[compiler][repro] Nested fbt test fixture

Ideally we should detect and bail out on this case to avoid babel build failures.

.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": "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"],

.eslintrc.js

@@ -615,8 +615,6 @@ module.exports = {
     GetAnimationsOptions: 'readonly',
     Animatable: 'readonly',
     ScrollTimeline: 'readonly',
-    EventListenerOptionsOrUseCapture: 'readonly',
-    FocusOptions: 'readonly',
 
     spyOnDev: 'readonly',
     spyOnDevAndProd: '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/workflows/compiler_discord_notify.yml

@@ -10,19 +10,7 @@ on:
 permissions: {}
 
 jobs:
-  check_access:
-    runs-on: ubuntu-latest
-    outputs:
-      is_member_or_collaborator: ${{ steps.check_is_member_or_collaborator.outputs.is_member_or_collaborator }}
-    steps:
-      - 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_prereleases.yml

@@ -16,9 +16,6 @@ on:
       version_name:
         required: true
         type: string
-      tag_version:
-        required: false
-        type: string
     secrets:
       NPM_TOKEN:
         required: true
@@ -58,4 +55,4 @@ jobs:
       - 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

@@ -14,9 +14,6 @@ on:
       version_name:
         required: true
         type: string
-      tag_version:
-        required: false
-        type: string
 
 permissions: {}
 
@@ -32,6 +29,5 @@ jobs:
       release_channel: ${{ inputs.release_channel }}
       dist_tag: ${{ inputs.dist_tag }}
       version_name: ${{ inputs.version_name }}
-      tag_version: ${{ inputs.tag_version }}
     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/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
@@ -167,12 +167,6 @@ jobs:
           rm $RENDERER_FOLDER/ReactFabric-{dev,prod,profiling}.js
           rm $RENDERER_FOLDER/ReactNativeRenderer-{dev,prod,profiling}.js
 
-          # Copy eslint-plugin-react-hooks
-          # NOTE: This is different from www, here we include the full package
-          #       including package.json to include dependencies in fbsource.
-          mkdir "$BASE_FOLDER/tools"
-          cp -r build/oss-experimental/eslint-plugin-react-hooks "$BASE_FOLDER/tools"
-
           # Move React Native version file
           mv build/facebook-react-native/VERSION_NATIVE_FB ./compiled-rn/VERSION_NATIVE_FB
 

.github/workflows/runtime_discord_notify.yml

@@ -10,19 +10,7 @@ on:
 permissions: {}
 
 jobs:
-  check_access:
-    runs-on: ubuntu-latest
-    outputs:
-      is_member_or_collaborator: ${{ steps.check_is_member_or_collaborator.outputs.is_member_or_collaborator }}
-    steps:
-      - 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

@@ -13,14 +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
     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:
@@ -65,11 +58,3 @@ jobs:
           GH_TOKEN=${{ secrets.GH_TOKEN }} scripts/release/prepare-release-from-ci.js --skipTests -r ${{ inputs.release_channel }} --commit=${{ inputs.commit_sha }}
           cp ./scripts/release/ci-npmrc ~/.npmrc
           scripts/release/publish.js --ci --tags ${{ inputs.dist_tag }}
-      - 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: 'Publish of $${{ inputs.release_channel }} release failed'
-          embed-url: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}/attempts/${{ github.run_attempt }}

.github/workflows/runtime_prereleases_nightly.yml

@@ -21,9 +21,7 @@ jobs:
       commit_sha: ${{ github.sha }}
       release_channel: stable
       dist_tag: canary,next
-      enableFailureNotification: true
     secrets:
-      DISCORD_WEBHOOK_URL: ${{ secrets.DISCORD_WEBHOOK_URL }}
       NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
@@ -42,8 +40,6 @@ jobs:
       commit_sha: ${{ github.sha }}
       release_channel: experimental
       dist_tag: experimental
-      enableFailureNotification: true
     secrets:
-      DISCORD_WEBHOOK_URL: ${{ secrets.DISCORD_WEBHOOK_URL }}
       NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.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: {}
 
@@ -12,19 +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:
-      - 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

.nvmrc

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

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

@@ -1,50 +1,3 @@
-## 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 Complier 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 [#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)
-
 ## 19.0.0 (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.

ReactVersions.js

@@ -18,7 +18,7 @@
 //
 //   0.0.0-experimental-241c4467e-20200129
 
-const ReactVersion = '19.2.0';
+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
@@ -33,7 +33,7 @@ const canaryChannelLabel = 'canary';
 const rcNumber = 0;
 
 const stablePackages = {
-  'eslint-plugin-react-hooks': '6.1.0',
+  'eslint-plugin-react-hooks': '5.2.0',
   'jest-react': '0.17.0',
   react: ReactVersion,
   'react-art': ReactVersion,
@@ -42,12 +42,12 @@ const stablePackages = {
   'react-server-dom-turbopack': ReactVersion,
   'react-server-dom-parcel': ReactVersion,
   'react-is': ReactVersion,
-  'react-reconciler': '0.33.0',
-  'react-refresh': '0.18.0',
+  'react-reconciler': '0.32.0',
+  'react-refresh': '0.17.0',
   'react-test-renderer': ReactVersion,
-  'use-subscription': '1.12.0',
-  'use-sync-external-store': '1.6.0',
-  scheduler: '0.27.0',
+  '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

compiler/CHANGELOG.md

@@ -1,59 +0,0 @@
-## 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/apps/playground/__tests__/e2e/__snapshots__/page.spec.ts/compilationMode-all-output.txt

@@ -1,5 +1,5 @@
 import { c as _c } from "react/compiler-runtime"; // 
-        @compilationMode:"all"
+        @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/page.spec.ts

@@ -92,7 +92,7 @@ function useFoo(propVal: {+baz: number}) {
   },
   {
     name: 'compilationMode-infer',
-    input: `// @compilationMode:"infer"
+    input: `// @compilationMode(infer)
 function nonReactFn() {
   return {};
 }
@@ -101,7 +101,7 @@ function nonReactFn() {
   },
   {
     name: 'compilationMode-all',
-    input: `// @compilationMode:"all"
+    input: `// @compilationMode(all)
 function nonReactFn() {
   return {};
 }

compiler/apps/playground/package.json

@@ -27,7 +27,7 @@
     "@babel/types": "7.26.3",
     "@heroicons/react": "^1.0.6",
     "@monaco-editor/react": "^4.4.6",
-    "@playwright/test": "^1.51.1",
+    "@playwright/test": "^1.42.1",
     "@use-gesture/react": "^10.2.22",
     "hermes-eslint": "^0.25.0",
     "hermes-parser": "^0.25.0",

compiler/apps/playground/yarn.lock

@@ -781,12 +781,12 @@
   resolved "https://registry.yarnpkg.com/@pkgjs/parseargs/-/parseargs-0.11.0.tgz#a77ea742fab25775145434eb1d2328cf5013ac33"
   integrity sha512-+1VkjdD0QBLPodGrJUeqarH8VAIvQODIbwh9XpP5Syisf7YoQgsJKPNFoqqLQlu+VQ/tVSshMR6loPMn8U+dPg==
 
-"@playwright/test@^1.51.1":
-  version "1.51.1"
-  resolved "https://registry.yarnpkg.com/@playwright/test/-/test-1.51.1.tgz#75357d513221a7be0baad75f01e966baf9c41a2e"
-  integrity sha512-nM+kEaTSAoVlXmMPH10017vn3FSiFqr/bh4fKg9vmAdMfd9SDqRZNvPSiAHADc/itWak+qPvMPZQOPwCBW7k7Q==
+"@playwright/test@^1.42.1":
+  version "1.47.2"
+  resolved "https://registry.yarnpkg.com/@playwright/test/-/test-1.47.2.tgz#dbe7051336bfc5cc599954214f9111181dbc7475"
+  integrity sha512-jTXRsoSPONAs8Za9QEQdyjFn+0ZQFjCiIztAIF6bi1HqhBzG9Ma7g1WotyiGqFSBRZjIEqMdT8RUlbk1QVhzCQ==
   dependencies:
-    playwright "1.51.1"
+    playwright "1.47.2"
 
 "@rtsao/scc@^1.1.0":
   version "1.1.0"
@@ -1249,14 +1249,14 @@ camelcase-css@^2.0.1:
   integrity sha512-QOSvevhslijgYwRx6Rv7zKdMF8lbRmx+uQGx2+vDc+KI/eBnsy9kit5aj23AgGu3pa4t9AgwbnXWqS+iOY+2aA==
 
 caniuse-lite@^1.0.30001579:
-  version "1.0.30001715"
-  resolved "https://registry.npmjs.org/caniuse-lite/-/caniuse-lite-1.0.30001715.tgz"
-  integrity sha512-7ptkFGMm2OAOgvZpwgA4yjQ5SQbrNVGdRjzH0pBdy1Fasvcr+KAeECmbCAECzTuDuoX0FCY8KzUxjf9+9kfZEw==
+  version "1.0.30001669"
+  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001669.tgz#fda8f1d29a8bfdc42de0c170d7f34a9cf19ed7a3"
+  integrity sha512-DlWzFDJqstqtIVx1zeSpIMLjunf5SmwOw0N2Ck/QSQdS8PLS4+9HrLaYei4w8BIAL7IB/UEDu889d8vhCTPA0w==
 
 caniuse-lite@^1.0.30001646, caniuse-lite@^1.0.30001663:
-  version "1.0.30001715"
-  resolved "https://registry.npmjs.org/caniuse-lite/-/caniuse-lite-1.0.30001715.tgz"
-  integrity sha512-7ptkFGMm2OAOgvZpwgA4yjQ5SQbrNVGdRjzH0pBdy1Fasvcr+KAeECmbCAECzTuDuoX0FCY8KzUxjf9+9kfZEw==
+  version "1.0.30001664"
+  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001664.tgz#d588d75c9682d3301956b05a3749652a80677df4"
+  integrity sha512-AmE7k4dXiNKQipgn7a2xg558IRqPN3jMQY/rOsbxDhrd0tyChwbITBfiwtnqz8bi2M5mIWbxAYBvk7W7QBUS2g==
 
 chalk@^2.4.2:
   version "2.4.2"
@@ -3008,17 +3008,17 @@ pirates@^4.0.1:
   resolved "https://registry.yarnpkg.com/pirates/-/pirates-4.0.6.tgz#3018ae32ecfcff6c29ba2267cbf21166ac1f36b9"
   integrity sha512-saLsH7WeYYPiD25LDuLRRY/i+6HaPYr6G1OUlN39otzkSTxKnubR9RTxS3/Kk50s1g2JTgFwWQDQyplC5/SHZg==
 
