[compiler] Fix inferEffectDependencies lint false positives

Currently, inferred effect dependencies are considered a "compiler-required" feature. This means that untransformed callsites should escalate to a build error.

`ValidateNoUntransformedReferences` iterates 'special effect' callsites and checks that the compiler was able to successfully transform them. Prior to this PR, this relied on checking the number of arguments passed to this special effect.

This obviously doesn't work with `noEmit: true`, which is used for our eslint plugin (this avoids mutating the babel program as other linters run with the same ast). This PR adds a set of `babel.SourceLocation`s to do best effort matching in this mode.

.codesandbox/ci.json

@@ -1,11 +1,10 @@
 {
-  "packages": ["packages/react", "packages/react-dom", "packages/react-server-dom-webpack", "packages/scheduler"],
+  "packages": ["packages/react", "packages/react-dom", "packages/scheduler"],
   "buildCommand": "download-build-in-codesandbox-ci",
-  "node": "20",
+  "node": "18",
   "publishDirectory": {
     "react": "build/oss-experimental/react",
     "react-dom": "build/oss-experimental/react-dom",
-    "react-server-dom-webpack": "build/oss-experimental/react-server-dom-webpack",
     "scheduler": "build/oss-experimental/scheduler"
   },
   "sandboxes": ["new"],

.eslintignore

@@ -28,6 +28,3 @@ packages/react-devtools-shared/src/hooks/__tests__/__source__/__untransformed__/
 packages/react-devtools-shell/dist
 packages/react-devtools-timeline/dist
 packages/react-devtools-timeline/static
-
-# Imported third-party Flow types
-flow-typed/

.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',
@@ -469,14 +468,13 @@ module.exports = {
       files: ['packages/react-server-dom-webpack/**/*.js'],
       globals: {
         __webpack_chunk_load__: 'readonly',
-        __webpack_get_script_filename__: 'readonly',
         __webpack_require__: 'readonly',
       },
     },
     {
       files: ['packages/react-server-dom-turbopack/**/*.js'],
       globals: {
-        __turbopack_load_by_url__: 'readonly',
+        __turbopack_load__: 'readonly',
         __turbopack_require__: 'readonly',
       },
     },
@@ -498,7 +496,6 @@ module.exports = {
         'packages/react-devtools-shared/src/devtools/views/**/*.js',
         'packages/react-devtools-shared/src/hook.js',
         'packages/react-devtools-shared/src/backend/console.js',
-        'packages/react-devtools-shared/src/backend/fiber/renderer.js',
         'packages/react-devtools-shared/src/backend/shared/DevToolsComponentStackFrame.js',
         'packages/react-devtools-shared/src/frontend/utils/withPermissionsCheck.js',
       ],
@@ -507,7 +504,6 @@ module.exports = {
         __IS_FIREFOX__: 'readonly',
         __IS_EDGE__: 'readonly',
         __IS_NATIVE__: 'readonly',
-        __IS_INTERNAL_MCP_BUILD__: 'readonly',
         __IS_INTERNAL_VERSION__: 'readonly',
         chrome: 'readonly',
       },
@@ -518,14 +514,6 @@ 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'],
@@ -556,10 +544,13 @@ module.exports = {
   },
 
   globals: {
+    $Call: 'readonly',
+    $ElementType: 'readonly',
     $Flow$ModuleRef: 'readonly',
     $FlowFixMe: 'readonly',
     $Keys: 'readonly',
     $NonMaybeType: 'readonly',
+    $PropertyType: 'readonly',
     $ReadOnly: 'readonly',
     $ReadOnlyArray: 'readonly',
     $ArrayBufferView: 'readonly',
@@ -568,13 +559,11 @@ module.exports = {
     ConsoleTask: 'readonly', // TOOD: Figure out what the official name of this will be.
     ReturnType: 'readonly',
     AnimationFrameID: 'readonly',
-    WeakRef: 'readonly',
     // For Flow type annotation. Only `BigInt` is valid at runtime.
     bigint: 'readonly',
     BigInt: 'readonly',
     BigInt64Array: 'readonly',
     BigUint64Array: 'readonly',
-    CacheType: 'readonly',
     Class: 'readonly',
     ClientRect: 'readonly',
     CopyInspectedElementPath: 'readonly',
@@ -586,19 +575,15 @@ module.exports = {
     $AsyncIterator: 'readonly',
     Iterator: 'readonly',
     AsyncIterator: 'readonly',
-    IntervalID: 'readonly',
     IteratorResult: 'readonly',
     JSONValue: 'readonly',
     JSResourceReference: 'readonly',
-    mixin$Animatable: 'readonly',
     MouseEventHandler: 'readonly',
-    NavigateEvent: 'readonly',
-    PerformanceMeasureOptions: 'readonly',
     PropagationPhases: 'readonly',
     PropertyDescriptor: 'readonly',
-    PropertyDescriptorMap: 'readonly',
-    Proxy$traps: 'readonly',
+    React$AbstractComponent: 'readonly',
     React$Component: 'readonly',
+    React$ComponentType: 'readonly',
     React$Config: 'readonly',
     React$Context: 'readonly',
     React$Element: 'readonly',
@@ -619,23 +604,18 @@ module.exports = {
     symbol: 'readonly',
     SyntheticEvent: 'readonly',
     SyntheticMouseEvent: 'readonly',
-    SyntheticPointerEvent: 'readonly',
     Thenable: 'readonly',
     TimeoutID: 'readonly',
     WheelEventHandler: 'readonly',
     FinalizationRegistry: 'readonly',
-    Exclude: 'readonly',
     Omit: 'readonly',
     Keyframe: 'readonly',
     PropertyIndexedKeyframes: 'readonly',
     KeyframeAnimationOptions: 'readonly',
     GetAnimationsOptions: 'readonly',
+    Animatable: 'readonly',
     ScrollTimeline: 'readonly',
-    EventListenerOptionsOrUseCapture: 'readonly',
-    FocusOptions: 'readonly',
-    OptionalEffectTiming: 'readonly',
 
-    __REACT_ROOT_PATH_TEST__: 'readonly',
     spyOnDev: 'readonly',
     spyOnDevAndProd: 'readonly',
     spyOnProd: 'readonly',
@@ -652,6 +632,5 @@ module.exports = {
     AsyncLocalStorage: 'readonly',
     async_hooks: 'readonly',
     globalThis: 'readonly',
-    navigation: 'readonly',
   },
 };

.github/ISSUE_TEMPLATE/19.md

@@ -0,0 +1,18 @@
+---
+name: "⚛React 19 beta issue"
+about: Report a issue with React 19 beta.
+title: '[React 19]'
+labels: 'React 19'
+
+---
+
+
+## Summary
+
+<!--
+  Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
+  repository on GitHub, or provide a minimal code example that reproduces the
+  problem. You may provide a screenshot of the application if you think it is
+  relevant to your bug report. Here are some tips for providing a minimal
+  example: https://stackoverflow.com/help/mcve.
+-->

.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:

.github/workflows/compiler_discord_notify.yml

@@ -10,21 +10,7 @@ on:
 permissions: {}
 
 jobs:
-  check_access:
-    if: ${{ github.event.pull_request.draft == false }}
-    runs-on: ubuntu-latest
-    outputs:
-      is_member_or_collaborator: ${{ steps.check_is_member_or_collaborator.outputs.is_member_or_collaborator }}
-    steps:
-      - run: echo ${{ github.event.pull_request.author_association }}
-      - name: Check is member or collaborator
-        id: check_is_member_or_collaborator
-        if: ${{ github.event.pull_request.author_association == 'MEMBER' || github.event.pull_request.author_association == 'COLLABORATOR' }}
-        run: echo "is_member_or_collaborator=true" >> "$GITHUB_OUTPUT"
-
   check_maintainer:
-    if: ${{ needs.check_access.outputs.is_member_or_collaborator == 'true' || needs.check_access.outputs.is_member_or_collaborator == true }}
-    needs: [check_access]
     uses: facebook/react/.github/workflows/shared_check_maintainer.yml@main
     permissions:
       # Used by check_maintainer

.github/workflows/compiler_playground.yml

@@ -57,6 +57,8 @@ jobs:
           key: playwright-browsers-v6-${{ runner.arch }}-${{ runner.os }}-${{ steps.playwright_version.outputs.playwright_version }}
       - run: npx playwright install --with-deps chromium
         if: steps.cache_playwright_browsers.outputs.cache-hit != 'true'
+      - run: npx playwright install-deps
+        if: steps.cache_playwright_browsers.outputs.cache-hit == 'true'
       - run: CI=true yarn test
       - run: ls -R test-results
         if: '!cancelled()'

.github/workflows/compiler_prereleases.yml

@@ -16,12 +16,6 @@ on:
       version_name:
         required: true
         type: string
-      tag_version:
-        required: false
-        type: string
-      dry_run:
-        required: false
-        type: boolean
     secrets:
       NPM_TOKEN:
         required: true
@@ -58,13 +52,7 @@ jobs:
           key: compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/yarn.lock') }}
       - run: yarn install --frozen-lockfile
         if: steps.node_modules.outputs.cache-hit != 'true'
-      - if: inputs.dry_run == true
-        name: Publish packages to npm (dry run)
+      - name: Publish packages to npm
         run: |
           cp ./scripts/release/ci-npmrc ~/.npmrc
-          scripts/release/publish.js --frfr --debug --ci --versionName=${{ inputs.version_name }} --tag=${{ inputs.dist_tag }} ${{ inputs.tag_version && format('--tagVersion={0}', inputs.tag_version) || '' }}
-      - if: inputs.dry_run != true
-        name: Publish packages to npm
-        run: |
-          cp ./scripts/release/ci-npmrc ~/.npmrc
-          scripts/release/publish.js --frfr --ci --versionName=${{ inputs.version_name }} --tag=${{ inputs.dist_tag }} ${{ inputs.tag_version && format('--tagVersion={0}', inputs.tag_version) || '' }}
+          scripts/release/publish.js --frfr --ci --versionName=${{ inputs.version_name }} --tag ${{ inputs.dist_tag }}

.github/workflows/compiler_prereleases_manual.yml

@@ -14,12 +14,6 @@ on:
       version_name:
         required: true
         type: string
-      tag_version:
-        required: false
-        type: string
-      dry_run:
-        required: false
-        type: boolean
 
 permissions: {}
 
@@ -35,7 +29,5 @@ jobs:
       release_channel: ${{ inputs.release_channel }}
       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 }}

.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 }}

.github/workflows/compiler_prereleases_weekly.yml

@@ -0,0 +1,23 @@
+name: (Compiler) Publish Prereleases Weekly
+
+on:
+  schedule:
+    # At 10 minutes past 9:00 on Mon
+    - cron: 10 9 * * 1
+
+permissions: {}
+
+env:
+  TZ: /usr/share/zoneinfo/America/Los_Angeles
+
+jobs:
+  publish_prerelease_beta:
+    name: Publish to beta channel
+    uses: facebook/react/.github/workflows/compiler_prereleases.yml@main
+    with:
+      commit_sha: ${{ github.sha }}
+      release_channel: beta
+      dist_tag: beta
+      version_name: '19.0.0'
+    secrets:
+      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/devtools_discord_notify.yml

@@ -1,49 +0,0 @@
-name: (DevTools) Discord Notify
-
-on:
-  pull_request_target:
-    types: [opened, ready_for_review]
-    paths:
-      - packages/react-devtools**
-      - .github/workflows/devtools_**.yml
-
-permissions: {}
-
-jobs:
-  check_access:
-    if: ${{ github.event.pull_request.draft == false }}
-    runs-on: ubuntu-latest
-    outputs:
-      is_member_or_collaborator: ${{ steps.check_is_member_or_collaborator.outputs.is_member_or_collaborator }}
-    steps:
-      - run: echo ${{ github.event.pull_request.author_association }}
-      - name: Check is member or collaborator
-        id: check_is_member_or_collaborator
-        if: ${{ github.event.pull_request.author_association == 'MEMBER' || github.event.pull_request.author_association == 'COLLABORATOR' }}
-        run: echo "is_member_or_collaborator=true" >> "$GITHUB_OUTPUT"
-
-  check_maintainer:
-    if: ${{ needs.check_access.outputs.is_member_or_collaborator == 'true' || needs.check_access.outputs.is_member_or_collaborator == true }}
-    needs: [check_access]
-    uses: facebook/react/.github/workflows/shared_check_maintainer.yml@main
-    permissions:
-      # Used by check_maintainer
-      contents: read
-    with:
-      actor: ${{ github.event.pull_request.user.login }}
-
-  notify:
-    if: ${{ needs.check_maintainer.outputs.is_core_team == 'true' }}
-    needs: check_maintainer
-    runs-on: ubuntu-latest
-    steps:
-      - name: Discord Webhook Action
-        uses: tsickert/discord-webhook@86dc739f3f165f16dadc5666051c367efa1692f4
-        with:
-          webhook-url: ${{ secrets.DEVTOOLS_DISCORD_WEBHOOK_URL }}
-          embed-author-name: ${{ github.event.pull_request.user.login }}
-          embed-author-url: ${{ github.event.pull_request.user.html_url }}
-          embed-author-icon-url: ${{ github.event.pull_request.user.avatar_url }}
-          embed-title: '#${{ github.event.number }} (+${{github.event.pull_request.additions}} -${{github.event.pull_request.deletions}}): ${{ github.event.pull_request.title }}'
-          embed-description: ${{ github.event.pull_request.body }}
-          embed-url: ${{ github.event.pull_request.html_url }}

.github/workflows/devtools_regression_tests.yml

@@ -92,7 +92,7 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: react-devtools
-          path: build/devtools
+          path: build/devtools.tgz
           if-no-files-found: error
       # Simplifies getting the extension for local testing
       - name: Archive chrome extension
@@ -201,5 +201,5 @@ jobs:
       - uses: actions/upload-artifact@v4
         with:
           name: screenshots
-          path: ./tmp/playwright-artifacts
+          path: ./tmp/screenshots
           if-no-files-found: warn

.github/workflows/runtime_build_and_test.yml

@@ -3,19 +3,9 @@ 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/**
-  workflow_dispatch:
-    inputs:
-      commit_sha:
-        required: false
-        type: string
-        default: ''
 
 permissions: {}
 
@@ -38,14 +28,14 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - name: Check cache hit
         uses: actions/cache/restore@v4
         id: node_modules
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
           lookup-only: true
       - uses: actions/setup-node@v4
         if: steps.node_modules.outputs.cache-hit != 'true'
@@ -59,8 +49,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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 }}-${{ runner.os }}-
+            runtime-node_modules-v6-
       - run: yarn install --frozen-lockfile
         if: steps.node_modules.outputs.cache-hit != 'true'
       - name: Save cache
@@ -69,7 +61,7 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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
@@ -77,14 +69,14 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - name: Check cache hit
         uses: actions/cache/restore@v4
         id: node_modules
         with:
           path: |
             **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
           lookup-only: true
       - uses: actions/setup-node@v4
         if: steps.node_modules.outputs.cache-hit != 'true'
@@ -100,8 +92,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ 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 }}-${{ runner.os }}-
+            runtime-and-compiler-node_modules-v6-
       - run: yarn install --frozen-lockfile
         if: steps.node_modules.outputs.cache-hit != 'true'
       - run: yarn --cwd compiler install --frozen-lockfile
@@ -112,7 +106,7 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ 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:
@@ -123,7 +117,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/github-script@v7
         id: set-matrix
         with:
@@ -142,7 +136,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -154,8 +148,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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
@@ -170,7 +166,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -182,15 +178,17 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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
         if: steps.node_modules.outputs.cache-hit != 'true'
       - run: |
           yarn generate-inline-fizz-runtime
-          git diff --exit-code || (echo "There was a change to the Fizz runtime. Run \`yarn generate-inline-fizz-runtime\` and check in the result." && false)
+          git diff --quiet || (echo "There was a change to the Fizz runtime. Run `yarn generate-inline-fizz-runtime` and check in the result." && false)
 
   # ----- FEATURE FLAGS -----
   flags:
@@ -200,7 +198,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -212,7 +210,7 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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
@@ -256,7 +254,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -270,8 +268,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ 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
@@ -280,37 +280,6 @@ jobs:
         if: steps.node_modules.outputs.cache-hit != 'true'
       - run: yarn test ${{ matrix.params }} --ci --shard=${{ matrix.shard }}
 
-  # Hardcoded to improve parallelism
-  test-linter:
-    name: Test eslint-plugin-react-hooks
-    needs: [runtime_compiler_node_modules_cache]
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path:  |
-            yarn.lock
-            compiler/yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: |
-            **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ 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'
-      - name: Install compiler dependencies
-        run: yarn install --frozen-lockfile
-        working-directory: compiler
-        if: steps.node_modules.outputs.cache-hit != 'true'
-      - run: ./scripts/react-compiler/build-compiler.sh && ./scripts/react-compiler/link-compiler.sh
-      - run: yarn workspace eslint-plugin-react-hooks test
-
   # ----- BUILD -----
   build_and_lint:
     name: yarn build and lint
@@ -325,7 +294,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -343,8 +312,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ 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 +353,9 @@ 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"
@@ -415,7 +389,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -429,8 +403,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-and-compiler-node_modules-v7-${{ 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 +423,6 @@ 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]
@@ -502,7 +434,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -514,8 +446,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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
@@ -528,7 +462,7 @@ jobs:
           merge-multiple: true
       - name: Display structure of build
         run: ls -R build
-      - run: echo ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
+      - run: echo ${{ github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
       - name: Scrape warning messages
         run: |
           mkdir -p ./build/__test_utils__
@@ -565,7 +499,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -577,8 +511,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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
@@ -594,7 +530,7 @@ jobs:
       - name: Search build artifacts for unminified errors
         run: |
           yarn extract-errors
-          git diff --exit-code || (echo "Found unminified errors. Either update the error codes map or disable error minification for the affected build, if appropriate." && false)
+          git diff --quiet || (echo "Found unminified errors. Either update the error codes map or disable error minification for the affected build, if appropriate." && false)
 
   check_release_dependencies:
     name: Check release dependencies
@@ -603,7 +539,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -615,8 +551,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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
@@ -638,7 +576,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -679,7 +617,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -753,7 +691,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -765,8 +703,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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 }}-${{ runner.os }}-
+            runtime-node_modules-v6-
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
@@ -789,11 +729,6 @@ jobs:
           name: react-devtools-${{ matrix.browser }}-extension
           path: build/devtools/${{ matrix.browser }}-extension.zip
           if-no-files-found: error
-      - name: Archive ${{ matrix.browser }} metadata
-        uses: actions/upload-artifact@v4
-        with:
-          name: react-devtools-${{ matrix.browser }}-metadata
-          path: build/devtools/webpack-stats.*.json
 
   merge_devtools_artifacts:
     name: Merge DevTools artifacts
@@ -804,7 +739,7 @@ jobs:
         uses: actions/upload-artifact/merge@v4
         with:
           name: react-devtools
-          pattern: react-devtools-*
+          pattern: react-devtools-*-extension
 
   run_devtools_e2e_tests:
     name: Run DevTools e2e tests
@@ -813,7 +748,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -825,8 +760,10 @@ jobs:
         with:
           path: |
             **/node_modules
-          key: runtime-node_modules-v7-${{ 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 }}-${{ runner.os }}-
+            runtime-node_modules-v6-
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
@@ -837,27 +774,12 @@ jobs:
           pattern: _build_*
           path: build
           merge-multiple: true
-      - name: Check Playwright version
-        id: playwright_version
-        run: echo "playwright_version=$(npm ls @playwright/test | grep @playwright | sed 's/.*@//' | head -1)" >> "$GITHUB_OUTPUT"
-      - name: Cache Playwright Browsers for version ${{ steps.playwright_version.outputs.playwright_version }}
-        id: cache_playwright_browsers
-        uses: actions/cache@v4
-        with:
-          path: ~/.cache/ms-playwright
-          key: playwright-browsers-v6-${{ runner.arch }}-${{ runner.os }}-${{ steps.playwright_version.outputs.playwright_version }}
-      - name: Playwright install deps
-        if: steps.cache_playwright_browsers.outputs.cache-hit != 'true'
-        run: npx playwright install --with-deps chromium
+      - run: |
+          npx playwright install
+          sudo npx playwright install-deps
       - run: ./scripts/ci/run_devtools_e2e_tests.js
         env:
           RELEASE_CHANNEL: experimental
-      - name: Archive Playwright report
-        uses: actions/upload-artifact@v4
-        with:
-          name: devtools-playwright-artifacts
-          path: tmp/playwright-artifacts
-          if-no-files-found: warn
 
   # ----- SIZEBOT -----
   sizebot:
@@ -871,7 +793,7 @@ jobs:
     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 }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -920,7 +842,7 @@ jobs:
           node ./scripts/print-warnings/print-warnings.js > build/__test_utils__/ReactAllWarnings.js
       - name: Display structure of build for PR
         run: ls -R build
-      - run: echo ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
+      - run: echo ${{ github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
       - run: node ./scripts/tasks/danger
       - name: Archive sizebot results
         uses: actions/upload-artifact@v4

.github/workflows/runtime_commit_artifacts.yml

@@ -132,9 +132,9 @@ jobs:
           mkdir ./compiled/facebook-www/__test_utils__
           mv build/__test_utils__/ReactAllWarnings.js ./compiled/facebook-www/__test_utils__/ReactAllWarnings.js
 
-          # Copy eslint-plugin-react-hooks
+          # Move eslint-plugin-react-hooks into eslint-plugin-react-hooks
           mkdir ./compiled/eslint-plugin-react-hooks
-          cp build/oss-experimental/eslint-plugin-react-hooks/cjs/eslint-plugin-react-hooks.development.js \
+          mv build/oss-experimental/eslint-plugin-react-hooks/cjs/eslint-plugin-react-hooks.development.js \
             ./compiled/eslint-plugin-react-hooks/index.js
 
           # Move unstable_server-external-runtime.js into facebook-www
@@ -162,19 +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 $SHIM_FOLDER/ReactNative.js
-
-          # Copy eslint-plugin-react-hooks
-          # NOTE: This is different from www, here we include the full package
-          #       including package.json to include dependencies in fbsource.
-          mkdir "$BASE_FOLDER/tools"
-          cp -r build/oss-experimental/eslint-plugin-react-hooks "$BASE_FOLDER/tools"
+          rm $RENDERER_FOLDER/ReactNativeRenderer-{dev,prod,profiling}.js
 
           # Move React Native version file
           mv build/facebook-react-native/VERSION_NATIVE_FB ./compiled-rn/VERSION_NATIVE_FB
@@ -335,10 +326,10 @@ jobs:
           git --no-pager diff -U0 --cached | grep '^[+-]' | head -n 100
           echo "===================="
           # Ignore REVISION or lines removing @generated headers.
-          if git diff --cached ':(exclude)*REVISION' ':(exclude)*/eslint-plugin-react-hooks/package.json' | grep -vE "^(@@|diff|index|\-\-\-|\+\+\+|\- \* @generated SignedSource)" | grep "^[+-]" > /dev/null; then
+          if git diff --cached ':(exclude)*REVISION' | grep -vE "^(@@|diff|index|\-\-\-|\+\+\+|\- \* @generated SignedSource)" | grep "^[+-]" > /dev/null; then
             echo "Changes detected"
             echo "===== Changes ====="
-            git --no-pager diff --cached ':(exclude)*REVISION' ':(exclude)*/eslint-plugin-react-hooks/package.json' | grep -vE "^(@@|diff|index|\-\-\-|\+\+\+|\- \* @generated SignedSource)" | grep "^[+-]" | head -n 50
+            git --no-pager diff --cached ':(exclude)*REVISION' | grep -vE "^(@@|diff|index|\-\-\-|\+\+\+|\- \* @generated SignedSource)" | grep "^[+-]" | head -n 50
             echo "==================="
             echo "should_commit=true" >> "$GITHUB_OUTPUT"
           else

.github/workflows/runtime_discord_notify.yml

@@ -4,29 +4,13 @@ on:
   pull_request_target:
     types: [opened, ready_for_review]
     paths-ignore:
-      - packages/react-devtools**
       - compiler/**
       - .github/workflows/compiler_**.yml
-      - .github/workflows/devtools**.yml
 
 permissions: {}
 
 jobs:
-  check_access:
-    if: ${{ github.event.pull_request.draft == false }}
-    runs-on: ubuntu-latest
-    outputs:
-      is_member_or_collaborator: ${{ steps.check_is_member_or_collaborator.outputs.is_member_or_collaborator }}
-    steps:
-      - run: echo ${{ github.event.pull_request.author_association }}
-      - name: Check is member or collaborator
-        id: check_is_member_or_collaborator
-        if: ${{ github.event.pull_request.author_association == 'MEMBER' || github.event.pull_request.author_association == 'COLLABORATOR' }}
-        run: echo "is_member_or_collaborator=true" >> "$GITHUB_OUTPUT"
-
   check_maintainer:
-    if: ${{ needs.check_access.outputs.is_member_or_collaborator == 'true' || needs.check_access.outputs.is_member_or_collaborator == true }}
-    needs: [check_access]
     uses: facebook/react/.github/workflows/shared_check_maintainer.yml@main
     permissions:
       # Used by check_maintainer

.github/workflows/runtime_prereleases.yml

@@ -13,25 +13,7 @@ on:
       dist_tag:
         required: true
         type: string
-      enableFailureNotification:
-        description: 'Whether to notify the team on Discord when the release fails. Useful if this workflow is called from an automation.'
-        required: false
-        type: boolean
-      only_packages:
-        description: Packages to publish (space separated)
-        type: string
-      skip_packages:
-        description: Packages to NOT publish (space separated)
-        type: string
-      dry:
-        required: true
-        description: Dry run instead of publish?
-        type: boolean
-        default: true
     secrets:
-      DISCORD_WEBHOOK_URL:
-        description: 'Discord webhook URL to notify on failure. Only required if enableFailureNotification is true.'
-        required: false
       GH_TOKEN:
         required: true
       NPM_TOKEN:
@@ -72,39 +54,7 @@ jobs:
         if: steps.node_modules.outputs.cache-hit != 'true'
       - run: yarn --cwd scripts/release install --frozen-lockfile
         if: steps.node_modules.outputs.cache-hit != 'true'
-      - run: cp ./scripts/release/ci-npmrc ~/.npmrc
       - run: |
           GH_TOKEN=${{ secrets.GH_TOKEN }} scripts/release/prepare-release-from-ci.js --skipTests -r ${{ inputs.release_channel }} --commit=${{ inputs.commit_sha }}
-      - name: Check prepared files
-        run: ls -R build/node_modules
-      - if: '${{ inputs.only_packages }}'
-        name: 'Publish ${{ inputs.only_packages }}'
-        run: |
-          scripts/release/publish.js \
-            --ci \
-            --tags=${{ inputs.dist_tag }} \
-            --onlyPackages=${{ inputs.only_packages }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
-      - if: '${{ inputs.skip_packages }}'
-        name: 'Publish all packages EXCEPT ${{ inputs.skip_packages }}'
-        run: |
-          scripts/release/publish.js \
-            --ci \
-            --tags=${{ inputs.dist_tag }} \
-            --skipPackages=${{ inputs.skip_packages }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
-      - if: '${{ !inputs.skip_packages && !inputs.only_packages }}'
-        name: 'Publish all packages'
-        run: |
-          scripts/release/publish.js \
-            --ci \
-            --tags=${{ inputs.dist_tag }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
-      - name: Notify Discord on failure
-        if: failure() && inputs.enableFailureNotification == true
-        uses: tsickert/discord-webhook@86dc739f3f165f16dadc5666051c367efa1692f4
-        with:
-          webhook-url: ${{ secrets.DISCORD_WEBHOOK_URL }}
-          embed-author-name: "GitHub Actions"
-          embed-title: '[Runtime] Publish of ${{ inputs.release_channel }}@${{ inputs.dist_tag}} release failed'
-          embed-url: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}/attempts/${{ github.run_attempt }}
+          cp ./scripts/release/ci-npmrc ~/.npmrc
+          scripts/release/publish.js --ci --tags ${{ inputs.dist_tag }}

.github/workflows/runtime_prereleases_manual.yml

@@ -5,25 +5,6 @@ on:
     inputs:
       prerelease_commit_sha:
         required: true
-      only_packages:
-        description: Packages to publish (space separated)
-        type: string
-      skip_packages:
-        description: Packages to NOT publish (space separated)
-        type: string
-      dry:
-        required: true
-        description: Dry run instead of publish?
-        type: boolean
-        default: true
-      experimental_only:
-        type: boolean
-        description: Only publish to the experimental tag
-        default: false
-      force_notify:
-        description: Force a Discord notification?
-        type: boolean
-        default: false
 
 permissions: {}
 
@@ -31,26 +12,8 @@ env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
 
 jobs:
-  notify:
-    if: ${{ inputs.force_notify || inputs.dry == false || inputs.dry == 'false' }}
-    runs-on: ubuntu-latest
-    steps:
-      - name: Discord Webhook Action
-        uses: tsickert/discord-webhook@86dc739f3f165f16dadc5666051c367efa1692f4
-        with:
-          webhook-url: ${{ secrets.DISCORD_WEBHOOK_URL }}
-          embed-author-name: ${{ github.event.sender.login }}
-          embed-author-url: ${{ github.event.sender.html_url }}
-          embed-author-icon-url: ${{ github.event.sender.avatar_url }}
-          embed-title: "⚠️ Publishing ${{ inputs.experimental_only && 'EXPERIMENTAL' || 'CANARY & EXPERIMENTAL' }} release ${{ (inputs.dry && ' (dry run)') || '' }}"
-          embed-description: |
-            ```json
-            ${{ toJson(inputs) }}
-            ```
-          embed-url: https://github.com/facebook/react/actions/runs/${{ github.run_id }}
 
   publish_prerelease_canary:
-    if: ${{ !inputs.experimental_only }}
     name: Publish to Canary channel
     uses: facebook/react/.github/workflows/runtime_prereleases.yml@main
     permissions:
@@ -70,9 +33,6 @@ jobs:
       # downstream consumers might still expect that tag. We can remove this
       # after some time has elapsed and the change has been communicated.
       dist_tag: canary,next
-      only_packages: ${{ inputs.only_packages }}
-      skip_packages: ${{ inputs.skip_packages }}
-      dry: ${{ inputs.dry }}
     secrets:
       NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -88,15 +48,10 @@ jobs:
     # different versions of the same package, even if they use different
     # dist tags.
     needs: publish_prerelease_canary
-    # Ensures the job runs even if canary is skipped
-    if: always()
     with:
       commit_sha: ${{ inputs.prerelease_commit_sha }}
       release_channel: experimental
       dist_tag: experimental
-      only_packages: ${{ inputs.only_packages }}
-      skip_packages: ${{ inputs.skip_packages }}
-      dry: ${{ inputs.dry }}
     secrets:
       NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/runtime_prereleases_nightly.yml

@@ -21,10 +21,7 @@ jobs:
       commit_sha: ${{ github.sha }}
       release_channel: stable
       dist_tag: canary,next
-      enableFailureNotification: true
-      dry: false
     secrets:
-      DISCORD_WEBHOOK_URL: ${{ secrets.DISCORD_WEBHOOK_URL }}
       NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
@@ -43,9 +40,6 @@ jobs:
       commit_sha: ${{ github.sha }}
       release_channel: experimental
       dist_tag: experimental
-      enableFailureNotification: true
-      dry: false
     secrets:
-      DISCORD_WEBHOOK_URL: ${{ secrets.DISCORD_WEBHOOK_URL }}
       NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/runtime_releases_from_npm_manual.yml

@@ -110,7 +110,7 @@ jobs:
             --tags=${{ inputs.tags }} \
             --publishVersion=${{ inputs.version_to_publish }} \
             --onlyPackages=${{ inputs.only_packages }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
+            ${{ inputs.dry && '--dry'}}
       - if: '${{ inputs.skip_packages }}'
         name: 'Publish all packages EXCEPT ${{ inputs.skip_packages }}'
         run: |
@@ -119,7 +119,7 @@ jobs:
             --tags=${{ inputs.tags }} \
             --publishVersion=${{ inputs.version_to_publish }} \
             --skipPackages=${{ inputs.skip_packages }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
+            ${{ inputs.dry && '--dry'}}
       - name: Archive released package for debugging
         uses: actions/upload-artifact@v4
         with:

.github/workflows/shared_close_direct_sync_branch_prs.yml

@@ -18,7 +18,6 @@ jobs:
     permissions:
       # Used to create a review and close PRs
       pull-requests: write
-      contents: write
     steps:
       - name: Close PR
         uses: actions/github-script@v7

.github/workflows/shared_label_core_team_prs.yml

@@ -2,7 +2,6 @@ name: (Shared) Label Core Team PRs
 
 on:
   pull_request_target:
-    types: [opened]
 
 permissions: {}
 
@@ -12,20 +11,7 @@ env:
   SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
 
 jobs:
-  check_access:
-    runs-on: ubuntu-latest
-    outputs:
-      is_member_or_collaborator: ${{ steps.check_is_member_or_collaborator.outputs.is_member_or_collaborator }}
-    steps:
-      - run: echo ${{ github.event.pull_request.author_association }}
-      - name: Check is member or collaborator
-        id: check_is_member_or_collaborator
-        if: ${{ github.event.pull_request.author_association == 'MEMBER' || github.event.pull_request.author_association == 'COLLABORATOR' }}
-        run: echo "is_member_or_collaborator=true" >> "$GITHUB_OUTPUT"
-
   check_maintainer:
-    if: ${{ needs.check_access.outputs.is_member_or_collaborator == 'true' || needs.check_access.outputs.is_member_or_collaborator == true }}
-    needs: [check_access]
     uses: facebook/react/.github/workflows/shared_check_maintainer.yml@main
     permissions:
       # Used by check_maintainer

.github/workflows/shared_stale.yml

@@ -6,10 +6,7 @@ on:
     - cron: '0 * * * *'
   workflow_dispatch:
 
-permissions:
-  # https://github.com/actions/stale/tree/v9/?tab=readme-ov-file#recommended-permissions
-  issues: write
-  pull-requests: write
+permissions: {}
 
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles

.gitignore

@@ -23,7 +23,6 @@ chrome-user-data
 .vscode
 *.swp
 *.swo
-/tmp
 
 packages/react-devtools-core/dist
 packages/react-devtools-extensions/chrome/build

.nvmrc

@@ -1 +1 @@
-v20.19.0
+v18.20.1

.prettierrc.js

@@ -3,12 +3,13 @@
 const {esNextPaths} = require('./scripts/shared/pathsByLanguageVersion');
 
 module.exports = {
+  plugins: ['prettier-plugin-hermes-parser'],
   bracketSpacing: false,
   singleQuote: true,
   bracketSameLine: true,
   trailingComma: 'es5',
   printWidth: 80,
-  parser: 'flow',
+  parser: 'hermes',
   arrowParens: 'avoid',
   overrides: [
     {

CHANGELOG-canary.md

@@ -0,0 +1,18 @@
+## March 22, 2024 (18.3.0-canary-670811593-20240322)
+
+## React
+- Added `useActionState` to replace `useFormState` and added `pending` value ([#28491](https://github.com/facebook/react/pull/28491)).
+
+## October 5, 2023 (18.3.0-canary-546178f91-20231005)
+
+### React
+
+- Added support for async functions to be passed to `startTransition`. 
+- `useTransition` now triggers the nearest error boundary instead of a global error.
+- Added `useOptimistic`, a new Hook for handling optimistic UI updates. It optimistically updates the UI before receiving confirmation from a server or external source.
+
+### React DOM
+
+- Added support for passing async functions to the `action` prop on `<form>`. When the function passed to `action` is marked with [`'use server'`](https://react.dev/reference/react/use-server), the form is [progressively enhanced](https://developer.mozilla.org/en-US/docs/Glossary/Progressive_Enhancement).
+- Added `useFormStatus`, a new Hook for checking the submission state of a form.
+- Added `useFormState`, a new Hook for updating state upon form submission. When the function passed to `useFormState` is marked with [`'use server'`](https://react.dev/reference/react/use-server), the update is [progressively enhanced](https://developer.mozilla.org/en-US/docs/Glossary/Progressive_Enhancement).

