let t0;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    const onSubmit = (data) => {
-      if (ref.current !== null) {
-        console.log(ref.current.value);
-      }
-    };
-    t0 = (
-      <>
-        <input ref={ref} />
-        <form onSubmit={handleSubmit(onSubmit)}>
-          <button type="submit">Submit</button>
-        </form>
-      </>
-    );
-    $[0] = t0;
-  } else {
-    t0 = $[0];
-  }
-  return t0;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{}],
-};
-
-```
-      
-### Eval output
-(kind: ok) <input><form><button type="submit">Submit</button></form>
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-access-in-event-handler-wrapper.tsx
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-access-in-event-handler-wrapper.tsx
@@ -1,36 +0,0 @@
-// @enableInferEventHandlers
-import {useRef} from 'react';
-
-// Simulates react-hook-form's handleSubmit or similar event handler wrappers
-function handleSubmit<T>(callback: (data: T) => void) {
-  return (event: any) => {
-    event.preventDefault();
-    callback({} as T);
-  };
-}
-
-function Component() {
-  const ref = useRef<HTMLInputElement>(null);
-
-  const onSubmit = (data: any) => {
-    // This should be allowed: accessing ref.current in an event handler
-    // that's wrapped by handleSubmit and passed to onSubmit prop
-    if (ref.current !== null) {
-      console.log(ref.current.value);
-    }
-  };
-
-  return (
-    <>
-      <input ref={ref} />
-      <form onSubmit={handleSubmit(onSubmit)}>
-        <button type="submit">Submit</button>
-      </form>
-    </>
-  );
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{}],
-};
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-type-cast-in-render.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/allow-ref-type-cast-in-render.expect.md
@@ -36,6 +36,7 @@ function useArrayOfRef() {
    const callback = (value) => {
      ref.current = value;
    };
+
    t0 = [callback];
    $[0] = t0;
  } else {
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/array-at-closure.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/array-at-closure.expect.md
@@ -35,6 +35,7 @@ function Component(props) {
      const arr = [...bar(props)];
      return arr.at(x);
    };
+
    t1 = fn();
    $[2] = props;
    $[3] = x;
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/array-pattern-spread-creates-array.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/array-pattern-spread-creates-array.expect.md
@@ -2,7 +2,7 @@
 ## Input

 ```javascript
-// @validatePreserveExistingMemoizationGuarantees @validateExhaustiveMemoizationDependencies:false
+// @validatePreserveExistingMemoizationGuarantees
 import {useMemo} from 'react';
 import {makeObject_Primitives, ValidateMemoization} from 'shared-runtime';

@@ -36,7 +36,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code

 ```javascript
-import { c as _c } from "react/compiler-runtime"; // @validatePreserveExistingMemoizationGuarantees @validateExhaustiveMemoizationDependencies:false
+import { c as _c } from "react/compiler-runtime"; // @validatePreserveExistingMemoizationGuarantees
 import { useMemo } from "react";
 import { makeObject_Primitives, ValidateMemoization } from "shared-runtime";

--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/array-pattern-spread-creates-array.js
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/array-pattern-spread-creates-array.js
@@ -1,4 +1,4 @@
-// @validatePreserveExistingMemoizationGuarantees @validateExhaustiveMemoizationDependencies:false
+// @validatePreserveExistingMemoizationGuarantees
 import {useMemo} from 'react';
 import {makeObject_Primitives, ValidateMemoization} from 'shared-runtime';

--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/array-spread-mutable-iterator.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/array-spread-mutable-iterator.expect.md
@@ -61,6 +61,7 @@ function useBar(t0) {
  if ($[0] !== arg) {
    const s = new Set([1, 5, 4]);
    const mutableIterator = s.values();
+
    t1 = [arg, ...mutableIterator];
    $[0] = arg;
    $[1] = t1;
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/block-scoping-switch-variable-scoping.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/block-scoping-switch-variable-scoping.expect.md
@@ -2,7 +2,6 @@
 ## Input

 ```javascript
-// @validateExhaustiveMemoizationDependencies:false
 import {useMemo} from 'react';

 function Component(props) {
@@ -31,7 +30,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code

 ```javascript
-import { c as _c } from "react/compiler-runtime"; // @validateExhaustiveMemoizationDependencies:false
+import { c as _c } from "react/compiler-runtime";
 import { useMemo } from "react";

 function Component(props) {
--- a/Show More
+++ b/Show More