-playwright-core@1.51.1:
-  version "1.51.1"
-  resolved "https://registry.yarnpkg.com/playwright-core/-/playwright-core-1.51.1.tgz#d57f0393e02416f32a47cf82b27533656a8acce1"
-  integrity sha512-/crRMj8+j/Nq5s8QcvegseuyeZPxpQCZb6HNk3Sos3BlZyAknRjoyJPFWkpNn8v0+P3WiwqFF8P+zQo4eqiNuw==
+playwright-core@1.47.2:
+  version "1.47.2"
+  resolved "https://registry.yarnpkg.com/playwright-core/-/playwright-core-1.47.2.tgz#7858da9377fa32a08be46ba47d7523dbd9460a4e"
+  integrity sha512-3JvMfF+9LJfe16l7AbSmU555PaTl2tPyQsVInqm3id16pdDfvZ8TTZ/pyzmkbDrZTQefyzU7AIHlZqQnxpqHVQ==
 
-playwright@1.51.1:
-  version "1.51.1"
-  resolved "https://registry.yarnpkg.com/playwright/-/playwright-1.51.1.tgz#ae1467ee318083968ad28d6990db59f47a55390f"
-  integrity sha512-kkx+MB2KQRkyxjYPc3a0wLZZoDczmppyGJIvQ43l+aZihkaVvmu/21kiyaHeHjiFxjxNNFnUncKmcGIyOojsaw==
+playwright@1.47.2:
+  version "1.47.2"
+  resolved "https://registry.yarnpkg.com/playwright/-/playwright-1.47.2.tgz#155688aa06491ee21fb3e7555b748b525f86eb20"
+  integrity sha512-nx1cLMmQWqmA3UsnjaaokyoUpdVaaDhJhMoxX2qj3McpjnsqFHs516QAKYhqHAgOP+oCFTEOCOAaD1RgD/RQfA==
   dependencies:
-    playwright-core "1.51.1"
+    playwright-core "1.47.2"
   optionalDependencies:
     fsevents "2.3.2"
 

compiler/package.json

@@ -37,7 +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",
@@ -45,6 +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/src/Entrypoint/Imports.ts

@@ -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, PluginOptions} 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>,
@@ -53,65 +52,32 @@ export function validateRestrictedImports(
   }
 }
 
-type ProgramContextOptions = {
-  program: NodePath<t.Program>;
-  suppressions: Array<SuppressionRange>;
-  opts: PluginOptions;
-  filename: string | null;
-  code: string | null;
-  hasModuleScopeOptOut: boolean;
-};
 export class ProgramContext {
-  /**
-   * Program and environment context
-   */
+  /* Program and environment context */
   scope: BabelScope;
-  opts: PluginOptions;
-  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])
       );
@@ -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(

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

@@ -37,10 +37,6 @@ 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>;
 
 export type PluginOptions = {
   environment: EnvironmentConfig;
@@ -69,28 +65,6 @@ export type PluginOptions = {
    */
   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;
 
   /*
@@ -124,7 +98,7 @@ export type PluginOptions = {
    * 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;
 
   flowSuppressions: boolean;
   /*
@@ -132,7 +106,7 @@ export type PluginOptions = {
    */
   ignoreUseNoForget: boolean;
 
-  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.
@@ -208,9 +182,7 @@ export type LoggerEvent =
   | CompileDiagnosticEvent
   | CompileSkipEvent
   | PipelineErrorEvent
-  | TimingEvent
-  | AutoDepsDecorationsEvent
-  | AutoDepsEligibleEvent;
+  | TimingEvent;
 
 export type CompileErrorEvent = {
   kind: 'CompileError';
@@ -247,16 +219,6 @@ 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;
@@ -270,7 +232,6 @@ export const defaultOptions: PluginOptions = {
   logger: null,
   gating: null,
   noEmit: false,
-  dynamicGating: null,
   eslintSuppressionRules: null,
   flowSuppressions: true,
   ignoreUseNoForget: false,
@@ -319,25 +280,6 @@ export function parsePluginOptions(obj: unknown): PluginOptions {
           }
           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;
-        }
         default: {
           parsedOptions[key] = value;
         }

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

@@ -103,7 +103,6 @@ import {transformFire} from '../Transform';
 import {validateNoImpureFunctionsInRender} from '../Validation/ValidateNoImpureFunctionsInRender';
 import {CompilerError} from '..';
 import {validateStaticComponents} from '../Validation/ValidateStaticComponents';
-import {validateNoFreezingKnownMutableFunctions} from '../Validation/ValidateNoFreezingKnownMutableFunctions';
 
 export type CompilerPipelineValue =
   | {kind: 'ast'; name: string; value: CodegenFunction}
@@ -275,10 +274,6 @@ function runWithEnvironment(
     if (env.config.validateNoImpureFunctionsInRender) {
       validateNoImpureFunctionsInRender(hir).unwrap();
     }
-
-    if (env.config.validateNoFreezingKnownMutableFunctions) {
-      validateNoFreezingKnownMutableFunctions(hir).unwrap();
-    }
   }
 
   inferReactivePlaces(hir);
@@ -397,11 +392,6 @@ function runWithEnvironment(
 
   if (env.config.inferEffectDependencies) {
     inferEffectDependencies(hir);
-    log({
-      kind: 'hir',
-      name: 'InferEffectDependencies',
-      value: hir,
-    });
   }
 
   if (env.config.inlineJsxTransform) {

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

@@ -12,7 +12,7 @@ import {
   CompilerErrorDetail,
   ErrorSeverity,
 } from '../CompilerError';
-import {ExternalFunction, ReactFunctionType} from '../HIR/Environment';
+import {EnvironmentConfig, ReactFunctionType} from '../HIR/Environment';
 import {CodegenFunction} from '../ReactiveScopes';
 import {isComponentDeclaration} from '../Utils/ComponentDeclaration';
 import {isHookDeclaration} from '../Utils/HookDeclaration';
@@ -31,7 +31,6 @@ import {
   suppressionsToCompilerError,
 } from './Suppression';
 import {GeneratedSource} from '../HIR';
-import {Err, Ok, Result} from '../Utils/Result';
 
 export type CompilerPass = {
   opts: PluginOptions;
@@ -41,93 +40,22 @@ export type CompilerPass = {
 };
 export const OPT_IN_DIRECTIVES = new Set(['use forget', 'use memo']);
 export const OPT_OUT_DIRECTIVES = new Set(['use no forget', 'use no memo']);
-const DYNAMIC_GATING_DIRECTIVE = new RegExp('^use memo if\\(([^\\)]*)\\)$');
 
-export function tryFindDirectiveEnablingMemoization(
+export function findDirectiveEnablingMemoization(
   directives: Array<t.Directive>,
-  opts: PluginOptions,
-): Result<t.Directive | null, CompilerError> {
-  const optIn = directives.find(directive =>
+): Array<t.Directive> {
+  return directives.filter(directive =>
     OPT_IN_DIRECTIVES.has(directive.value.value),
   );
-  if (optIn != null) {
-    return Ok(optIn);
-  }
-  const dynamicGating = findDirectivesDynamicGating(directives, opts);
-  if (dynamicGating.isOk()) {
-    return Ok(dynamicGating.unwrap()?.directive ?? null);
-  } else {
-    return Err(dynamicGating.unwrapErr());
-  }
 }
 
 export function findDirectiveDisablingMemoization(
   directives: Array<t.Directive>,
-): t.Directive | null {
-  return (
-    directives.find(directive =>
-      OPT_OUT_DIRECTIVES.has(directive.value.value),
-    ) ?? null
+): Array<t.Directive> {
+  return directives.filter(directive =>
+    OPT_OUT_DIRECTIVES.has(directive.value.value),
   );
 }
-function findDirectivesDynamicGating(
-  directives: Array<t.Directive>,
-  opts: PluginOptions,
-): Result<
-  {
-    gating: ExternalFunction;
-    directive: t.Directive;
-  } | null,
-  CompilerError
-> {
-  if (opts.dynamicGating === null) {
-    return Ok(null);
-  }
-  const errors = new CompilerError();
-  const result: Array<{directive: t.Directive; match: string}> = [];
-
-  for (const directive of directives) {
-    const maybeMatch = DYNAMIC_GATING_DIRECTIVE.exec(directive.value.value);
-    if (maybeMatch != null && maybeMatch[1] != null) {
-      if (t.isValidIdentifier(maybeMatch[1])) {
-        result.push({directive, match: maybeMatch[1]});
-      } else {
-        errors.push({
-          reason: `Dynamic gating directive is not a valid JavaScript identifier`,
-          description: `Found '${directive.value.value}'`,
-          severity: ErrorSeverity.InvalidReact,
-          loc: directive.loc ?? null,
-          suggestions: null,
-        });
-      }
-    }
-  }
-  if (errors.hasErrors()) {
-    return Err(errors);
-  } else if (result.length > 1) {
-    const error = new CompilerError();
-    error.push({
-      reason: `Multiple dynamic gating directives found`,
-      description: `Expected a single directive but found [${result
-        .map(r => r.directive.value.value)
-        .join(', ')}]`,
-      severity: ErrorSeverity.InvalidReact,
-      loc: result[0].directive.loc ?? null,
-      suggestions: null,
-    });
-    return Err(error);
-  } else if (result.length === 1) {
-    return Ok({
-      gating: {
-        source: opts.dynamicGating.source,
-        importSpecifierName: result[0].match,
-      },
-      directive: result[0].directive,
-    });
-  } else {
-    return Ok(null);
-  }
-}
 
 function isCriticalError(err: unknown): boolean {
   return !(err instanceof CompilerError) || err.isCritical();
@@ -160,16 +88,13 @@ export type CompileResult = {
 
 function logError(
   err: unknown,
-  context: {
-    opts: PluginOptions;
-    filename: string | null;
-  },
+  pass: CompilerPass,
   fnLoc: t.SourceLocation | null,
 ): void {
-  if (context.opts.logger) {
+  if (pass.opts.logger) {
     if (err instanceof CompilerError) {
       for (const detail of err.details) {
-        context.opts.logger.logEvent(context.filename, {
+        pass.opts.logger.logEvent(pass.filename, {
           kind: 'CompileError',
           fnLoc,
           detail: detail.options,
@@ -183,7 +108,7 @@ function logError(
         stringifiedError = err?.toString() ?? '[ null ]';
       }
 
-      context.opts.logger.logEvent(context.filename, {
+      pass.opts.logger.logEvent(pass.filename, {
         kind: 'PipelineError',
         fnLoc,
         data: stringifiedError,
@@ -193,17 +118,13 @@ function logError(
 }
 function handleError(
   err: unknown,
-  context: {
-    opts: PluginOptions;
-    filename: string | null;
-  },
+  pass: CompilerPass,
   fnLoc: t.SourceLocation | null,
 ): void {
-  logError(err, context, fnLoc);
+  logError(err, pass, fnLoc);
   if (
-    context.opts.panicThreshold === 'all_errors' ||
-    (context.opts.panicThreshold === 'critical_errors' &&
-      isCriticalError(err)) ||
+    pass.opts.panicThreshold === 'all_errors' ||
+    (pass.opts.panicThreshold === 'critical_errors' && isCriticalError(err)) ||
     isConfigError(err) // Always throws regardless of panic threshold
   ) {
     throw err;
@@ -266,6 +187,7 @@ export function createNewFunctionNode(
     }
   }
   // Avoid visiting the new transformed version
+  ALREADY_COMPILED.add(transformedFn);
   return transformedFn;
 }
 