CHANGELOG.md

@@ -1,146 +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
-* Fixed Owner Stacks to work with ES2015 function.name semantics ([#33680](https://github.com/facebook/react/pull/33680) by @hoxyq)
-
-## 19.1.0 (March 28, 2025)
-
-### Owner Stack
-
-An Owner Stack is a string representing the components that are directly responsible for rendering a particular component. You can log Owner Stacks when debugging or use Owner Stacks to enhance error overlays or other development tools. Owner Stacks are only available in development builds. Component Stacks in production are unchanged.
-
-* An Owner Stack is a development-only stack trace that helps identify which components are responsible for rendering a particular component. An Owner Stack is distinct from a Component Stacks, which shows the hierarchy of components leading to an error.
-* The [captureOwnerStack API](https://react.dev/reference/react/captureOwnerStack) is only available in development mode and returns a Owner Stack, if available. The API can be used to enhance error overlays or log component relationships when debugging. [#29923](https://github.com/facebook/react/pull/29923), [#32353](https://github.com/facebook/react/pull/32353), [#30306](https://github.com/facebook/react/pull/30306),
-[#32538](https://github.com/facebook/react/pull/32538), [#32529](https://github.com/facebook/react/pull/32529), [#32538](https://github.com/facebook/react/pull/32538)
-
-### React
-* Enhanced support for Suspense boundaries to be used anywhere, including the client, server, and during hydration. [#32069](https://github.com/facebook/react/pull/32069), [#32163](https://github.com/facebook/react/pull/32163), [#32224](https://github.com/facebook/react/pull/32224), [#32252](https://github.com/facebook/react/pull/32252)
-* Reduced unnecessary client rendering through improved hydration scheduling [#31751](https://github.com/facebook/react/pull/31751)
-* Increased priority of client rendered Suspense boundaries [#31776](https://github.com/facebook/react/pull/31776)
-* Fixed frozen fallback states by rendering unfinished Suspense boundaries on the client. [#31620](https://github.com/facebook/react/pull/31620)
-* Reduced garbage collection pressure by improving Suspense boundary retries. [#31667](https://github.com/facebook/react/pull/31667)
-* Fixed erroneous “Waiting for Paint” log when the passive effect phase was not delayed [#31526](https://github.com/facebook/react/pull/31526)
-* Fixed a regression causing key warnings for flattened positional children in development mode. [#32117](https://github.com/facebook/react/pull/32117)
-* Updated `useId` to use valid CSS selectors, changing format from `:r123:` to `«r123»`. [#32001](https://github.com/facebook/react/pull/32001)
-* Added a dev-only warning for null/undefined created in useEffect, useInsertionEffect, and useLayoutEffect. [#32355](https://github.com/facebook/react/pull/32355)
-* Fixed a bug where dev-only methods were exported in production builds. React.act is no longer available in production builds. [#32200](https://github.com/facebook/react/pull/32200)
-* Improved consistency across prod and dev to improve compatibility with Google Closure Compiler and bindings [#31808](https://github.com/facebook/react/pull/31808)
-* Improve passive effect scheduling for consistent task yielding. [#31785](https://github.com/facebook/react/pull/31785)
-* Fixed asserts in React Native when passChildrenWhenCloningPersistedNodes is enabled for OffscreenComponent rendering. [#32528](https://github.com/facebook/react/pull/32528)
-* Fixed component name resolution for Portal [#32640](https://github.com/facebook/react/pull/32640)
-* Added support for beforetoggle and toggle events on the dialog element. [#32479](https://github.com/facebook/react/pull/32479)
-
-### React DOM
-* Fixed double warning when the `href` attribute is an empty string [#31783](https://github.com/facebook/react/pull/31783)
- * Fixed an edge case where `getHoistableRoot()` didn’t work properly when the container was a Document [#32321](https://github.com/facebook/react/pull/32321)
-* Removed support for using HTML comments (e.g. `<!-- -->`) as a DOM container. [#32250](https://github.com/facebook/react/pull/32250)
-* Added support for `<script>` and `<template>` tags to be nested within `<select>` tags. [#31837](https://github.com/facebook/react/pull/31837)
-* Fixed responsive images to be preloaded as HTML instead of headers [#32445](https://github.com/facebook/react/pull/32445)
-
-### use-sync-external-store
-* Added `exports` field to `package.json` for `use-sync-external-store` to support various entrypoints. [#25231](https://github.com/facebook/react/pull/25231)
-
-### React Server Components
-* Added `unstable_prerender`, a new experimental API for prerendering React Server Components on the server [#31724](https://github.com/facebook/react/pull/31724)
-* Fixed an issue where streams would hang when receiving new chunks after a global error [#31840](https://github.com/facebook/react/pull/31840), [#31851](https://github.com/facebook/react/pull/31851)
-* Fixed an issue where pending chunks were counted twice. [#31833](https://github.com/facebook/react/pull/31833)
-* Added support for streaming in edge environments [#31852](https://github.com/facebook/react/pull/31852)
-* Added support for sending custom error names from a server so that they are available in the client for console replaying. [#32116](https://github.com/facebook/react/pull/32116)
-* Updated the server component wire format to remove IDs for hints and console.log because they have no return value [#31671](https://github.com/facebook/react/pull/31671)
-* 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.

MAINTAINERS

@@ -1,6 +1,5 @@
 acdlite
 eps1lon
-EugeneChoi4
 gaearon
 gnoff
 unstubbable

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 = '19.1.0';
 
 // 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': '5.2.0',
+  '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': '0.32.0',
+  'react-refresh': '0.17.0',
   'react-test-renderer': ReactVersion,
-  'use-subscription': '1.13.0',
-  'use-sync-external-store': '1.7.0',
-  scheduler: '0.28.0',
+  'use-subscription': '1.11.0',
+  'use-sync-external-store': '1.5.0',
+  scheduler: '0.26.0',
 };
 
 // These packages do not exist in the @canary or @latest channel, only

babel.config-ts.js

@@ -8,7 +8,6 @@ module.exports = {
     '@babel/plugin-syntax-jsx',
     '@babel/plugin-transform-flow-strip-types',
     ['@babel/plugin-transform-class-properties', {loose: true}],
-    ['@babel/plugin-transform-private-methods', {loose: true}],
     '@babel/plugin-transform-classes',
   ],
   presets: [

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": []
-  }
-}

compiler/.gitignore

@@ -1,14 +1,28 @@
 .DS_Store
 .spr.yml
 
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+
 node_modules
 .watchmanconfig
 .watchman-cookie-*
 dist
 .vscode
 !packages/playground/.vscode
+.spr.yml
 testfilter.txt
 
+bundle-oss.sh
+
 # forgive
 *.vsix
 .vscode-test

compiler/CHANGELOG.md

@@ -1,65 +0,0 @@
-## 19.1.0-rc.2 (May 14, 2025)
-
-## babel-plugin-react-compiler
-
-* Fix for string attribute values with emoji [#33096](https://github.com/facebook/react/pull/33096) by [@josephsavona](https://github.com/josephsavona)
-
-## 19.1.0-rc.1 (April 21, 2025)
-
-## eslint-plugin-react-hooks
-* Temporarily disable ref access in render validation [#32839](https://github.com/facebook/react/pull/32839) by [@poteto](https://github.com/poteto)
-* Fix type error with recommended config [#32666](https://github.com/facebook/react/pull/32666) by [@niklasholm](https://github.com/niklasholm)
-* Merge rule from eslint-plugin-react-compiler into `react-hooks` plugin [#32416](https://github.com/facebook/react/pull/32416) by [@michaelfaith](https://github.com/michaelfaith)
-* Add dev dependencies for typescript migration [#32279](https://github.com/facebook/react/pull/32279) by [@michaelfaith](https://github.com/michaelfaith)
-* Support v9 context api [#32045](https://github.com/facebook/react/pull/32045) by [@michaelfaith](https://github.com/michaelfaith)
-* Support eslint 8+ flat plugin syntax out of the box for eslint-plugin-react-compiler [#32120](https://github.com/facebook/react/pull/32120) by [@orta](https://github.com/orta)
-
-## babel-plugin-react-compiler
-* Support satisfies operator [#32742](https://github.com/facebook/react/pull/32742) by [@rodrigofariow](https://github.com/rodrigofariow)
-* Fix inferEffectDependencies lint false positives [#32769](https://github.com/facebook/react/pull/32769) by [@mofeiZ](https://github.com/mofeiZ)
-* Fix hoisting of let declarations [#32724](https://github.com/facebook/react/pull/32724) by [@mofeiZ](https://github.com/mofeiZ)
-* Avoid failing builds when import specifiers conflict or shadow vars [#32663](https://github.com/facebook/react/pull/32663) by [@mofeiZ](https://github.com/mofeiZ)
-* Optimize components declared with arrow function and implicit return and `compilationMode: 'infer'` [#31792](https://github.com/facebook/react/pull/31792) by [@dimaMachina](https://github.com/dimaMachina)
-* Validate static components [#32683](https://github.com/facebook/react/pull/32683) by [@josephsavona](https://github.com/josephsavona)
-* Hoist dependencies from functions more conservatively [#32616](https://github.com/facebook/react/pull/32616) by [@mofeiZ](https://github.com/mofeiZ)
-* Implement NumericLiteral as ObjectPropertyKey [#31791](https://github.com/facebook/react/pull/31791) by [@dimaMachina](https://github.com/dimaMachina)
-* Avoid bailouts when inserting gating [#32598](https://github.com/facebook/react/pull/32598) by [@mofeiZ](https://github.com/mofeiZ)
-* Stop bailing out early for hoisted gated functions [#32597](https://github.com/facebook/react/pull/32597) by [@mofeiZ](https://github.com/mofeiZ)
-* Add shape for Array.from [#32522](https://github.com/facebook/react/pull/32522) by [@mofeiZ](https://github.com/mofeiZ)
-* Patch array and argument spread mutability [#32521](https://github.com/facebook/react/pull/32521) by [@mofeiZ](https://github.com/mofeiZ)
-* Make CompilerError compatible with reflection [#32539](https://github.com/facebook/react/pull/32539) by [@poteto](https://github.com/poteto)
-* Add simple walltime measurement [#32331](https://github.com/facebook/react/pull/32331) by [@poteto](https://github.com/poteto)
-* Improve error messages for unhandled terminal and instruction kinds [#32324](https://github.com/facebook/react/pull/32324) by [@inottn](https://github.com/inottn)
-* Handle TSInstantiationExpression in lowerExpression [#32302](https://github.com/facebook/react/pull/32302) by [@inottn](https://github.com/inottn)
-* Fix invalid Array.map type [#32095](https://github.com/facebook/react/pull/32095) by [@mofeiZ](https://github.com/mofeiZ)
-* Patch for JSX escape sequences in @babel/generator [#32131](https://github.com/facebook/react/pull/32131) by [@mofeiZ](https://github.com/mofeiZ)
-* `JSXText` emits incorrect with bracket [#32138](https://github.com/facebook/react/pull/32138) by [@himself65](https://github.com/himself65)
-* Validation against calling impure functions [#31960](https://github.com/facebook/react/pull/31960) by [@josephsavona](https://github.com/josephsavona)
-* Always target node [#32091](https://github.com/facebook/react/pull/32091) by [@poteto](https://github.com/poteto)
-* Patch compilationMode:infer object method edge case [#32055](https://github.com/facebook/react/pull/32055) by [@mofeiZ](https://github.com/mofeiZ)
-* Generate ts defs [#31994](https://github.com/facebook/react/pull/31994) by [@poteto](https://github.com/poteto)
-* Relax react peer dep requirement [#31915](https://github.com/facebook/react/pull/31915) by [@poteto](https://github.com/poteto)
-* Allow type cast expressions with refs [#31871](https://github.com/facebook/react/pull/31871) by [@josephsavona](https://github.com/josephsavona)
-* Add shape for global Object.keys [#31583](https://github.com/facebook/react/pull/31583) by [@mofeiZ](https://github.com/mofeiZ)
-* Optimize method calls w props receiver [#31775](https://github.com/facebook/react/pull/31775) by [@josephsavona](https://github.com/josephsavona)
-* Fix dropped ref with spread props in InlineJsxTransform [#31726](https://github.com/facebook/react/pull/31726) by [@jackpope](https://github.com/jackpope)
-* Support for non-declatation for in/of iterators [#31710](https://github.com/facebook/react/pull/31710) by [@mvitousek](https://github.com/mvitousek)
-* Support for context variable loop iterators [#31709](https://github.com/facebook/react/pull/31709) by [@mvitousek](https://github.com/mvitousek)
-* Replace deprecated dependency in `eslint-plugin-react-compiler` [#31629](https://github.com/facebook/react/pull/31629) by [@rakleed](https://github.com/rakleed)
-* Support enableRefAsProp in jsx transform [#31558](https://github.com/facebook/react/pull/31558) by [@jackpope](https://github.com/jackpope)
-* Fix: ref.current now correctly reactive [#31521](https://github.com/facebook/react/pull/31521) by [@mofeiZ](https://github.com/mofeiZ)
-* Outline JSX with non-jsx children [#31442](https://github.com/facebook/react/pull/31442) by [@gsathya](https://github.com/gsathya)
-* Outline jsx with duplicate attributes [#31441](https://github.com/facebook/react/pull/31441) by [@gsathya](https://github.com/gsathya)
-* Store original and new prop names [#31440](https://github.com/facebook/react/pull/31440) by [@gsathya](https://github.com/gsathya)
-* Stabilize compiler output: sort deps and decls by name [#31362](https://github.com/facebook/react/pull/31362) by [@mofeiZ](https://github.com/mofeiZ)
-* Bugfix for hoistable deps for nested functions [#31345](https://github.com/facebook/react/pull/31345) by [@mofeiZ](https://github.com/mofeiZ)
-* Remove compiler runtime-compat fixture library [#31430](https://github.com/facebook/react/pull/31430) by [@poteto](https://github.com/poteto)
-* Wrap inline jsx transform codegen in conditional [#31267](https://github.com/facebook/react/pull/31267) by [@jackpope](https://github.com/jackpope)
-* Check if local identifier is a hook when resolving globals [#31384](https://github.com/facebook/react/pull/31384) by [@poteto](https://github.com/poteto)
-* Handle member expr as computed property [#31344](https://github.com/facebook/react/pull/31344) by [@gsathya](https://github.com/gsathya)
-* Fix to ref access check to ban ref?.current [#31360](https://github.com/facebook/react/pull/31360) by [@mvitousek](https://github.com/mvitousek)
-* InlineJSXTransform transforms jsx inside function expressions [#31282](https://github.com/facebook/react/pull/31282) by [@josephsavona](https://github.com/josephsavona)
-
-## Other
-* Add shebang to banner [#32225](https://github.com/facebook/react/pull/32225) by [@Jeremy-Hibiki](https://github.com/Jeremy-Hibiki)
-* remove terser from react-compiler-runtime build [#31326](https://github.com/facebook/react/pull/31326) by [@henryqdineen](https://github.com/henryqdineen)

compiler/CLAUDE.md

@@ -1,251 +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 tests matching a pattern
-# Example: yarn snap -p 'error.*'
-yarn snap -p <pattern>
-
-# Run a single fixture in debug mode. Use the path relative to the __tests__/fixtures/compiler directory
-# For each step of compilation, outputs the step name and state of the compiled program
-# Example: yarn snap -p simple.js -d
-yarn snap -p <file-basename> -d
-
-# Update fixture outputs (also works with -p)
-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

compiler/apps/playground/.gitignore

@@ -12,7 +12,6 @@
 # next.js
 /.next/
 /out/
-/next-env.d.ts
 
 # production
 /build

compiler/apps/playground/__tests__/e2e/__snapshots__/page.spec.ts/compilationMode-all-output.txt

@@ -1,4 +1,5 @@
-import { c as _c } from "react/compiler-runtime"; // @compilationMode:"all"
+import { c as _c } from "react/compiler-runtime"; // 
+        @compilationMode(all)
 function nonReactFn() {
   const $ = _c(1);
   let t0;

compiler/apps/playground/__tests__/e2e/__snapshots__/page.spec.ts/compilationMode-infer-output.txt

@@ -1,4 +1,4 @@
-// @compilationMode:"infer"
+// @compilationMode(infer)
 function nonReactFn() {
   return {};
 }

compiler/apps/playground/__tests__/e2e/__snapshots__/page.spec.ts/default-config.txt

@@ -1,5 +0,0 @@
-import type { PluginOptions } from 
-'babel-plugin-react-compiler/dist';
-({
-  //compilationMode: "all"
-} satisfies PluginOptions);

compiler/apps/playground/__tests__/e2e/__snapshots__/page.spec.ts/disableMemoizationForDebugging-output.txt

@@ -1,14 +0,0 @@
-import { c as _c } from "react/compiler-runtime";
-export default function TestComponent(t0) {
-  const $ = _c(2);
-  const { x } = t0;
-  let t1;
-  if ($[0] !== x || true) {
-    t1 = <Button>{x}</Button>;
-    $[0] = x;
-    $[1] = t1;
-  } else {
-    t1 = $[1];
-  }
-  return t1;
-}

compiler/apps/playground/__tests__/e2e/page.spec.ts

@@ -5,9 +5,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {expect, test, type Page} from '@playwright/test';
+import {expect, test} from '@playwright/test';
 import {encodeStore, type Store} from '../../lib/stores';
-import {defaultConfig} from '../../lib/defaultStore';
 import {format} from 'prettier';
 
 function isMonacoLoaded(): boolean {
@@ -21,16 +20,6 @@ function formatPrint(data: Array<string>): Promise<string> {
   return format(data.join(''), {parser: 'babel'});
 }
 
-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'});
-}
-
-const TEST_SOURCE = `export default function TestComponent({ x }) {
-  return <Button>{x}</Button>;
-}`;
-
 const TEST_CASE_INPUTS = [
   {
     name: 'module-scope-use-memo',
@@ -103,7 +92,7 @@ function useFoo(propVal: {+baz: number}) {
   },
   {
     name: 'compilationMode-infer',
-    input: `// @compilationMode:"infer"
+    input: `// @compilationMode(infer)
 function nonReactFn() {
   return {};
 }
@@ -112,7 +101,7 @@ function nonReactFn() {
   },
   {
     name: 'compilationMode-all',
-    input: `// @compilationMode:"all"
+    input: `// @compilationMode(all)
 function nonReactFn() {
   return {};
 }
@@ -132,9 +121,10 @@ test('editor should open successfully', async ({page}) => {
 
 test('editor should compile from hash successfully', async ({page}) => {
   const store: Store = {
-    source: TEST_SOURCE,
-    config: defaultConfig,
-    showInternals: false,
+    source: `export default function TestComponent({ x }) {
+      return <Button>{x}</Button>;
+    }
+    `,
   };
   const hash = encodeStore(store);
   await page.goto(`/#${hash}`, {waitUntil: 'networkidle'});
@@ -146,7 +136,7 @@ test('editor should compile from hash successfully', async ({page}) => {
     path: 'test-results/01-compiles-from-hash.png',
   });
   const text =
-    (await page.locator('.monaco-editor-output').allInnerTexts()) ?? [];
+    (await page.locator('.monaco-editor').nth(1).allInnerTexts()) ?? [];
   const output = await formatPrint(text);
 
   expect(output).not.toEqual('');
@@ -155,9 +145,10 @@ test('editor should compile from hash successfully', async ({page}) => {
 
 test('reset button works', async ({page}) => {
   const store: Store = {
-    source: TEST_SOURCE,
-    config: defaultConfig,
-    showInternals: false,
+    source: `export default function TestComponent({ x }) {
+      return <Button>{x}</Button>;
+    }
+    `,
   };
   const hash = encodeStore(store);
   await page.goto(`/#${hash}`, {waitUntil: 'networkidle'});
@@ -166,201 +157,33 @@ test('reset button works', async ({page}) => {
   // Reset button works
   page.on('dialog', dialog => dialog.accept());
   await page.getByRole('button', {name: 'Reset'}).click();
-  await expandConfigs(page);
-
   await page.screenshot({
     fullPage: true,
     path: 'test-results/02-reset-button-works.png',
   });
   const text =
-    (await page.locator('.monaco-editor-output').allInnerTexts()) ?? [];
+    (await page.locator('.monaco-editor').nth(1).allInnerTexts()) ?? [];
   const output = await formatPrint(text);
 
-  const configText =
-    (await page.locator('.monaco-editor-config').allInnerTexts()) ?? [];
-  const configOutput = configText.join('');
-
   expect(output).not.toEqual('');
   expect(output).toMatchSnapshot('02-default-output.txt');
-  expect(configOutput).not.toEqual('');
-  expect(configOutput).toMatchSnapshot('default-config.txt');
-});
-
-test('defaults load when only source is in Store', async ({page}) => {
-  // Test for backwards compatibility
-  const partial = {
-    source: TEST_SOURCE,
-  };
-  const hash = encodeStore(partial as Store);
-  await page.goto(`/#${hash}`, {waitUntil: 'networkidle'});
-  await page.waitForFunction(isMonacoLoaded);
-  await expandConfigs(page);
-
-  await page.screenshot({
-    fullPage: true,
-    path: 'test-results/03-missing-defaults.png',
-  });
-
-  // Config editor has default config
-  const configText =
-    (await page.locator('.monaco-editor-config').allInnerTexts()) ?? [];
-  const configOutput = configText.join('');
-
-  expect(configOutput).not.toEqual('');
-  expect(configOutput).toMatchSnapshot('default-config.txt');
-
-  const checkbox = page.locator('label.show-internals');
-  await expect(checkbox).not.toBeChecked();
-  const ssaTab = page.locator('text=SSA');
-  await expect(ssaTab).not.toBeVisible();
-});
-
-test('show internals button toggles correctly', async ({page}) => {
-  await page.goto(`/`, {waitUntil: 'networkidle'});
-  await page.waitForFunction(isMonacoLoaded);
-
-  // show internals should be off
-  const checkbox = page.locator('label.show-internals');
-  await checkbox.click();
-
-  await page.screenshot({
-    fullPage: true,
-    path: 'test-results/04-show-internals-on.png',
-  });
-
-  await expect(checkbox).toBeChecked();
-
-  const ssaTab = page.locator('text=SSA');
-  await expect(ssaTab).toBeVisible();
-});
-
-test('error is displayed when config has syntax error', async ({page}) => {
-  const store: Store = {
-    source: TEST_SOURCE,
-    config: `compilationMode: `,
-    showInternals: false,
-  };
-  const hash = encodeStore(store);
-  await page.goto(`/#${hash}`, {waitUntil: 'networkidle'});
-  await page.waitForFunction(isMonacoLoaded);
-  await expandConfigs(page);
-  await page.screenshot({
-    fullPage: true,
-    path: 'test-results/05-config-syntax-error.png',
-  });
-
-  const text =
-    (await page.locator('.monaco-editor-output').allInnerTexts()) ?? [];
-  const output = text.join('');
-
-  // Remove hidden chars
-  expect(output.replace(/\s+/g, ' ')).toContain('Invalid override format');
-});
-
-test('error is displayed when config has validation error', async ({page}) => {
-  const store: Store = {
-    source: TEST_SOURCE,
-    config: `import type { PluginOptions } from 'babel-plugin-react-compiler/dist';
-
-({
-  compilationMode: "123"
-} satisfies PluginOptions);`,
-    showInternals: false,
-  };
-  const hash = encodeStore(store);
-  await page.goto(`/#${hash}`, {waitUntil: 'networkidle'});
-  await page.waitForFunction(isMonacoLoaded);
-  await expandConfigs(page);
-  await page.screenshot({
-    fullPage: true,
-    path: 'test-results/06-config-validation-error.png',
-  });
-
-  const text =
-    (await page.locator('.monaco-editor-output').allInnerTexts()) ?? [];
-  const output = text.join('');
-
-  expect(output.replace(/\s+/g, ' ')).toContain('Unexpected compilationMode');
-});
-
-test('disableMemoizationForDebugging flag works as expected', async ({
-  page,
-}) => {
-  const store: Store = {
-    source: TEST_SOURCE,
-    config: `import type { PluginOptions } from 'babel-plugin-react-compiler/dist';
-
-({
-  environment: {
-    disableMemoizationForDebugging: true
-  }
-} satisfies PluginOptions);`,
-    showInternals: false,
-  };
-  const hash = encodeStore(store);
-  await page.goto(`/#${hash}`, {waitUntil: 'networkidle'});
-  await page.waitForFunction(isMonacoLoaded);
-  await expandConfigs(page);
-  await page.screenshot({
-    fullPage: true,
-    path: 'test-results/07-config-disableMemoizationForDebugging-flag.png',
-  });
-
-  const text =
-    (await page.locator('.monaco-editor-output').allInnerTexts()) ?? [];
-  const output = await formatPrint(text);
-
-  expect(output).not.toEqual('');
-  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: ${t.name}`, async ({page}) => {
     const store: Store = {
       source: t.input,
-      config: defaultConfig,
-      showInternals: false,
     };
     const hash = encodeStore(store);
     await page.goto(`/#${hash}`, {waitUntil: 'networkidle'});
     await page.waitForFunction(isMonacoLoaded);
     await page.screenshot({
       fullPage: true,
-      path: `test-results/08-0${idx}-${t.name}.png`,
+      path: `test-results/03-0${idx}-${t.name}.png`,
     });
 
     const text =
-      (await page.locator('.monaco-editor-output').allInnerTexts()) ?? [];
+      (await page.locator('.monaco-editor').nth(1).allInnerTexts()) ?? [];
     let output: string;
     if (t.noFormat) {
       output = text.join('');

compiler/apps/playground/app/index.tsx

@@ -0,0 +1,56 @@
+/**
+ * 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 type {NextPage} from 'next';
+import Head from 'next/head';
+import {SnackbarProvider} from 'notistack';
+import {Editor, Header, StoreProvider} from '../components';
+import MessageSnackbar from '../components/Message';
+
+const Home: NextPage = () => {
+  return (
+    <div className="flex flex-col w-screen h-screen font-light">
+      <Head>
+        <title>
+          {process.env.NODE_ENV === 'development'
+            ? '[DEV] React Compiler Playground'
+            : 'React Compiler Playground'}
+        </title>
+        <meta
+          name="viewport"
+          content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0"></meta>
+        <link rel="icon" href="/favicon.ico" />
+        <link rel="manifest" href="/site.webmanifest" />
+        <link
+          rel="preload"
+          href="/fonts/Source-Code-Pro-Regular.woff2"
+          as="font"
+          type="font/woff2"
+          crossOrigin="anonymous"
+        />
+        <link
+          rel="preload"
+          href="/fonts/Optimistic_Display_W_Lt.woff2"
+          as="font"
+          type="font/woff2"
+          crossOrigin="anonymous"
+        />
+      </Head>
+      <StoreProvider>
+        <SnackbarProvider
+          preventDuplicate
+          maxSnack={10}
+          Components={{message: MessageSnackbar}}>
+          <Header />
+          <Editor />
+        </SnackbarProvider>
+      </StoreProvider>
+    </div>
+  );
+};
+
+export default Home;

compiler/apps/playground/components/AccordionWindow.tsx

@@ -1,126 +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 {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';
-
-type TabsRecord = Map<string, React.ReactNode>;
-
-export default function AccordionWindow(props: {
-  defaultTab: string | null;
-  tabs: TabsRecord;
-  tabsOpen: Set<string>;
-  setTabsOpen: (newTab: Set<string>) => void;
-  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>
-  );
-}
-
-function AccordionWindowItem({
-  name,
-  tabs,
-  tabsOpen,
-  setTabsOpen,
-  hasChanged,
-}: {
-  name: string;
-  tabs: TabsRecord;
-  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);
-    });
-  };
-
-  // Replace spaces with non-breaking spaces
-  const displayName = name.replace(/ /g, '\u00A0');
-
-  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>
-      ) : (
-        <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>
-  );
-}