@@ -317,6 +239,13 @@ function insertNewOutlinedFunctionNode(
   }
 }
 
+/*
+ * 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.
+ */
+const ALREADY_COMPILED: WeakSet<object> | Set<object> = new (WeakSet ?? Set)();
+
 const DEFAULT_ESLINT_SUPPRESSIONS = [
   'react-hooks/exhaustive-deps',
   'react-hooks/rules-of-hooks',
@@ -339,43 +268,41 @@ function isFilePartOfSources(
   return false;
 }
 
-export type CompileProgramMetadata = {
+export type CompileProgramResult = {
   retryErrors: Array<{fn: BabelFn; error: CompilerError}>;
   inferredEffectLocations: Set<t.SourceLocation>;
 };
 /**
- * Main entrypoint for React Compiler.
- *
- * @param program The Babel program node to compile
- * @param pass Compiler configuration and context
- * @returns Compilation results or null if compilation was skipped
+ * `compileProgram` is directly invoked by the react-compiler babel plugin, so
+ * exceptions thrown by this function will fail the babel build.
+ * - call `handleError` if your error is recoverable.
+ *   Unless the error is a warning / info diagnostic, compilation of a function
+ *   / entire file should also be skipped.
+ * - throw an exception if the error is fatal / not recoverable.
+ *   Examples of this are invalid compiler configs or failure to codegen outlined
+ *   functions *after* already emitting optimized components / hooks that invoke
+ *   the outlined functions.
  */
 export function compileProgram(
   program: NodePath<t.Program>,
   pass: CompilerPass,
-): CompileProgramMetadata | null {
-  /**
-   * This is directly invoked by the react-compiler babel plugin, so exceptions
-   * thrown by this function will fail the babel build.
-   * - call `handleError` if your error is recoverable.
-   *   Unless the error is a warning / info diagnostic, compilation of a function
-   *   / entire file should also be skipped.
-   * - throw an exception if the error is fatal / not recoverable.
-   *   Examples of this are invalid compiler configs or failure to codegen outlined
-   *   functions *after* already emitting optimized components / hooks that invoke
-   *   the outlined functions.
-   */
+): CompileProgramResult | null {
   if (shouldSkipCompilation(program, pass)) {
     return null;
   }
-  const restrictedImportsErr = validateRestrictedImports(
-    program,
-    pass.opts.environment,
-  );
+
+  const environment = pass.opts.environment;
+  const restrictedImportsErr = validateRestrictedImports(program, environment);
   if (restrictedImportsErr) {
     handleError(restrictedImportsErr, pass, null);
     return null;
   }
+
+  const programContext = new ProgramContext(
+    program,
+    pass.opts.target,
+    environment.hookPattern,
+  );
   /*
    * Record lint errors and critical errors as depending on Forget's config,
    * we may still need to run Forget's analysis on every function (even if we
@@ -386,102 +313,16 @@ export function compileProgram(
     pass.opts.eslintSuppressionRules ?? DEFAULT_ESLINT_SUPPRESSIONS,
     pass.opts.flowSuppressions,
   );
-
-  const programContext = new ProgramContext({
-    program: program,
-    opts: pass.opts,
-    filename: pass.filename,
-    code: pass.code,
-    suppressions,
-    hasModuleScopeOptOut:
-      findDirectiveDisablingMemoization(program.node.directives) != null,
-  });
-
-  const queue: Array<CompileSource> = findFunctionsToCompile(
-    program,
-    pass,
-    programContext,
-  );
+  const queue: Array<{
+    kind: 'original' | 'outlined';
+    fn: BabelFn;
+    fnType: ReactFunctionType;
+  }> = [];
   const compiledFns: Array<CompileResult> = [];
 
-  while (queue.length !== 0) {
-    const current = queue.shift()!;
-    const compiled = processFn(current.fn, current.fnType, programContext);
-
-    if (compiled != null) {
-      for (const outlined of compiled.outlined) {
-        CompilerError.invariant(outlined.fn.outlined.length === 0, {
-          reason: 'Unexpected nested outlined functions',
-          loc: outlined.fn.loc,
-        });
-        const fn = insertNewOutlinedFunctionNode(
-          program,
-          current.fn,
-          outlined.fn,
-        );
-        fn.skip();
-        programContext.alreadyCompiled.add(fn.node);
-        if (outlined.type !== null) {
-          queue.push({
-            kind: 'outlined',
-            fn,
-            fnType: outlined.type,
-          });
-        }
-      }
-      compiledFns.push({
-        kind: current.kind,
-        originalFn: current.fn,
-        compiledFn: compiled,
-      });
-    }
-  }
-
-  // Avoid modifying the program if we find a program level opt-out
-  if (programContext.hasModuleScopeOptOut) {
-    if (compiledFns.length > 0) {
-      const error = new CompilerError();
-      error.pushErrorDetail(
-        new CompilerErrorDetail({
-          reason:
-            'Unexpected compiled functions when module scope opt-out is present',
-          severity: ErrorSeverity.Invariant,
-          loc: null,
-        }),
-      );
-      handleError(error, programContext, null);
-    }
-    return null;
-  }
-
-  // Insert React Compiler generated functions into the Babel AST
-  applyCompiledFunctions(program, compiledFns, pass, programContext);
-
-  return {
-    retryErrors: programContext.retryErrors,
-    inferredEffectLocations: programContext.inferredEffectLocations,
-  };
-}
-
-type CompileSource = {
-  kind: 'original' | 'outlined';
-  fn: BabelFn;
-  fnType: ReactFunctionType;
-};
-/**
- * Find all React components and hooks that need to be compiled
- *
- * @returns An array of React functions from @param program to transform
- */
-function findFunctionsToCompile(
-  program: NodePath<t.Program>,
-  pass: CompilerPass,
-  programContext: ProgramContext,
-): Array<CompileSource> {
-  const queue: Array<CompileSource> = [];
   const traverseFunction = (fn: BabelFn, pass: CompilerPass): void => {
-    const fnType = getReactFunctionType(fn, pass);
-    if (fnType === null || programContext.alreadyCompiled.has(fn.node)) {
+    const fnType = getReactFunctionType(fn, pass, environment);
+    if (fnType === null || ALREADY_COMPILED.has(fn.node)) {
       return;
     }
 
@@ -490,7 +331,7 @@ function findFunctionsToCompile(
      * traversal will loop infinitely.
      * Ensure we avoid visiting the original function again.
      */
-    programContext.alreadyCompiled.add(fn.node);
+    ALREADY_COMPILED.add(fn.node);
     fn.skip();
 
     queue.push({kind: 'original', fn, fnType});
@@ -505,6 +346,7 @@ function findFunctionsToCompile(
          * can reference `this` which is unsafe for compilation
          */
         node.skip();
+        return;
       },
 
       ClassExpression(node: NodePath<t.ClassExpression>) {
@@ -513,6 +355,7 @@ function findFunctionsToCompile(
          * can reference `this` which is unsafe for compilation
          */
         node.skip();
+        return;
       },
 
       FunctionDeclaration: traverseFunction,
@@ -527,251 +370,223 @@ function findFunctionsToCompile(
       filename: pass.filename ?? null,
     },
   );
-  return queue;
-}
+  const retryErrors: Array<{fn: BabelFn; error: CompilerError}> = [];
+  const inferredEffectLocations = new Set<t.SourceLocation>();
+  const processFn = (
+    fn: BabelFn,
+    fnType: ReactFunctionType,
+  ): null | CodegenFunction => {
+    let optInDirectives: Array<t.Directive> = [];
+    let optOutDirectives: Array<t.Directive> = [];
+    if (fn.node.body.type === 'BlockStatement') {
+      optInDirectives = findDirectiveEnablingMemoization(
+        fn.node.body.directives,
+      );
+      optOutDirectives = findDirectiveDisablingMemoization(
+        fn.node.body.directives,
+      );
+    }
 
-/**
- * Try to compile a source function, taking into account all local suppressions,
- * opt-ins, and opt-outs.
- *
- * Errors encountered during compilation are either logged (if recoverable) or
- * thrown (if non-recoverable).
- *
- * @returns the compiled function or null if the function was skipped (due to
- * config settings and/or outputs)
- */
-function processFn(
-  fn: BabelFn,
-  fnType: ReactFunctionType,
-  programContext: ProgramContext,
-): null | CodegenFunction {
-  let directives: {
-    optIn: t.Directive | null;
-    optOut: t.Directive | null;
-  };
-  if (fn.node.body.type !== 'BlockStatement') {
-    directives = {
-      optIn: null,
-      optOut: null,
-    };
-  } else {
-    const optIn = tryFindDirectiveEnablingMemoization(
-      fn.node.body.directives,
-      programContext.opts,
+    /**
+     * Note that Babel does not attach comment nodes to nodes; they are dangling off of the
+     * Program node itself. We need to figure out whether an eslint suppression range
+     * applies to this function first.
+     */
+    const suppressionsInFunction = filterSuppressionsThatAffectFunction(
+      suppressions,
+      fn,
     );
-    if (optIn.isErr()) {
-      /**
-       * If parsing opt-in directive fails, it's most likely that React Compiler
-       * was not tested or rolled out on this function. In that case, we handle
-       * the error and fall back to the safest option which is to not optimize
-       * the function.
-       */
-      handleError(optIn.unwrapErr(), programContext, fn.node.loc ?? null);
-      return null;
-    }
-    directives = {
-      optIn: optIn.unwrapOr(null),
-      optOut: findDirectiveDisablingMemoization(fn.node.body.directives),
-    };
-  }
-
-  let compiledFn: CodegenFunction;
-  const compileResult = tryCompileFunction(fn, fnType, programContext);
-  if (compileResult.kind === 'error') {
-    if (directives.optOut != null) {
-      logError(compileResult.error, programContext, fn.node.loc ?? null);
+    let compileResult:
+      | {kind: 'compile'; compiledFn: CodegenFunction}
+      | {kind: 'error'; error: unknown};
+    if (suppressionsInFunction.length > 0) {
+      compileResult = {
+        kind: 'error',
+        error: suppressionsToCompilerError(suppressionsInFunction),
+      };
     } else {
-      handleError(compileResult.error, programContext, fn.node.loc ?? null);
+      try {
+        compileResult = {
+          kind: 'compile',
+          compiledFn: compileFn(
+            fn,
+            environment,
+            fnType,
+            'all_features',
+            programContext,
+            pass.opts.logger,
+            pass.filename,
+            pass.code,
+          ),
+        };
+      } catch (err) {
+        compileResult = {kind: 'error', error: err};
+      }
     }
-    const retryResult = retryCompileFunction(fn, fnType, programContext);
-    if (retryResult == null) {
+
+    if (compileResult.kind === 'error') {
+      /**
+       * If an opt out directive is present, log only instead of throwing and don't mark as
+       * containing a critical error.
+       */
+      if (optOutDirectives.length > 0) {
+        logError(compileResult.error, pass, fn.node.loc ?? null);
+      } else {
+        handleError(compileResult.error, pass, fn.node.loc ?? null);
+      }
+      // If non-memoization features are enabled, retry regardless of error kind
+      if (
+        !(environment.enableFire || environment.inferEffectDependencies != null)
+      ) {
+        return null;
+      }
+      try {
+        compileResult = {
+          kind: 'compile',
+          compiledFn: compileFn(
+            fn,
+            environment,
+            fnType,
+            'no_inferred_memo',
+            programContext,
+            pass.opts.logger,
+            pass.filename,
+            pass.code,
+          ),
+        };
+        if (
+          !compileResult.compiledFn.hasFireRewrite &&
+          !compileResult.compiledFn.hasInferredEffect
+        ) {
+          return null;
+        }
+      } catch (err) {
+        // TODO: we might want to log error here, but this will also result in duplicate logging
+        if (err instanceof CompilerError) {
+          retryErrors.push({fn, error: err});
+        }
+        return null;
+      }
+    }
+
+    pass.opts.logger?.logEvent(pass.filename, {
+      kind: 'CompileSuccess',
+      fnLoc: fn.node.loc ?? null,
+      fnName: compileResult.compiledFn.id?.name ?? null,
+      memoSlots: compileResult.compiledFn.memoSlotsUsed,
+      memoBlocks: compileResult.compiledFn.memoBlocks,
+      memoValues: compileResult.compiledFn.memoValues,
+      prunedMemoBlocks: compileResult.compiledFn.prunedMemoBlocks,
+      prunedMemoValues: compileResult.compiledFn.prunedMemoValues,
+    });
+
+    /**
+     * Always compile functions with opt in directives.
+     */
+    if (optInDirectives.length > 0) {
+      return compileResult.compiledFn;
+    } else if (pass.opts.compilationMode === 'annotation') {
+      /**
+       * No opt-in directive in annotation mode, so don't insert the compiled function.
+       */
       return null;
     }
-    compiledFn = retryResult;
-  } else {
-    compiledFn = compileResult.compiledFn;
-  }
 
-  /**
-   * If 'use no forget/memo' is present and we still ran the code through the
-   * compiler for validation, log a skip event and don't mutate the babel AST.
-   * This allows us to flag if there is an unused 'use no forget/memo'
-   * directive.
-   */
-  if (
-    programContext.opts.ignoreUseNoForget === false &&
-    directives.optOut != null
-  ) {
-    programContext.logEvent({
-      kind: 'CompileSkip',
-      fnLoc: fn.node.body.loc ?? null,
-      reason: `Skipped due to '${directives.optOut.value}' directive.`,
-      loc: directives.optOut.loc ?? null,
-    });
-    return null;
-  }
-  programContext.logEvent({
-    kind: 'CompileSuccess',
-    fnLoc: fn.node.loc ?? null,
-    fnName: compiledFn.id?.name ?? null,
-    memoSlots: compiledFn.memoSlotsUsed,
-    memoBlocks: compiledFn.memoBlocks,
-    memoValues: compiledFn.memoValues,
-    prunedMemoBlocks: compiledFn.prunedMemoBlocks,
-    prunedMemoValues: compiledFn.prunedMemoValues,
-  });
+    /**
+     * Otherwise if 'use no forget/memo' is present, we still run the code through the compiler
+     * for validation but we don't mutate the babel AST. This allows us to flag if there is an
+     * unused 'use no forget/memo' directive.
+     */
+    if (pass.opts.ignoreUseNoForget === false && optOutDirectives.length > 0) {
+      for (const directive of optOutDirectives) {
+        pass.opts.logger?.logEvent(pass.filename, {
+          kind: 'CompileSkip',
+          fnLoc: fn.node.body.loc ?? null,
+          reason: `Skipped due to '${directive.value.value}' directive.`,
+          loc: directive.loc ?? null,
+        });
+      }
+      return null;
+    }
 
-  if (programContext.hasModuleScopeOptOut) {
-    return null;
-  } else if (programContext.opts.noEmit) {
+    if (!pass.opts.noEmit) {
+      return compileResult.compiledFn;
+    }
     /**
      * inferEffectDependencies + noEmit is currently only used for linting. In
      * this mode, add source locations for where the compiler *can* infer effect
      * dependencies.
      */
-    for (const loc of compiledFn.inferredEffectLocations) {
-      if (loc !== GeneratedSource) {
-        programContext.inferredEffectLocations.add(loc);
+    for (const loc of compileResult.compiledFn.inferredEffectLocations) {
+      if (loc !== GeneratedSource) inferredEffectLocations.add(loc);
+    }
+    return null;
+  };
+
+  while (queue.length !== 0) {
+    const current = queue.shift()!;
+    const compiled = processFn(current.fn, current.fnType);
+    if (compiled === null) {
+      continue;
+    }
+    for (const outlined of compiled.outlined) {
+      CompilerError.invariant(outlined.fn.outlined.length === 0, {
+        reason: 'Unexpected nested outlined functions',
+        loc: outlined.fn.loc,
+      });
+      const fn = insertNewOutlinedFunctionNode(
+        program,
+        current.fn,
+        outlined.fn,
+      );
+      fn.skip();
+      ALREADY_COMPILED.add(fn.node);
+      if (outlined.type !== null) {
+        queue.push({
+          kind: 'outlined',
+          fn,
+          fnType: outlined.type,
+        });
       }
     }
-    return null;
-  } else if (
-    programContext.opts.compilationMode === 'annotation' &&
-    directives.optIn == null
-  ) {
-    /**
-     * If no opt-in directive is found and the compiler is configured in
-     * annotation mode, don't insert the compiled function.
-     */
-    return null;
-  } else {
-    return compiledFn;
+    compiledFns.push({
+      kind: current.kind,
+      compiledFn: compiled,
+      originalFn: current.fn,
+    });
   }
-}
 
-function tryCompileFunction(
-  fn: BabelFn,
-  fnType: ReactFunctionType,
-  programContext: ProgramContext,
-):
-  | {kind: 'compile'; compiledFn: CodegenFunction}
-  | {kind: 'error'; error: unknown} {
   /**
-   * Note that Babel does not attach comment nodes to nodes; they are dangling off of the
-   * Program node itself. We need to figure out whether an eslint suppression range
-   * applies to this function first.
+   * Do not modify source if there is a module scope level opt out directive.
    */
-  const suppressionsInFunction = filterSuppressionsThatAffectFunction(
-    programContext.suppressions,
-    fn,
+  const moduleScopeOptOutDirectives = findDirectiveDisablingMemoization(
+    program.node.directives,
   );
-  if (suppressionsInFunction.length > 0) {
-    return {
-      kind: 'error',
-      error: suppressionsToCompilerError(suppressionsInFunction),
-    };
-  }
-
-  try {
-    return {
-      kind: 'compile',
-      compiledFn: compileFn(
-        fn,
-        programContext.opts.environment,
-        fnType,
-        'all_features',
-        programContext,
-        programContext.opts.logger,
-        programContext.filename,
-        programContext.code,
-      ),
-    };
-  } catch (err) {
-    return {kind: 'error', error: err};
-  }
-}
-
-/**
- * If non-memo feature flags are enabled, retry compilation with a more minimal
- * feature set.
- *
- * @returns a CodegenFunction if retry was successful
- */
-function retryCompileFunction(
-  fn: BabelFn,
-  fnType: ReactFunctionType,
-  programContext: ProgramContext,
-): CodegenFunction | null {
-  const environment = programContext.opts.environment;
-  if (
-    !(environment.enableFire || environment.inferEffectDependencies != null)
-  ) {
+  if (moduleScopeOptOutDirectives.length > 0) {
     return null;
   }
-  /**
-   * Note that function suppressions are not checked in the retry pipeline, as
-   * they only affect auto-memoization features.
+  /*
+   * Only insert Forget-ified functions if we have not encountered a critical
+   * error elsewhere in the file, regardless of bailout mode.
    */
-  try {
-    const retryResult = compileFn(
-      fn,
-      environment,
-      fnType,
-      'no_inferred_memo',
-      programContext,
-      programContext.opts.logger,
-      programContext.filename,
-      programContext.code,
-    );
-
-    if (!retryResult.hasFireRewrite && !retryResult.hasInferredEffect) {
-      return null;
-    }
-    return retryResult;
-  } catch (err) {
-    // TODO: we might want to log error here, but this will also result in duplicate logging
-    if (err instanceof CompilerError) {
-      programContext.retryErrors.push({fn, error: err});
-    }
-    return null;
-  }
-}
-
-/**
- * Applies React Compiler generated functions to the babel AST by replacing
- * existing functions in place or inserting new declarations.
- */
-function applyCompiledFunctions(
-  program: NodePath<t.Program>,
-  compiledFns: Array<CompileResult>,
-  pass: CompilerPass,
-  programContext: ProgramContext,
-): void {
-  let referencedBeforeDeclared = null;
+  const referencedBeforeDeclared =
+    pass.opts.gating != null
+      ? getFunctionReferencedBeforeDeclarationAtTopLevel(program, compiledFns)
+      : null;
   for (const result of compiledFns) {
     const {kind, originalFn, compiledFn} = result;
     const transformedFn = createNewFunctionNode(originalFn, compiledFn);
-    programContext.alreadyCompiled.add(transformedFn);
 
-    let dynamicGating: ExternalFunction | null = null;
-    if (originalFn.node.body.type === 'BlockStatement') {
-      const result = findDirectivesDynamicGating(
-        originalFn.node.body.directives,
-        pass.opts,
-      );
-      if (result.isOk()) {
-        dynamicGating = result.unwrap()?.gating ?? null;
-      }
-    }
-    const functionGating = dynamicGating ?? pass.opts.gating;
-    if (kind === 'original' && functionGating != null) {
-      referencedBeforeDeclared ??=
-        getFunctionReferencedBeforeDeclarationAtTopLevel(program, compiledFns);
+    if (referencedBeforeDeclared != null && kind === 'original') {
+      CompilerError.invariant(pass.opts.gating != null, {
+        reason: "Expected 'gating' import to be present",
+        loc: null,
+      });
       insertGatedFunctionDeclaration(
         originalFn,
         transformedFn,
         programContext,
-        functionGating,
+        pass.opts.gating,
         referencedBeforeDeclared.has(result),
       );
     } else {
@@ -783,6 +598,7 @@ function applyCompiledFunctions(
   if (compiledFns.length > 0) {
     addImportsToProgram(program, programContext);
   }
+  return {retryErrors, inferredEffectLocations};
 }
 
 function shouldSkipCompilation(
@@ -824,16 +640,15 @@ function shouldSkipCompilation(
 function getReactFunctionType(
   fn: BabelFn,
   pass: CompilerPass,
+  /**
+   * TODO(mofeiZ): remove once we validate PluginOptions with Zod
+   */
+  environment: EnvironmentConfig,
 ): ReactFunctionType | null {
-  const hookPattern = pass.opts.environment.hookPattern;
+  const hookPattern = environment.hookPattern;
   if (fn.node.body.type === 'BlockStatement') {
-    const optInDirectives = tryFindDirectiveEnablingMemoization(
-      fn.node.body.directives,
-      pass.opts,
-    );
-    if (optInDirectives.unwrapOr(null) != null) {
+    if (findDirectiveEnablingMemoization(fn.node.body.directives).length > 0)
       return getComponentOrHookLike(fn, hookPattern) ?? 'Other';
-    }
   }
 