compiler/apps/playground/components/Editor/ConfigEditor.tsx

@@ -1,221 +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 MonacoEditor, {loader, type Monaco} from '@monaco-editor/react';
-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 {Resizable} from 're-resizable';
-import {useStore, useStoreDispatch} from '../StoreContext';
-import {monacoConfigOptions} from './monacoOptions';
-import {IconChevron} from '../Icons/IconChevron';
-import {CONFIG_PANEL_TRANSITION} from '../../lib/transitionTypes';
-
-// @ts-expect-error - webpack asset/source loader handles .d.ts files as strings
-import compilerTypeDefs from 'babel-plugin-react-compiler/dist/index.d.ts';
-
-loader.config({monaco});
-
-export default function ConfigEditor({
-  formattedAppliedConfig,
-}: {
-  formattedAppliedConfig: string;
-}): React.ReactElement {
-  const [isExpanded, setIsExpanded] = useState(false);
-
-  // TODO: Add back <Activity> after upgrading next.js
-  return (
-    <>
-      <div
-        style={{
-          display: isExpanded ? 'block' : 'none',
-        }}>
-        {/* <Activity mode={isExpanded ? 'visible' : 'hidden'}> */}
-        <ExpandedEditor
-          onToggle={() => {
-            startTransition(() => {
-              addTransitionType(CONFIG_PANEL_TRANSITION);
-              setIsExpanded(false);
-            });
-          }}
-          formattedAppliedConfig={formattedAppliedConfig}
-        />
-      </div>
-      <div
-        style={{
-          display: !isExpanded ? 'block' : 'none',
-        }}>
-        {/* </Activity>
-        <Activity mode={isExpanded ? 'hidden' : 'visible'}></Activity> */}
-        <CollapsedEditor
-          onToggle={() => {
-            startTransition(() => {
-              addTransitionType(CONFIG_PANEL_TRANSITION);
-              setIsExpanded(true);
-            });
-          }}
-        />
-      </div>
-      {/* </Activity> */}
-    </>
-  );
-}
-
-function ExpandedEditor({
-  onToggle,
-  formattedAppliedConfig,
-}: {
-  onToggle: (expanded: boolean) => void;
-  formattedAppliedConfig: string;
-}): React.ReactElement {
-  const store = useStore();
-  const dispatchStore = useStoreDispatch();
-  const debounceTimerRef = useRef<NodeJS.Timeout | null>(null);
-
-  const handleChange: (value: string | undefined) => void = (
-    value: string | undefined,
-  ) => {
-    if (value === undefined) return;
-
-    if (debounceTimerRef.current) {
-      clearTimeout(debounceTimerRef.current);
-    }
-
-    debounceTimerRef.current = setTimeout(() => {
-      dispatchStore({
-        type: 'updateConfig',
-        payload: {
-          config: value,
-        },
-      });
-    }, 500); // 500ms debounce delay
-  };
-
-  const handleMount: (
-    _: editor.IStandaloneCodeEditor,
-    monaco: Monaco,
-  ) => void = (_, monaco) => {
-    // Add the babel-plugin-react-compiler type definitions to Monaco
-    monaco.languages.typescript.typescriptDefaults.addExtraLib(
-      //@ts-expect-error - compilerTypeDefs is a string
-      compilerTypeDefs,
-      'file:///node_modules/babel-plugin-react-compiler/dist/index.d.ts',
-    );
-    monaco.languages.typescript.typescriptDefaults.setCompilerOptions({
-      target: monaco.languages.typescript.ScriptTarget.Latest,
-      allowNonTsExtensions: true,
-      moduleResolution: monaco.languages.typescript.ModuleResolutionKind.NodeJs,
-      module: monaco.languages.typescript.ModuleKind.ESNext,
-      noEmit: true,
-      strict: false,
-      esModuleInterop: true,
-      allowSyntheticDefaultImports: true,
-      jsx: monaco.languages.typescript.JsxEmit.React,
-    });
-  };
-
-  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>
-
-          <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>
-          </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>
-        </div>
-      </Resizable>
-    </ViewTransition>
-  );
-}
-
-function CollapsedEditor({
-  onToggle,
-}: {
-  onToggle: () => void;
-}): React.ReactElement {
-  return (
-    <div
-      className="w-4 !h-[calc(100vh_-_3.5rem)]"
-      style={{position: 'relative'}}>
-      <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}
-        style={{
-          top: '50%',
-          marginTop: '-32px',
-          left: '-8px',
-          borderTopLeftRadius: 0,
-          borderBottomLeftRadius: 0,
-        }}>
-        <IconChevron displayDirection="right" className="text-blue-50" />
-      </div>
-    </div>
-  );
-}

compiler/apps/playground/components/Editor/EditorImpl.tsx

@@ -5,63 +5,289 @@
  * 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,
+  ErrorSeverity,
+  parseConfigPragmaForTests,
+  ValueKind,
+  type Hook,
+  PluginOptions,
+  CompilerPipelineValue,
+  parsePluginOptions,
+  printReactiveFunctionWithOutlined,
+  printFunctionWithOutlined,
 } from 'babel-plugin-react-compiler';
-import {useDeferredValue, useMemo, useState} from 'react';
-import {useStore} from '../StoreContext';
-import ConfigEditor from './ConfigEditor';
+import clsx from 'clsx';
+import invariant from 'invariant';
+import {useSnackbar} from 'notistack';
+import {useDeferredValue, useMemo} from 'react';
+import {useMountEffect} from '../../hooks';
+import {defaultStore} from '../../lib/defaultStore';
+import {
+  createMessage,
+  initStoreFromUrlOrLocalStorage,
+  MessageLevel,
+  MessageSource,
+  type Store,
+} from '../../lib/stores';
+import {useStore, useStoreDispatch} from '../StoreContext';
 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 compile(source: string): [CompilerOutput, 'flow' | 'typescript'] {
+  const results = new Map<string, Array<PrintedCompilerPipelineValue>>();
+  const error = new CompilerError();
+  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;
+  try {
+    // Extract the first line to quickly check for custom test directives
+    const pragma = source.substring(0, source.indexOf('\n'));
+    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}`);
+        }
+      }
+    };
+    const parsedOptions = parseConfigPragmaForTests(pragma, {
+      compilationMode: 'infer',
+    });
+    const opts: PluginOptions = parsePluginOptions({
+      ...parsedOptions,
+      environment: {
+        ...parsedOptions.environment,
+        customHooks: new Map([...COMMON_HOOKS]),
+      },
+      logger: {
+        debugLogIRs: logIR,
+        logEvent: () => {},
+      },
+    });
+    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.details.push(...err.details);
+    } else {
+      /**
+       * Handle unexpected failures by logging (to get a stack trace)
+       * and reporting
+       */
+      console.error(err);
+      error.details.push(
+        new CompilerErrorDetail({
+          severity: ErrorSeverity.Invariant,
+          reason: `Unexpected failure when transforming input! ${err}`,
+          loc: null,
+          suggestions: null,
+        }),
+      );
+    }
+  }
+  if (error.hasErrors()) {
+    return [{kind: 'err', results, error: error}, language];
+  }
+  return [{kind: 'ok', results, transformOutput}, language];
+}
 
 export default function Editor(): JSX.Element {
   const store = useStore();
   const deferredStore = useDeferredValue(store);
-  const [compilerOutput, language, appliedOptions] = useMemo(
-    () => compile(deferredStore.source, 'compiler', deferredStore.config),
-    [deferredStore.source, deferredStore.config],
+  const dispatchStore = useStoreDispatch();
+  const {enqueueSnackbar} = useSnackbar();
+  const [compilerOutput, language] = useMemo(
+    () => compile(deferredStore.source),
+    [deferredStore.source],
   );
-  const [linterOutput] = useMemo(
-    () => compile(deferredStore.source, 'linter', deferredStore.config),
-    [deferredStore.source, deferredStore.config],
-  );
-  const [formattedAppliedConfig, setFormattedAppliedConfig] = useState('');
 
-  let mergedOutput: CompilerOutput;
-  let errors: Array<CompilerErrorDetail | CompilerDiagnostic>;
-  if (compilerOutput.kind === 'ok') {
-    errors = linterOutput.kind === 'ok' ? [] : linterOutput.error.details;
-    mergedOutput = {
-      ...compilerOutput,
-      errors,
-    };
-  } else {
-    mergedOutput = compilerOutput;
-    errors = compilerOutput.error.details;
-  }
-
-  if (appliedOptions) {
-    const formatted = prettyFormat(appliedOptions, {
-      printFunctionName: false,
-      printBasicPrototype: false,
-    });
-    if (formatted !== formattedAppliedConfig) {
-      setFormattedAppliedConfig(formatted);
+  useMountEffect(() => {
+    let mountStore: Store;
+    try {
+      mountStore = initStoreFromUrlOrLocalStorage();
+    } catch (e) {
+      invariant(e instanceof Error, 'Only Error may be caught.');
+      enqueueSnackbar(e.message, {
+        variant: 'warning',
+        ...createMessage(
+          'Bad URL - fell back to the default Playground.',
+          MessageLevel.Info,
+          MessageSource.Playground,
+        ),
+      });
+      mountStore = defaultStore;
     }
-  }
+    dispatchStore({
+      type: 'setStore',
+      payload: {store: mountStore},
+    });
+  });
 
   return (
     <>
-      <div className="relative flex top-14">
-        <div className="flex-shrink-0">
-          <ConfigEditor formattedAppliedConfig={formattedAppliedConfig} />
+      <div className="relative flex basis top-14">
+        <div className={clsx('relative sm:basis-1/4')}>
+          <Input
+            language={language}
+            errors={
+              compilerOutput.kind === 'err' ? compilerOutput.error.details : []
+            }
+          />
         </div>
-        <div className="flex flex-1 min-w-0">
-          <Input language={language} errors={errors} />
-          <Output store={deferredStore} compilerOutput={mergedOutput} />
+        <div className={clsx('flex sm:flex flex-wrap')}>
+          <Output store={deferredStore} compilerOutput={compilerOutput} />
         </div>
       </div>
     </>

compiler/apps/playground/components/Editor/Input.tsx

@@ -6,31 +6,22 @@
  */
 
 import MonacoEditor, {loader, type Monaco} from '@monaco-editor/react';
-import {
-  CompilerErrorDetail,
-  CompilerDiagnostic,
-} from 'babel-plugin-react-compiler';
+import {CompilerErrorDetail} from 'babel-plugin-react-compiler';
 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 {Resizable} from 're-resizable';
+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';
 
 loader.config({monaco});
 
 type Props = {
-  errors: Array<CompilerErrorDetail | CompilerDiagnostic>;
+  errors: Array<CompilerErrorDetail>;
   language: 'flow' | 'typescript';
 };
 
@@ -45,13 +36,13 @@ export default function Input({errors, language}: Props): JSX.Element {
     const uri = monaco.Uri.parse(`file:///index.js`);
     const model = monaco.editor.getModel(uri);
     invariant(model, 'Model must exist for the selected input file.');
-    renderReactCompilerMarkers({
-      monaco,
-      model,
-      details: errors,
-      source: store.source,
-    });
-  }, [monaco, errors, store.source]);
+    renderReactCompilerMarkers({monaco, model, details: errors});
+    /**
+     * N.B. that `tabSize` is a model property, not an editor property.
+     * So, the tab size has to be set per model.
+     */
+    model.updateOptions({tabSize: 2});
+  }, [monaco, errors]);
 
   useEffect(() => {
     /**
@@ -83,11 +74,11 @@ export default function Input({errors, language}: Props): JSX.Element {
     });
   }, [monaco, language]);
 
-  const handleChange: (value: string | undefined) => void = async value => {
+  const handleChange: (value: string | undefined) => void = value => {
     if (!value) return;
 
     dispatchStore({
-      type: 'updateSource',
+      type: 'updateFile',
       payload: {
         source: value,
       },
@@ -139,42 +130,30 @@ export default function Input({errors, language}: Props): JSX.Element {
     });
   };
 
-  const editorContent = (
-    <MonacoEditor
-      path={'index.js'}
-      /**
-       * .js and .jsx files are specified to be TS so that Monaco can actually
-       * check their syntax using its TS language service. They are still JS files
-       * due to their extensions, so TS language features don't work.
-       */
-      language={'javascript'}
-      value={store.source}
-      onMount={handleMount}
-      onChange={handleChange}
-      className="monaco-editor-input"
-      options={monacoOptions}
-      loading={''}
-    />
-  );
-
-  const tabs = new Map([['Input', editorContent]]);
-  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">
-          <TabbedWindow
-            tabs={tabs}
-            activeTab={activeTab}
-            onTabChange={setActiveTab}
-          />
-        </div>
-      </div>
-    </ViewTransition>
+    <div className="relative flex flex-col flex-none border-r border-gray-200">
+      <Resizable
+        minWidth={650}
+        enable={{right: true}}
+        /**
+         * Restrict MonacoEditor's height, since the config autoLayout:true
+         * will grow the editor to fit within parent element
+         */
+        className="!h-[calc(100vh_-_3.5rem)]">
+        <MonacoEditor
+          path={'index.js'}
+          /**
+           * .js and .jsx files are specified to be TS so that Monaco can actually
+           * check their syntax using its TS language service. They are still JS files
+           * due to their extensions, so TS language features don't work.
+           */
+          language={'javascript'}
+          value={store.source}
+          onMount={handleMount}
+          onChange={handleChange}
+          options={monacoOptions}
+        />
+      </Resizable>
+    </div>
   );
 }

compiler/apps/playground/components/Editor/Output.tsx

@@ -11,46 +11,19 @@ import {
   InformationCircleIcon,
 } from '@heroicons/react/outline';
 import MonacoEditor, {DiffEditor} from '@monaco-editor/react';
-import {
-  CompilerErrorDetail,
-  CompilerDiagnostic,
-  type CompilerError,
-} from 'babel-plugin-react-compiler';
+import {type CompilerError} from 'babel-plugin-react-compiler';
 import parserBabel from 'prettier/plugins/babel';
 import * as prettierPluginEstree from 'prettier/plugins/estree';
 import * as prettier from 'prettier/standalone';
+import {memo, ReactNode, useEffect, useState} from 'react';
 import {type Store} from '../../lib/stores';
-import {
-  memo,
-  ReactNode,
-  use,
-  useState,
-  Suspense,
-  unstable_ViewTransition as ViewTransition,
-  unstable_addTransitionType as addTransitionType,
-  startTransition,
-} 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);
 
 export default MemoizedOutput;
 
-export const BASIC_OUTPUT_TAB_NAMES = ['Output', 'SourceMap'];
-
-const tabifyCache = new LRUCache<Store, Promise<Map<string, ReactNode>>>({
-  max: 5,
-});
-
 export type PrintedCompilerPipelineValue =
   | {
       kind: 'hir';
@@ -71,7 +44,6 @@ export type CompilerOutput =
       kind: 'ok';
       transformOutput: CompilerTransformOutput;
       results: Map<string, Array<PrintedCompilerPipelineValue>>;
-      errors: Array<CompilerErrorDetail | CompilerDiagnostic>;
     }
   | {
       kind: 'err';
@@ -87,16 +59,12 @@ type Props = {
 async function tabify(
   source: string,
   compilerOutput: CompilerOutput,
-  showInternals: boolean,
 ): Promise<Map<string, ReactNode>> {
   const tabs = new Map<string, React.ReactNode>();
   const reorderedTabs = new Map<string, React.ReactNode>();
   const concattedResults = new Map<string, string>();
   // Concat all top level function declaration results into a single tab for each pass
   for (const [passName, results] of compilerOutput.results) {
-    if (!showInternals && !BASIC_OUTPUT_TAB_NAMES.includes(passName)) {
-      continue;
-    }
     for (const result of results) {
       switch (result.kind) {
         case 'hir': {
@@ -155,36 +123,10 @@ async function tabify(
       parser: transformOutput.language === 'flow' ? 'babel-flow' : 'babel-ts',
       plugins: [parserBabel, prettierPluginEstree],
     });
-
-    let output: string;
-    let language: string;
-    if (compilerOutput.errors.length === 0) {
-      output = code;
-      language = 'javascript';
-    } else {
-      language = 'markdown';
-      output = `
-# Summary
-
-React Compiler compiled this function successfully, but there are lint errors that indicate potential issues with the original code.
-
-## ${compilerOutput.errors.length} Lint Errors
-
-${compilerOutput.errors.map(e => e.printErrorMessage(source, {eslint: false})).join('\n\n')}
-
-## Output
-
-\`\`\`js
-${code}
-\`\`\`
-`.trim();
-    }
-
     reorderedTabs.set(
-      'Output',
+      'JS',
       <TextTabContent
-        output={output}
-        language={language}
+        output={code}
         diff={null}
         showInfoPanel={false}></TextTabContent>,
     );
@@ -200,18 +142,6 @@ ${code}
         </>,
       );
     }
-  } else if (compilerOutput.kind === 'err') {
-    const errors = compilerOutput.error.printErrorMessage(source, {
-      eslint: false,
-    });
-    reorderedTabs.set(
-      'Output',
-      <TextTabContent
-        output={errors}
-        language="markdown"
-        diff={null}
-        showInfoPanel={false}></TextTabContent>,
-    );
   }
   tabs.forEach((tab, name) => {
     reorderedTabs.set(name, tab);
@@ -219,25 +149,6 @@ ${code}
   return reorderedTabs;
 }
 
-function tabifyCached(
-  store: Store,
-  compilerOutput: CompilerOutput,
-): Promise<Map<string, ReactNode>> {
-  const cached = tabifyCache.get(store);
-  if (cached) return cached;
-  const result = tabify(store.source, compilerOutput, store.showInternals);
-  tabifyCache.set(store, result);
-  return result;
-}
-
-function Fallback(): JSX.Element {
-  return (
-    <div className="w-full h-monaco_small sm:h-monaco flex items-center justify-center">
-      Loading...
-    </div>
-  );
-}
-
 function utf16ToUTF8(s: string): string {
   return unescape(encodeURIComponent(s));
 }
@@ -251,40 +162,17 @@ function getSourceMapUrl(code: string, map: string): string | null {
 }
 
 function Output({store, compilerOutput}: Props): JSX.Element {
-  return (
-    <Suspense fallback={<Fallback />}>
-      <OutputContent store={store} compilerOutput={compilerOutput} />
-    </Suspense>
+  const [tabsOpen, setTabsOpen] = useState<Set<string>>(() => new Set(['JS']));
+  const [tabs, setTabs] = useState<Map<string, React.ReactNode>>(
+    () => new Map(),
   );
-}
+  useEffect(() => {
+    tabify(store.source, compilerOutput).then(tabs => {
+      setTabs(tabs);
+    });
+  }, [store.source, compilerOutput]);
 
-function OutputContent({store, compilerOutput}: Props): JSX.Element {
-  const [tabsOpen, setTabsOpen] = useState<Set<string>>(
-    () => new Set(['Output']),
-  );
-  const [activeTab, setActiveTab] = useState<string>('Output');
-
-  /*
-   * Update the active tab back to the output or errors tab when the compilation state
-   * changes between success/failure.
-   */
-  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');
-      });
-    }
-  }
-
-  const changedPasses: Set<string> = new Set(['Output', 'HIR']); // Initial and final passes should always be bold
+  const changedPasses: Set<string> = new Set(['JS', 'HIR']); // Initial and final passes should always be bold
   let lastResult: string = '';
   for (const [passName, results] of compilerOutput.results) {
     for (const result of results) {
@@ -298,40 +186,31 @@ function OutputContent({store, compilerOutput}: Props): JSX.Element {
       lastResult = currResult;
     }
   }
-  const tabs = use(tabifyCached(store, compilerOutput));
-
-  if (!store.showInternals) {
-    return (
-      <ViewTransition
-        update={{
-          [CONFIG_PANEL_TRANSITION]: 'container',
-          [TOGGLE_INTERNALS_TRANSITION]: '',
-          default: 'none',
-        }}>
-        <TabbedWindow
-          tabs={tabs}
-          activeTab={activeTab}
-          onTabChange={setActiveTab}
-        />
-      </ViewTransition>
-    );
-  }
 
   return (
-    <ViewTransition
-      update={{
-        [CONFIG_PANEL_TRANSITION]: 'accordion-container',
-        [TOGGLE_INTERNALS_TRANSITION]: '',
-        default: 'none',
-      }}>
-      <AccordionWindow
-        defaultTab={store.showInternals ? 'HIR' : 'Output'}
+    <>
+      <TabbedWindow
+        defaultTab="HIR"
         setTabsOpen={setTabsOpen}
         tabsOpen={tabsOpen}
         tabs={tabs}
         changedPasses={changedPasses}
       />
-    </ViewTransition>
+      {compilerOutput.kind === 'err' ? (
+        <div
+          className="flex flex-wrap absolute bottom-0 bg-white grow border-y border-grey-200 transition-all ease-in"
+          style={{width: 'calc(100vw - 650px)'}}>
+          <div className="w-full p-4 basis-full border-b">
+            <h2>COMPILER ERRORS</h2>
+          </div>
+          <pre
+            className="p-4 basis-full text-red-600 overflow-y-scroll whitespace-pre-wrap"
+            style={{width: 'calc(100vw - 650px)', height: '150px'}}>
+            <code>{compilerOutput.error.toString()}</code>
+          </pre>
+        </div>
+      ) : null}
+    </>
   );
 }
 
@@ -339,12 +218,10 @@ function TextTabContent({
   output,
   diff,
   showInfoPanel,
-  language,
 }: {
   output: string;
   diff: string | null;
   showInfoPanel: boolean;
-  language: string;
 }): JSX.Element {
   const [diffMode, setDiffMode] = useState(false);
   return (
@@ -383,29 +260,20 @@ function TextTabContent({
         <DiffEditor
           original={diff}
           modified={output}
-          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,
           }}
         />
       ) : (
         <MonacoEditor
-          language={language ?? 'javascript'}
+          defaultLanguage="javascript"
           value={output}
-          loading={''}
-          className="monaco-editor-output"
           options={{
             ...monacoOptions,
             readOnly: true,

compiler/apps/playground/components/Editor/monacoOptions.ts

@@ -28,18 +28,5 @@ export const monacoOptions: Partial<EditorProps['options']> = {
 
   automaticLayout: true,
   wordWrap: 'on',
-  wrappingIndent: 'same',
-
-  tabSize: 2,
-};
-
-export const monacoConfigOptions: Partial<EditorProps['options']> = {
-  ...monacoOptions,
-  lineNumbers: 'off',
-  renderLineHighlight: 'none',
-  overviewRulerBorder: false,
-  overviewRulerLanes: 0,
-  fontSize: 12,
-  scrollBeyondLastLine: false,
-  glyphMargin: false,
+  wrappingIndent: 'deepIndent',
 };

compiler/apps/playground/components/Header.tsx

@@ -10,20 +10,14 @@ 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';
+import {useStoreDispatch} from './StoreContext';
 
 export default function Header(): JSX.Element {
   const [showCheck, setShowCheck] = useState(false);
-  const store = useStore();
   const dispatchStore = useStoreDispatch();
   const {enqueueSnackbar, closeSnackbar} = useSnackbar();
 
@@ -62,32 +56,6 @@ export default function Header(): JSX.Element {
         <p className="hidden select-none sm:block">React Compiler Playground</p>
       </div>
       <div className="flex items-center text-[15px] gap-4">
-        <div className="flex items-center gap-2">
-          <label className="show-internals relative inline-block w-[34px] h-5">
-            <input
-              type="checkbox"
-              checked={store.showInternals}
-              onChange={() =>
-                startTransition(() => {
-                  addTransitionType(TOGGLE_INTERNALS_TRANSITION);
-                  dispatchStore({type: 'toggleInternals'});
-                })
-              }
-              className="absolute opacity-0 cursor-pointer h-full w-full m-0"
-            />
-            <span
-              className={clsx(
-                'absolute inset-0 rounded-full cursor-pointer transition-all duration-250',
-                "before:content-[''] before:absolute before:w-4 before:h-4 before:left-0.5 before:bottom-0.5",
-                'before:bg-white before:rounded-full before:transition-transform before:duration-250',
-                'focus-within:shadow-[0_0_1px_#2196F3]',
-                store.showInternals
-                  ? 'bg-link before:translate-x-3.5'
-                  : 'bg-gray-300',
-              )}></span>
-          </label>
-          <span className="text-secondary">Show Internals</span>
-        </div>
         <button
           title="Reset Playground"
           aria-label="Reset Playground"

compiler/apps/playground/components/Icons/IconChevron.tsx

@@ -1,41 +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 {memo} from 'react';
-
-export const IconChevron = memo<
-  JSX.IntrinsicElements['svg'] & {
-    /**
-     * The direction the arrow should point.
-     */
-    displayDirection: 'right' | 'left';
-  }
->(function IconChevron({className, displayDirection, ...props}) {
-  const rotationClass =
-    displayDirection === 'left' ? 'rotate-90' : '-rotate-90';
-  const classes = className ? `${rotationClass} ${className}` : rotationClass;
-
-  return (
-    <svg
-      className={classes}
-      xmlns="http://www.w3.org/2000/svg"
-      width="20"
-      height="20"
-      viewBox="0 0 20 20"
-      {...props}>
-      <g fill="none" fillRule="evenodd" transform="translate(-446 -398)">
-        <path
-          fill="currentColor"
-          fillRule="nonzero"
-          d="M95.8838835,240.366117 C95.3957281,239.877961 94.6042719,239.877961 94.1161165,240.366117 C93.6279612,240.854272 93.6279612,241.645728 94.1161165,242.133883 L98.6161165,246.633883 C99.1042719,247.122039 99.8957281,247.122039 100.383883,246.633883 L104.883883,242.133883 C105.372039,241.645728 105.372039,240.854272 104.883883,240.366117 C104.395728,239.877961 103.604272,239.877961 103.116117,240.366117 L99.5,243.982233 L95.8838835,240.366117 Z"
-          transform="translate(356.5 164.5)"
-        />
-        <polygon points="446 418 466 418 466 398 446 398" />
-      </g>
-    </svg>
-  );
-});

compiler/apps/playground/components/StoreContext.tsx

@@ -6,14 +6,10 @@
  */
 
 import type {Dispatch, ReactNode} from 'react';
-import {useState, useEffect, useReducer} from 'react';
+import {useEffect, useReducer} from 'react';
 import createContext from '../lib/createContext';
-import {emptyStore, defaultStore} from '../lib/defaultStore';
-import {
-  saveStore,
-  initStoreFromUrlOrLocalStorage,
-  type Store,
-} from '../lib/stores';
+import {emptyStore} from '../lib/defaultStore';
+import {saveStore, type Store} from '../lib/stores';
 
 const StoreContext = createContext<Store>();
 
@@ -34,20 +30,6 @@ export const useStoreDispatch = StoreDispatchContext.useContext;
  */
 export function StoreProvider({children}: {children: ReactNode}): JSX.Element {
   const [store, dispatch] = useReducer(storeReducer, emptyStore);
-  const [isPageReady, setIsPageReady] = useState<boolean>(false);
-
-  useEffect(() => {
-    let mountStore: Store;
-    try {
-      mountStore = initStoreFromUrlOrLocalStorage();
-    } catch (e) {
-      console.error('Failed to initialize store from URL or local storage', e);
-      mountStore = defaultStore;
-    }
-    dispatch({type: 'setStore', payload: {store: mountStore}});
-    setIsPageReady(true);
-  }, []);
-
   useEffect(() => {
     if (store !== emptyStore) {
       saveStore(store);
@@ -57,7 +39,7 @@ export function StoreProvider({children}: {children: ReactNode}): JSX.Element {
   return (
     <StoreContext.Provider value={store}>
       <StoreDispatchContext.Provider value={dispatch}>
-        {isPageReady ? children : null}
+        {children}
       </StoreDispatchContext.Provider>
     </StoreContext.Provider>
   );
@@ -71,19 +53,10 @@ type ReducerAction =
       };
     }
   | {
-      type: 'updateSource';
+      type: 'updateFile';
       payload: {
         source: string;
       };
-    }
-  | {
-      type: 'updateConfig';
-      payload: {
-        config: string;
-      };
-    }
-  | {
-      type: 'toggleInternals';
     };
 
 function storeReducer(store: Store, action: ReducerAction): Store {
@@ -92,28 +65,13 @@ function storeReducer(store: Store, action: ReducerAction): Store {
       const newStore = action.payload.store;
       return newStore;
     }
-    case 'updateSource': {
-      const source = action.payload.source;
+    case 'updateFile': {
+      const {source} = action.payload;
       const newStore = {
         ...store,
         source,
       };
       return newStore;
     }
-    case 'updateConfig': {
-      const config = action.payload.config;
-      const newStore = {
-        ...store,
-        config,
-      };
-      return newStore;
-    }
-    case 'toggleInternals': {
-      const newStore = {
-        ...store,
-        showInternals: !store.showInternals,
-      };
-      return newStore;
-    }
   }
 }

compiler/apps/playground/components/TabbedWindow.tsx

@@ -4,78 +4,103 @@
  * 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 clsx from 'clsx';
-import {TOGGLE_TAB_TRANSITION} from '../lib/transitionTypes';
 
-export default function TabbedWindow({
-  tabs,
-  activeTab,
-  onTabChange,
-}: {
-  tabs: Map<string, React.ReactNode>;
-  activeTab: string;
-  onTabChange: (tab: string) => void;
+import {Resizable} from 're-resizable';
+import React, {useCallback} from 'react';
+
+type TabsRecord = Map<string, React.ReactNode>;
+
+export default function TabbedWindow(props: {
+  defaultTab: string | null;
+  tabs: TabsRecord;
+  tabsOpen: Set<string>;
+  setTabsOpen: (newTab: Set<string>) => void;
+  changedPasses: Set<string>;
 }): 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>
+  if (props.tabs.size === 0) {
+    return (
+      <div
+        className="flex items-center justify-center"
+        style={{width: 'calc(100vw - 650px)'}}>
+        No compiler output detected, see errors below
       </div>
+    );
+  }
+  return (
+    <div className="flex flex-row">
+      {Array.from(props.tabs.keys()).map(name => {
+        return (
+          <TabbedWindowItem
+            name={name}
+            key={name}
+            tabs={props.tabs}
+            tabsOpen={props.tabsOpen}
+            setTabsOpen={props.setTabsOpen}
+            hasChanged={props.changedPasses.has(name)}
+          />
+        );
+      })}
+    </div>
+  );
+}
+
+function TabbedWindowItem({
+  name,
+  tabs,
+  tabsOpen,
+  setTabsOpen,
+  hasChanged,
+}: {
+  name: string;
+  tabs: TabsRecord;
+  tabsOpen: Set<string>;
+  setTabsOpen: (newTab: Set<string>) => void;
+  hasChanged: boolean;
+}): React.ReactElement {
+  const isShow = tabsOpen.has(name);
+
+  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');
+
+  return (
+    <div key={name} className="flex flex-row">
+      {isShow ? (
+        <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>
+      ) : (
+        <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>
   );
 }

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,
-  ];
-}

compiler/apps/playground/lib/defaultStore.ts

@@ -13,21 +13,10 @@ export default function MyApp() {
 }
 `;
 