   // Component and hook declarations are known components/hooks

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Reanimated.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 type * as BabelCore from '@babel/core';
 import {hasOwnProperty} from '../Utils/utils';
 import {PluginOptions} from './Options';

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/ValidateNoUntransformedReferences.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 {NodePath} from '@babel/core';
 import * as t from '@babel/types';
 
@@ -18,7 +11,7 @@ import {
 import {getOrInsertWith} from '../Utils/utils';
 import {Environment} from '../HIR';
 import {DEFAULT_EXPORT} from '../HIR/Environment';
-import {CompileProgramMetadata} from './Program';
+import {CompileProgramResult} from './Program';
 
 function throwInvalidReact(
   options: Omit<CompilerErrorDetailOptions, 'severity'>,
@@ -109,7 +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,
@@ -236,7 +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/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,

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

@@ -2406,19 +2406,6 @@ function lowerExpression(
         kind: 'TypeCastExpression',
         value: lowerExpressionToTemporary(builder, expr.get('expression')),
         typeAnnotation: typeAnnotation.node,
-        typeAnnotationKind: 'cast',
-        type: lowerType(typeAnnotation.node),
-        loc: exprLoc,
-      };
-    }
-    case 'TSSatisfiesExpression': {
-      let expr = exprPath as NodePath<t.TSSatisfiesExpression>;
-      const typeAnnotation = expr.get('typeAnnotation');
-      return {
-        kind: 'TypeCastExpression',
-        value: lowerExpressionToTemporary(builder, expr.get('expression')),
-        typeAnnotation: typeAnnotation.node,
-        typeAnnotationKind: 'satisfies',
         type: lowerType(typeAnnotation.node),
         loc: exprLoc,
       };
@@ -2430,7 +2417,6 @@ function lowerExpression(
         kind: 'TypeCastExpression',
         value: lowerExpressionToTemporary(builder, expr.get('expression')),
         typeAnnotation: typeAnnotation.node,
-        typeAnnotationKind: 'as',
         type: lowerType(typeAnnotation.node),
         loc: exprLoc,
       };
@@ -3609,40 +3595,31 @@ function lowerAssignment(
 
       let temporary;
       if (builder.isContextIdentifier(lvalue)) {
-        if (kind === InstructionKind.Const && !isHoistedIdentifier) {
-          builder.errors.push({
-            reason: `Expected \`const\` declaration not to be reassigned`,
-            severity: ErrorSeverity.InvalidJS,
-            loc: lvalue.node.loc ?? null,
-            suggestions: null,
+        if (kind !== InstructionKind.Reassign && !isHoistedIdentifier) {
+          if (kind === InstructionKind.Const) {
+            builder.errors.push({
+              reason: `Expected \`const\` declaration not to be reassigned`,
+              severity: ErrorSeverity.InvalidJS,
+              loc: lvalue.node.loc ?? null,
+              suggestions: null,
+            });
+          }
+          lowerValueToTemporary(builder, {
+            kind: 'DeclareContext',
+            lvalue: {
+              kind: InstructionKind.Let,
+              place: {...place},
+            },
+            loc: place.loc,
           });
         }
 
-        if (
-          kind !== InstructionKind.Const &&
-          kind !== InstructionKind.Reassign &&
-          kind !== InstructionKind.Let &&
-          kind !== InstructionKind.Function
-        ) {
-          builder.errors.push({
-            reason: `Unexpected context variable kind`,
-            severity: ErrorSeverity.InvalidJS,
-            loc: lvalue.node.loc ?? null,
-            suggestions: null,
-          });
-          temporary = lowerValueToTemporary(builder, {
-            kind: 'UnsupportedNode',
-            node: lvalueNode,
-            loc: lvalueNode.loc ?? GeneratedSource,
-          });
-        } else {
-          temporary = lowerValueToTemporary(builder, {
-            kind: 'StoreContext',
-            lvalue: {place: {...place}, kind},
-            value,
-            loc,
-          });
-        }
+        temporary = lowerValueToTemporary(builder, {
+          kind: 'StoreContext',
+          lvalue: {place: {...place}, kind: InstructionKind.Reassign},
+          value,
+          loc,
+        });
       } else {
         const typeAnnotation = lvalue.get('typeAnnotation');
         let type: t.FlowType | t.TSType | null;

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';

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>;

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 {

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

@@ -9,7 +9,15 @@ import * as t from '@babel/types';
 import {ZodError, z} from 'zod';
 import {fromZodError} from 'zod-validation-error';
 import {CompilerError} from '../CompilerError';
-import {Logger, ProgramContext} from '../Entrypoint';
+import {
+  CompilationMode,
+  defaultOptions,
+  Logger,
+  PanicThresholdOptions,
+  parsePluginOptions,
+  PluginOptions,
+  ProgramContext,
+} from '../Entrypoint';
 import {Err, Ok, Result} from '../Utils/Result';
 import {
   DEFAULT_GLOBALS,
@@ -150,7 +158,7 @@ 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()),
 
   /**
@@ -359,11 +367,6 @@ export const EnvironmentConfigSchema = z.object({
    */
   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
@@ -632,6 +635,191 @@ export const EnvironmentConfigSchema = z.object({
 
 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';

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

@@ -9,7 +9,6 @@ import {Effect, ValueKind, ValueReason} from './HIR';
 import {
   BUILTIN_SHAPES,
   BuiltInArrayId,
-  BuiltInFireFunctionId,
   BuiltInFireId,
   BuiltInMapId,
   BuiltInMixedReadonlyId,
@@ -25,9 +24,6 @@ import {
   BuiltInUseRefId,
   BuiltInUseStateId,
   BuiltInUseTransitionId,
-  BuiltInWeakMapId,
-  BuiltInWeakSetId,
-  ReanimatedSharedValueId,
   ShapeRegistry,
   addFunction,
   addHook,
@@ -494,38 +490,6 @@ 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
 ];
 
@@ -710,12 +674,7 @@ 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,
       },
@@ -943,7 +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

@@ -746,27 +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 {
@@ -901,20 +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;
@@ -943,21 +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';
@@ -1725,18 +1684,6 @@ 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';
 }
@@ -1767,12 +1714,6 @@ 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 isStableType(id: Identifier): boolean {
   return (
     isSetStateType(id) ||
@@ -1783,40 +1724,6 @@ export function isStableType(id: Identifier): boolean {
   );
 }
 
-export function isStableTypeContainer(id: Identifier): boolean {
-  const type_ = id.type;
-  if (type_.kind !== 'Object') {
-    return false;
-  }
-  return (
-    isUseStateType(id) || // setState
-    type_.shapeId === 'BuiltInUseActionState' || // setActionState
-    isUseReducerType(id) || // dispatcher
-    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':
-        return true;
-    }
-  }
-  return false;
-}
-
 export function isUseEffectHookType(id: Identifier): boolean {
   return (
     id.type.kind === 'Function' && id.type.shapeId === 'BuiltInUseEffectHook'

compiler/packages/babel-plugin-react-compiler/src/HIR/MergeOverlappingReactiveScopesHIR.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 {
   HIRFunction,
   InstructionId,

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

@@ -203,8 +203,6 @@ export const BuiltInPropsId = 'BuiltInProps';
 export const BuiltInArrayId = 'BuiltInArray';
 export const BuiltInSetId = 'BuiltInSet';
 export const BuiltInMapId = 'BuiltInMap';
-export const BuiltInWeakSetId = 'BuiltInWeakSet';
-export const BuiltInWeakMapId = 'BuiltInWeakMap';
 export const BuiltInFunctionId = 'BuiltInFunction';
 export const BuiltInJsxId = 'BuiltInJsx';
 export const BuiltInObjectId = 'BuiltInObject';
@@ -225,10 +223,6 @@ export const BuiltInUseContextHookId = 'BuiltInUseContextHook';
 export const BuiltInUseTransitionId = 'BuiltInUseTransition';
 export const BuiltInStartTransitionId = 'BuiltInStartTransition';
 export const BuiltInFireId = 'BuiltInFire';
-export const BuiltInFireFunctionId = 'BuiltInFireFunction';
-
-// See getReanimatedModuleType() in Globals.ts — this is part of supporting Reanimated's ref-like types
-export const ReanimatedSharedValueId = 'ReanimatedSharedValueId';
 
 // ShapeRegistry with default definitions for built-ins.
 export const BUILTIN_SHAPES: ShapeRegistry = new Map();
@@ -769,101 +763,6 @@ addObject(BUILTIN_SHAPES, BuiltInMapId, [
   ],
 ]);
 
-addObject(BUILTIN_SHAPES, BuiltInWeakSetId, [
-  [
-    /**
-     * add(value)
-     * Parameters
-     *   value: the value of the element to add to the Set object.
-     * Returns the Set object with added value.
-     */
-    'add',
-    addFunction(BUILTIN_SHAPES, [], {
-      positionalParams: [Effect.Capture],
-      restParam: null,
-      returnType: {kind: 'Object', shapeId: BuiltInWeakSetId},
-      calleeEffect: Effect.Store,
-      // returnValueKind is technically dependent on the ValueKind of the set itself
-      returnValueKind: ValueKind.Mutable,
-    }),
-  ],
-  [
-    /**
-     * setInstance.delete(value)
-     * Returns true if value was already in Set; otherwise false.
-     */
-    'delete',
-    addFunction(BUILTIN_SHAPES, [], {
-      positionalParams: [Effect.Read],
-      restParam: null,
-      returnType: PRIMITIVE_TYPE,
-      calleeEffect: Effect.Store,
-      returnValueKind: ValueKind.Primitive,
-    }),
-  ],
-  [
-    'has',
-    addFunction(BUILTIN_SHAPES, [], {
-      positionalParams: [Effect.Read],
-      restParam: null,
-      returnType: PRIMITIVE_TYPE,
-      calleeEffect: Effect.Read,
-      returnValueKind: ValueKind.Primitive,
-    }),
-  ],
-]);
-
-addObject(BUILTIN_SHAPES, BuiltInWeakMapId, [
-  [
-    'delete',
-    addFunction(BUILTIN_SHAPES, [], {
-      positionalParams: [Effect.Read],
-      restParam: null,
-      returnType: PRIMITIVE_TYPE,
-      calleeEffect: Effect.Store,
-      returnValueKind: ValueKind.Primitive,
-    }),
-  ],
-  [
-    'get',
-    addFunction(BUILTIN_SHAPES, [], {
-      positionalParams: [Effect.Read],
-      restParam: null,
-      returnType: {kind: 'Poly'},
-      calleeEffect: Effect.Capture,
-      returnValueKind: ValueKind.Mutable,
-    }),
-  ],
-  [
-    'has',
-    addFunction(BUILTIN_SHAPES, [], {
-      positionalParams: [Effect.Read],
-      restParam: null,
-      returnType: PRIMITIVE_TYPE,
-      calleeEffect: Effect.Read,
-      returnValueKind: ValueKind.Primitive,
-    }),
-  ],
-  [
-    /**
-     * Params
-     *   key: the key of the element to add to the Map object. The key may be
-     *   any JavaScript type (any primitive value or any type of JavaScript
-     *   object).
-     *   value: the value of the element to add to the Map object.
-     * Returns the Map object.
-     */
-    'set',
-    addFunction(BUILTIN_SHAPES, [], {
-      positionalParams: [Effect.Capture, Effect.Capture],
-      restParam: null,
-      returnType: {kind: 'Object', shapeId: BuiltInWeakMapId},
-      calleeEffect: Effect.Store,
-      returnValueKind: ValueKind.Mutable,
-    }),
-  ],
-]);
-
 addObject(BUILTIN_SHAPES, BuiltInUseStateId, [
   ['0', {kind: 'Poly'}],
   [

compiler/packages/babel-plugin-react-compiler/src/HIR/PropagateScopeDependenciesHIR.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 {
   ScopeId,
   HIRFunction,
@@ -30,7 +23,6 @@ import {
   FunctionExpression,
   ObjectMethod,
   PropertyLiteral,
-  convertHoistedLValueKind,
 } from './HIR';
 import {
   collectHoistablePropertyLoads,
@@ -117,7 +109,7 @@ export function propagateScopeDependenciesHIR(fn: HIRFunction): void {
   }
 }
 
-export function findTemporariesUsedOutsideDeclaringScope(
+function findTemporariesUsedOutsideDeclaringScope(
   fn: HIRFunction,
 ): ReadonlySet<DeclarationId> {
   /*
@@ -247,18 +239,12 @@ function isLoadContextMutable(
   id: InstructionId,
 ): instrValue is LoadContext {
   if (instrValue.kind === 'LoadContext') {
-    /**
-     * Not all context variables currently have scopes due to limitations of
-     * mutability analysis for function expressions.
-     *
-     * Currently, many function expressions references are inferred to be
-     * 'Read' | 'Freeze' effects which don't replay mutable effects of captured
-     * context.
-     */
-    return (
-      instrValue.place.identifier.scope != null &&
-      id >= instrValue.place.identifier.scope.range.end
-    );
+    CompilerError.invariant(instrValue.place.identifier.scope != null, {
+      reason:
+        '[PropagateScopeDependencies] Expected all context variables to be assigned a scope',
+      loc: instrValue.loc,
+    });
+    return id >= instrValue.place.identifier.scope.range.end;
   }
   return false;
 }
@@ -385,7 +371,7 @@ type Decl = {
   scope: Stack<ReactiveScope>;
 };
 
-export class DependencyCollectionContext {
+class Context {
   #declarations: Map<DeclarationId, Decl> = new Map();
   #reassignments: Map<Identifier, Decl> = new Map();
 
@@ -478,9 +464,6 @@ export class DependencyCollectionContext {
     }
     this.#reassignments.set(identifier, decl);
   }
-  hasDeclared(identifier: Identifier): boolean {
-    return this.#declarations.has(identifier.declarationId);
-  }
 
   // Checks if identifier is a valid dependency in the current scope
   #checkValidDependency(maybeDependency: ReactiveScopeDependency): boolean {
@@ -655,10 +638,7 @@ enum HIRValue {
   Terminal,
 }
 
-export function handleInstruction(
-  instr: Instruction,
-  context: DependencyCollectionContext,
-): void {
+function handleInstruction(instr: Instruction, context: Context): void {
   const {id, value, lvalue} = instr;
   context.declare(lvalue.identifier, {
     id,
@@ -682,21 +662,21 @@ export function handleInstruction(
     });
   } else if (value.kind === 'DeclareLocal' || value.kind === 'DeclareContext') {
     /*
-     * Some variables may be declared and never initialized. We need to retain
-     * (and hoist) these declarations if they are included in a reactive scope.
-     * One approach is to simply add all `DeclareLocal`s as scope declarations.
-     *
-     * Context variables with hoisted declarations only become live after their
-     * first assignment. We only declare real DeclareLocal / DeclareContext
-     * instructions (not hoisted ones) to avoid generating dependencies on
-     * hoisted declarations.
+     * Some variables may be declared and never initialized. We need
+     * to retain (and hoist) these declarations if they are included
+     * in a reactive scope. One approach is to simply add all `DeclareLocal`s
+     * as scope declarations.
      */
-    if (convertHoistedLValueKind(value.lvalue.kind) === null) {
-      context.declare(value.lvalue.place.identifier, {
-        id,
-        scope: context.currentScope,
-      });
-    }
+
+    /*
+     * We add context variable declarations here, not at `StoreContext`, since
+     * context Store / Loads are modeled as reads and mutates to the underlying
+     * variable reference (instead of through intermediate / inlined temporaries)
+     */
+    context.declare(value.lvalue.place.identifier, {
+      id,
+      scope: context.currentScope,
+    });
   } else if (value.kind === 'Destructure') {
     context.visitOperand(value.value);
     for (const place of eachPatternOperand(value.lvalue.pattern)) {
@@ -708,26 +688,6 @@ export function handleInstruction(
         scope: context.currentScope,
       });
     }
-  } else if (value.kind === 'StoreContext') {
-    /**
-     * Some StoreContext variables have hoisted declarations. If we're storing
-     * to a context variable that hasn't yet been declared, the StoreContext is
-     * the declaration.
-     * (see corresponding logic in PruneHoistedContext)
-     */
-    if (
-      !context.hasDeclared(value.lvalue.place.identifier) ||
-      value.lvalue.kind !== InstructionKind.Reassign
-    ) {
-      context.declare(value.lvalue.place.identifier, {
-        id,
-        scope: context.currentScope,
-      });
-    }
-
-    for (const operand of eachInstructionValueOperand(value)) {
-      context.visitOperand(operand);
-    }
   } else {
     for (const operand of eachInstructionValueOperand(value)) {
       context.visitOperand(operand);
@@ -741,7 +701,7 @@ function collectDependencies(
   temporaries: ReadonlyMap<IdentifierId, ReactiveScopeDependency>,
   processedInstrsInOptional: ReadonlySet<Instruction | Terminal>,
 ): Map<ReactiveScope, Array<ReactiveScopeDependency>> {
-  const context = new DependencyCollectionContext(
+  const context = new Context(
     usedOutsideDeclaringScope,
     temporaries,
     processedInstrsInOptional,

compiler/packages/babel-plugin-react-compiler/src/HIR/PruneUnusedLabelsHIR.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, GotoVariant, HIRFunction} from './HIR';
 

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

@@ -17,6 +17,7 @@ export {buildReactiveScopeTerminalsHIR} from './BuildReactiveScopeTerminalsHIR';
 export {computeDominatorTree, computePostDominatorTree} from './Dominator';
 export {
   Environment,
+  parseConfigPragmaForTests,
   validateEnvironmentConfig,
   type EnvironmentConfig,
   type ExternalFunction,

compiler/packages/babel-plugin-react-compiler/src/Inference/InerAliasForUncalledFunctions.ts

@@ -1,134 +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,
-  HIRFunction,
-  Identifier,
-  isMutableEffect,
-  isRefOrRefLikeMutableType,
-  makeInstructionId,
-} from '../HIR/HIR';
-import {eachInstructionValueOperand} from '../HIR/visitors';
-import {isMutable} from '../ReactiveScopes/InferReactiveScopeVariables';
-import DisjointSet from '../Utils/DisjointSet';
-
-/**
- * If a function captures a mutable value but never gets called, we don't infer a
- * mutable range for that function. This means that we also don't alias the function
- * with its mutable captures.
- *
- * This case is tricky, because we don't generally know for sure what is a mutation
- * and what may just be a normal function call. For example:
- *
- * ```
- * hook useFoo() {
- *   const x = makeObject();
- *   return () => {
- *     return readObject(x); // could be a mutation!
- *   }
- * }
- * ```
- *
- * If we pessimistically assume that all such cases are mutations, we'd have to group
- * lots of memo scopes together unnecessarily. However, if there is definitely a mutation:
- *
- * ```
- * hook useFoo(createEntryForKey) {
- *   const cache = new WeakMap();
- *   return (key) => {
- *     let entry = cache.get(key);
- *     if (entry == null) {
- *       entry = createEntryForKey(key);
- *       cache.set(key, entry); // known mutation!
- *     }
- *     return entry;
- *   }
- * }
- * ```
- *
- * Then we have to ensure that the function and its mutable captures alias together and
- * end up in the same scope. However, aliasing together isn't enough if the function
- * and operands all have empty mutable ranges (end = start + 1).
- *
- * This pass finds function expressions and object methods that have an empty mutable range
- * and known-mutable operands which also don't have a mutable range, and ensures that the
- * function and those operands are aliased together *and* that their ranges are updated to
- * end after the function expression. This is sufficient to ensure that a reactive scope is
- * created for the alias set.
- */
-export function inferAliasForUncalledFunctions(
-  fn: HIRFunction,
-  aliases: DisjointSet<Identifier>,
-): void {
-  for (const block of fn.body.blocks.values()) {
-    instrs: for (const instr of block.instructions) {
-      const {lvalue, value} = instr;
-      if (
-        value.kind !== 'ObjectMethod' &&
-        value.kind !== 'FunctionExpression'
-      ) {
-        continue;
-      }
-      /*
-       * If the function is known to be mutated, we will have
-       * already aliased any mutable operands with it
-       */
-      const range = lvalue.identifier.mutableRange;
-      if (range.end > range.start + 1) {
-        continue;
-      }
-      /*
-       * If the function already has operands with an active mutable range,
-       * then we don't need to do anything — the function will have already
-       * been visited and included in some mutable alias set. This case can
-       * also occur due to visiting the same function in an earlier iteration
-       * of the outer fixpoint loop.
-       */
-      for (const operand of eachInstructionValueOperand(value)) {
-        if (isMutable(instr, operand)) {
-          continue instrs;
-        }
-      }
-      const operands: Set<Identifier> = new Set();
-      for (const effect of value.loweredFunc.func.effects ?? []) {
-        if (effect.kind !== 'ContextMutation') {
-          continue;
-        }
-        /*
-         * We're looking for known-mutations only, so we look at the effects
-         * rather than function context
-         */
-        if (effect.effect === Effect.Store || effect.effect === Effect.Mutate) {
-          for (const operand of effect.places) {
-            /*
-             * It's possible that function effect analysis thinks there was a context mutation,
-             * but then InferReferenceEffects figures out some operands are globals and therefore
-             * creates a non-mutable effect for those operands.
-             * We should change InferReferenceEffects to swap the ContextMutation for a global
-             * mutation in that case, but for now we just filter them out here
-             */
-            if (
-              isMutableEffect(operand.effect, operand.loc) &&
-              !isRefOrRefLikeMutableType(operand.identifier.type)
-            ) {
-              operands.add(operand.identifier);
-            }
-          }
-        }
-      }
-      if (operands.size !== 0) {
-        operands.add(lvalue.identifier);
-        aliases.union([...operands]);
-        // Update mutable ranges, if the ranges are empty then a reactive scope isn't created
-        for (const operand of operands) {
-          operand.mutableRange.end = makeInstructionId(instr.id + 1);
-        }
-      }
-    }
-  }
-}

compiler/packages/babel-plugin-react-compiler/src/Inference/InferEffectDependencies.ts