-export const defaultConfig = `\
-import type { PluginOptions } from 'babel-plugin-react-compiler/dist';
-
-({
-  //compilationMode: "all"
-} satisfies PluginOptions);`;
-
 export const defaultStore: Store = {
   source: index,
-  config: defaultConfig,
-  showInternals: false,
 };
 
 export const emptyStore: Store = {
   source: '',
-  config: '',
-  showInternals: false,
 };

compiler/apps/playground/lib/reactCompilerMonacoDiagnostics.ts

@@ -6,11 +6,7 @@
  */
 
 import {Monaco} from '@monaco-editor/react';
-import {
-  CompilerDiagnostic,
-  CompilerErrorDetail,
-  ErrorSeverity,
-} from 'babel-plugin-react-compiler';
+import {CompilerErrorDetail, ErrorSeverity} from 'babel-plugin-react-compiler';
 import {MarkerSeverity, type editor} from 'monaco-editor';
 
 function mapReactCompilerSeverityToMonaco(
@@ -26,46 +22,38 @@ function mapReactCompilerSeverityToMonaco(
 }
 
 function mapReactCompilerDiagnosticToMonacoMarker(
-  detail: CompilerErrorDetail | CompilerDiagnostic,
+  detail: CompilerErrorDetail,
   monaco: Monaco,
-  source: string,
 ): editor.IMarkerData | null {
-  const loc = detail.primaryLocation();
-  if (loc == null || typeof loc === 'symbol') {
+  if (detail.loc == null || typeof detail.loc === 'symbol') {
     return null;
   }
   const severity = mapReactCompilerSeverityToMonaco(detail.severity, monaco);
-  let message = detail.printErrorMessage(source, {eslint: true});
+  let message = detail.printErrorMessage();
   return {
     severity,
     message,
-    startLineNumber: loc.start.line,
-    startColumn: loc.start.column + 1,
-    endLineNumber: loc.end.line,
-    endColumn: loc.end.column + 1,
+    startLineNumber: detail.loc.start.line,
+    startColumn: detail.loc.start.column + 1,
+    endLineNumber: detail.loc.end.line,
+    endColumn: detail.loc.end.column + 1,
   };
 }
 
 type ReactCompilerMarkerConfig = {
   monaco: Monaco;
   model: editor.ITextModel;
-  details: Array<CompilerErrorDetail | CompilerDiagnostic>;
-  source: string;
+  details: Array<CompilerErrorDetail>;
 };
 let decorations: Array<string> = [];
 export function renderReactCompilerMarkers({
   monaco,
   model,
   details,
-  source,
 }: ReactCompilerMarkerConfig): void {
   const markers: Array<editor.IMarkerData> = [];
   for (const detail of details) {
-    const marker = mapReactCompilerDiagnosticToMonacoMarker(
-      detail,
-      monaco,
-      source,
-    );
+    const marker = mapReactCompilerDiagnosticToMonacoMarker(detail, monaco);
     if (marker == null) {
       continue;
     }

compiler/apps/playground/lib/stores/store.ts

@@ -10,20 +10,18 @@ import {
   compressToEncodedURIComponent,
   decompressFromEncodedURIComponent,
 } from 'lz-string';
-import {defaultStore, defaultConfig} from '../defaultStore';
+import {defaultStore} from '../defaultStore';
 
 /**
  * Global Store for Playground
  */
 export interface Store {
   source: string;
-  config: string;
-  showInternals: boolean;
 }
 export function encodeStore(store: Store): string {
   return compressToEncodedURIComponent(JSON.stringify(store));
 }
-export function decodeStore(hash: string): any {
+export function decodeStore(hash: string): Store {
   return JSON.parse(decompressFromEncodedURIComponent(hash));
 }
 
@@ -64,14 +62,8 @@ export function initStoreFromUrlOrLocalStorage(): Store {
    */
   if (!encodedSource) return defaultStore;
 
-  const raw: any = decodeStore(encodedSource);
+  const raw = decodeStore(encodedSource);
 
   invariant(isValidStore(raw), 'Invalid Store');
-
-  // Make sure all properties are populated
-  return {
-    source: raw.source,
-    config: 'config' in raw && raw['config'] ? raw.config : defaultConfig,
-    showInternals: 'showInternals' in raw ? raw.showInternals : false,
-  };
+  return raw;
 }

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';

compiler/apps/playground/next-env.d.ts

@@ -0,0 +1,5 @@
+/// <reference types="next" />
+/// <reference types="next/image-types/global" />
+
+// NOTE: This file should not be edited
+// see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

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) => {

compiler/apps/playground/package.json

@@ -26,39 +26,34 @@
     "@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": "^1.42.1",
     "@use-gesture/react": "^10.2.22",
     "hermes-eslint": "^0.25.0",
     "hermes-parser": "^0.25.0",
     "invariant": "^2.2.4",
-    "lru-cache": "^11.2.2",
     "lz-string": "^1.5.0",
     "monaco-editor": "^0.52.0",
-    "next": "15.5.9",
+    "next": "^15.2.0-canary.64",
     "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": "^19.0.0",
+    "react-dom": "^19.0.0"
   },
   "devDependencies": {
     "@types/node": "18.11.9",
-    "@types/react": "19.2",
-    "@types/react-dom": "19.2",
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0",
     "autoprefixer": "^10.4.13",
     "clsx": "^1.2.1",
     "concurrently": "^7.4.0",
     "eslint": "^8.28.0",
-    "eslint-config-next": "15.5.2",
+    "eslint-config-next": "^15.0.1",
     "monaco-editor-webpack-plugin": "^7.1.0",
     "postcss": "^8.4.31",
     "tailwindcss": "^3.2.4",
     "wait-on": "^7.2.0"
-  },
-  "resolutions": {
-    "@types/react": "19.2",
-    "@types/react-dom": "19.2"
   }
 }

compiler/apps/playground/playwright.config.js

@@ -55,16 +55,12 @@ export default defineConfig({
     // contextOptions: {
     //   ignoreHTTPSErrors: true,
     // },
-    viewport: {width: 1920, height: 1080},
   },
 
   projects: [
     {
       name: 'chromium',
-      use: {
-        ...devices['Desktop Chrome'],
-        viewport: {width: 1920, height: 1080},
-      },
+      use: {...devices['Desktop Chrome']},
     },
     // {
     //   name: 'Desktop Firefox',

compiler/apps/playground/scripts/link-compiler.sh

@@ -8,8 +8,8 @@ set -eo pipefail
 
 HERE=$(pwd)
 
-cd ../../packages/react-compiler-runtime && yarn --silent link && cd "$HERE"
-cd ../../packages/babel-plugin-react-compiler && yarn --silent link && cd "$HERE"
+cd ../../packages/react-compiler-runtime && yarn --silent link && cd $HERE
+cd ../../packages/babel-plugin-react-compiler && yarn --silent link && cd $HERE
 
 yarn --silent link babel-plugin-react-compiler
 yarn --silent link react-compiler-runtime

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;
-}

compiler/apps/playground/tsconfig.json

@@ -6,9 +6,6 @@
       "dom.iterable",
       "esnext"
     ],
-    "types": [
-      "react/experimental"
-    ],
     "allowJs": true,
     "skipLibCheck": true,
     "strict": true,

compiler/package.json

@@ -19,8 +19,7 @@
     "test": "yarn workspaces run test",
     "snap": "yarn workspace babel-plugin-react-compiler run snap",
     "snap:build": "yarn workspace snap run build",
-    "npm:publish": "node scripts/release/publish",
-    "eslint-docs": "yarn workspace babel-plugin-react-compiler build && node scripts/build-eslint-docs.js"
+    "npm:publish": "node scripts/release/publish"
   },
   "dependencies": {
     "fs-extra": "^4.0.2",
@@ -38,7 +37,7 @@
     "prettier": "^3.3.3",
     "prettier-plugin-hermes-parser": "^0.26.0",
     "prompt-promise": "^1.0.3",
-    "rimraf": "^6.0.1",
+    "rimraf": "^5.0.10",
     "to-fast-properties": "^2.0.0",
     "tsup": "^8.4.0",
     "typescript": "^5.4.3",
@@ -46,6 +45,7 @@
     "yargs": "^17.7.2"
   },
   "resolutions": {
+    "rimraf": "5.0.10",
     "@babel/types": "7.26.3"
   },
   "packageManager": "yarn@1.22.22"

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",

compiler/packages/babel-plugin-react-compiler/src/Babel/BabelPlugin.ts

@@ -12,7 +12,6 @@ import {
   pipelineUsesReanimatedPlugin,
 } from '../Entrypoint/Reanimated';
 import validateNoUntransformedReferences from '../Entrypoint/ValidateNoUntransformedReferences';
-import {CompilerError} from '..';
 
 const ENABLE_REACT_COMPILER_TIMINGS =
   process.env['ENABLE_REACT_COMPILER_TIMINGS'] === '1';
@@ -35,58 +34,51 @@ export default function BabelPluginReactCompiler(
        */
       Program: {
         enter(prog, pass): void {
-          try {
-            const filename = pass.filename ?? 'unknown';
-            if (ENABLE_REACT_COMPILER_TIMINGS === true) {
-              performance.mark(`${filename}:start`, {
-                detail: 'BabelPlugin:Program:start',
-              });
-            }
-            let opts = parsePluginOptions(pass.opts);
-            const isDev =
-              (typeof __DEV__ !== 'undefined' && __DEV__ === true) ||
-              process.env['NODE_ENV'] === 'development';
-            if (
-              opts.enableReanimatedCheck === true &&
-              pipelineUsesReanimatedPlugin(pass.file.opts.plugins)
-            ) {
-              opts = injectReanimatedFlag(opts);
-            }
-            if (
-              opts.environment.enableResetCacheOnSourceFileChanges !== false &&
-              isDev
-            ) {
-              opts = {
-                ...opts,
-                environment: {
-                  ...opts.environment,
-                  enableResetCacheOnSourceFileChanges: true,
-                },
-              };
-            }
-            const result = compileProgram(prog, {
-              opts,
-              filename: pass.filename ?? null,
-              comments: pass.file.ast.comments ?? [],
-              code: pass.file.code,
+          const filename = pass.filename ?? 'unknown';
+          if (ENABLE_REACT_COMPILER_TIMINGS === true) {
+            performance.mark(`${filename}:start`, {
+              detail: 'BabelPlugin:Program:start',
+            });
+          }
+          let opts = parsePluginOptions(pass.opts);
+          const isDev =
+            (typeof __DEV__ !== 'undefined' && __DEV__ === true) ||
+            process.env['NODE_ENV'] === 'development';
+          if (
+            opts.enableReanimatedCheck === true &&
+            pipelineUsesReanimatedPlugin(pass.file.opts.plugins)
+          ) {
+            opts = injectReanimatedFlag(opts);
+          }
+          if (
+            opts.environment.enableResetCacheOnSourceFileChanges !== false &&
+            isDev
+          ) {
+            opts = {
+              ...opts,
+              environment: {
+                ...opts.environment,
+                enableResetCacheOnSourceFileChanges: true,
+              },
+            };
+          }
+          const result = compileProgram(prog, {
+            opts,
+            filename: pass.filename ?? null,
+            comments: pass.file.ast.comments ?? [],
+            code: pass.file.code,
+          });
+          validateNoUntransformedReferences(
+            prog,
+            pass.filename ?? null,
+            opts.logger,
+            opts.environment,
+            result,
+          );
+          if (ENABLE_REACT_COMPILER_TIMINGS === true) {
+            performance.mark(`${filename}:end`, {
+              detail: 'BabelPlugin:Program:end',
             });
-            validateNoUntransformedReferences(
-              prog,
-              pass.filename ?? null,
-              opts.logger,
-              opts.environment,
-              result,
-            );
-            if (ENABLE_REACT_COMPILER_TIMINGS === true) {
-              performance.mark(`${filename}:end`, {
-                detail: 'BabelPlugin:Program:end',
-              });
-            }
-          } catch (e) {
-            if (e instanceof CompilerError) {
-              throw e.withPrintedMessage(pass.file.code, {eslint: false});
-            }
-            throw e;
           }
         },
         exit(_, pass): void {

compiler/packages/babel-plugin-react-compiler/src/Babel/RunReactCompilerBabelPlugin.ts

@@ -17,7 +17,7 @@ export function runBabelPluginReactCompiler(
   text: string,
   file: string,
   language: 'flow' | 'typescript',
-  options: PluginOptions | null,
+  options: Partial<PluginOptions> | null,
   includeAst: boolean = false,
 ): BabelCore.BabelFileResult {
   const ast = BabelParser.parse(text, {

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Gating.ts

@@ -51,26 +51,12 @@ function insertAdditionalFunctionDeclaration(
   CompilerError.invariant(originalFnName != null && compiled.id != null, {
     reason:
       'Expected function declarations that are referenced elsewhere to have a named identifier',
-    description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: fnPath.node.loc ?? null,
-        message: null,
-      },
-    ],
+    loc: fnPath.node.loc ?? null,
   });
   CompilerError.invariant(originalFnParams.length === compiledParams.length, {
     reason:
       'Expected React Compiler optimized function declarations to have the same number of parameters as source',
-    description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: fnPath.node.loc ?? null,
-        message: null,
-      },
-    ],
+    loc: fnPath.node.loc ?? null,
   });
 
   const gatingCondition = t.identifier(
@@ -154,13 +140,7 @@ export function insertGatedFunctionDeclaration(
     CompilerError.invariant(compiled.type === 'FunctionDeclaration', {
       reason: 'Expected compiled node type to match input type',
       description: `Got ${compiled.type} but expected FunctionDeclaration`,
-      details: [
-        {
-          kind: 'error',
-          loc: fnPath.node.loc ?? null,
-          message: null,
-        },
-      ],
+      loc: fnPath.node.loc ?? null,
     });
     insertAdditionalFunctionDeclaration(
       fnPath,

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Imports.ts

@@ -9,7 +9,7 @@ import {NodePath} from '@babel/core';
 import * as t from '@babel/types';
 import {Scope as BabelScope} from '@babel/traverse';
 
-import {CompilerError, ErrorCategory} from '../CompilerError';
+import {CompilerError, ErrorSeverity} from '../CompilerError';
 import {
   EnvironmentConfig,
   GeneratedSource,
@@ -18,9 +18,8 @@ import {
 import {getOrInsertWith} from '../Utils/utils';
 import {ExternalFunction, isHookName} from '../HIR/Environment';
 import {Err, Ok, Result} from '../Utils/Result';
-import {LoggerEvent, ParsedPluginOptions} from './Options';
-import {BabelFn, getReactCompilerRuntimeModule} from './Program';
-import {SuppressionRange} from './Suppression';
+import {CompilerReactTarget} from './Options';
+import {getReactCompilerRuntimeModule} from './Program';
 
 export function validateRestrictedImports(
   path: NodePath<t.Program>,
@@ -38,7 +37,7 @@ export function validateRestrictedImports(
     ImportDeclaration(importDeclPath) {
       if (restrictedImports.has(importDeclPath.node.source.value)) {
         error.push({
-          category: ErrorCategory.Todo,
+          severity: ErrorSeverity.Todo,
           reason: 'Bailing out due to blocklisted import',
           description: `Import from module ${importDeclPath.node.source.value}`,
           loc: importDeclPath.node.loc ?? null,
@@ -46,72 +45,39 @@ export function validateRestrictedImports(
       }
     },
   });
-  if (error.hasAnyErrors()) {
+  if (error.hasErrors()) {
     return error;
   } else {
     return null;
   }
 }
 
-type ProgramContextOptions = {
-  program: NodePath<t.Program>;
-  suppressions: Array<SuppressionRange>;
-  opts: ParsedPluginOptions;
-  filename: string | null;
-  code: string | null;
-  hasModuleScopeOptOut: boolean;
-};
 export class ProgramContext {
-  /**
-   * Program and environment context
-   */
+  /* Program and environment context */
   scope: BabelScope;
-  opts: ParsedPluginOptions;
-  filename: string | null;
-  code: string | null;
   reactRuntimeModule: string;
-  suppressions: Array<SuppressionRange>;
-  hasModuleScopeOptOut: boolean;
+  hookPattern: string | null;
 
-  /*
-   * This is a hack to work around what seems to be a Babel bug. Babel doesn't
-   * consistently respect the `skip()` function to avoid revisiting a node within
-   * a pass, so we use this set to track nodes that we have compiled.
-   */
-  alreadyCompiled: WeakSet<object> | Set<object> = new (WeakSet ?? Set)();
   // known generated or referenced identifiers in the program
   knownReferencedNames: Set<string> = new Set();
   // generated imports
   imports: Map<string, Map<string, NonLocalImportSpecifier>> = new Map();
 
-  /**
-   * Metadata from compilation
-   */
-  retryErrors: Array<{fn: BabelFn; error: CompilerError}> = [];
-  inferredEffectLocations: Set<t.SourceLocation> = new Set();
-
-  constructor({
-    program,
-    suppressions,
-    opts,
-    filename,
-    code,
-    hasModuleScopeOptOut,
-  }: ProgramContextOptions) {
+  constructor(
+    program: NodePath<t.Program>,
+    reactRuntimeModule: CompilerReactTarget,
+    hookPattern: string | null,
+  ) {
+    this.hookPattern = hookPattern;
     this.scope = program.scope;
-    this.opts = opts;
-    this.filename = filename;
-    this.code = code;
-    this.reactRuntimeModule = getReactCompilerRuntimeModule(opts.target);
-    this.suppressions = suppressions;
-    this.hasModuleScopeOptOut = hasModuleScopeOptOut;
+    this.reactRuntimeModule = getReactCompilerRuntimeModule(reactRuntimeModule);
   }
 
   isHookName(name: string): boolean {
-    if (this.opts.environment.hookPattern == null) {
+    if (this.hookPattern == null) {
       return isHookName(name);
     } else {
-      const match = new RegExp(this.opts.environment.hookPattern).exec(name);
+      const match = new RegExp(this.hookPattern).exec(name);
       return (
         match != null && typeof match[1] === 'string' && isHookName(match[1])
       );
@@ -205,7 +171,7 @@ export class ProgramContext {
     }
     const error = new CompilerError();
     error.push({
-      category: ErrorCategory.Todo,
+      severity: ErrorSeverity.Todo,
       reason: 'Encountered conflicting global in generated program',
       description: `Conflict from local binding ${name}`,
       loc: scope.getBinding(name)?.path.node.loc ?? null,
@@ -213,12 +179,6 @@ export class ProgramContext {
     });
     return Err(error);
   }
-
-  logEvent(event: LoggerEvent): void {
-    if (this.opts.logger != null) {
-      this.opts.logger.logEvent(this.filename, event);
-    }
-  }
 }
 
 function getExistingImports(
@@ -240,7 +200,7 @@ export function addImportsToProgram(
   programContext: ProgramContext,
 ): void {
   const existingImports = getExistingImports(path);
-  const stmts: Array<t.ImportDeclaration | t.VariableDeclaration> = [];
+  const stmts: Array<t.ImportDeclaration> = [];
   const sortedModules = [...programContext.imports.entries()].sort(([a], [b]) =>
     a.localeCompare(b),
   );
@@ -256,14 +216,8 @@ export function addImportsToProgram(
         {
           reason:
             'Encountered conflicting import specifiers in generated program',
-          description: `Conflict from import ${loweredImport.module}:(${loweredImport.imported} as ${loweredImport.name})`,
-          details: [
-            {
-              kind: 'error',
-              loc: GeneratedSource,
-              message: null,
-            },
-          ],
+          description: `Conflict from import ${loweredImport.module}:(${loweredImport.imported} as ${loweredImport.name}).`,
+          loc: GeneratedSource,
           suggestions: null,
         },
       );
@@ -274,13 +228,7 @@ export function addImportsToProgram(
           reason:
             'Found inconsistent import specifier. This is an internal bug.',
           description: `Expected import ${moduleName}:${specifierName} but found ${loweredImport.module}:${loweredImport.imported}`,
-          details: [
-            {
-              kind: 'error',
-              loc: GeneratedSource,
-              message: null,
-            },
-          ],
+          loc: GeneratedSource,
         },
       );
     }
@@ -303,29 +251,9 @@ export function addImportsToProgram(
     if (maybeExistingImports != null) {
       maybeExistingImports.pushContainer('specifiers', importSpecifiers);
     } else {
-      if (path.node.sourceType === 'module') {
-        stmts.push(
-          t.importDeclaration(importSpecifiers, t.stringLiteral(moduleName)),
-        );
-      } else {
-        stmts.push(
-          t.variableDeclaration('const', [
-            t.variableDeclarator(
-              t.objectPattern(
-                sortedImport.map(specifier => {
-                  return t.objectProperty(
-                    t.identifier(specifier.imported),
-                    t.identifier(specifier.name),
-                  );
-                }),
-              ),
-              t.callExpression(t.identifier('require'), [
-                t.stringLiteral(moduleName),
-              ]),
-            ),
-          ]),
-        );
-      }
+      stmts.push(
+        t.importDeclaration(importSpecifiers, t.stringLiteral(moduleName)),
+      );
     }
   }
   path.unshiftContainer('body', stmts);

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Options.ts

@@ -6,13 +6,8 @@
  */
 
 import * as t from '@babel/types';
-import {z} from 'zod/v4';
-import {
-  CompilerDiagnostic,
-  CompilerError,
-  CompilerErrorDetail,
-  CompilerErrorDetailOptions,
-} from '../CompilerError';
+import {z} from 'zod';
+import {CompilerError, CompilerErrorDetailOptions} from '../CompilerError';
 import {
   EnvironmentConfig,
   ExternalFunction,
@@ -20,7 +15,7 @@ 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([
@@ -42,17 +37,9 @@ const PanicThresholdOptionsSchema = z.enum([
 ]);
 
 export type PanicThresholdOptions = z.infer<typeof PanicThresholdOptionsSchema>;
-const DynamicGatingOptionsSchema = z.object({
-  source: z.string(),
-});
-export type DynamicGatingOptions = z.infer<typeof DynamicGatingOptionsSchema>;
-const CustomOptOutDirectiveSchema = z
-  .nullable(z.array(z.string()))
-  .default(null);
-type CustomOptOutDirective = z.infer<typeof CustomOptOutDirectiveSchema>;
 
-export type PluginOptions = Partial<{
-  environment: Partial<EnvironmentConfig>;
+export type PluginOptions = {
+  environment: EnvironmentConfig;
 
   logger: Logger | null;
 
@@ -78,49 +65,16 @@ export type PluginOptions = Partial<{
    */
   gating: ExternalFunction | null;
 
-  /**
-   * If specified, this enables dynamic gating which matches `use memo if(...)`
-   * directives.
-   *
-   * Example usage:
-   * ```js
-   * // @dynamicGating:{"source":"myModule"}
-   * export function MyComponent() {
-   *   'use memo if(isEnabled)';
-   *    return <div>...</div>;
-   * }
-   * ```
-   * This will emit:
-   * ```js
-   * import {isEnabled} from 'myModule';
-   * export const MyComponent = isEnabled()
-   *   ? <optimized version>
-   *   : <original version>;
-   * ```
-   */
-  dynamicGating: DynamicGatingOptions | null;
-
   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
@@ -144,25 +98,15 @@ export type PluginOptions = Partial<{
    * provided rules will skip compilation. To disable this feature (never bailout of compilation
    * even if the default ESLint is suppressed), pass an empty array.
    */
-  eslintSuppressionRules: Array<string> | null | undefined;
+  eslintSuppressionRules?: Array<string> | null | undefined;
 
-  /**
-   * Whether to report "suppression" errors for Flow suppressions. If false, suppression errors
-   * are only emitted for ESLint suppressions
-   */
   flowSuppressions: boolean;
-
   /*
    * Ignore 'use no forget' annotations. Helpful during testing but should not be used in production.
    */
   ignoreUseNoForget: boolean;
 
-  /**
-   * Unstable / do not use
-   */
-  customOptOutDirectives: CustomOptOutDirective;
-
-  sources: Array<string> | ((filename: string) => boolean) | null;
+  sources?: Array<string> | ((filename: string) => boolean) | null;
 
   /**
    * The compiler has customized support for react-native-reanimated, intended as a temporary workaround.
@@ -177,11 +121,7 @@ export type PluginOptions = Partial<{
    * a userspace approximation of runtime APIs.
    */
   target: CompilerReactTarget;
-}>;
-
-export type ParsedPluginOptions = Required<
-  Omit<PluginOptions, 'environment'>
-> & {environment: EnvironmentConfig};
+};
 
 const CompilerReactTargetSchema = z.union([
   z.literal('17'),
@@ -223,19 +163,6 @@ 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).
@@ -255,14 +182,12 @@ export type LoggerEvent =
   | CompileDiagnosticEvent
   | CompileSkipEvent
   | PipelineErrorEvent
-  | TimingEvent
-  | AutoDepsDecorationsEvent
-  | AutoDepsEligibleEvent;
+  | TimingEvent;
 
 export type CompileErrorEvent = {
   kind: 'CompileError';
   fnLoc: t.SourceLocation | null;
-  detail: CompilerErrorDetail | CompilerDiagnostic;
+  detail: CompilerErrorDetailOptions;
 };
 export type CompileDiagnosticEvent = {
   kind: 'CompileDiagnostic';
@@ -294,31 +219,19 @@ export type TimingEvent = {
   kind: 'Timing';
   measurement: PerformanceMeasure;
 };
-export type AutoDepsDecorationsEvent = {
-  kind: 'AutoDepsDecorations';
-  fnLoc: t.SourceLocation;
-  decorations: Array<t.SourceLocation>;
-};
-export type AutoDepsEligibleEvent = {
-  kind: 'AutoDepsEligible';
-  fnLoc: t.SourceLocation;
-  depArrayLoc: t.SourceLocation;
-};
 
 export type Logger = {
   logEvent: (filename: string | null, event: LoggerEvent) => void;
   debugLogIRs?: (value: CompilerPipelineValue) => void;
 };
 
-export const defaultOptions: ParsedPluginOptions = {
+export const defaultOptions: PluginOptions = {
   compilationMode: 'infer',
   panicThreshold: 'none',
   environment: parseEnvironmentConfig({}).unwrap(),
   logger: null,
   gating: null,
   noEmit: false,
-  outputMode: null,
-  dynamicGating: null,
   eslintSuppressionRules: null,
   flowSuppressions: true,
   ignoreUseNoForget: false,
@@ -326,11 +239,10 @@ export const defaultOptions: ParsedPluginOptions = {
     return filename.indexOf('node_modules') === -1;
   },
   enableReanimatedCheck: true,
-  customOptOutDirectives: null,
   target: '19',
-};
+} as const;
 
-export function parsePluginOptions(obj: unknown): ParsedPluginOptions {
+export function parsePluginOptions(obj: unknown): PluginOptions {
   if (obj == null || typeof obj !== 'object') {
     return defaultOptions;
   }
@@ -368,40 +280,6 @@ export function parsePluginOptions(obj: unknown): ParsedPluginOptions {
           }
           break;
         }
-        case 'dynamicGating': {
-          if (value == null) {
-            parsedOptions[key] = null;
-          } else {
-            const result = DynamicGatingOptionsSchema.safeParse(value);
-            if (result.success) {
-              parsedOptions[key] = result.data;
-            } else {
-              CompilerError.throwInvalidConfig({
-                reason:
-                  'Could not parse dynamic gating. Update React Compiler config to fix the error',
-                description: `${fromZodError(result.error)}`,
-                loc: null,
-                suggestions: null,
-              });
-            }
-          }
-          break;
-        }
-        case 'customOptOutDirectives': {
-          const result = CustomOptOutDirectiveSchema.safeParse(value);
-          if (result.success) {
-            parsedOptions[key] = result.data;
-          } else {
-            CompilerError.throwInvalidConfig({
-              reason:
-                'Could not parse custom opt out directives. Update React Compiler config to fix the error',
-              description: `${fromZodError(result.error)}`,
-              loc: null,
-              suggestions: null,
-            });
-          }
-          break;
-        }
         default: {
           parsedOptions[key] = value;
         }

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,
@@ -32,7 +33,9 @@ import {findContextIdentifiers} from '../HIR/FindContextIdentifiers';
 import {
   analyseFunctions,
   dropManualMemoization,
+  inferMutableRanges,
   inferReactivePlaces,
+  inferReferenceEffects,
   inlineImmediatelyInvokedFunctionExpressions,
   inferEffectDependencies,
 } from '../Inference';
@@ -89,24 +92,17 @@ import {
 } from '../Validation';
 import {validateLocalsNotReassignedAfterRender} from '../Validation/ValidateLocalsNotReassignedAfterRender';
 import {outlineFunctions} from '../Optimization/OutlineFunctions';
+import {propagatePhiTypes} from '../TypeInference/PropagatePhiTypes';
 import {lowerContextAccess} from '../Optimization/LowerContextAccess';
-import {validateNoSetStateInEffects} from '../Validation/ValidateNoSetStateInEffects';
+import {validateNoSetStateInPassiveEffects} from '../Validation/ValidateNoSetStateInPassiveEffects';
 import {validateNoJSXInTryStatement} from '../Validation/ValidateNoJSXInTryStatement';
 import {propagateScopeDependenciesHIR} from '../HIR/PropagateScopeDependenciesHIR';
 import {outlineJSX} from '../Optimization/OutlineJsx';
 import {optimizePropsMethodCalls} from '../Optimization/OptimizePropsMethodCalls';
 import {transformFire} from '../Transform';
+import {validateNoImpureFunctionsInRender} from '../Validation/ValidateNoImpureFunctionsInRender';
+import {CompilerError} from '..';
 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 +116,7 @@ function run(
   >,
   config: EnvironmentConfig,
   fnType: ReactFunctionType,
-  mode: CompilerOutputMode,
+  mode: CompilerMode,
   programContext: ProgramContext,
   logger: Logger | null,
   filename: string | null,
@@ -133,7 +129,6 @@ function run(
     mode,
     config,
     contextIdentifiers,
-    func,
     logger,
     filename,
     code,
@@ -170,12 +165,12 @@ function runWithEnvironment(
   validateUseMemo(hir).unwrap();
 
   if (
-    env.enableDropManualMemoization &&
+    env.isInferredMemoEnabled &&
     !env.config.enablePreserveExistingManualUseMemo &&
     !env.config.disableMemoizationForDebugging &&
     !env.config.enableChangeDetectionForDebugging
   ) {
-    dropManualMemoization(hir).unwrap();
+    dropManualMemoization(hir);
     log({kind: 'hir', name: 'DropManualMemoization', value: hir});
   }
 
@@ -206,7 +201,7 @@ function runWithEnvironment(
   inferTypes(hir);
   log({kind: 'hir', name: 'InferTypes', value: hir});
 
-  if (env.enableValidations) {
+  if (env.isInferredMemoEnabled) {
     if (env.config.validateHooksUsage) {
       validateHooksUsage(hir).unwrap();
     }
@@ -230,18 +225,15 @@ function runWithEnvironment(
   analyseFunctions(hir);
   log({kind: 'hir', name: 'AnalyseFunctions', value: hir});
 
-  const mutabilityAliasingErrors = inferMutationAliasingEffects(hir);
-  log({kind: 'hir', name: 'InferMutationAliasingEffects', value: hir});
-  if (env.enableValidations) {
-    if (mutabilityAliasingErrors.isErr()) {
-      throw mutabilityAliasingErrors.unwrapErr();
+  const fnEffectErrors = inferReferenceEffects(hir);
+  if (env.isInferredMemoEnabled) {
+    if (fnEffectErrors.length > 0) {
+      CompilerError.throw(fnEffectErrors[0]);
     }
   }
+  log({kind: 'hir', name: 'InferReferenceEffects', value: hir});
 
-  if (env.outputMode === 'ssr') {
-    optimizeForSSR(hir);
-    log({kind: 'hir', name: 'OptimizeForSSR', value: hir});
-  }
+  validateLocalsNotReassignedAfterRender(hir);
 
   // Note: Has to come after infer reference effects because "dead" code may still affect inference
   deadCodeElimination(hir);
@@ -255,70 +247,38 @@ function runWithEnvironment(
   pruneMaybeThrows(hir);
   log({kind: 'hir', name: 'PruneMaybeThrows', value: hir});
 
-  const mutabilityAliasingRangeErrors = inferMutationAliasingRanges(hir, {
-    isFunctionExpression: false,
-  });
-  log({kind: 'hir', name: 'InferMutationAliasingRanges', value: hir});
-  if (env.enableValidations) {
-    if (mutabilityAliasingRangeErrors.isErr()) {
-      throw mutabilityAliasingRangeErrors.unwrapErr();
-    }
-    validateLocalsNotReassignedAfterRender(hir);
-  }
+  inferMutableRanges(hir);
+  log({kind: 'hir', name: 'InferMutableRanges', value: hir});
 
-  if (env.enableValidations) {
+  if (env.isInferredMemoEnabled) {
     if (env.config.assertValidMutableRanges) {
       assertValidMutableRanges(hir);
     }
 
-    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) {
-      validateNoDerivedComputationsInEffects(hir);
-    }
-
-    if (env.config.validateNoSetStateInEffects && env.outputMode === 'lint') {
-      env.logErrors(validateNoSetStateInEffects(hir, env));
-    }
-
-    if (env.config.validateNoJSXInTryStatements && env.outputMode === 'lint') {
-      env.logErrors(validateNoJSXInTryStatement(hir));
-    }
-
-    if (
-      env.config.validateNoImpureFunctionsInRender ||
-      env.config.validateRefAccessDuringRender
-    ) {
-      validateNoImpureValuesInRender(hir).unwrap();
-    }
-
     if (env.config.validateRefAccessDuringRender) {
       validateNoRefAccessInRender(hir).unwrap();
     }
 
-    validateNoFreezingKnownMutableFunctions(hir).unwrap();
+    if (env.config.validateNoSetStateInRender) {
+      validateNoSetStateInRender(hir).unwrap();
+    }
+
+    if (env.config.validateNoSetStateInPassiveEffects) {
+      env.logErrors(validateNoSetStateInPassiveEffects(hir));
+    }
+
+    if (env.config.validateNoJSXInTryStatements) {
+      env.logErrors(validateNoJSXInTryStatement(hir));
+    }
+
+    if (env.config.validateNoImpureFunctionsInRender) {
+      validateNoImpureFunctionsInRender(hir).unwrap();
+    }
   }
 
   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 +286,18 @@ function runWithEnvironment(
     value: hir,
   });
 
-  if (
-    env.enableValidations &&
-    env.config.validateStaticComponents &&
-    env.outputMode === 'lint'
-  ) {
-    env.logErrors(validateStaticComponents(hir));
-  }
+  propagatePhiTypes(hir);
+  log({
+    kind: 'hir',
+    name: 'PropagatePhiTypes',
+    value: 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
@@ -355,15 +318,6 @@ function runWithEnvironment(
     outlineJSX(hir);
   }
 
-  if (env.config.enableNameAnonymousFunctions) {
-    nameAnonymousFunctions(hir);
-    log({
-      kind: 'hir',
-      name: 'NameAnonymousFunctions',
-      value: hir,
-    });
-  }
-
   if (env.config.enableFunctionOutlining) {
     outlineFunctions(hir, fbtOperands);
     log({kind: 'hir', name: 'OutlineFunctions', value: hir});
@@ -438,11 +392,6 @@ function runWithEnvironment(
 
   if (env.config.inferEffectDependencies) {
     inferEffectDependencies(hir);
-    log({
-      kind: 'hir',
-      name: 'InferEffectDependencies',
-      value: hir,
-    });
   }
 
   if (env.config.inlineJsxTransform) {
@@ -584,10 +533,6 @@ 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 +551,7 @@ export function compileFn(
   >,
   config: EnvironmentConfig,
   fnType: ReactFunctionType,
-  mode: CompilerOutputMode,
+  mode: CompilerMode,
   programContext: ProgramContext,
   logger: Logger | null,
   filename: string | null,

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Reanimated.ts

@@ -1,13 +1,6 @@
-/**
- * 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 type * as BabelCore from '@babel/core';
 import {hasOwnProperty} from '../Utils/utils';
-import {ParsedPluginOptions} from './Options';
+import {PluginOptions} from './Options';
 
 function hasModule(name: string): boolean {
   if (typeof require === 'undefined') {
@@ -52,9 +45,7 @@ export function pipelineUsesReanimatedPlugin(
   return hasModule('react-native-reanimated');
 }
 
-export function injectReanimatedFlag(
-  options: ParsedPluginOptions,
-): ParsedPluginOptions {
+export function injectReanimatedFlag(options: PluginOptions): PluginOptions {
   return {
     ...options,
     environment: {

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Suppression.ts

@@ -8,10 +8,10 @@
 import {NodePath} from '@babel/core';
 import * as t from '@babel/types';
 import {
-  CompilerDiagnostic,
   CompilerError,
+  CompilerErrorDetail,
   CompilerSuggestionOperation,
-  ErrorCategory,
+  ErrorSeverity,
 } from '../CompilerError';
 import {assertExhaustive} from '../Utils/utils';
 import {GeneratedSource} from '../HIR';
@@ -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> = [];
@@ -86,18 +86,12 @@ export function findProgramSuppressions(
   let enableComment: t.Comment | null = null;
   let source: SuppressionSource | null = null;
 
-  let disableNextLinePattern: RegExp | null = null;
-  let disablePattern: RegExp | null = null;
-  let enablePattern: RegExp | null = null;
-  if (ruleNames != null && ruleNames.length !== 0) {
-    const rulePattern = `(${ruleNames.join('|')})`;
-    disableNextLinePattern = new RegExp(
-      `eslint-disable-next-line ${rulePattern}`,
-    );
-    disablePattern = new RegExp(`eslint-disable ${rulePattern}`);
-    enablePattern = new RegExp(`eslint-enable ${rulePattern}`);
-  }
-
+  const rulePattern = `(${ruleNames.join('|')})`;
+  const disableNextLinePattern = new RegExp(
+    `eslint-disable-next-line ${rulePattern}`,
+  );
+  const disablePattern = new RegExp(`eslint-disable ${rulePattern}`);
+  const enablePattern = new RegExp(`eslint-enable ${rulePattern}`);
   const flowSuppressionPattern = new RegExp(
     '\\$(FlowFixMe\\w*|FlowExpectedError|FlowIssue)\\[react\\-rule',
   );
@@ -113,7 +107,6 @@ export function findProgramSuppressions(
        * CommentLine within the block.
        */
       disableComment == null &&
-      disableNextLinePattern != null &&
       disableNextLinePattern.test(comment.value)
     ) {
       disableComment = comment;
@@ -131,16 +124,12 @@ export function findProgramSuppressions(
       source = 'Flow';
     }
 
-    if (disablePattern != null && disablePattern.test(comment.value)) {
+    if (disablePattern.test(comment.value)) {
       disableComment = comment;
       source = 'Eslint';
     }
 
-    if (
-      enablePattern != null &&
-      enablePattern.test(comment.value) &&
-      source === 'Eslint'
-    ) {
+    if (enablePattern.test(comment.value) && source === 'Eslint') {
       enableComment = comment;
     }
 
@@ -163,14 +152,7 @@ export function suppressionsToCompilerError(
 ): CompilerError {
   CompilerError.invariant(suppressionRanges.length !== 0, {
     reason: `Expected at least suppression comment source range`,
-    description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: GeneratedSource,
-        message: null,
-      },
-    ],
+    loc: GeneratedSource,
   });
   const error = new CompilerError();
   for (const suppressionRange of suppressionRanges) {
@@ -199,11 +181,12 @@ export function suppressionsToCompilerError(
           'Unhandled suppression source',
         );
     }
-    error.pushDiagnostic(
-      CompilerDiagnostic.create({
-        reason: reason,
-        description: `React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior. Found suppression \`${suppressionRange.disableComment.value.trim()}\``,
-        category: ErrorCategory.Suppression,
+    error.pushErrorDetail(
+      new CompilerErrorDetail({
+        reason: `${reason}. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior`,
+        description: suppressionRange.disableComment.value.trim(),
+        severity: ErrorSeverity.InvalidReact,
+        loc: suppressionRange.disableComment.loc ?? null,
         suggestions: [
           {
             description: suggestion,
@@ -214,10 +197,6 @@ export function suppressionsToCompilerError(
             op: CompilerSuggestionOperation.Remove,
           },
         ],
-      }).withDetails({
-        kind: 'error',
-        loc: suppressionRange.disableComment.loc ?? null,
-        message: 'Found React rule suppression',
       }),
     );
   }

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/ValidateNoUntransformedReferences.ts

@@ -1,70 +1,35 @@
-/**
- * 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/core';
 import * as t from '@babel/types';
 
-import {CompilerError, EnvironmentConfig, Logger} from '..';
-import {getOrInsertWith} from '../Utils/utils';
-import {Environment, GeneratedSource} from '../HIR';
-import {DEFAULT_EXPORT} from '../HIR/Environment';
-import {CompileProgramMetadata} from './Program';
 import {
-  CompilerDiagnostic,
-  CompilerDiagnosticOptions,
-  ErrorCategory,
-} from '../CompilerError';
+  CompilerError,
+  CompilerErrorDetailOptions,
+  EnvironmentConfig,
+  ErrorSeverity,
+  Logger,
+} from '..';
+import {getOrInsertWith} from '../Utils/utils';
+import {Environment} from '../HIR';
+import {DEFAULT_EXPORT} from '../HIR/Environment';
+import {CompileProgramResult} from './Program';
 
 function throwInvalidReact(
-  options: CompilerDiagnosticOptions,
+  options: Omit<CompilerErrorDetailOptions, 'severity'>,
   {logger, filename}: TraversalState,
 ): never {
+  const detail: CompilerErrorDetailOptions = {
+    ...options,
+    severity: ErrorSeverity.InvalidReact,
+  };
   logger?.logEvent(filename, {
     kind: 'CompileError',
     fnLoc: null,
-    detail: new CompilerDiagnostic(options),
+    detail,
   });
-  CompilerError.throwDiagnostic(options);
-}
-
-function isAutodepsSigil(
-  arg: NodePath<t.ArgumentPlaceholder | t.SpreadElement | t.Expression>,
-): boolean {
-  // Check for AUTODEPS identifier imported from React
-  if (arg.isIdentifier() && arg.node.name === 'AUTODEPS') {
-    const binding = arg.scope.getBinding(arg.node.name);
-    if (binding && binding.path.isImportSpecifier()) {
-      const importSpecifier = binding.path.node as t.ImportSpecifier;
-      if (importSpecifier.imported.type === 'Identifier') {
-        return (importSpecifier.imported as t.Identifier).name === 'AUTODEPS';
-      }
-    }
-    return false;
-  }
-
-  // Check for React.AUTODEPS member expression
-  if (arg.isMemberExpression() && !arg.node.computed) {
-    const object = arg.get('object');
-    const property = arg.get('property');
-
-    if (
-      object.isIdentifier() &&
-      object.node.name === 'React' &&
-      property.isIdentifier() &&
-      property.node.name === 'AUTODEPS'
-    ) {
-      return true;
-    }
-  }
-
-  return false;
+  CompilerError.throw(detail);
 }
 function assertValidEffectImportReference(
-  autodepsIndex: number,
+  numArgs: number,
   paths: Array<NodePath<t.Node>>,
   context: TraversalState,
 ): void {
@@ -77,10 +42,11 @@ function assertValidEffectImportReference(
         maybeCalleeLoc != null &&
         context.inferredEffectLocations.has(maybeCalleeLoc);
       /**
-       * Error on effect calls that still have AUTODEPS in their args
+       * Only error on untransformed references of the form `useMyEffect(...)`
+       * or `moduleNamespace.useMyEffect(...)`, with matching argument counts.
+       * TODO: do we also want a mode to also hard error on non-call references?
        */
-      const hasAutodepsArg = args.some(isAutodepsSigil);
-      if (hasAutodepsArg && !hasInferredEffect) {
+      if (args.length === numArgs && !hasInferredEffect) {
         const maybeErrorDiagnostic = matchCompilerDiagnostic(
           path,
           context.transformErrors,
@@ -92,19 +58,14 @@ function assertValidEffectImportReference(
          */
         throwInvalidReact(
           {
-            category: ErrorCategory.AutomaticEffectDependencies,
             reason:
-              'Cannot infer dependencies of this effect. This will break your build!',
-            description:
-              'To resolve, either pass a dependency array or fix reported compiler bailout diagnostics' +
-              (maybeErrorDiagnostic ? ` ${maybeErrorDiagnostic}` : ''),
-            details: [
-              {
-                kind: 'error',
-                message: 'Cannot infer dependencies',
-                loc: parent.node.loc ?? GeneratedSource,
-              },
-            ],
+              '[InferEffectDependencies] React Compiler is unable to infer dependencies of this effect. ' +
+              'This will break your build! ' +
+              'To resolve, either pass your own dependency array or fix reported compiler bailout diagnostics.',
+            description: maybeErrorDiagnostic
+              ? `(Bailout reason: ${maybeErrorDiagnostic})`
+              : null,
+            loc: parent.node.loc ?? null,
           },
           context,
         );
@@ -124,18 +85,13 @@ function assertValidFireImportReference(
     );
     throwInvalidReact(
       {
-        category: ErrorCategory.Fire,
-        reason: '[Fire] Untransformed reference to compiler-required feature.',
-        description:
-          'Either remove this `fire` call or ensure it is successfully transformed by the compiler' +
-          (maybeErrorDiagnostic != null ? ` ${maybeErrorDiagnostic}` : ''),
-        details: [
-          {
-            kind: 'error',
-            message: 'Untransformed `fire` call',
-            loc: paths[0].node.loc ?? GeneratedSource,
-          },
-        ],
+        reason:
+          '[Fire] Untransformed reference to compiler-required feature. ' +
+          'Either remove this `fire` call or ensure it is successfully transformed by the compiler',
+        description: maybeErrorDiagnostic
+          ? `(Bailout reason: ${maybeErrorDiagnostic})`
+          : null,
+        loc: paths[0].node.loc ?? null,
       },
       context,
     );
@@ -146,7 +102,7 @@ export default function validateNoUntransformedReferences(
   filename: string | null,
   logger: Logger | null,
   env: EnvironmentConfig,
-  compileResult: CompileProgramMetadata | null,
+  compileResult: CompileProgramResult | null,
 ): void {
   const moduleLoadChecks = new Map<
     string,
@@ -165,12 +121,12 @@ export default function validateNoUntransformedReferences(
   if (env.inferEffectDependencies) {
     for (const {
       function: {source, importSpecifierName},
-      autodepsIndex,
+      numRequiredArgs,
     } of env.inferEffectDependencies) {
       const module = getOrInsertWith(moduleLoadChecks, source, () => new Map());
       module.set(
         importSpecifierName,
-        assertValidEffectImportReference.bind(null, autodepsIndex),
+        assertValidEffectImportReference.bind(null, numRequiredArgs),
       );
     }
   }
@@ -215,14 +171,7 @@ function validateImportSpecifier(
   const binding = local.scope.getBinding(local.node.name);
   CompilerError.invariant(binding != null, {
     reason: 'Expected binding to be found for import specifier',
-    description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: local.node.loc ?? null,
-        message: null,
-      },
-    ],
+    loc: local.node.loc ?? null,
   });
   checkFn(binding.referencePaths, state);
 }
@@ -242,14 +191,7 @@ function validateNamespacedImport(
 
   CompilerError.invariant(binding != null, {
     reason: 'Expected binding to be found for import specifier',
-    description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: local.node.loc ?? null,
-        message: null,
-      },
-    ],
+    loc: local.node.loc ?? null,
   });
   const filteredReferences = new Map<
     CheckInvalidReferenceFn,
@@ -287,7 +229,7 @@ function transformProgram(
   moduleLoadChecks: Map<string, Map<string, CheckInvalidReferenceFn>>,
   filename: string | null,
   logger: Logger | null,
-  compileResult: CompileProgramMetadata | null,
+  compileResult: CompileProgramResult | null,
 ): void {
   const traversalState: TraversalState = {
     shouldInvalidateScopes: true,

compiler/packages/babel-plugin-react-compiler/src/Flood/FlowTypes.ts

@@ -1,752 +0,0 @@
-/**
- * TypeScript definitions for Flow type JSON representations
- * Based on the output of /data/sandcastle/boxes/fbsource/fbcode/flow/src/typing/convertTypes.ml
- */
-
-// Base type for all Flow types with a kind field
-export interface BaseFlowType {
-  kind: string;
-}
-
-// Type for representing polarity
-export type Polarity = 'positive' | 'negative' | 'neutral';
-
-// Type for representing a name that might be null
-export type OptionalName = string | null;
-
-// Open type
-export interface OpenType extends BaseFlowType {
-  kind: 'Open';
-}
-
-// Def type
-export interface DefType extends BaseFlowType {
-  kind: 'Def';
-  def: DefT;
-}
-
-// Eval type
-export interface EvalType extends BaseFlowType {
-  kind: 'Eval';
-  type: FlowType;
-  destructor: Destructor;
-}
-
-// Generic type
-export interface GenericType extends BaseFlowType {
-  kind: 'Generic';
-  name: string;
-  bound: FlowType;
-  no_infer: boolean;
-}
-
-// ThisInstance type
-export interface ThisInstanceType extends BaseFlowType {
-  kind: 'ThisInstance';
-  instance: InstanceT;
-  is_this: boolean;
-  name: string;
-}
-
-// ThisTypeApp type
-export interface ThisTypeAppType extends BaseFlowType {
-  kind: 'ThisTypeApp';
-  t1: FlowType;
-  t2: FlowType;
-  t_list?: Array<FlowType>;
-}
-
-// TypeApp type
-export interface TypeAppType extends BaseFlowType {
-  kind: 'TypeApp';
-  type: FlowType;
-  targs: Array<FlowType>;
-  from_value: boolean;
-  use_desc: boolean;
-}
-
-// FunProto type
-export interface FunProtoType extends BaseFlowType {
-  kind: 'FunProto';
-}
-
-// ObjProto type
-export interface ObjProtoType extends BaseFlowType {
-  kind: 'ObjProto';
-}
-
-// NullProto type
-export interface NullProtoType extends BaseFlowType {
-  kind: 'NullProto';
-}
-
-// FunProtoBind type
-export interface FunProtoBindType extends BaseFlowType {
-  kind: 'FunProtoBind';
-}
-
-// Intersection type
-export interface IntersectionType extends BaseFlowType {
-  kind: 'Intersection';
-  members: Array<FlowType>;
-}
-
-// Union type
-export interface UnionType extends BaseFlowType {
-  kind: 'Union';
-  members: Array<FlowType>;
-}
-
-// Maybe type
-export interface MaybeType extends BaseFlowType {
-  kind: 'Maybe';
-  type: FlowType;
-}
-
-// Optional type
-export interface OptionalType extends BaseFlowType {
-  kind: 'Optional';
-  type: FlowType;
-  use_desc: boolean;
-}
-
-// Keys type
-export interface KeysType extends BaseFlowType {
-  kind: 'Keys';
-  type: FlowType;
-}
-
-// Annot type
-export interface AnnotType extends BaseFlowType {
-  kind: 'Annot';
-  type: FlowType;
-  use_desc: boolean;
-}
-
-// Opaque type
-export interface OpaqueType extends BaseFlowType {
-  kind: 'Opaque';
-  opaquetype: {
-    opaque_id: string;
-    underlying_t: FlowType | null;
-    super_t: FlowType | null;
-    opaque_type_args: Array<{
-      name: string;
-      type: FlowType;
-      polarity: Polarity;
-    }>;
-    opaque_name: string;
-  };
-}
-
-// Namespace type
-export interface NamespaceType extends BaseFlowType {
-  kind: 'Namespace';
-  namespace_symbol: {
-    symbol: string;
-  };
-  values_type: FlowType;
-  types_tmap: PropertyMap;
-}
-
-// Any type
-export interface AnyType extends BaseFlowType {
-  kind: 'Any';
-}
-
-// StrUtil type
-export interface StrUtilType extends BaseFlowType {
-  kind: 'StrUtil';
-  op: 'StrPrefix' | 'StrSuffix';
-  prefix?: string;
-  suffix?: string;
-  remainder?: FlowType;
-}
-
-// TypeParam definition
-export interface TypeParam {
-  name: string;
-  bound: FlowType;
-  polarity: Polarity;
-  default: FlowType | null;
-}
-
-// EnumInfo types
-export type EnumInfo = ConcreteEnum | AbstractEnum;
-
-export interface ConcreteEnum {
-  kind: 'ConcreteEnum';
-  enum_name: string;
-  enum_id: string;
-  members: Array<string>;
-  representation_t: FlowType;
-  has_unknown_members: boolean;
-}
-
-export interface AbstractEnum {
-  kind: 'AbstractEnum';
-  representation_t: FlowType;
-}
-
-// CanonicalRendersForm types
-export type CanonicalRendersForm =
-  | InstrinsicRenders
-  | NominalRenders
-  | StructuralRenders
-  | DefaultRenders;
-
-export interface InstrinsicRenders {
-  kind: 'InstrinsicRenders';
-  name: string;
-}
-
-export interface NominalRenders {
-  kind: 'NominalRenders';
-  renders_id: string;
-  renders_name: string;
-  renders_super: FlowType;
-}
-
-export interface StructuralRenders {
-  kind: 'StructuralRenders';
-  renders_variant: 'RendersNormal' | 'RendersMaybe' | 'RendersStar';
-  renders_structural_type: FlowType;
-}
-
-export interface DefaultRenders {
-  kind: 'DefaultRenders';
-}
-
-// InstanceT definition
-export interface InstanceT {
-  inst: InstType;
-  static: FlowType;
-  super: FlowType;
-  implements: Array<FlowType>;
-}
-
-// InstType definition
-export interface InstType {
-  class_name: string | null;
-  class_id: string;
-  type_args: Array<{
-    name: string;
-    type: FlowType;
-    polarity: Polarity;
-  }>;
-  own_props: PropertyMap;
-  proto_props: PropertyMap;
-  call_t: null | {
-    id: number;
-    call: FlowType;
-  };
-}
-
-// DefT types
-export type DefT =
-  | NumGeneralType
-  | StrGeneralType
-  | BoolGeneralType
-  | BigIntGeneralType
-  | EmptyType
-  | MixedType
-  | NullType
-  | VoidType
-  | SymbolType
-  | FunType
-  | ObjType
-  | ArrType
-  | ClassType
-  | InstanceType
-  | SingletonStrType
-  | NumericStrKeyType
-  | SingletonNumType
-  | SingletonBoolType
-  | SingletonBigIntType
-  | TypeType
-  | PolyType
-  | ReactAbstractComponentType
-  | RendersType
-  | EnumValueType
-  | EnumObjectType;
-
-export interface NumGeneralType extends BaseFlowType {
-  kind: 'NumGeneral';
-}
-
-export interface StrGeneralType extends BaseFlowType {
-  kind: 'StrGeneral';
-}
-
-export interface BoolGeneralType extends BaseFlowType {
-  kind: 'BoolGeneral';
-}
-
-export interface BigIntGeneralType extends BaseFlowType {
-  kind: 'BigIntGeneral';
-}
-
-export interface EmptyType extends BaseFlowType {
-  kind: 'Empty';
-}
-
-export interface MixedType extends BaseFlowType {
-  kind: 'Mixed';
-}
-
-export interface NullType extends BaseFlowType {
-  kind: 'Null';
-}
-
-export interface VoidType extends BaseFlowType {
-  kind: 'Void';
-}
-
-export interface SymbolType extends BaseFlowType {
-  kind: 'Symbol';
-}
-
-export interface FunType extends BaseFlowType {
-  kind: 'Fun';
-  static: FlowType;
-  funtype: FunTypeObj;
-}
-
-export interface ObjType extends BaseFlowType {
-  kind: 'Obj';
-  objtype: ObjTypeObj;
-}
-
-export interface ArrType extends BaseFlowType {
-  kind: 'Arr';
-  arrtype: ArrTypeObj;
-}
-
-export interface ClassType extends BaseFlowType {
-  kind: 'Class';
-  type: FlowType;
-}
-
-export interface InstanceType extends BaseFlowType {
-  kind: 'Instance';
-  instance: InstanceT;
-}
-
-export interface SingletonStrType extends BaseFlowType {
-  kind: 'SingletonStr';
-  from_annot: boolean;
-  value: string;
-}
-
-export interface NumericStrKeyType extends BaseFlowType {
-  kind: 'NumericStrKey';
-  number: string;
-  string: string;
-}
-
-export interface SingletonNumType extends BaseFlowType {
-  kind: 'SingletonNum';
-  from_annot: boolean;
-  number: string;
-  string: string;
-}
-
-export interface SingletonBoolType extends BaseFlowType {
-  kind: 'SingletonBool';
-  from_annot: boolean;
-  value: boolean;
-}
-
-export interface SingletonBigIntType extends BaseFlowType {
-  kind: 'SingletonBigInt';
-  from_annot: boolean;
-  value: string;
-}
-
-export interface TypeType extends BaseFlowType {
-  kind: 'Type';
-  type_kind: TypeTKind;
-  type: FlowType;
-}
-
-export type TypeTKind =
-  | 'TypeAliasKind'
-  | 'TypeParamKind'
-  | 'OpaqueKind'
-  | 'ImportTypeofKind'
-  | 'ImportClassKind'
-  | 'ImportEnumKind'
-  | 'InstanceKind'
-  | 'RenderTypeKind';
-
-export interface PolyType extends BaseFlowType {
-  kind: 'Poly';
-  tparams: Array<TypeParam>;
-  t_out: FlowType;
-  id: string;
-}
-
-export interface ReactAbstractComponentType extends BaseFlowType {
-  kind: 'ReactAbstractComponent';
-  config: FlowType;
-  renders: FlowType;
-  instance: ComponentInstance;
-  component_kind: ComponentKind;
-}
-
-export type ComponentInstance =
-  | {kind: 'RefSetterProp'; type: FlowType}
-  | {kind: 'Omitted'};
-
-export type ComponentKind =
-  | {kind: 'Structural'}
-  | {kind: 'Nominal'; id: string; name: string; types: Array<FlowType> | null};
-
-export interface RendersType extends BaseFlowType {
-  kind: 'Renders';
-  form: CanonicalRendersForm;
-}
-
-export interface EnumValueType extends BaseFlowType {
-  kind: 'EnumValue';
-  enum_info: EnumInfo;
-}
-
-export interface EnumObjectType extends BaseFlowType {
-  kind: 'EnumObject';
-  enum_value_t: FlowType;
-  enum_info: EnumInfo;
-}
-
-// ObjKind types
-export type ObjKind =
-  | {kind: 'Exact'}
-  | {kind: 'Inexact'}
-  | {kind: 'Indexed'; dicttype: DictType};
-
-// DictType definition
-export interface DictType {
-  dict_name: string | null;
-  key: FlowType;
-  value: FlowType;
-  dict_polarity: Polarity;
-}
-
-// ArrType types
-export type ArrTypeObj = ArrayAT | TupleAT | ROArrayAT;
-
-export interface ArrayAT {
-  kind: 'ArrayAT';
-  elem_t: FlowType;
-}
-
-export interface TupleAT {
-  kind: 'TupleAT';
-  elem_t: FlowType;
-  elements: Array<TupleElement>;
-  min_arity: number;
-  max_arity: number;
-  inexact: boolean;
-}
-
-export interface ROArrayAT {
-  kind: 'ROArrayAT';
-  elem_t: FlowType;
-}
-
-// TupleElement definition
-export interface TupleElement {
-  name: string | null;
-  t: FlowType;
-  polarity: Polarity;
-  optional: boolean;
-}
-
-// Flags definition
-export interface Flags {
-  obj_kind: ObjKind;
-}
-
-// Property types
-export type Property =
-  | FieldProperty
-  | GetProperty
-  | SetProperty
-  | GetSetProperty
-  | MethodProperty;
-
-export interface FieldProperty {
-  kind: 'Field';
-  type: FlowType;
-  polarity: Polarity;
-}
-
-export interface GetProperty {
-  kind: 'Get';
-  type: FlowType;
-}
-
-export interface SetProperty {
-  kind: 'Set';
-  type: FlowType;
-}
-
-export interface GetSetProperty {
-  kind: 'GetSet';
-  get_type: FlowType;
-  set_type: FlowType;
-}
-
-export interface MethodProperty {
-  kind: 'Method';
-  type: FlowType;
-}
-
-// PropertyMap definition
-export interface PropertyMap {
-  [key: string]: Property; // For other properties in the map
-}
-
-// ObjType definition
-export interface ObjTypeObj {
-  flags: Flags;
-  props: PropertyMap;
-  proto_t: FlowType;
-  call_t: number | null;
-}
-
-// FunType definition
-export interface FunTypeObj {
-  this_t: {
-    type: FlowType;
-    status: ThisStatus;
-  };
-  params: Array<{
-    name: string | null;
-    type: FlowType;
-  }>;
-  rest_param: null | {
-    name: string | null;
-    type: FlowType;
-  };
-  return_t: FlowType;
-  type_guard: null | {
-    inferred: boolean;
-    param_name: string;
-    type_guard: FlowType;
-    one_sided: boolean;
-  };
-  effect: Effect;
-}
-
-// ThisStatus types
-export type ThisStatus =
-  | {kind: 'This_Method'; unbound: boolean}
-  | {kind: 'This_Function'};
-
-// Effect types
-export type Effect =
-  | {kind: 'HookDecl'; id: string}
-  | {kind: 'HookAnnot'}
-  | {kind: 'ArbitraryEffect'}
-  | {kind: 'AnyEffect'};
-
-// Destructor types
-export type Destructor =
-  | NonMaybeTypeDestructor
-  | PropertyTypeDestructor
-  | ElementTypeDestructor
-  | OptionalIndexedAccessNonMaybeTypeDestructor
-  | OptionalIndexedAccessResultTypeDestructor
-  | ExactTypeDestructor
-  | ReadOnlyTypeDestructor
-  | PartialTypeDestructor
-  | RequiredTypeDestructor
-  | SpreadTypeDestructor
-  | SpreadTupleTypeDestructor
-  | RestTypeDestructor
-  | ValuesTypeDestructor
-  | ConditionalTypeDestructor
-  | TypeMapDestructor
-  | ReactElementPropsTypeDestructor
-  | ReactElementConfigTypeDestructor
-  | ReactCheckComponentConfigDestructor
-  | ReactDRODestructor
-  | MakeHooklikeDestructor
-  | MappedTypeDestructor
-  | EnumTypeDestructor;
-
-export interface NonMaybeTypeDestructor {
-  kind: 'NonMaybeType';
-}
-
-export interface PropertyTypeDestructor {
-  kind: 'PropertyType';
-  name: string;
-}
-
-export interface ElementTypeDestructor {
-  kind: 'ElementType';
-  index_type: FlowType;
-}
-
-export interface OptionalIndexedAccessNonMaybeTypeDestructor {
-  kind: 'OptionalIndexedAccessNonMaybeType';
-  index: OptionalIndexedAccessIndex;
-}
-
-export type OptionalIndexedAccessIndex =
-  | {kind: 'StrLitIndex'; name: string}
-  | {kind: 'TypeIndex'; type: FlowType};
-
-export interface OptionalIndexedAccessResultTypeDestructor {
-  kind: 'OptionalIndexedAccessResultType';
-}
-
-export interface ExactTypeDestructor {
-  kind: 'ExactType';
-}
-
-export interface ReadOnlyTypeDestructor {
-  kind: 'ReadOnlyType';
-}
-
-export interface PartialTypeDestructor {
-  kind: 'PartialType';
-}
-
-export interface RequiredTypeDestructor {
-  kind: 'RequiredType';
-}
-
-export interface SpreadTypeDestructor {
-  kind: 'SpreadType';
-  target: SpreadTarget;
-  operands: Array<SpreadOperand>;
-  operand_slice: Slice | null;
-}
-
-export type SpreadTarget =
-  | {kind: 'Value'; make_seal: 'Sealed' | 'Frozen' | 'As_Const'}
-  | {kind: 'Annot'; make_exact: boolean};
-
-export type SpreadOperand = {kind: 'Type'; type: FlowType} | Slice;
-
-export interface Slice {
-  kind: 'Slice';
-  prop_map: PropertyMap;
-  generics: Array<string>;
-  dict: DictType | null;
-  reachable_targs: Array<{
-    type: FlowType;
-    polarity: Polarity;
-  }>;
-}
-
-export interface SpreadTupleTypeDestructor {
-  kind: 'SpreadTupleType';
-  inexact: boolean;
-  resolved_rev: string;
-  unresolved: string;
-}
-
-export interface RestTypeDestructor {
-  kind: 'RestType';
-  merge_mode: RestMergeMode;
-  type: FlowType;
-}
-
-export type RestMergeMode =
-  | {kind: 'SpreadReversal'}
-  | {kind: 'ReactConfigMerge'; polarity: Polarity}
-  | {kind: 'Omit'};
-
-export interface ValuesTypeDestructor {
-  kind: 'ValuesType';
-}
-
-export interface ConditionalTypeDestructor {
-  kind: 'ConditionalType';
-  distributive_tparam_name: string | null;
-  infer_tparams: string;
-  extends_t: FlowType;
-  true_t: FlowType;
-  false_t: FlowType;
-}
-
-export interface TypeMapDestructor {
-  kind: 'ObjectKeyMirror';
-}
-
-export interface ReactElementPropsTypeDestructor {
-  kind: 'ReactElementPropsType';
-}
-
-export interface ReactElementConfigTypeDestructor {
-  kind: 'ReactElementConfigType';
-}
-
-export interface ReactCheckComponentConfigDestructor {
-  kind: 'ReactCheckComponentConfig';
-  props: {
-    [key: string]: Property;
-  };
-}
-
-export interface ReactDRODestructor {
-  kind: 'ReactDRO';
-  dro_type:
-    | 'HookReturn'
-    | 'HookArg'
-    | 'Props'
-    | 'ImmutableAnnot'
-    | 'DebugAnnot';
-}
-
-export interface MakeHooklikeDestructor {
-  kind: 'MakeHooklike';
-}
-
-export interface MappedTypeDestructor {
-  kind: 'MappedType';
-  homomorphic: Homomorphic;
-  distributive_tparam_name: string | null;
-  property_type: FlowType;
-  mapped_type_flags: {
-    variance: Polarity;
-    optional: 'MakeOptional' | 'RemoveOptional' | 'KeepOptionality';
-  };
-}
-
-export type Homomorphic =
-  | {kind: 'Homomorphic'}
-  | {kind: 'Unspecialized'}
-  | {kind: 'SemiHomomorphic'; type: FlowType};
-
-export interface EnumTypeDestructor {
-  kind: 'EnumType';
-}
-
-// Union of all possible Flow types
-export type FlowType =
-  | OpenType
-  | DefType
-  | EvalType
-  | GenericType
-  | ThisInstanceType
-  | ThisTypeAppType
-  | TypeAppType
-  | FunProtoType
-  | ObjProtoType
-  | NullProtoType
-  | FunProtoBindType
-  | IntersectionType
-  | UnionType
-  | MaybeType
-  | OptionalType
-  | KeysType
-  | AnnotType
-  | OpaqueType
-  | NamespaceType
-  | AnyType
-  | StrUtilType;