@@ -1,11 +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 * as t from '@babel/types';
 import {CompilerError, SourceLocation} from '..';
 import {
   ArrayExpression,
@@ -22,30 +14,17 @@ import {
   ScopeId,
   ReactiveScopeDependency,
   Place,
-  ReactiveScope,
   ReactiveScopeDependencies,
-  Terminal,
   isUseRefType,
   isSetStateType,
-  isFireFunctionType,
-  makeScopeId,
 } from '../HIR';
-import {collectHoistablePropertyLoadsInInnerFn} from '../HIR/CollectHoistablePropertyLoads';
-import {collectOptionalChainSidemap} from '../HIR/CollectOptionalChainDependencies';
-import {ReactiveScopeDependencyTreeHIR} from '../HIR/DeriveMinimalDependenciesHIR';
 import {DEFAULT_EXPORT} from '../HIR/Environment';
 import {
   createTemporaryPlace,
   fixScopeAndIdentifierRanges,
   markInstructionIds,
 } from '../HIR/HIRBuilder';
-import {
-  collectTemporariesSidemap,
-  DependencyCollectionContext,
-  handleInstruction,
-} from '../HIR/PropagateScopeDependenciesHIR';
 import {eachInstructionOperand, eachTerminalOperand} from '../HIR/visitors';
-import {empty} from '../Utils/Stack';
 import {getOrInsertWith} from '../Utils/utils';
 
 /**
@@ -74,7 +53,10 @@ export function inferEffectDependencies(fn: HIRFunction): void {
   const autodepFnLoads = new Map<IdentifierId, number>();
   const autodepModuleLoads = new Map<IdentifierId, Map<string, number>>();
 
-  const scopeInfos = new Map<ScopeId, ReactiveScopeDependencies>();
+  const scopeInfos = new Map<
+    ScopeId,
+    {pruned: boolean; deps: ReactiveScopeDependencies; hasSingleInstr: boolean}
+  >();
 
   const loadGlobals = new Set<IdentifierId>();
 
@@ -88,18 +70,19 @@ export function inferEffectDependencies(fn: HIRFunction): void {
   const reactiveIds = inferReactiveIdentifiers(fn);
 
   for (const [, block] of fn.body.blocks) {
-    if (block.terminal.kind === 'scope') {
+    if (
+      block.terminal.kind === 'scope' ||
+      block.terminal.kind === 'pruned-scope'
+    ) {
       const scopeBlock = fn.body.blocks.get(block.terminal.block)!;
-      if (
-        scopeBlock.instructions.length === 1 &&
-        scopeBlock.terminal.kind === 'goto' &&
-        scopeBlock.terminal.block === block.terminal.fallthrough
-      ) {
-        scopeInfos.set(
-          block.terminal.scope.id,
-          block.terminal.scope.dependencies,
-        );
-      }
+      scopeInfos.set(block.terminal.scope.id, {
+        pruned: block.terminal.kind === 'pruned-scope',
+        deps: block.terminal.scope.dependencies,
+        hasSingleInstr:
+          scopeBlock.instructions.length === 1 &&
+          scopeBlock.terminal.kind === 'goto' &&
+          scopeBlock.terminal.block === block.terminal.fallthrough,
+      });
     }
     const rewriteInstrs = new Map<InstructionId, Array<Instruction>>();
     for (const instr of block.instructions) {
@@ -181,12 +164,22 @@ export function inferEffectDependencies(fn: HIRFunction): void {
               fnExpr.lvalue.identifier.scope != null
                 ? scopeInfos.get(fnExpr.lvalue.identifier.scope.id)
                 : null;
-            let minimalDeps: Set<ReactiveScopeDependency>;
-            if (scopeInfo != null) {
-              minimalDeps = new Set(scopeInfo);
-            } else {
-              minimalDeps = inferMinimalDependencies(fnExpr);
+            CompilerError.invariant(scopeInfo != null, {
+              reason: 'Expected function expression scope to exist',
+              loc: value.loc,
+            });
+            if (scopeInfo.pruned || !scopeInfo.hasSingleInstr) {
+              /**
+               * TODO: retry pipeline that ensures effect function expressions
+               * are placed into their own scope
+               */
+              CompilerError.throwTodo({
+                reason:
+                  '[InferEffectDependencies] Expected effect function to have non-pruned scope and its scope to have exactly one instruction',
+                loc: fnExpr.loc,
+              });
             }
+
             /**
              * Step 1: push dependencies to the effect deps array
              *
@@ -194,14 +187,11 @@ export function inferEffectDependencies(fn: HIRFunction): void {
              * the `infer-effect-deps/pruned-nonreactive-obj` fixture for an
              * explanation.
              */
-
-            const usedDeps = [];
-            for (const dep of minimalDeps) {
+            for (const dep of scopeInfo.deps) {
               if (
-                ((isUseRefType(dep.identifier) ||
+                (isUseRefType(dep.identifier) ||
                   isSetStateType(dep.identifier)) &&
-                  !reactiveIds.has(dep.identifier.id)) ||
-                isFireFunctionType(dep.identifier)
+                !reactiveIds.has(dep.identifier.id)
               ) {
                 // exclude non-reactive hook results, which will never be in a memo block
                 continue;
@@ -215,23 +205,6 @@ export function inferEffectDependencies(fn: HIRFunction): void {
               );
               newInstructions.push(...instructions);
               effectDeps.push(place);
-              usedDeps.push(dep);
-            }
-
-            // For LSP autodeps feature.
-            const decorations: Array<t.SourceLocation> = [];
-            for (const loc of collectDepUsages(usedDeps, fnExpr.value)) {
-              if (typeof loc === 'symbol') {
-                continue;
-              }
-              decorations.push(loc);
-            }
-            if (typeof value.loc !== 'symbol') {
-              fn.env.logger?.logEvent(fn.env.filename, {
-                kind: 'AutoDepsDecorations',
-                fnLoc: value.loc,
-                decorations,
-              });
             }
 