compiler/packages/babel-plugin-react-compiler/src/Flood/TypeErrors.ts

@@ -1,138 +0,0 @@
-import {CompilerError, SourceLocation} from '..';
-import {
-  ConcreteType,
-  printConcrete,
-  printType,
-  StructuralValue,
-  Type,
-  VariableId,
-} from './Types';
-
-export function unsupportedLanguageFeature(
-  desc: string,
-  loc: SourceLocation,
-): never {
-  CompilerError.throwInvalidJS({
-    reason: `Typedchecker does not currently support language feature: ${desc}`,
-    loc,
-  });
-}
-
-export type UnificationError =
-  | {
-      kind: 'TypeUnification';
-      left: ConcreteType<Type>;
-      right: ConcreteType<Type>;
-    }
-  | {
-      kind: 'StructuralUnification';
-      left: StructuralValue;
-      right: ConcreteType<Type>;
-    };
-
-function printUnificationError(err: UnificationError): string {
-  if (err.kind === 'TypeUnification') {
-    return `${printConcrete(err.left, printType)} is incompatible with ${printConcrete(err.right, printType)}`;
-  } else {
-    return `structural ${err.left.kind} is incompatible with ${printConcrete(err.right, printType)}`;
-  }
-}
-
-export function raiseUnificationErrors(
-  errs: null | Array<UnificationError>,
-  loc: SourceLocation,
-): void {
-  if (errs != null) {
-    if (errs.length === 0) {
-      CompilerError.invariant(false, {
-        reason: 'Should not have array of zero errors',
-        description: null,
-        details: [
-          {
-            kind: 'error',
-            loc,
-            message: null,
-          },
-        ],
-      });
-    } else if (errs.length === 1) {
-      CompilerError.throwInvalidJS({
-        reason: `Unable to unify types because ${printUnificationError(errs[0])}`,
-        loc,
-      });
-    } else {
-      const messages = errs
-        .map(err => `\t* ${printUnificationError(err)}`)
-        .join('\n');
-      CompilerError.throwInvalidJS({
-        reason: `Unable to unify types because:\n${messages}`,
-        loc,
-      });
-    }
-  }
-}
-
-export function unresolvableTypeVariable(
-  id: VariableId,
-  loc: SourceLocation,
-): never {
-  CompilerError.throwInvalidJS({
-    reason: `Unable to resolve free variable ${id} to a concrete type`,
-    loc,
-  });
-}
-
-export function cannotAddVoid(explicit: boolean, loc: SourceLocation): never {
-  if (explicit) {
-    CompilerError.throwInvalidJS({
-      reason: `Undefined is not a valid operand of \`+\``,
-      loc,
-    });
-  } else {
-    CompilerError.throwInvalidJS({
-      reason: `Value may be undefined, which is not a valid operand of \`+\``,
-      loc,
-    });
-  }
-}
-
-export function unsupportedTypeAnnotation(
-  desc: string,
-  loc: SourceLocation,
-): never {
-  CompilerError.throwInvalidJS({
-    reason: `Typedchecker does not currently support type annotation: ${desc}`,
-    loc,
-  });
-}
-
-export function checkTypeArgumentArity(
-  desc: string,
-  expected: number,
-  actual: number,
-  loc: SourceLocation,
-): void {
-  if (expected !== actual) {
-    CompilerError.throwInvalidJS({
-      reason: `Expected ${desc} to have ${expected} type parameters, got ${actual}`,
-      loc,
-    });
-  }
-}
-
-export function notAFunction(desc: string, loc: SourceLocation): void {
-  CompilerError.throwInvalidJS({
-    reason: `Cannot call ${desc} because it is not a function`,
-    loc,
-  });
-}
-
-export function notAPolymorphicFunction(
-  desc: string,
-  loc: SourceLocation,
-): void {
-  CompilerError.throwInvalidJS({
-    reason: `Cannot call ${desc} with type arguments because it is not a polymorphic function`,
-    loc,
-  });
-}

compiler/packages/babel-plugin-react-compiler/src/Flood/TypeUtils.ts

@@ -1,312 +0,0 @@
-import {GeneratedSource} from '../HIR';
-import {assertExhaustive} from '../Utils/utils';
-import {unsupportedLanguageFeature} from './TypeErrors';
-import {
-  ConcreteType,
-  ResolvedType,
-  TypeParameter,
-  TypeParameterId,
-  DEBUG,
-  printConcrete,
-  printType,
-} from './Types';
-
-export function substitute(
-  type: ConcreteType<ResolvedType>,
-  typeParameters: Array<TypeParameter<ResolvedType>>,
-  typeArguments: Array<ResolvedType>,
-): ResolvedType {
-  const substMap = new Map<TypeParameterId, ResolvedType>();
-  for (let i = 0; i < typeParameters.length; i++) {
-    // TODO: Length checks to make sure type params match up with args
-    const typeParameter = typeParameters[i];
-    const typeArgument = typeArguments[i];
-    substMap.set(typeParameter.id, typeArgument);
-  }
-  const substitutionFunction = (t: ResolvedType): ResolvedType => {
-    // TODO: We really want a stateful mapper or visitor here so that we can model nested polymorphic types
-    if (t.type.kind === 'Generic' && substMap.has(t.type.id)) {
-      const substitutedType = substMap.get(t.type.id)!;
-      return substitutedType;
-    }
-
-    return {
-      kind: 'Concrete',
-      type: mapType(substitutionFunction, t.type),
-      platform: t.platform,
-    };
-  };
-
-  const substituted = mapType(substitutionFunction, type);
-
-  if (DEBUG) {
-    let substs = '';
-    for (let i = 0; i < typeParameters.length; i++) {
-      const typeParameter = typeParameters[i];
-      const typeArgument = typeArguments[i];
-      substs += `[${typeParameter.name}${typeParameter.id} := ${printType(typeArgument)}]`;
-    }
-    console.log(
-      `${printConcrete(type, printType)}${substs} = ${printConcrete(substituted, printType)}`,
-    );
-  }
-
-  return {kind: 'Concrete', type: substituted, platform: /* TODO */ 'shared'};
-}
-
-export function mapType<T, U>(
-  f: (t: T) => U,
-  type: ConcreteType<T>,
-): ConcreteType<U> {
-  switch (type.kind) {
-    case 'Mixed':
-    case 'Number':
-    case 'String':
-    case 'Boolean':
-    case 'Void':
-      return type;
-
-    case 'Nullable':
-      return {
-        kind: 'Nullable',
-        type: f(type.type),
-      };
-
-    case 'Array':
-      return {
-        kind: 'Array',
-        element: f(type.element),
-      };
-
-    case 'Set':
-      return {
-        kind: 'Set',
-        element: f(type.element),
-      };
-
-    case 'Map':
-      return {
-        kind: 'Map',
-        key: f(type.key),
-        value: f(type.value),
-      };
-
-    case 'Function':
-      return {
-        kind: 'Function',
-        typeParameters:
-          type.typeParameters?.map(param => ({
-            id: param.id,
-            name: param.name,
-            bound: f(param.bound),
-          })) ?? null,
-        params: type.params.map(f),
-        returnType: f(type.returnType),
-      };
-
-    case 'Component': {
-      return {
-        kind: 'Component',
-        children: type.children != null ? f(type.children) : null,
-        props: new Map([...type.props.entries()].map(([k, v]) => [k, f(v)])),
-      };
-    }
-
-    case 'Generic':
-      return {
-        kind: 'Generic',
-        id: type.id,
-        bound: f(type.bound),
-      };
-
-    case 'Object':
-      return type;
-
-    case 'Tuple':
-      return {
-        kind: 'Tuple',
-        id: type.id,
-        members: type.members.map(f),
-      };
-
-    case 'Structural':
-      return type;
-
-    case 'Enum':
-    case 'Union':
-    case 'Instance':
-      unsupportedLanguageFeature(type.kind, GeneratedSource);
-
-    default:
-      assertExhaustive(type, 'Unknown type kind');
-  }
-}
-
-export function diff<R, T>(
-  a: ConcreteType<T>,
-  b: ConcreteType<T>,
-  onChild: (a: T, b: T) => R,
-  onChildMismatch: (child: R, cur: R) => R,
-  onMismatch: (a: ConcreteType<T>, b: ConcreteType<T>, cur: R) => R,
-  init: R,
-): R {
-  let errors = init;
-
-  // Check if kinds match
-  if (a.kind !== b.kind) {
-    errors = onMismatch(a, b, errors);
-    return errors;
-  }
-
-  // Based on kind, check other properties
-  switch (a.kind) {
-    case 'Mixed':
-    case 'Number':
-    case 'String':
-    case 'Boolean':
-    case 'Void':
-      // Simple types, no further checks needed
-      break;
-
-    case 'Nullable':
-      // Check the nested type
-      errors = onChildMismatch(onChild(a.type, (b as typeof a).type), errors);
-      break;
-
-    case 'Array':
-    case 'Set':
-      // Check the element type
-      errors = onChildMismatch(
-        onChild(a.element, (b as typeof a).element),
-        errors,
-      );
-      break;
-
-    case 'Map':
-      // Check both key and value types
-      errors = onChildMismatch(onChild(a.key, (b as typeof a).key), errors);
-      errors = onChildMismatch(onChild(a.value, (b as typeof a).value), errors);
-      break;
-
-    case 'Function': {
-      const bFunc = b as typeof a;
-
-      // Check type parameters
-      if ((a.typeParameters == null) !== (bFunc.typeParameters == null)) {
-        errors = onMismatch(a, b, errors);
-      }
-
-      if (a.typeParameters != null && bFunc.typeParameters != null) {
-        if (a.typeParameters.length !== bFunc.typeParameters.length) {
-          errors = onMismatch(a, b, errors);
-        }
-
-        // Type parameters are just numbers, so we can compare them directly
-        for (let i = 0; i < a.typeParameters.length; i++) {
-          if (a.typeParameters[i] !== bFunc.typeParameters[i]) {
-            errors = onMismatch(a, b, errors);
-          }
-        }
-      }
-
-      // Check parameters
-      if (a.params.length !== bFunc.params.length) {
-        errors = onMismatch(a, b, errors);
-      }
-
-      for (let i = 0; i < a.params.length; i++) {
-        errors = onChildMismatch(onChild(a.params[i], bFunc.params[i]), errors);
-      }
-
-      // Check return type
-      errors = onChildMismatch(onChild(a.returnType, bFunc.returnType), errors);
-      break;
-    }
-
-    case 'Component': {
-      const bComp = b as typeof a;
-
-      // Check children
-      if (a.children !== bComp.children) {
-        errors = onMismatch(a, b, errors);
-      }
-
-      // Check props
-      if (a.props.size !== bComp.props.size) {
-        errors = onMismatch(a, b, errors);
-      }
-
-      for (const [k, v] of a.props) {
-        const bProp = bComp.props.get(k);
-        if (bProp == null) {
-          errors = onMismatch(a, b, errors);
-        } else {
-          errors = onChildMismatch(onChild(v, bProp), errors);
-        }
-      }
-
-      break;
-    }
-
-    case 'Generic': {
-      // Check that the type parameter IDs match
-      if (a.id !== (b as typeof a).id) {
-        errors = onMismatch(a, b, errors);
-      }
-      break;
-    }
-    case 'Structural': {
-      const bStruct = b as typeof a;
-
-      // Check that the structural IDs match
-      if (a.id !== bStruct.id) {
-        errors = onMismatch(a, b, errors);
-      }
-      break;
-    }
-    case 'Object': {
-      const bNom = b as typeof a;
-
-      // Check that the nominal IDs match
-      if (a.id !== bNom.id) {
-        errors = onMismatch(a, b, errors);
-      }
-      break;
-    }
-
-    case 'Tuple': {
-      const bTuple = b as typeof a;
-
-      // Check that the tuple IDs match
-      if (a.id !== bTuple.id) {
-        errors = onMismatch(a, b, errors);
-      }
-      for (let i = 0; i < a.members.length; i++) {
-        errors = onChildMismatch(
-          onChild(a.members[i], bTuple.members[i]),
-          errors,
-        );
-      }
-
-      break;
-    }
-
-    case 'Enum':
-    case 'Instance':
-    case 'Union': {
-      unsupportedLanguageFeature(a.kind, GeneratedSource);
-    }
-
-    default:
-      assertExhaustive(a, 'Unknown type kind');
-  }
-
-  return errors;
-}
-
-export function filterOptional(t: ResolvedType): ResolvedType {
-  if (t.kind === 'Concrete' && t.type.kind === 'Nullable') {
-    return t.type.type;
-  }
-  return t;
-}

compiler/packages/babel-plugin-react-compiler/src/HIR/AssertConsistentIdentifiers.ts

@@ -38,13 +38,7 @@ export function assertConsistentIdentifiers(fn: HIRFunction): void {
       CompilerError.invariant(instr.lvalue.identifier.name === null, {
         reason: `Expected all lvalues to be temporaries`,
         description: `Found named lvalue \`${instr.lvalue.identifier.name}\``,
-        details: [
-          {
-            kind: 'error',
-            loc: instr.lvalue.loc,
-            message: null,
-          },
-        ],
+        loc: instr.lvalue.loc,
         suggestions: null,
       });
       CompilerError.invariant(!assignments.has(instr.lvalue.identifier.id), {
@@ -52,13 +46,7 @@ export function assertConsistentIdentifiers(fn: HIRFunction): void {
         description: `Found duplicate assignment of '${printPlace(
           instr.lvalue,
         )}'`,
-        details: [
-          {
-            kind: 'error',
-            loc: instr.lvalue.loc,
-            message: null,
-          },
-        ],
+        loc: instr.lvalue.loc,
         suggestions: null,
       });
       assignments.add(instr.lvalue.identifier.id);
@@ -89,13 +77,7 @@ function validate(
     CompilerError.invariant(identifier === previous, {
       reason: `Duplicate identifier object`,
       description: `Found duplicate identifier object for id ${identifier.id}`,
-      details: [
-        {
-          kind: 'error',
-          loc: loc ?? GeneratedSource,
-          message: null,
-        },
-      ],
+      loc: loc ?? GeneratedSource,
       suggestions: null,
     });
   }

compiler/packages/babel-plugin-react-compiler/src/HIR/AssertTerminalBlocksExist.ts

@@ -18,13 +18,7 @@ export function assertTerminalSuccessorsExist(fn: HIRFunction): void {
         description: `Block bb${successor} does not exist for terminal '${printTerminal(
           block.terminal,
         )}'`,
-        details: [
-          {
-            kind: 'error',
-            loc: (block.terminal as any).loc ?? GeneratedSource,
-            message: null,
-          },
-        ],
+        loc: (block.terminal as any).loc ?? GeneratedSource,
         suggestions: null,
       });
       return successor;
@@ -39,26 +33,14 @@ export function assertTerminalPredsExist(fn: HIRFunction): void {
       CompilerError.invariant(predBlock != null, {
         reason: 'Expected predecessor block to exist',
         description: `Block ${block.id} references non-existent ${pred}`,
-        details: [
-          {
-            kind: 'error',
-            loc: GeneratedSource,
-            message: null,
-          },
-        ],
+        loc: GeneratedSource,
       });
       CompilerError.invariant(
         [...eachTerminalSuccessor(predBlock.terminal)].includes(block.id),
         {
           reason: 'Terminal successor does not reference correct predecessor',
           description: `Block bb${block.id} has bb${predBlock.id} as a predecessor, but bb${predBlock.id}'s successors do not include bb${block.id}`,
-          details: [
-            {
-              kind: 'error',
-              loc: GeneratedSource,
-              message: null,
-            },
-          ],
+          loc: GeneratedSource,
         },
       );
     }

compiler/packages/babel-plugin-react-compiler/src/HIR/AssertValidBlockNesting.ts

@@ -1,10 +1,3 @@
-/**
- * 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 {
   BlockId,
@@ -131,13 +124,7 @@ export function recursivelyTraverseItems<T, TContext>(
       CompilerError.invariant(disjoint || nested, {
         reason: 'Invalid nesting in program blocks or scopes',
         description: `Items overlap but are not nested: ${maybeParentRange.start}:${maybeParentRange.end}(${currRange.start}:${currRange.end})`,
-        details: [
-          {
-            kind: 'error',
-            loc: GeneratedSource,
-            message: null,
-          },
-        ],
+        loc: GeneratedSource,
       });
       if (disjoint) {
         exit(maybeParent, context);

compiler/packages/babel-plugin-react-compiler/src/HIR/AssertValidMutableRanges.ts

@@ -5,14 +5,13 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {HIRFunction, MutableRange, Place} from './HIR';
+import invariant from 'invariant';
+import {HIRFunction, Identifier, MutableRange} from './HIR';
 import {
   eachInstructionLValue,
   eachInstructionOperand,
   eachTerminalOperand,
 } from './visitors';
-import {CompilerError} from '..';
-import {printPlace} from './PrintHIR';
 
 /*
  * Checks that all mutable ranges in the function are well-formed, with
@@ -21,49 +20,38 @@ import {printPlace} from './PrintHIR';
 export function assertValidMutableRanges(fn: HIRFunction): void {
   for (const [, block] of fn.body.blocks) {
     for (const phi of block.phis) {
-      visit(phi.place, `phi for block bb${block.id}`);
-      for (const [pred, operand] of phi.operands) {
-        visit(operand, `phi predecessor bb${pred} for block bb${block.id}`);
+      visitIdentifier(phi.place.identifier);
+      for (const [, operand] of phi.operands) {
+        visitIdentifier(operand.identifier);
       }
     }
     for (const instr of block.instructions) {
       for (const operand of eachInstructionLValue(instr)) {
-        visit(operand, `instruction [${instr.id}]`);
+        visitIdentifier(operand.identifier);
       }
       for (const operand of eachInstructionOperand(instr)) {
-        visit(operand, `instruction [${instr.id}]`);
+        visitIdentifier(operand.identifier);
       }
     }
     for (const operand of eachTerminalOperand(block.terminal)) {
-      visit(operand, `terminal [${block.terminal.id}]`);
+      visitIdentifier(operand.identifier);
     }
   }
 }
 
-function visit(place: Place, description: string): void {
-  validateMutableRange(place, place.identifier.mutableRange, description);
-  if (place.identifier.scope !== null) {
-    validateMutableRange(place, place.identifier.scope.range, description);
+function visitIdentifier(identifier: Identifier): void {
+  validateMutableRange(identifier.mutableRange);
+  if (identifier.scope !== null) {
+    validateMutableRange(identifier.scope.range);
   }
 }
 
-function validateMutableRange(
-  place: Place,
-  range: MutableRange,
-  description: string,
-): void {
-  CompilerError.invariant(
-    (range.start === 0 && range.end === 0) || range.end > range.start,
-    {
-      reason: `Invalid mutable range: [${range.start}:${range.end}]`,
-      description: `${printPlace(place)} in ${description}`,
-      details: [
-        {
-          kind: 'error',
-          loc: place.loc,
-          message: null,
-        },
-      ],
-    },
+function validateMutableRange(mutableRange: MutableRange): void {
+  invariant(
+    (mutableRange.start === 0 && mutableRange.end === 0) ||
+      mutableRange.end > mutableRange.start,
+    'Identifier scope mutableRange was invalid: [%s:%s]',
+    mutableRange.start,
+    mutableRange.end,
   );
 }

compiler/packages/babel-plugin-react-compiler/src/HIR/BuildReactiveScopeTerminalsHIR.ts

@@ -1,10 +1,3 @@
-/**
- * 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 '../CompilerError';
 import {getScopes, recursivelyTraverseItems} from './AssertValidBlockNesting';
 import {Environment} from './Environment';
@@ -234,14 +227,7 @@ function pushEndScopeTerminal(
   const fallthroughId = context.fallthroughs.get(scope.id);
   CompilerError.invariant(fallthroughId != null, {
     reason: 'Expected scope to exist',
-    description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: GeneratedSource,
-        message: null,
-      },
-    ],
+    loc: GeneratedSource,
   });
   context.rewrites.push({
     kind: 'EndScope',

compiler/packages/babel-plugin-react-compiler/src/HIR/CollectHoistablePropertyLoads.ts

@@ -1,10 +1,3 @@
-/**
- * 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 '../CompilerError';
 import {inRange} from '../ReactiveScopes/InferReactiveScopeVariables';
 import {printDependency} from '../ReactiveScopes/PrintReactiveFunction';
@@ -19,7 +12,6 @@ import {
   BasicBlock,
   BlockId,
   DependencyPathEntry,
-  FunctionExpression,
   GeneratedSource,
   getHookKind,
   HIRFunction,
@@ -31,7 +23,6 @@ import {
   PropertyLiteral,
   ReactiveScopeDependency,
   ScopeId,
-  TInstruction,
 } from './HIR';
 
 const DEBUG_PRINT = false;
@@ -129,33 +120,6 @@ export function collectHoistablePropertyLoads(
   });
 }
 
-export function collectHoistablePropertyLoadsInInnerFn(
-  fnInstr: TInstruction<FunctionExpression>,
-  temporaries: ReadonlyMap<IdentifierId, ReactiveScopeDependency>,
-  hoistableFromOptionals: ReadonlyMap<BlockId, ReactiveScopeDependency>,
-): ReadonlyMap<BlockId, BlockInfo> {
-  const fn = fnInstr.value.loweredFunc.func;
-  const initialContext: CollectHoistablePropertyLoadsContext = {
-    temporaries,
-    knownImmutableIdentifiers: new Set(),
-    hoistableFromOptionals,
-    registry: new PropertyPathRegistry(),
-    nestedFnImmutableContext: null,
-    assumedInvokedFns: fn.env.config.enableTreatFunctionDepsAsConditional
-      ? new Set()
-      : getAssumedInvokedFunctions(fn),
-  };
-  const nestedFnImmutableContext = new Set(
-    fn.context
-      .filter(place =>
-        isImmutableAtInstr(place.identifier, fnInstr.id, initialContext),
-      )
-      .map(place => place.identifier.id),
-  );
-  initialContext.nestedFnImmutableContext = nestedFnImmutableContext;
-  return collectHoistablePropertyLoadsImpl(fn, initialContext);
-}
-
 type CollectHoistablePropertyLoadsContext = {
   temporaries: ReadonlyMap<IdentifierId, ReactiveScopeDependency>;
   knownImmutableIdentifiers: ReadonlySet<IdentifierId>;
@@ -241,10 +205,7 @@ type PropertyPathNode =
 class PropertyPathRegistry {
   roots: Map<IdentifierId, RootNode> = new Map();
 
-  getOrCreateIdentifier(
-    identifier: Identifier,
-    reactive: boolean,
-  ): PropertyPathNode {
+  getOrCreateIdentifier(identifier: Identifier): PropertyPathNode {
     /**
      * Reads from a statically scoped variable are always safe in JS,
      * with the exception of TDZ (not addressed by this pass).
@@ -258,26 +219,12 @@ class PropertyPathRegistry {
         optionalProperties: new Map(),
         fullPath: {
           identifier,
-          reactive,
           path: [],
         },
         hasOptional: false,
         parent: null,
       };
       this.roots.set(identifier.id, rootNode);
-    } else {
-      CompilerError.invariant(reactive === rootNode.fullPath.reactive, {
-        reason:
-          '[HoistablePropertyLoads] Found inconsistencies in `reactive` flag when deduping identifier reads within the same scope',
-        description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: identifier.loc,
-            message: null,
-          },
-        ],
-      });
     }
     return rootNode;
   }
@@ -295,7 +242,6 @@ class PropertyPathRegistry {
         parent: parent,
         fullPath: {
           identifier: parent.fullPath.identifier,
-          reactive: parent.fullPath.reactive,
           path: parent.fullPath.path.concat(entry),
         },
         hasOptional: parent.hasOptional || entry.optional,
@@ -311,7 +257,7 @@ class PropertyPathRegistry {
      * so all subpaths of a PropertyLoad should already exist
      * (e.g. a.b is added before a.b.c),
      */
-    let currNode = this.getOrCreateIdentifier(n.identifier, n.reactive);
+    let currNode = this.getOrCreateIdentifier(n.identifier);
     if (n.path.length === 0) {
       return currNode;
     }
@@ -333,11 +279,10 @@ function getMaybeNonNullInInstruction(
   instr: InstructionValue,
   context: CollectHoistablePropertyLoadsContext,
 ): PropertyPathNode | null {
-  let path: ReactiveScopeDependency | null = null;
+  let path = null;
   if (instr.kind === 'PropertyLoad') {
     path = context.temporaries.get(instr.object.identifier.id) ?? {
       identifier: instr.object.identifier,
-      reactive: instr.object.reactive,
       path: [],
     };
   } else if (instr.kind === 'Destructure') {
@@ -400,7 +345,7 @@ function collectNonNullsInBlocks(
   ) {
     const identifier = fn.params[0].identifier;
     knownNonNullIdentifiers.add(
-      context.registry.getOrCreateIdentifier(identifier, true),
+      context.registry.getOrCreateIdentifier(identifier),
     );
   }
   const nodes = new Map<
@@ -454,32 +399,6 @@ 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);
-            }
-          }
-        }
       }
     }
 
@@ -531,14 +450,7 @@ function propagateNonNull(
     if (node == null) {
       CompilerError.invariant(false, {
         reason: `Bad node ${nodeId}, kind: ${direction}`,
-        description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: GeneratedSource,
-            message: null,
-          },
-        ],
+        loc: GeneratedSource,
       });
     }
     const neighbors = Array.from(
@@ -610,14 +522,7 @@ function propagateNonNull(
     CompilerError.invariant(i++ < 100, {
       reason:
         '[CollectHoistablePropertyLoads] fixed point iteration did not terminate after 100 loops',
-      description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: GeneratedSource,
-          message: null,
-        },
-      ],
+      loc: GeneratedSource,
     });
 
     changed = false;
@@ -649,13 +554,7 @@ export function assertNonNull<T extends NonNullable<U>, U>(
   CompilerError.invariant(value != null, {
     reason: 'Unexpected null',
     description: source != null ? `(from ${source})` : null,
-    details: [
-      {
-        kind: 'error',
-        loc: GeneratedSource,
-        message: null,
-      },
-    ],
+    loc: GeneratedSource,
   });
   return value;
 }
@@ -681,11 +580,9 @@ function reduceMaybeOptionalChains(
     changed = false;
 
     for (const original of optionalChainNodes) {
-      let {identifier, path: origPath, reactive} = original.fullPath;
-      let currNode: PropertyPathNode = registry.getOrCreateIdentifier(
-        identifier,
-        reactive,
-      );
+      let {identifier, path: origPath} = original.fullPath;
+      let currNode: PropertyPathNode =
+        registry.getOrCreateIdentifier(identifier);
       for (let i = 0; i < origPath.length; i++) {
         const entry = origPath[i];
         // If the base is known to be non-null, replace with a non-optional load

compiler/packages/babel-plugin-react-compiler/src/HIR/CollectOptionalChainDependencies.ts

@@ -1,10 +1,3 @@
-/**
- * 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 {assertNonNull} from './CollectHoistablePropertyLoads';
 import {
@@ -186,13 +179,7 @@ function matchOptionalTestBlock(
         reason:
           '[OptionalChainDeps] Inconsistent optional chaining property load',
         description: `Test=${printIdentifier(terminal.test.identifier)} PropertyLoad base=${printIdentifier(propertyLoad.value.object.identifier)}`,
-        details: [
-          {
-            kind: 'error',
-            loc: propertyLoad.loc,
-            message: null,
-          },
-        ],
+        loc: propertyLoad.loc,
       },
     );
 
@@ -200,14 +187,7 @@ function matchOptionalTestBlock(
       storeLocal.value.identifier.id === propertyLoad.lvalue.identifier.id,
       {
         reason: '[OptionalChainDeps] Unexpected storeLocal',
-        description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: propertyLoad.loc,
-            message: null,
-          },
-        ],
+        loc: propertyLoad.loc,
       },
     );
     if (
@@ -224,14 +204,7 @@ function matchOptionalTestBlock(
         alternate.instructions[1].value.kind === 'StoreLocal',
       {
         reason: 'Unexpected alternate structure',
-        description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: terminal.loc,
-            message: null,
-          },
-        ],
+        loc: terminal.loc,
       },
     );
 
@@ -267,14 +240,7 @@ function traverseOptionalBlock(
   if (maybeTest.terminal.kind === 'branch') {
     CompilerError.invariant(optional.terminal.optional, {
       reason: '[OptionalChainDeps] Expect base case to be always optional',
-      description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: optional.terminal.loc,
-          message: null,
-        },
-      ],
+      loc: optional.terminal.loc,
     });
     /**
      * Optional base expressions are currently within value blocks which cannot
@@ -312,19 +278,11 @@ function traverseOptionalBlock(
         maybeTest.instructions.at(-1)!.lvalue.identifier.id,
       {
         reason: '[OptionalChainDeps] Unexpected test expression',
-        description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: maybeTest.terminal.loc,
-            message: null,
-          },
-        ],
+        loc: maybeTest.terminal.loc,
       },
     );
     baseObject = {
       identifier: maybeTest.instructions[0].value.place.identifier,
-      reactive: maybeTest.instructions[0].value.place.reactive,
       path,
     };
     test = maybeTest.terminal;
@@ -408,14 +366,7 @@ function traverseOptionalBlock(
       reason:
         '[OptionalChainDeps] Unexpected instructions an inner optional block. ' +
         'This indicates that the compiler may be incorrectly concatenating two unrelated optional chains',
-      description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: optional.terminal.loc,
-          message: null,
-        },
-      ],
+      loc: optional.terminal.loc,
     });
   }
   const matchConsequentResult = matchOptionalTestBlock(test, context.blocks);
@@ -428,18 +379,11 @@ function traverseOptionalBlock(
     {
       reason: '[OptionalChainDeps] Unexpected optional goto-fallthrough',
       description: `${matchConsequentResult.consequentGoto} != ${optional.terminal.fallthrough}`,
-      details: [
-        {
-          kind: 'error',
-          loc: optional.terminal.loc,
-          message: null,
-        },
-      ],
+      loc: optional.terminal.loc,
     },
   );
   const load = {
     identifier: baseObject.identifier,
-    reactive: baseObject.reactive,
     path: [
       ...baseObject.path,
       {

compiler/packages/babel-plugin-react-compiler/src/HIR/ComputeUnconditionalBlocks.ts

@@ -24,14 +24,7 @@ export function computeUnconditionalBlocks(fn: HIRFunction): Set<BlockId> {
     CompilerError.invariant(!unconditionalBlocks.has(current), {
       reason:
         'Internal error: non-terminating loop in ComputeUnconditionalBlocks',
-      description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: null,
-          message: null,
-        },
-      ],
+      loc: null,
       suggestions: null,
     });
     unconditionalBlocks.add(current);

compiler/packages/babel-plugin-react-compiler/src/HIR/DefaultModuleTypeProvider.ts

@@ -1,109 +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 {Effect, ValueKind} from '..';
-import {TypeConfig} from './TypeSchema';
-
-/**
- * Libraries developed before we officially documented the [Rules of React](https://react.dev/reference/rules)
- * implement APIs which cannot be memoized safely, either via manual or automatic memoization.
- *
- * Any non-hook API that is designed to be called during render (not events/effects) should be safe to memoize:
- *
- * ```js
- * function Component() {
- *   const {someFunction} = useLibrary();
- *   // it should always be safe to memoize functions like this
- *  const result = useMemo(() => someFunction(), [someFunction]);
- * }
- * ```
- *
- * However, some APIs implement "interior mutability" — mutating values rather than copying into a new value
- * and setting state with the new value. Such functions (`someFunction()` in the example) could return different
- * values even though the function itself is the same object. This breaks memoization, since React relies on
- * the outer object (or function) changing if part of its value has changed.
- *
- * Given that we didn't have the Rules of React precisely documented prior to the introduction of React compiler,
- * it's understandable that some libraries accidentally shipped APIs that break this rule. However, developers
- * can easily run into pitfalls with these APIs. They may manually memoize them, which can break their app. Or
- * they may try using React Compiler, and think that the compiler has broken their code.
- *
- * To help ensure that developers can successfully use the compiler with existing code, this file teaches the
- * compiler about specific APIs that are known to be incompatible with memoization. We've tried to be as precise
- * as possible.
- *
- * The React team is open to collaborating with library authors to help develop compatible versions of these APIs,
- * and we have already reached out to the teams who own any API listed here to ensure they are aware of the issue.
- */
-export function defaultModuleTypeProvider(
-  moduleName: string,
-): TypeConfig | null {
-  switch (moduleName) {
-    case 'react-hook-form': {
-      return {
-        kind: 'object',
-        properties: {
-          useForm: {
-            kind: 'hook',
-            returnType: {
-              kind: 'object',
-              properties: {
-                // Only the `watch()` function returned by react-hook-form's `useForm()` API is incompatible
-                watch: {
-                  kind: 'function',
-                  positionalParams: [],
-                  restParam: Effect.Read,
-                  calleeEffect: Effect.Read,
-                  returnType: {kind: 'type', name: 'Any'},
-                  returnValueKind: ValueKind.Mutable,
-                  knownIncompatible: `React Hook Form's \`useForm()\` API returns a \`watch()\` function which cannot be memoized safely.`,
-                },
-              },
-            },
-          },
-        },
-      };
-    }
-    case '@tanstack/react-table': {
-      return {
-        kind: 'object',
-        properties: {
-          /*
-           * Many of the properties of `useReactTable()`'s return value are incompatible, so we mark the entire hook
-           * as incompatible
-           */
-          useReactTable: {
-            kind: 'hook',
-            positionalParams: [],
-            restParam: Effect.Read,
-            returnType: {kind: 'type', name: 'Any'},
-            knownIncompatible: `TanStack Table's \`useReactTable()\` API returns functions that cannot be memoized safely`,
-          },
-        },
-      };
-    }
-    case '@tanstack/react-virtual': {
-      return {
-        kind: 'object',
-        properties: {
-          /*
-           * Many of the properties of `useVirtualizer()`'s return value are incompatible, so we mark the entire hook
-           * as incompatible
-           */
-          useVirtualizer: {
-            kind: 'hook',
-            positionalParams: [],
-            restParam: Effect.Read,
-            returnType: {kind: 'type', name: 'Any'},
-            knownIncompatible: `TanStack Virtual's \`useVirtualizer()\` API returns functions that cannot be memoized safely`,
-          },
-        },
-      };
-    }
-  }
-  return null;
-}

compiler/packages/babel-plugin-react-compiler/src/HIR/DeriveMinimalDependenciesHIR.ts

@@ -25,9 +25,8 @@ export class ReactiveScopeDependencyTreeHIR {
    * `identifier.path`, or `identifier?.path` is in this map, it is safe to
    * evaluate (non-optional) PropertyLoads from.
    */
-  #hoistableObjects: Map<Identifier, HoistableNode & {reactive: boolean}> =
-    new Map();
-  #deps: Map<Identifier, DependencyNode & {reactive: boolean}> = new Map();
+  #hoistableObjects: Map<Identifier, HoistableNode> = new Map();
+  #deps: Map<Identifier, DependencyNode> = new Map();
 
   /**
    * @param hoistableObjects a set of paths from which we can safely evaluate
@@ -36,10 +35,9 @@ export class ReactiveScopeDependencyTreeHIR {
    * duplicates when traversing the CFG.
    */
   constructor(hoistableObjects: Iterable<ReactiveScopeDependency>) {
-    for (const {path, identifier, reactive} of hoistableObjects) {
+    for (const {path, identifier} of hoistableObjects) {
       let currNode = ReactiveScopeDependencyTreeHIR.#getOrCreateRoot(
         identifier,
-        reactive,
         this.#hoistableObjects,
         path.length > 0 && path[0].optional ? 'Optional' : 'NonNull',
       );
@@ -54,14 +52,7 @@ export class ReactiveScopeDependencyTreeHIR {
           prevAccessType == null || prevAccessType === accessType,
           {
             reason: 'Conflicting access types',
-            description: null,
-            details: [
-              {
-                kind: 'error',
-                loc: GeneratedSource,
-                message: null,
-              },
-            ],
+            loc: GeneratedSource,
           },
         );
         let nextNode = currNode.properties.get(path[i].property);
@@ -79,8 +70,7 @@ export class ReactiveScopeDependencyTreeHIR {
 
   static #getOrCreateRoot<T extends string>(
     identifier: Identifier,
-    reactive: boolean,
-    roots: Map<Identifier, TreeNode<T> & {reactive: boolean}>,
+    roots: Map<Identifier, TreeNode<T>>,
     defaultAccessType: T,
   ): TreeNode<T> {
     // roots can always be accessed unconditionally in JS
@@ -89,22 +79,9 @@ export class ReactiveScopeDependencyTreeHIR {
     if (rootNode === undefined) {
       rootNode = {
         properties: new Map(),
-        reactive,
         accessType: defaultAccessType,
       };
       roots.set(identifier, rootNode);
-    } else {
-      CompilerError.invariant(reactive === rootNode.reactive, {
-        reason: '[DeriveMinimalDependenciesHIR] Conflicting reactive root flag',
-        description: `Identifier ${printIdentifier(identifier)}`,
-        details: [
-          {
-            kind: 'error',
-            loc: GeneratedSource,
-            message: null,
-          },
-        ],
-      });
     }
     return rootNode;
   }
@@ -115,10 +92,9 @@ export class ReactiveScopeDependencyTreeHIR {
    * safe-to-evaluate subpath
    */
   addDependency(dep: ReactiveScopeDependency): void {
-    const {identifier, reactive, path} = dep;
+    const {identifier, path} = dep;
     let depCursor = ReactiveScopeDependencyTreeHIR.#getOrCreateRoot(
       identifier,
-      reactive,
       this.#deps,
       PropertyAccessType.UnconditionalAccess,
     );
@@ -196,13 +172,7 @@ export class ReactiveScopeDependencyTreeHIR {
   deriveMinimalDependencies(): Set<ReactiveScopeDependency> {
     const results = new Set<ReactiveScopeDependency>();
     for (const [rootId, rootNode] of this.#deps.entries()) {
-      collectMinimalDependenciesInSubtree(
-        rootNode,
-        rootNode.reactive,
-        rootId,
-        [],
-        results,
-      );
+      collectMinimalDependenciesInSubtree(rootNode, rootId, [], results);
     }
 
     return results;
@@ -324,24 +294,25 @@ type HoistableNode = TreeNode<'Optional' | 'NonNull'>;
 type DependencyNode = TreeNode<PropertyAccessType>;
 
 /**
+ * TODO: this is directly pasted from DeriveMinimalDependencies. Since we no
+ * longer have conditionally accessed nodes, we can simplify
+ *
  * Recursively calculates minimal dependencies in a subtree.
  * @param node DependencyNode representing a dependency subtree.
  * @returns a minimal list of dependencies in this subtree.
  */
 function collectMinimalDependenciesInSubtree(
   node: DependencyNode,
-  reactive: boolean,
   rootIdentifier: Identifier,
   path: Array<DependencyPathEntry>,
   results: Set<ReactiveScopeDependency>,
 ): void {
   if (isDependency(node.accessType)) {
-    results.add({identifier: rootIdentifier, reactive, path});
+    results.add({identifier: rootIdentifier, path});
   } else {
     for (const [childName, childNode] of node.properties) {
       collectMinimalDependenciesInSubtree(
         childNode,
-        reactive,
         rootIdentifier,
         [
           ...path,

compiler/packages/babel-plugin-react-compiler/src/HIR/Dominator.ts

@@ -89,13 +89,7 @@ export class Dominator<T> {
     CompilerError.invariant(dominator !== undefined, {
       reason: 'Unknown node',
       description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: null,
-          message: null,
-        },
-      ],
+      loc: null,
       suggestions: null,
     });
     return dominator === id ? null : dominator;
@@ -136,13 +130,7 @@ export class PostDominator<T> {
     CompilerError.invariant(dominator !== undefined, {
       reason: 'Unknown node',
       description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: null,
-          message: null,
-        },
-      ],
+      loc: null,
       suggestions: null,
     });
     return dominator === id ? null : dominator;
@@ -187,13 +175,7 @@ function computeImmediateDominators<T>(graph: Graph<T>): Map<T, T> {
       CompilerError.invariant(newIdom !== null, {
         reason: `At least one predecessor must have been visited for block ${id}`,
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
+        loc: null,
         suggestions: null,
       });
 

compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts

@@ -6,10 +6,18 @@
  */
 
 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 {
+  CompilationMode,
+  defaultOptions,
+  Logger,
+  PanicThresholdOptions,
+  parsePluginOptions,
+  PluginOptions,
+  ProgramContext,
+} from '../Entrypoint';
 import {Err, Ok, Result} from '../Utils/Result';
 import {
   DEFAULT_GLOBALS,
@@ -47,11 +55,8 @@ import {
   ShapeRegistry,
   addHook,
 } from './ObjectShape';
-import {Scope as BabelScope, NodePath} from '@babel/traverse';
+import {Scope as BabelScope} 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 +89,21 @@ 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({
   /*
@@ -143,14 +158,14 @@ export type Hook = z.infer<typeof HookSchema>;
  *   missing some recursive Object / Function shapeIds
  */
 
-export const EnvironmentConfigSchema = z.object({
+const EnvironmentConfigSchema = z.object({
   customHooks: z.map(z.string(), HookSchema).default(new Map()),
 
   /**
    * 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 +216,7 @@ 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 +233,6 @@ 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
@@ -253,12 +251,6 @@ export const EnvironmentConfigSchema = z.object({
    */
   enableUseTypeAnnotations: z.boolean().default(false),
 
-  /**
-   * Allows specifying a function that can populate HIR with type information from
-   * Flow
-   */
-  flowTypeProvider: z.nullable(z.any()).default(null),
-
   /**
    * Enables inference of optional dependency chains. Without this flag
    * a property chain such as `props?.items?.foo` will infer as a dep on
@@ -269,8 +261,6 @@ export const EnvironmentConfigSchema = z.object({
 
   enableFire: z.boolean().default(false),
 
-  enableNameAnonymousFunctions: z.boolean().default(false),
-
   /**
    * Enables inference and auto-insertion of effect dependencies. Takes in an array of
    * configurable module and import pairs to allow for user-land experimentation. For example,
@@ -278,19 +268,21 @@ export const EnvironmentConfigSchema = z.object({
    *   {
    *     module: 'react',
    *     imported: 'useEffect',
-   *     autodepsIndex: 1,
+   *     numRequiredArgs: 1,
    *   },{
    *     module: 'MyExperimentalEffectHooks',
    *     imported: 'useExperimentalEffect',
-   *     autodepsIndex: 2,
+   *     numRequiredArgs: 2,
    *   },
    * ]
    * would insert dependencies for calls of `useEffect` imported from `react` and calls of
    * useExperimentalEffect` from `MyExperimentalEffectHooks`.
    *
-   * `autodepsIndex` tells the compiler which index we expect the AUTODEPS to appear in.
-   *  With the configuration above, we'd insert dependencies for `useEffect` if it has two
-   *  arguments, and the second is AUTODEPS.
+   * `numRequiredArgs` tells the compiler the amount of arguments required to append a dependency
+   *  array to the end of the call. With the configuration above, we'd insert dependencies for
+   *  `useEffect` if it is only given a single argument and it would be appended to the argument list.
+   *
+   * numRequiredArgs must always be greater than 0, otherwise there is no function to analyze for dependencies
    *
    * Still experimental.
    */
@@ -299,7 +291,7 @@ export const EnvironmentConfigSchema = z.object({
       z.array(
         z.object({
           function: ExternalFunctionSchema,
-          autodepsIndex: z.number().min(1, 'autodepsIndex must be > 0'),
+          numRequiredArgs: z.number().min(1, 'numRequiredArgs must be > 0'),
         }),
       ),
     )
@@ -331,28 +323,10 @@ 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).
+   * Validates that setState is not called directly within a passive effect (useEffect).
    * Scheduling a setState (with an event listener, subscription, etc) is valid.
    */
-  validateNoSetStateInEffects: z.boolean().default(false),
-
-  /**
-   * Validates that effects are not used to calculate derived data which could instead be computed
-   * during render.
-   */
-  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),
+  validateNoSetStateInPassiveEffects: z.boolean().default(false),
 
   /**
    * Validates against creating JSX within a try block and recommends using an error boundary
@@ -388,23 +362,11 @@ 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
    */
   validateNoImpureFunctionsInRender: z.boolean().default(false),
 
-  /**
-   * Validate against passing mutable functions to hooks
-   */
-  validateNoFreezingKnownMutableFunctions: z.boolean().default(false),
-
   /*
    * When enabled, the compiler assumes that hooks follow the Rules of React:
    * - Hooks may memoize computation based on any of their parameters, thus
@@ -646,14 +608,7 @@ export const EnvironmentConfigSchema = z.object({
    *
    * Here the variables `ref` and `myRef` will be typed as Refs.
    */
-  enableTreatRefLikeIdentifiersAsRefs: z.boolean().default(true),
-
-  /**
-   * Treat identifiers as SetState type if both
-   * - they are named with a "set-" prefix
-   * - they are called somewhere
-   */
-  enableTreatSetIdentifiersAsStateSetters: z.boolean().default(false),
+  enableTreatRefLikeIdentifiersAsRefs: z.boolean().default(false),
 
   /*
    * If specified a value, the compiler lowers any calls to `useContext` to use
@@ -676,59 +631,195 @@ export const EnvironmentConfigSchema = z.object({
    * ```
    */
   lowerContextAccess: ExternalFunctionSchema.nullable().default(null),
-
-  /**
-   * If enabled, will validate useMemos that don't return any values:
-   *
-   * Valid:
-   *   useMemo(() => foo, [foo]);
-   *   useMemo(() => { return foo }, [foo]);
-   * Invalid:
-   *   useMemo(() => { ... }, [...]);
-   */
-  validateNoVoidUseMemo: z.boolean().default(true),
-
-  /**
-   * Validates that Components/Hooks are always defined at module level. This prevents scope
-   * reference errors that occur when the compiler attempts to optimize the nested component/hook
-   * while its parent function remains uncompiled.
-   */
-  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.
-   */
-  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>;
 
+/**
+ * For test fixtures and playground only.
+ *
+ * Pragmas are straightforward to parse for boolean options (`:true` and
+ * `:false`). These are 'enabled' config values for non-boolean configs (i.e.
+ * what is used when parsing `:true`).
+ */
+const testComplexConfigDefaults: PartialEnvironmentConfig = {
+  validateNoCapitalizedCalls: [],
+  enableChangeDetectionForDebugging: {
+    source: 'react-compiler-runtime',
+    importSpecifierName: '$structuralCheck',
+  },
+  enableEmitFreeze: {
+    source: 'react-compiler-runtime',
+    importSpecifierName: 'makeReadOnly',
+  },
+  enableEmitInstrumentForget: {
+    fn: {
+      source: 'react-compiler-runtime',
+      importSpecifierName: 'useRenderCounter',
+    },
+    gating: {
+      source: 'react-compiler-runtime',
+      importSpecifierName: 'shouldInstrument',
+    },
+    globalGating: 'DEV',
+  },
+  enableEmitHookGuards: {
+    source: 'react-compiler-runtime',
+    importSpecifierName: '$dispatcherGuard',
+  },
+  inlineJsxTransform: {
+    elementSymbol: 'react.transitional.element',
+    globalDevVar: 'DEV',
+  },
+  lowerContextAccess: {
+    source: 'react-compiler-runtime',
+    importSpecifierName: 'useContext_withSelector',
+  },
+  inferEffectDependencies: [
+    {
+      function: {
+        source: 'react',
+        importSpecifierName: 'useEffect',
+      },
+      numRequiredArgs: 1,
+    },
+    {
+      function: {
+        source: 'shared-runtime',
+        importSpecifierName: 'useSpecialEffect',
+      },
+      numRequiredArgs: 2,
+    },
+    {
+      function: {
+        source: 'useEffectWrapper',
+        importSpecifierName: 'default',
+      },
+      numRequiredArgs: 1,
+    },
+  ],
+};
+
+/**
+ * For snap test fixtures and playground only.
+ */
+function parseConfigPragmaEnvironmentForTest(
+  pragma: string,
+): EnvironmentConfig {
+  const maybeConfig: any = {};
+  // Get the defaults to programmatically check for boolean properties
+  const defaultConfig = EnvironmentConfigSchema.parse({});
+
+  for (const token of pragma.split(' ')) {
+    if (!token.startsWith('@')) {
+      continue;
+    }
+    const keyVal = token.slice(1);
+    let [key, val = undefined] = keyVal.split(':');
+    const isSet = val === undefined || val === 'true';
+
+    if (isSet && key in testComplexConfigDefaults) {
+      maybeConfig[key] =
+        testComplexConfigDefaults[key as keyof PartialEnvironmentConfig];
+      continue;
+    }
+
+    if (key === 'customMacros' && val) {
+      const valSplit = val.split('.');
+      if (valSplit.length > 0) {
+        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;
+    }
+
+    if (
+      key !== 'enableResetCacheOnSourceFileChanges' &&
+      typeof defaultConfig[key as keyof EnvironmentConfig] !== 'boolean'
+    ) {
+      // skip parsing non-boolean properties
+      continue;
+    }
+    if (val === undefined || val === 'true') {
+      maybeConfig[key] = true;
+    } else {
+      maybeConfig[key] = false;
+    }
+  }
+  const config = EnvironmentConfigSchema.safeParse(maybeConfig);
+  if (config.success) {
+    /**
+     * Unless explicitly enabled, do not insert HMR handling code
+     * in test fixtures or playground to reduce visual noise.
+     */
+    if (config.data.enableResetCacheOnSourceFileChanges == null) {
+      config.data.enableResetCacheOnSourceFileChanges = false;
+    }
+    return config.data;
+  }
+  CompilerError.invariant(false, {
+    reason: 'Internal error, could not parse config from pragma string',
+    description: `${fromZodError(config.error)}`,
+    loc: null,
+    suggestions: null,
+  });
+}
+export function parseConfigPragmaForTests(
+  pragma: string,
+  defaults: {
+    compilationMode: CompilationMode;
+  },
+): PluginOptions {
+  const environment = parseConfigPragmaEnvironmentForTest(pragma);
+  let compilationMode: CompilationMode = defaults.compilationMode;
+  let panicThreshold: PanicThresholdOptions = 'all_errors';
+  let noEmit: boolean = defaultOptions.noEmit;
+  for (const token of pragma.split(' ')) {
+    if (!token.startsWith('@')) {
+      continue;
+    }
+    switch (token) {
+      case '@compilationMode(annotation)': {
+        compilationMode = 'annotation';
+        break;
+      }
+      case '@compilationMode(infer)': {
+        compilationMode = 'infer';
+        break;
+      }
+      case '@compilationMode(all)': {
+        compilationMode = 'all';
+        break;
+      }
+      case '@compilationMode(syntax)': {
+        compilationMode = 'syntax';
+        break;
+      }
+      case '@panicThreshold(none)': {
+        panicThreshold = 'none';
+        break;
+      }
+      case '@noEmit': {
+        noEmit = true;
+        break;
+      }
+    }
+  }
+  return parsePluginOptions({
+    environment,
+    compilationMode,
+    panicThreshold,
+    noEmit,
+  });
+}
+
 export type PartialEnvironmentConfig = Partial<EnvironmentConfig>;
 
 export type ReactFunctionType = 'Component' | 'Hook' | 'Other';
@@ -764,7 +855,7 @@ export class Environment {
   code: string | null;
   config: EnvironmentConfig;
   fnType: ReactFunctionType;
-  outputMode: CompilerOutputMode;
+  compilerMode: CompilerMode;
   programContext: ProgramContext;
   hasFireRewrite: boolean;
   hasInferredEffect: boolean;
@@ -772,17 +863,13 @@ export class Environment {
 
   #contextIdentifiers: Set<t.Identifier>;
   #hoistedIdentifiers: Set<t.Identifier>;
-  parentFunction: NodePath<t.Function>;
-
-  #flowTypeEnvironment: FlowTypeEnv | null;
 
   constructor(
     scope: BabelScope,
     fnType: ReactFunctionType,
-    outputMode: CompilerOutputMode,
+    compilerMode: CompilerMode,
     config: EnvironmentConfig,
     contextIdentifiers: Set<t.Identifier>,
-    parentFunction: NodePath<t.Function>, // the outermost function being compiled
     logger: Logger | null,
     filename: string | null,
     code: string | null,
@@ -790,7 +877,7 @@ export class Environment {
   ) {
     this.#scope = scope;
     this.fnType = fnType;
-    this.outputMode = outputMode;
+    this.compilerMode = compilerMode;
     this.config = config;
     this.filename = filename;
     this.code = code;
@@ -817,13 +904,7 @@ export class Environment {
       CompilerError.invariant(!this.#globals.has(hookName), {
         reason: `[Globals] Found existing definition in global registry for custom hook ${hookName}`,
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
+        loc: null,
         suggestions: null,
       });
       this.#globals.set(
@@ -847,104 +928,12 @@ export class Environment {
       this.#moduleTypes.set(REANIMATED_MODULE_NAME, reanimatedModuleType);
     }
 
-    this.parentFunction = parentFunction;
     this.#contextIdentifiers = contextIdentifiers;
     this.#hoistedIdentifiers = new Set();
-
-    if (config.flowTypeProvider != null) {
-      this.#flowTypeEnvironment = new FlowTypeEnv();
-      CompilerError.invariant(code != null, {
-        reason:
-          'Expected Environment to be initialized with source code when a Flow type provider is specified',
-        description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
-      });
-      this.#flowTypeEnvironment.init(this, code);
-    } else {
-      this.#flowTypeEnvironment = null;
-    }
   }
 
-  get typeContext(): FlowTypeEnv {
-    CompilerError.invariant(this.#flowTypeEnvironment != null, {
-      reason: 'Flow type environment not initialized',
-      description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: null,
-          message: null,
-        },
-      ],
-    });
-    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 {
@@ -1005,22 +994,10 @@ export class Environment {
   #resolveModuleType(moduleName: string, loc: SourceLocation): Global | null {
     let moduleType = this.#moduleTypes.get(moduleName);
     if (moduleType === undefined) {
-      /*
-       * NOTE: Zod doesn't work when specifying a function as a default, so we have to
-       * fallback to the default value here
-       */
-      const moduleTypeProvider =
-        this.config.moduleTypeProvider ?? defaultModuleTypeProvider;
-      if (moduleTypeProvider == null) {
+      if (this.config.moduleTypeProvider == null) {
         return null;
       }
-      if (typeof moduleTypeProvider !== 'function') {
-        CompilerError.throwInvalidConfig({
-          reason: `Expected a function for \`moduleTypeProvider\``,
-          loc,
-        });
-      }
-      const unparsedModuleConfig = moduleTypeProvider(moduleName);
+      const unparsedModuleConfig = this.config.moduleTypeProvider(moduleName);
       if (unparsedModuleConfig != null) {
         const parsedModuleConfig = TypeSchema.safeParse(unparsedModuleConfig);
         if (!parsedModuleConfig.success) {
@@ -1194,13 +1171,7 @@ export class Environment {
       CompilerError.invariant(shape !== undefined, {
         reason: `[HIR] Forget internal error: cannot resolve shape ${shapeId}`,
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
+        loc: null,
         suggestions: null,
       });
       return shape.properties.get('*') ?? null;
@@ -1225,13 +1196,7 @@ export class Environment {
       CompilerError.invariant(shape !== undefined, {
         reason: `[HIR] Forget internal error: cannot resolve shape ${shapeId}`,
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
+        loc: null,
         suggestions: null,
       });
       if (typeof property === 'string') {
@@ -1256,13 +1221,7 @@ export class Environment {
       CompilerError.invariant(shape !== undefined, {
         reason: `[HIR] Forget internal error: cannot resolve shape ${shapeId}`,
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
+        loc: null,
         suggestions: null,
       });
       return shape.functionType;

compiler/packages/babel-plugin-react-compiler/src/HIR/FindContextIdentifiers.ts

@@ -184,13 +184,7 @@ function handleAssignment(
           CompilerError.invariant(valuePath.isLVal(), {
             reason: `[FindContextIdentifiers] Expected object property value to be an LVal, got: ${valuePath.type}`,
             description: null,
-            details: [
-              {
-                kind: 'error',
-                loc: valuePath.node.loc ?? GeneratedSource,
-                message: null,
-              },
-            ],
+            loc: valuePath.node.loc ?? GeneratedSource,
             suggestions: null,
           });
           handleAssignment(currentFn, identifiers, valuePath);
@@ -198,13 +192,7 @@ function handleAssignment(
           CompilerError.invariant(property.isRestElement(), {
             reason: `[FindContextIdentifiers] Invalid assumptions for babel types.`,
             description: null,
-            details: [
-              {
-                kind: 'error',
-                loc: property.node.loc ?? GeneratedSource,
-                message: null,
-              },
-            ],
+            loc: property.node.loc ?? GeneratedSource,
             suggestions: null,
           });
           handleAssignment(currentFn, identifiers, property);

compiler/packages/babel-plugin-react-compiler/src/HIR/Globals.ts

@@ -9,8 +9,6 @@ import {Effect, ValueKind, ValueReason} from './HIR';
 import {
   BUILTIN_SHAPES,
   BuiltInArrayId,
-  BuiltInAutodepsId,
-  BuiltInFireFunctionId,
   BuiltInFireId,
   BuiltInMapId,
   BuiltInMixedReadonlyId,
@@ -18,27 +16,21 @@ import {
   BuiltInSetId,
   BuiltInUseActionStateId,
   BuiltInUseContextHookId,
-  BuiltInUseEffectEventId,
   BuiltInUseEffectHookId,
   BuiltInUseInsertionEffectHookId,
   BuiltInUseLayoutEffectHookId,
   BuiltInUseOperatorId,
-  BuiltInUseOptimisticId,
   BuiltInUseReducerId,
   BuiltInUseRefId,
   BuiltInUseStateId,
   BuiltInUseTransitionId,
-  BuiltInWeakMapId,
-  BuiltInWeakSetId,
-  BuiltInEffectEventId,
-  ReanimatedSharedValueId,
   ShapeRegistry,
   addFunction,
   addHook,
   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 '..';
@@ -115,99 +107,6 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
           returnValueKind: ValueKind.Mutable,
         }),
       ],
-      [
-        'entries',
-        addFunction(DEFAULT_SHAPES, [], {
-          positionalParams: [Effect.Capture],
-          restParam: null,
-          returnType: {kind: 'Object', shapeId: BuiltInArrayId},
-          calleeEffect: Effect.Read,
-          returnValueKind: ValueKind.Mutable,
-          aliasing: {
-            receiver: '@receiver',
-            params: ['@object'],
-            rest: null,
-            returns: '@returns',
-            temporaries: [],
-            effects: [
-              {
-                kind: 'Create',
-                into: '@returns',
-                reason: ValueReason.KnownReturnSignature,
-                value: ValueKind.Mutable,
-              },
-              // Object values are captured into the return
-              {
-                kind: 'Capture',
-                from: '@object',
-                into: '@returns',
-              },
-            ],
-          },
-        }),
-      ],
-      [
-        'keys',
-        addFunction(DEFAULT_SHAPES, [], {
-          positionalParams: [Effect.Read],
-          restParam: null,
-          returnType: {kind: 'Object', shapeId: BuiltInArrayId},
-          calleeEffect: Effect.Read,
-          returnValueKind: ValueKind.Mutable,
-          aliasing: {
-            receiver: '@receiver',
-            params: ['@object'],
-            rest: null,
-            returns: '@returns',
-            temporaries: [],
-            effects: [
-              {
-                kind: 'Create',
-                into: '@returns',
-                reason: ValueReason.KnownReturnSignature,
-                value: ValueKind.Mutable,
-              },
-              // Only keys are captured, and keys are immutable
-              {
-                kind: 'ImmutableCapture',
-                from: '@object',
-                into: '@returns',
-              },
-            ],
-          },
-        }),
-      ],
-      [
-        'values',
-        addFunction(DEFAULT_SHAPES, [], {
-          positionalParams: [Effect.Capture],
-          restParam: null,
-          returnType: {kind: 'Object', shapeId: BuiltInArrayId},
-          calleeEffect: Effect.Read,
-          returnValueKind: ValueKind.Mutable,
-          aliasing: {
-            receiver: '@receiver',
-            params: ['@object'],
-            rest: null,
-            returns: '@returns',
-            temporaries: [],
-            effects: [
-              {
-                kind: 'Create',
-                into: '@returns',
-                reason: ValueReason.KnownReturnSignature,
-                value: ValueKind.Mutable,
-              },
-              // Object values are captured into the return
-              {
-                kind: 'Capture',
-                from: '@object',
-                into: '@returns',
-              },
-            ],
-          },
-        }),
-      ],
     ]),
   ],
   [
@@ -591,171 +490,14 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
       true,
     ),
   ],
-  [
-    'WeakMap',
-    addFunction(
-      DEFAULT_SHAPES,
-      [],
-      {
-        positionalParams: [Effect.ConditionallyMutateIterator],
-        restParam: null,
-        returnType: {kind: 'Object', shapeId: BuiltInWeakMapId},
-        calleeEffect: Effect.Read,
-        returnValueKind: ValueKind.Mutable,
-      },
-      null,
-      true,
-    ),
-  ],
-  [
-    'WeakSet',
-    addFunction(
-      DEFAULT_SHAPES,
-      [],
-      {
-        positionalParams: [Effect.ConditionallyMutateIterator],
-        restParam: null,
-        returnType: {kind: 'Object', shapeId: BuiltInWeakSetId},
-        calleeEffect: Effect.Read,
-        returnValueKind: ValueKind.Mutable,
-      },
-      null,
-      true,
-    ),
-  ],
   // TODO: rest of Global objects
 ];
 
-const createRenderHookAliasing: (
-  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: 'Freeze',
-          value: '@value',
-          reason: ValueReason.HookCaptured,
-        },
-        {kind: 'Assign', from: '@value', into: '@return'},
-      ],
-    },
-  },
-  BuiltInUseEffectEventId,
-);
 const REACT_APIS: Array<[string, BuiltInType]> = [
   [
     'useContext',
@@ -769,7 +511,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         hookKind: 'useContext',
         returnValueKind: ValueKind.Frozen,
         returnValueReason: ValueReason.Context,
-        aliasing: createRenderHookAliasing(ValueReason.Context),
       },
       BuiltInUseContextHookId,
     ),
@@ -784,7 +525,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       hookKind: 'useState',
       returnValueKind: ValueKind.Frozen,
       returnValueReason: ValueReason.State,
-      aliasing: createRenderHookAliasing(ValueReason.State),
     }),
   ],
   [
@@ -797,7 +537,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       hookKind: 'useActionState',
       returnValueKind: ValueKind.Frozen,
       returnValueReason: ValueReason.State,
-      aliasing: createRenderHookAliasing(ValueReason.HookCaptured),
     }),
   ],
   [
@@ -810,7 +549,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       hookKind: 'useReducer',
       returnValueKind: ValueKind.Frozen,
       returnValueReason: ValueReason.ReducerState,
-      aliasing: createRenderHookAliasing(ValueReason.ReducerState),
     }),
   ],
   [
@@ -822,22 +560,6 @@ 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 +582,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       calleeEffect: Effect.Read,
       hookKind: 'useMemo',
       returnValueKind: ValueKind.Frozen,
-      aliasing: createRenderHookAliasing(ValueReason.HookCaptured),
     }),
   ],
   [
@@ -868,16 +589,10 @@ 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: createRenderHookAliasing(ValueReason.HookCaptured),
     }),
   ],
   [
@@ -891,7 +606,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         calleeEffect: Effect.Read,
         hookKind: 'useEffect',
         returnValueKind: ValueKind.Frozen,
-        aliasing: EffectHookAliasing,
       },
       BuiltInUseEffectHookId,
     ),
@@ -907,7 +621,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         calleeEffect: Effect.Read,
         hookKind: 'useLayoutEffect',
         returnValueKind: ValueKind.Frozen,
-        aliasing: EffectHookAliasing,
       },
       BuiltInUseLayoutEffectHookId,
     ),
@@ -923,7 +636,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         calleeEffect: Effect.Read,
         hookKind: 'useInsertionEffect',
         returnValueKind: ValueKind.Frozen,
-        aliasing: EffectHookAliasing,
       },
       BuiltInUseInsertionEffectHookId,
     ),
@@ -937,20 +649,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       calleeEffect: Effect.Read,
       hookKind: 'useTransition',
       returnValueKind: ValueKind.Frozen,
-      aliasing: createRenderHookAliasing(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: createRenderHookAliasing(ValueReason.HookCaptured),
     }),
   ],
   [
@@ -964,7 +662,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         returnType: {kind: 'Poly'},
         calleeEffect: Effect.Read,
         returnValueKind: ValueKind.Frozen,
-        aliasing: createRenderHookAliasing(ValueReason.HookCaptured),
       },
       BuiltInUseOperatorId,
     ),
@@ -977,21 +674,13 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       {
         positionalParams: [],
         restParam: null,
-        returnType: {
-          kind: 'Function',
-          return: {kind: 'Poly'},
-          shapeId: BuiltInFireFunctionId,
-          isConstructor: false,
-        },
+        returnType: {kind: 'Primitive'},
         calleeEffect: Effect.Read,
         returnValueKind: ValueKind.Frozen,
       },
       BuiltInFireId,
     ),
   ],
-  ['useEffectEvent', useEffectEvent],
-  ['experimental_useEffectEvent', useEffectEvent],
-  ['AUTODEPS', addObject(DEFAULT_SHAPES, BuiltInAutodepsId, [])],
 ];
 
 TYPED_GLOBALS.push(
@@ -1117,8 +806,6 @@ export function installTypeConfig(
         noAlias: typeConfig.noAlias === true,
         mutableOnlyIfOperandsAreMutable:
           typeConfig.mutableOnlyIfOperandsAreMutable === true,
-        aliasing: typeConfig.aliasing,
-        knownIncompatible: typeConfig.knownIncompatible ?? null,
       });
     }
     case 'hook': {
@@ -1136,8 +823,6 @@ export function installTypeConfig(
         ),
         returnValueKind: typeConfig.returnValueKind ?? ValueKind.Frozen,
         noAlias: typeConfig.noAlias === true,
-        aliasing: typeConfig.aliasing,
-        knownIncompatible: typeConfig.knownIncompatible ?? null,
       });
     }
     case 'object': {
@@ -1217,7 +902,7 @@ export function getReanimatedModuleType(registry: ShapeRegistry): ObjectType {
       addHook(registry, {
         positionalParams: [],
         restParam: Effect.Freeze,
-        returnType: {kind: 'Object', shapeId: ReanimatedSharedValueId},
+        returnType: {kind: 'Poly'},
         returnValueKind: ValueKind.Mutable,
         noAlias: true,
         calleeEffect: Effect.Read,

compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts

@@ -7,19 +7,12 @@
 
 import {BindingKind} from '@babel/traverse';
 import * as t from '@babel/types';
-import {
-  CompilerDiagnostic,
-  CompilerError,
-  ErrorCategory,
-} from '../CompilerError';
+import {CompilerError, CompilerErrorDetailOptions} from '../CompilerError';
 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 type {AliasingEffect} from '../Inference/AliasingEffects';
-import {isReservedWord} from '../Utils/Keyword';
-import {Err, Ok, Result} from '../Utils/Result';
+import {z} from 'zod';
 
 /*
  * *******************************************************************************************
@@ -58,8 +51,7 @@ export type SourceLocation = t.SourceLocation | typeof GeneratedSource;
  */
 export type ReactiveFunction = {
   loc: SourceLocation;
-  id: ValidIdentifierName | null;
-  nameHint: string | null;
+  id: string | null;
   params: Array<Place | SpreadPattern>;
   generator: boolean;
   async: boolean;
@@ -108,7 +100,6 @@ export type ReactiveInstruction = {
   id: InstructionId;
   lvalue: Place | null;
   value: ReactiveValue;
-  effects?: Array<AliasingEffect> | null; // TODO make non-optional
   loc: SourceLocation;
 };
 
@@ -281,21 +272,36 @@ export type ReactiveTryTerminal = {
 // A function lowered to HIR form, ie where its body is lowered to an HIR control-flow graph
 export type HIRFunction = {
   loc: SourceLocation;
-  id: ValidIdentifierName | null;
-  nameHint: string | null;
+  id: string | null;
   fnType: ReactFunctionType;
   env: Environment;
   params: Array<Place | SpreadPattern>;
   returnTypeAnnotation: t.FlowType | t.TSType | null;
-  returns: Place;
+  returnType: Type;
   context: Array<Place>;
+  effects: Array<FunctionEffect> | null;
   body: HIR;
   generator: boolean;
   async: boolean;
   directives: Array<string>;
-  aliasingEffects: Array<AliasingEffect> | null;
 };
 
+export type FunctionEffect =
+  | {
+      kind: 'GlobalMutation';
+      error: CompilerErrorDetailOptions;
+    }
+  | {
+      kind: 'ReactMutation';
+      error: CompilerErrorDetailOptions;
+    }
+  | {
+      kind: 'ContextMutation';
+      places: ReadonlySet<Place>;
+      effect: Effect;
+      loc: SourceLocation;
+    };
+
 /*
  * Each reactive scope may have its own control-flow, so the instructions form
  * a control-flow graph. The graph comprises a set of basic blocks which reference
@@ -437,25 +443,12 @@ export type ThrowTerminal = {
 };
 export type Case = {test: Place | null; block: BlockId};
 
-export type ReturnVariant = 'Void' | 'Implicit' | 'Explicit';
 export type ReturnTerminal = {
   kind: 'return';
-  /**
-   * Void:
-   *   () => { ... }
-   *   function() { ... }
-   * Implicit (ArrowFunctionExpression only):
-   *   () => foo
-   * Explicit:
-   *   () => { return ... }
-   *   function () { return ... }
-   */
-  returnVariant: ReturnVariant;
   loc: SourceLocation;
   value: Place;
   id: InstructionId;
   fallthrough?: never;
-  effects: Array<AliasingEffect> | null;
 };
 
 export type GotoTerminal = {
@@ -616,7 +609,6 @@ export type MaybeThrowTerminal = {
   id: InstructionId;
   loc: SourceLocation;
   fallthrough?: never;
-  effects: Array<AliasingEffect> | null;
 };
 
 export type ReactiveScopeTerminal = {
@@ -653,14 +645,12 @@ export type Instruction = {
   lvalue: Place;
   value: InstructionValue;
   loc: SourceLocation;
-  effects: Array<AliasingEffect> | null;
 };
 
 export type TInstruction<T extends InstructionValue> = {
   id: InstructionId;
   lvalue: Place;
   value: T;
-  effects: Array<AliasingEffect> | null;
   loc: SourceLocation;
 };
 
@@ -694,13 +684,11 @@ 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 =
@@ -758,27 +746,6 @@ export enum InstructionKind {
   Function = 'Function',
 }
 
-export function convertHoistedLValueKind(
-  kind: InstructionKind,
-): InstructionKind | null {
-  switch (kind) {
-    case InstructionKind.HoistedLet:
-      return InstructionKind.Let;
-    case InstructionKind.HoistedConst:
-      return InstructionKind.Const;
-    case InstructionKind.HoistedFunction:
-      return InstructionKind.Function;
-    case InstructionKind.Let:
-    case InstructionKind.Const:
-    case InstructionKind.Function:
-    case InstructionKind.Reassign:
-    case InstructionKind.Catch:
-      return null;
-    default:
-      assertExhaustive(kind, 'Unexpected lvalue kind');
-  }
-}
-
 function _staticInvariantInstructionValueHasLocation(
   value: InstructionValue,
 ): SourceLocation {
@@ -805,11 +772,9 @@ export type ManualMemoDependency = {
     | {
         kind: 'NamedLocal';
         value: Place;
-        constant: boolean;
       }
     | {kind: 'Global'; identifierName: string};
   path: DependencyPath;
-  loc: SourceLocation;
 };
 
 export type StartMemoize = {
@@ -821,11 +786,6 @@ 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 = {
@@ -920,20 +880,8 @@ export type InstructionValue =
   | StoreLocal
   | {
       kind: 'StoreContext';
-      /**
-       * StoreContext kinds:
-       * Reassign: context variable reassignment in source
-       * Const:    const declaration + assignment in source
-       *           ('const' context vars are ones whose declarations are hoisted)
-       * Let:      let declaration + assignment in source
-       * Function: function declaration in source (similar to `const`)
-       */
       lvalue: {
-        kind:
-          | InstructionKind.Reassign
-          | InstructionKind.Const
-          | InstructionKind.Let
-          | InstructionKind.Function;
+        kind: InstructionKind.Reassign;
         place: Place;
       };
       value: Place;
@@ -962,21 +910,13 @@ export type InstructionValue =
       value: Place;
       loc: SourceLocation;
     }
-  | ({
+  | {
       kind: 'TypeCastExpression';
       value: Place;
+      typeAnnotation: t.FlowType | t.TSType;
       type: Type;
       loc: SourceLocation;
-    } & (
-      | {
-          typeAnnotation: t.FlowType;
-          typeAnnotationKind: 'cast';
-        }
-      | {
-          typeAnnotation: t.TSType;
-          typeAnnotationKind: 'as' | 'satisfies';
-        }
-    ))
+    }
   | JsxExpression
   | {
       kind: 'ObjectExpression';
@@ -1139,8 +1079,7 @@ export type JsxAttribute =
 
 export type FunctionExpression = {
   kind: 'FunctionExpression';
-  name: ValidIdentifierName | null;
-  nameHint: string | null;
+  name: string | null;
   loweredFunc: LoweredFunction;
   type:
     | 'ArrowFunctionExpression'
@@ -1315,52 +1254,22 @@ export function forkTemporaryIdentifier(
   };
 }
 
-export function validateIdentifierName(
-  name: string,
-): Result<ValidatedIdentifier, CompilerError> {
-  if (isReservedWord(name)) {
-    const error = new CompilerError();
-    error.pushDiagnostic(
-      CompilerDiagnostic.create({
-        category: ErrorCategory.Syntax,
-        reason: 'Expected a non-reserved identifier name',
-        description: `\`${name}\` is a reserved word in JavaScript and cannot be used as an identifier name`,
-        suggestions: null,
-      }).withDetails({
-        kind: 'error',
-        loc: GeneratedSource,
-        message: 'reserved word',
-      }),
-    );
-    return Err(error);
-  } else if (!t.isValidIdentifier(name)) {
-    const error = new CompilerError();
-    error.pushDiagnostic(
-      CompilerDiagnostic.create({
-        category: ErrorCategory.Syntax,
-        reason: `Expected a valid identifier name`,
-        description: `\`${name}\` is not a valid JavaScript identifier`,
-        suggestions: null,
-      }).withDetails({
-        kind: 'error',
-        loc: GeneratedSource,
-        message: 'reserved word',
-      }),
-    );
-  }
-  return Ok({
-    kind: 'named',
-    value: name as ValidIdentifierName,
-  });
-}
-
 /**
  * Creates a valid identifier name. This should *not* be used for synthesizing
  * identifier names: only call this method for identifier names that appear in the
  * original source code.
  */
 export function makeIdentifierName(name: string): ValidatedIdentifier {
-  return validateIdentifierName(name).unwrap();
+  CompilerError.invariant(t.isValidIdentifier(name), {
+    reason: `Expected a valid identifier name`,
+    loc: GeneratedSource,
+    description: `\`${name}\` is not a valid JavaScript identifier`,
+    suggestions: null,
+  });
+  return {
+    kind: 'named',
+    value: name as ValidIdentifierName,
+  };
 }
 
 /**
@@ -1372,14 +1281,8 @@ export function makeIdentifierName(name: string): ValidatedIdentifier {
 export function promoteTemporary(identifier: Identifier): void {
   CompilerError.invariant(identifier.name === null, {
     reason: `Expected a temporary (unnamed) identifier`,
+    loc: GeneratedSource,
     description: `Identifier already has a name, \`${identifier.name}\``,
-    details: [
-      {
-        kind: 'error',
-        loc: GeneratedSource,
-        message: null,
-      },
-    ],
     suggestions: null,
   });
   identifier.name = {
@@ -1402,14 +1305,8 @@ export function isPromotedTemporary(name: string): boolean {
 export function promoteTemporaryJsxTag(identifier: Identifier): void {
   CompilerError.invariant(identifier.name === null, {
     reason: `Expected a temporary (unnamed) identifier`,
+    loc: GeneratedSource,
     description: `Identifier already has a name, \`${identifier.name}\``,
-    details: [
-      {
-        kind: 'error',
-        loc: GeneratedSource,
-        message: null,
-      },
-    ],
     suggestions: null,
   });
   identifier.name = {
@@ -1442,21 +1339,6 @@ export enum ValueReason {
    */
   JsxCaptured = 'jsx-captured',
 
-  /**
-   * Argument to a hook
-   */
-  HookCaptured = 'hook-captured',
-
-  /**
-   * Return value of a hook
-   */
-  HookReturn = 'hook-return',
-
-  /**
-   * Passed to an effect
-   */
-  Effect = 'effect',
-
   /**
    * Return value of a function with known frozen return value, e.g. `useState`.
    */
@@ -1507,20 +1389,6 @@ export const ValueKindSchema = z.enum([
   ValueKind.Context,
 ]);
 
-export const ValueReasonSchema = z.enum([
-  ValueReason.Context,
-  ValueReason.Effect,
-  ValueReason.Global,
-  ValueReason.HookCaptured,
-  ValueReason.HookReturn,
-  ValueReason.JsxCaptured,
-  ValueReason.KnownReturnSignature,
-  ValueReason.Other,
-  ValueReason.ReactiveFunctionArgument,
-  ValueReason.ReducerState,
-  ValueReason.State,
-]);
-
 // The effect with which a value is modified.
 export enum Effect {
   // Default value: not allowed after lifetime inference
@@ -1577,13 +1445,7 @@ export function isMutableEffect(
       CompilerError.invariant(false, {
         reason: 'Unexpected unknown effect',
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: location,
-            message: null,
-          },
-        ],
+        loc: location,
         suggestions: null,
       });
     }
@@ -1665,18 +1527,6 @@ export type DependencyPathEntry = {
 export type DependencyPath = Array<DependencyPathEntry>;
 export type ReactiveScopeDependency = {
   identifier: Identifier;
-  /**
-   * Reflects whether the base identifier is reactive. Note that some reactive
-   * objects may have non-reactive properties, but we do not currently track
-   * this.
-   *
-   * ```js
-   * // Technically, result[0] is reactive and result[1] is not.
-   * // Currently, both dependencies would be marked as reactive.
-   * const result = useState();
-   * ```
-   */
-  reactive: boolean;
   path: DependencyPath;
 };
 
@@ -1689,28 +1539,6 @@ 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,
@@ -1738,13 +1566,7 @@ export function makeBlockId(id: number): BlockId {
   CompilerError.invariant(id >= 0 && Number.isInteger(id), {
     reason: 'Expected block id to be a non-negative integer',
     description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: null,
-        message: null,
-      },
-    ],
+    loc: null,
     suggestions: null,
   });
   return id as BlockId;
@@ -1761,13 +1583,7 @@ export function makeScopeId(id: number): ScopeId {
   CompilerError.invariant(id >= 0 && Number.isInteger(id), {
     reason: 'Expected block id to be a non-negative integer',
     description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: null,
-        message: null,
-      },
-    ],
+    loc: null,
     suggestions: null,
   });
   return id as ScopeId;
@@ -1784,13 +1600,7 @@ export function makeIdentifierId(id: number): IdentifierId {
   CompilerError.invariant(id >= 0 && Number.isInteger(id), {
     reason: 'Expected identifier id to be a non-negative integer',
     description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: null,
-        message: null,
-      },
-    ],
+    loc: null,
     suggestions: null,
   });
   return id as IdentifierId;
@@ -1807,13 +1617,7 @@ export function makeDeclarationId(id: number): DeclarationId {
   CompilerError.invariant(id >= 0 && Number.isInteger(id), {
     reason: 'Expected declaration id to be a non-negative integer',
     description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: null,
-        message: null,
-      },
-    ],
+    loc: null,
     suggestions: null,
   });
   return id as DeclarationId;
@@ -1830,13 +1634,7 @@ export function makeInstructionId(id: number): InstructionId {
   CompilerError.invariant(id >= 0 && Number.isInteger(id), {
     reason: 'Expected instruction id to be a non-negative integer',
     description: null,
-    details: [
-      {
-        kind: 'error',
-        loc: null,
-        message: null,
-      },
-    ],
+    loc: null,
     suggestions: null,
   });
   return id as InstructionId;
@@ -1854,10 +1652,6 @@ 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';
 }
@@ -1879,48 +1673,17 @@ 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 {
   return id.type.kind === 'Object' && id.type.shapeId === 'BuiltInUseState';
 }
 
-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);
 }
 
-/*
- * Returns true if the type is a Ref or a custom user type that acts like a ref when it
- * shouldn't. For now the only other case of this is Reanimated's shared values.
- */
-export function isRefOrRefLikeMutableType(type: Type): boolean {
-  return (
-    type.kind === 'Object' &&
-    (type.shapeId === 'BuiltInUseRefId' ||
-      type.shapeId == 'ReanimatedSharedValueId')
-  );
-}
-
 export function isSetStateType(id: Identifier): boolean {
   return id.type.kind === 'Function' && id.type.shapeId === 'BuiltInSetState';
 }
@@ -1937,18 +1700,6 @@ 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'
@@ -1963,66 +1714,16 @@ export function isDispatcherType(id: Identifier): boolean {
   return id.type.kind === 'Function' && id.type.shapeId === 'BuiltInDispatch';
 }
 
-export function isFireFunctionType(id: Identifier): boolean {
-  return (
-    id.type.kind === 'Function' && id.type.shapeId === 'BuiltInFireFunction'
-  );
-}
-
-export function isEffectEventFunctionType(id: Identifier): boolean {
-  return (
-    id.type.kind === 'Function' &&
-    id.type.shapeId === 'BuiltInEffectEventFunction'
-  );
-}
-
 export function isStableType(id: Identifier): boolean {
   return (
     isSetStateType(id) ||
     isSetActionStateType(id) ||
     isDispatcherType(id) ||
     isUseRefType(id) ||
-    isStartTransitionType(id) ||
-    isSetOptimisticType(id)
+    isStartTransitionType(id)
   );
 }
 
-export function isStableTypeContainer(id: Identifier): boolean {
-  const type_ = id.type;
-  if (type_.kind !== 'Object') {
-    return false;
-  }
-  return (
-    isUseStateType(id) || // setState
-    isUseActionStateType(id) || // setActionState
-    isUseReducerType(id) || // dispatcher
-    isUseOptimisticType(id) || // setOptimistic
-    type_.shapeId === 'BuiltInUseTransition' // startTransition
-  );
-}
-
-export function evaluatesToStableTypeOrContainer(
-  env: Environment,
-  {value}: Instruction,
-): boolean {
-  if (value.kind === 'CallExpression' || value.kind === 'MethodCall') {
-    const callee =
-      value.kind === 'CallExpression' ? value.callee : value.property;
-
-    const calleeHookKind = getHookKind(env, callee.identifier);
-    switch (calleeHookKind) {
-      case 'useState':
-      case 'useReducer':
-      case 'useActionState':
-      case 'useRef':
-      case 'useTransition':
-      case 'useOptimistic':
-        return true;
-    }
-  }
-  return false;
-}
-
 export function isUseEffectHookType(id: Identifier): boolean {
   return (
     id.type.kind === 'Function' && id.type.shapeId === 'BuiltInUseEffectHook'
@@ -2040,11 +1741,6 @@ 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 +1769,4 @@ 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';

compiler/packages/babel-plugin-react-compiler/src/HIR/HIRBuilder.ts

@@ -7,7 +7,7 @@
 
 import {Binding, NodePath} from '@babel/traverse';
 import * as t from '@babel/types';
-import {CompilerError, ErrorCategory} from '../CompilerError';
+import {CompilerError} from '../CompilerError';
 import {Environment} from './Environment';
 import {
   BasicBlock,
@@ -106,10 +106,11 @@ export default class HIRBuilder {
   #current: WipBlock;
   #entry: BlockId;
   #scopes: Array<Scope> = [];
-  #context: Map<t.Identifier, SourceLocation>;
+  #context: Array<t.Identifier>;
   #bindings: Bindings;
   #env: Environment;
   #exceptionHandlerStack: Array<BlockId> = [];
+  parentFunction: NodePath<t.Function>;
   errors: CompilerError = new CompilerError();
   /**
    * Traversal context: counts the number of `fbt` tag parents
@@ -121,7 +122,7 @@ export default class HIRBuilder {
     return this.#env.nextIdentifierId;
   }
 
-  get context(): Map<t.Identifier, SourceLocation> {
+  get context(): Array<t.Identifier> {
     return this.#context;
   }
 
@@ -135,17 +136,16 @@ export default class HIRBuilder {
 
   constructor(
     env: Environment,
-    options?: {
-      bindings?: Bindings | null;
-      context?: Map<t.Identifier, SourceLocation>;
-      entryBlockKind?: BlockKind;
-    },
+    parentFunction: NodePath<t.Function>, // the outermost function being compiled
+    bindings: Bindings | null = null,
+    context: Array<t.Identifier> | null = null,
   ) {
     this.#env = env;
-    this.#bindings = options?.bindings ?? new Map();
-    this.#context = options?.context ?? new Map();
+    this.#bindings = bindings ?? new Map();
+    this.parentFunction = parentFunction;
+    this.#context = context ?? [];
     this.#entry = makeBlockId(env.nextBlockId);
-    this.#current = newBlock(this.#entry, options?.entryBlockKind ?? 'block');
+    this.#current = newBlock(this.#entry, 'block');
   }
 
   currentBlockKind(): BlockKind {
@@ -165,7 +165,6 @@ export default class HIRBuilder {
           handler: exceptionHandler,
           id: makeInstructionId(0),
           loc: instruction.loc,
-          effects: null,
         },
         continuationBlock,
       );
@@ -240,7 +239,7 @@ export default class HIRBuilder {
 
     // Check if the binding is from module scope
     const outerBinding =
-      this.#env.parentFunction.scope.parent.getBinding(originalName);
+      this.parentFunction.scope.parent.getBinding(originalName);
     if (babelBinding === outerBinding) {
       const path = babelBinding.path;
       if (path.isImportDefaultSpecifier()) {
@@ -294,7 +293,7 @@ export default class HIRBuilder {
     const binding = this.#resolveBabelBinding(path);
     if (binding) {
       // Check if the binding is from module scope, if so return null
-      const outerBinding = this.#env.parentFunction.scope.parent.getBinding(
+      const outerBinding = this.parentFunction.scope.parent.getBinding(
         path.node.name,
       );
       if (binding === outerBinding) {
@@ -308,33 +307,9 @@ export default class HIRBuilder {
 
   resolveBinding(node: t.Identifier): Identifier {
     if (node.name === 'fbt') {
-      CompilerError.throwDiagnostic({
-        category: ErrorCategory.Todo,
-        reason: 'Support local variables named `fbt`',
-        description:
-          'Local variables named `fbt` may conflict with the fbt plugin and are not yet supported',
-        details: [
-          {
-            kind: 'error',
-            message: 'Rename to avoid conflict with fbt plugin',
-            loc: node.loc ?? GeneratedSource,
-          },
-        ],
-      });
-    }
-    if (node.name === 'this') {
-      CompilerError.throwDiagnostic({
-        category: ErrorCategory.UnsupportedSyntax,
-        reason: '`this` is not supported syntax',
-        description:
-          'React Compiler does not support compiling functions that use `this`',
-        details: [
-          {
-            kind: 'error',
-            message: '`this` was used here',
-            loc: node.loc ?? GeneratedSource,
-          },
-        ],
+      CompilerError.throwTodo({
+        reason: 'Support local variables named "fbt"',
+        loc: node.loc ?? null,
       });
     }
     const originalName = node.name;
@@ -401,7 +376,7 @@ export default class HIRBuilder {
   }
 
   // Terminate the current block w the given terminal, and start a new block
-  terminate(terminal: Terminal, nextBlockKind: BlockKind | null): BlockId {
+  terminate(terminal: Terminal, nextBlockKind: BlockKind | null): void {
     const {id: blockId, kind, instructions} = this.#current;
     this.#completed.set(blockId, {
       kind,
@@ -415,7 +390,6 @@ export default class HIRBuilder {
       const nextId = this.#env.nextBlockId;
       this.#current = newBlock(nextId, nextBlockKind);
     }
-    return blockId;
   }
 
   /*
@@ -507,13 +481,7 @@ export default class HIRBuilder {
       {
         reason: 'Mismatched label',
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
+        loc: null,
         suggestions: null,
       },
     );
@@ -536,13 +504,7 @@ export default class HIRBuilder {
       {
         reason: 'Mismatched label',
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
+        loc: null,
         suggestions: null,
       },
     );
@@ -578,13 +540,7 @@ export default class HIRBuilder {
       {
         reason: 'Mismatched loops',
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
+        loc: null,
         suggestions: null,
       },
     );
@@ -609,13 +565,7 @@ export default class HIRBuilder {
     CompilerError.invariant(false, {
       reason: 'Expected a loop or switch to be in scope',
       description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: null,
-          message: null,
-        },
-      ],
+      loc: null,
       suggestions: null,
     });
   }
@@ -636,13 +586,7 @@ export default class HIRBuilder {
         CompilerError.invariant(false, {
           reason: 'Continue may only refer to a labeled loop',
           description: null,
-          details: [
-            {
-              kind: 'error',
-              loc: null,
-              message: null,
-            },
-          ],
+          loc: null,
           suggestions: null,
         });
       }
@@ -650,13 +594,7 @@ export default class HIRBuilder {
     CompilerError.invariant(false, {
       reason: 'Expected a loop to be in scope',
       description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: null,
-          message: null,
-        },
-      ],
+      loc: null,
       suggestions: null,
     });
   }
@@ -679,13 +617,7 @@ function _shrink(func: HIR): void {
     CompilerError.invariant(block != null, {
       reason: `expected block ${blockId} to exist`,
       description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: null,
-          message: null,
-        },
-      ],
+      loc: null,
       suggestions: null,
     });
     target = getTargetIfIndirection(block);
@@ -814,17 +746,6 @@ function getReversePostorderedBlocks(func: HIR): HIR['blocks'] {
      * (eg bb2 then bb1), we ensure that they get reversed back to the correct order.
      */
     const block = func.blocks.get(blockId)!;
-    CompilerError.invariant(block != null, {
-      reason: '[HIRBuilder] Unexpected null block',
-      description: `expected block ${blockId} to exist`,
-      details: [
-        {
-          kind: 'error',
-          loc: GeneratedSource,
-          message: null,
-        },
-      ],
-    });
     const successors = [...eachTerminalSuccessor(block.terminal)].reverse();
     const fallthrough = terminalFallthrough(block.terminal);
 
@@ -879,13 +800,7 @@ export function markInstructionIds(func: HIR): void {
       CompilerError.invariant(!visited.has(instr), {
         reason: `${printInstruction(instr)} already visited!`,
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: instr.loc,
-            message: null,
-          },
-        ],
+        loc: instr.loc,
         suggestions: null,
       });
       visited.add(instr);
@@ -908,13 +823,7 @@ export function markPredecessors(func: HIR): void {
     CompilerError.invariant(block != null, {
       reason: 'unexpected missing block',
       description: `block ${blockId}`,
-      details: [
-        {
-          kind: 'error',
-          loc: GeneratedSource,
-          message: null,
-        },
-      ],
+      loc: GeneratedSource,
     });
     if (prevBlock) {
       block.preds.add(prevBlock.id);
@@ -988,7 +897,7 @@ export function createTemporaryPlace(
     identifier: makeTemporaryIdentifier(env.nextIdentifierId, loc),
     reactive: false,
     effect: Effect.Unknown,
-    loc,
+    loc: GeneratedSource,
   };
 }
 

compiler/packages/babel-plugin-react-compiler/src/HIR/MergeConsecutiveBlocks.ts

@@ -12,7 +12,6 @@ import {
   GeneratedSource,
   HIRFunction,
   Instruction,
-  Place,
 } from './HIR';
 import {markPredecessors} from './HIRBuilder';
 import {terminalFallthrough, terminalHasFallthrough} from './visitors';
@@ -61,13 +60,7 @@ export function mergeConsecutiveBlocks(fn: HIRFunction): void {
     CompilerError.invariant(predecessor !== undefined, {
       reason: `Expected predecessor ${predecessorId} to exist`,
       description: null,
-      details: [
-        {
-          kind: 'error',
-          loc: null,
-          message: null,
-        },
-      ],
+      loc: null,
       suggestions: null,
     });
     if (predecessor.terminal.kind !== 'goto' || predecessor.kind !== 'block') {
@@ -83,32 +76,24 @@ export function mergeConsecutiveBlocks(fn: HIRFunction): void {
       CompilerError.invariant(phi.operands.size === 1, {
         reason: `Found a block with a single predecessor but where a phi has multiple (${phi.operands.size}) operands`,
         description: null,
-        details: [
-          {
-            kind: 'error',
-            loc: null,
-            message: null,
-          },
-        ],
+        loc: null,
         suggestions: null,
       });
       const operand = Array.from(phi.operands.values())[0]!;
-      const lvalue: Place = {
-        kind: 'Identifier',
-        identifier: phi.place.identifier,
-        effect: Effect.ConditionallyMutate,
-        reactive: false,
-        loc: GeneratedSource,
-      };
       const instr: Instruction = {
         id: predecessor.terminal.id,
-        lvalue: {...lvalue},
+        lvalue: {
+          kind: 'Identifier',
+          identifier: phi.place.identifier,
+          effect: Effect.ConditionallyMutate,
+          reactive: false,
+          loc: GeneratedSource,
+        },
         value: {
           kind: 'LoadLocal',
           place: {...operand},
           loc: GeneratedSource,
         },
-        effects: [{kind: 'Alias', from: {...operand}, into: {...lvalue}}],
         loc: GeneratedSource,
       };
       predecessor.instructions.push(instr);
@@ -119,17 +104,6 @@ export function mergeConsecutiveBlocks(fn: HIRFunction): void {
     merged.merge(block.id, predecessorId);
     fn.body.blocks.delete(block.id);
   }
-  for (const [, block] of fn.body.blocks) {
-    for (const phi of block.phis) {
-      for (const [predecessorId, operand] of phi.operands) {
-        const mapped = merged.get(predecessorId);
-        if (mapped !== predecessorId) {
-          phi.operands.delete(predecessorId);
-          phi.operands.set(mapped, operand);
-        }
-      }
-    }
-  }
   markPredecessors(fn.body);
   for (const [, {terminal}] of fn.body.blocks) {
     if (terminalHasFallthrough(terminal)) {