             newInstructions.push({
@@ -257,31 +230,6 @@ export function inferEffectDependencies(fn: HIRFunction): void {
             rewriteInstrs.set(instr.id, newInstructions);
             fn.env.inferredEffectLocations.add(callee.loc);
           }
-        } else if (
-          value.args.length >= 2 &&
-          value.args.length - 1 === autodepFnLoads.get(callee.identifier.id) &&
-          value.args[0] != null &&
-          value.args[0].kind === 'Identifier'
-        ) {
-          const penultimateArg = value.args[value.args.length - 2];
-          const depArrayArg = value.args[value.args.length - 1];
-          if (
-            depArrayArg.kind !== 'Spread' &&
-            penultimateArg.kind !== 'Spread' &&
-            typeof depArrayArg.loc !== 'symbol' &&
-            typeof penultimateArg.loc !== 'symbol' &&
-            typeof value.loc !== 'symbol'
-          ) {
-            fn.env.logger?.logEvent(fn.env.filename, {
-              kind: 'AutoDepsEligible',
-              fnLoc: value.loc,
-              depArrayLoc: {
-                ...depArrayArg.loc,
-                start: penultimateArg.loc.end,
-                end: depArrayArg.loc.end,
-              },
-            });
-          }
         }
       }
     }
@@ -390,163 +338,3 @@ function inferReactiveIdentifiers(fn: HIRFunction): Set<IdentifierId> {
   }
   return reactiveIds;
 }
-
-function collectDepUsages(
-  deps: Array<ReactiveScopeDependency>,
-  fnExpr: FunctionExpression,
-): Array<SourceLocation> {
-  const identifiers: Map<IdentifierId, ReactiveScopeDependency> = new Map();
-  const loadedDeps: Set<IdentifierId> = new Set();
-  const sourceLocations = [];
-  for (const dep of deps) {
-    identifiers.set(dep.identifier.id, dep);
-  }
-
-  for (const [, block] of fnExpr.loweredFunc.func.body.blocks) {
-    for (const instr of block.instructions) {
-      if (
-        instr.value.kind === 'LoadLocal' &&
-        identifiers.has(instr.value.place.identifier.id)
-      ) {
-        loadedDeps.add(instr.lvalue.identifier.id);
-      }
-      for (const place of eachInstructionOperand(instr)) {
-        if (loadedDeps.has(place.identifier.id)) {
-          // TODO(@jbrown215): handle member exprs!!
-          sourceLocations.push(place.identifier.loc);
-        }
-      }
-    }
-  }
-
-  return sourceLocations;
-}
-
-function inferMinimalDependencies(
-  fnInstr: TInstruction<FunctionExpression>,
-): Set<ReactiveScopeDependency> {
-  const fn = fnInstr.value.loweredFunc.func;
-
-  const temporaries = collectTemporariesSidemap(fn, new Set());
-  const {
-    hoistableObjects,
-    processedInstrsInOptional,
-    temporariesReadInOptional,
-  } = collectOptionalChainSidemap(fn);
-
-  const hoistablePropertyLoads = collectHoistablePropertyLoadsInInnerFn(
-    fnInstr,
-    temporaries,
-    hoistableObjects,
-  );
-  const hoistableToFnEntry = hoistablePropertyLoads.get(fn.body.entry);
-  CompilerError.invariant(hoistableToFnEntry != null, {
-    reason:
-      '[InferEffectDependencies] Internal invariant broken: missing entry block',
-    loc: fnInstr.loc,
-  });
-
-  const dependencies = inferDependencies(
-    fnInstr,
-    new Map([...temporaries, ...temporariesReadInOptional]),
-    processedInstrsInOptional,
-  );
-
-  const tree = new ReactiveScopeDependencyTreeHIR(
-    [...hoistableToFnEntry.assumedNonNullObjects].map(o => o.fullPath),
-  );
-  for (const dep of dependencies) {
-    tree.addDependency({...dep});
-  }
-
-  return tree.deriveMinimalDependencies();
-}
-
-function inferDependencies(
-  fnInstr: TInstruction<FunctionExpression>,
-  temporaries: ReadonlyMap<IdentifierId, ReactiveScopeDependency>,
-  processedInstrsInOptional: ReadonlySet<Instruction | Terminal>,
-): Set<ReactiveScopeDependency> {
-  const fn = fnInstr.value.loweredFunc.func;
-  const context = new DependencyCollectionContext(
-    new Set(),
-    temporaries,
-    processedInstrsInOptional,
-  );
-  for (const dep of fn.context) {
-    context.declare(dep.identifier, {
-      id: makeInstructionId(0),
-      scope: empty(),
-    });
-  }
-  const placeholderScope: ReactiveScope = {
-    id: makeScopeId(0),
-    range: {
-      start: fnInstr.id,
-      end: makeInstructionId(fnInstr.id + 1),
-    },
-    dependencies: new Set(),
-    reassignments: new Set(),
-    declarations: new Map(),
-    earlyReturnValue: null,
-    merged: new Set(),
-    loc: GeneratedSource,
-  };
-  context.enterScope(placeholderScope);
-  inferDependenciesInFn(fn, context, temporaries);
-  context.exitScope(placeholderScope, false);
-  const resultUnfiltered = context.deps.get(placeholderScope);
-  CompilerError.invariant(resultUnfiltered != null, {
-    reason:
-      '[InferEffectDependencies] Internal invariant broken: missing scope dependencies',
-    loc: fn.loc,
-  });
-
-  const fnContext = new Set(fn.context.map(dep => dep.identifier.id));
-  const result = new Set<ReactiveScopeDependency>();
-  for (const dep of resultUnfiltered) {
-    if (fnContext.has(dep.identifier.id)) {
-      result.add(dep);
-    }
-  }
-
-  return result;
-}
-
-function inferDependenciesInFn(
-  fn: HIRFunction,
-  context: DependencyCollectionContext,
-  temporaries: ReadonlyMap<IdentifierId, ReactiveScopeDependency>,
-): void {
-  for (const [, block] of fn.body.blocks) {
-    // Record referenced optional chains in phis
-    for (const phi of block.phis) {
-      for (const operand of phi.operands) {
-        const maybeOptionalChain = temporaries.get(operand[1].identifier.id);
-        if (maybeOptionalChain) {
-          context.visitDependency(maybeOptionalChain);
-        }
-      }
-    }
-    for (const instr of block.instructions) {
-      if (
-        instr.value.kind === 'FunctionExpression' ||
-        instr.value.kind === 'ObjectMethod'
-      ) {
-        context.declare(instr.lvalue.identifier, {
-          id: instr.id,
-          scope: context.currentScope,
-        });
-        /**
-         * Recursively visit the inner function to extract dependencies
-         */
-        const innerFn = instr.value.loweredFunc.func;
-        context.enterInnerFn(instr as TInstruction<FunctionExpression>, () => {
-          inferDependenciesInFn(innerFn, context, temporaries);
-        });
-      } else {
-        handleInstruction(instr, context);
-      }
-    }
-  }
-}

compiler/packages/babel-plugin-react-compiler/src/Inference/InferMutableLifetimes.ts

@@ -176,15 +176,9 @@ export function inferMutableLifetimes(
       if (
         instr.value.kind === 'DeclareContext' ||
         (instr.value.kind === 'StoreContext' &&
-          instr.value.lvalue.kind !== InstructionKind.Reassign &&
-          !contextVariableDeclarationInstructions.has(
-            instr.value.lvalue.place.identifier,
-          ))
+          instr.value.lvalue.kind !== InstructionKind.Reassign)
       ) {
-        /**
-         * Save declarations of context variables if they hasn't already been
-         * declared (due to hoisted declarations).
-         */
+        // Save declarations of context variables
         contextVariableDeclarationInstructions.set(
           instr.value.lvalue.place.identifier,
           instr.id,

compiler/packages/babel-plugin-react-compiler/src/Inference/InferMutableRanges.ts

@@ -6,7 +6,6 @@
  */
 
 import {HIRFunction, Identifier} from '../HIR/HIR';
-import {inferAliasForUncalledFunctions} from './InerAliasForUncalledFunctions';
 import {inferAliases} from './InferAlias';
 import {inferAliasForPhis} from './InferAliasForPhis';
 import {inferAliasForStores} from './InferAliasForStores';
@@ -77,7 +76,6 @@ export function inferMutableRanges(ir: HIRFunction): void {
   while (true) {
     inferMutableRangesForAlias(ir, aliases);
     inferAliasForPhis(ir, aliases);
-    inferAliasForUncalledFunctions(ir, aliases);
     const nextAliases = aliases.canonicalize();
     if (areEqualMaps(prevAliases, nextAliases)) {
       break;

compiler/packages/babel-plugin-react-compiler/src/Inference/InferReactivePlaces.ts

@@ -9,19 +9,14 @@ import {CompilerError} from '..';
 import {
   BlockId,
   Effect,
-  Environment,
   HIRFunction,
   Identifier,
   IdentifierId,
-  Instruction,
   Place,
   computePostDominatorTree,
-  evaluatesToStableTypeOrContainer,
   getHookKind,
   isStableType,
-  isStableTypeContainer,
   isUseOperator,
-  isUseRefType,
 } from '../HIR';
 import {PostDominator} from '../HIR/Dominator';
 import {
@@ -36,103 +31,6 @@ import {
 import DisjointSet from '../Utils/DisjointSet';
 import {assertExhaustive} from '../Utils/utils';
 
-/**
- * Side map to track and propagate sources of stability (i.e. hook calls such as
- * `useRef()` and property reads such as `useState()[1]). Note that this
- * requires forward data flow analysis since stability is not part of React
- * Compiler's type system.
- */
-class StableSidemap {
-  map: Map<IdentifierId, {isStable: boolean}> = new Map();
-  env: Environment;
-
-  constructor(env: Environment) {
-    this.env = env;
-  }
-
-  handleInstruction(instr: Instruction): void {
-    const {value, lvalue} = instr;
-
-    switch (value.kind) {
-      case 'CallExpression':
-      case 'MethodCall': {
-        /**
-         * Sources of stability are known hook calls
-         */
-        if (evaluatesToStableTypeOrContainer(this.env, instr)) {
-          if (isStableType(lvalue.identifier)) {
-            this.map.set(lvalue.identifier.id, {
-              isStable: true,
-            });
-          } else {
-            this.map.set(lvalue.identifier.id, {
-              isStable: false,
-            });
-          }
-        } else if (
-          this.env.config.enableTreatRefLikeIdentifiersAsRefs &&
-          isUseRefType(lvalue.identifier)
-        ) {
-          this.map.set(lvalue.identifier.id, {
-            isStable: true,
-          });
-        }
-        break;
-      }
-
-      case 'Destructure':
-      case 'PropertyLoad': {
-        /**
-         * PropertyLoads may from stable containers may also produce stable
-         * values. ComputedLoads are technically safe for now (as all stable
-         * containers have differently-typed elements), but are not handled as
-         * they should be rare anyways.
-         */
-        const source =
-          value.kind === 'Destructure'
-            ? value.value.identifier.id
-            : value.object.identifier.id;
-        const entry = this.map.get(source);
-        if (entry) {
-          for (const lvalue of eachInstructionLValue(instr)) {
-            if (isStableTypeContainer(lvalue.identifier)) {
-              this.map.set(lvalue.identifier.id, {
-                isStable: false,
-              });
-            } else if (isStableType(lvalue.identifier)) {
-              this.map.set(lvalue.identifier.id, {
-                isStable: true,
-              });
-            }
-          }
-        }
-        break;
-      }
-
-      case 'StoreLocal': {
-        const entry = this.map.get(value.value.identifier.id);
-        if (entry) {
-          this.map.set(lvalue.identifier.id, entry);
-          this.map.set(value.lvalue.place.identifier.id, entry);
-        }
-        break;
-      }
-
-      case 'LoadLocal': {
-        const entry = this.map.get(value.place.identifier.id);
-        if (entry) {
-          this.map.set(lvalue.identifier.id, entry);
-        }
-        break;
-      }
-    }
-  }
-
-  isStable(id: IdentifierId): boolean {
-    const entry = this.map.get(id);
-    return entry != null ? entry.isStable : false;
-  }
-}
 /*
  * Infers which `Place`s are reactive, ie may *semantically* change
  * over the course of the component/hook's lifetime. Places are reactive
@@ -213,7 +111,6 @@ class StableSidemap {
  */
 export function inferReactivePlaces(fn: HIRFunction): void {
   const reactiveIdentifiers = new ReactivityMap(findDisjointMutableValues(fn));
-  const stableIdentifierSources = new StableSidemap(fn.env);
   for (const param of fn.params) {
     const place = param.kind === 'Identifier' ? param : param.place;
     reactiveIdentifiers.markReactive(place);
@@ -287,7 +184,6 @@ export function inferReactivePlaces(fn: HIRFunction): void {
         }
       }
       for (const instruction of block.instructions) {
-        stableIdentifierSources.handleInstruction(instruction);
         const {value} = instruction;
         let hasReactiveInput = false;
         /*
@@ -322,13 +218,7 @@ export function inferReactivePlaces(fn: HIRFunction): void {
 
         if (hasReactiveInput) {
           for (const lvalue of eachInstructionLValue(instruction)) {
-            /**
-             * Note that it's not correct to mark all stable-typed identifiers
-             * as non-reactive, since ternaries and other value blocks can
-             * produce reactive identifiers typed as these.
-             * (e.g. `props.cond ? setState1 : setState2`)
-             */
-            if (stableIdentifierSources.isStable(lvalue.identifier.id)) {
+            if (isStableType(lvalue.identifier)) {
               continue;
             }
             reactiveIdentifiers.markReactive(lvalue);

compiler/packages/babel-plugin-react-compiler/src/Inference/InferReferenceEffects.ts

@@ -111,10 +111,7 @@ export default function inferReferenceEffects(
    * Initial state contains function params
    * TODO: include module declarations here as well
    */
-  const initialState = InferenceState.empty(
-    fn.env,
-    options.isFunctionExpression,
-  );
+  const initialState = InferenceState.empty(fn.env);
   const value: InstructionValue = {
     kind: 'Primitive',
     loc: fn.loc,
@@ -258,7 +255,6 @@ type FreezeAction = {values: Set<InstructionValue>; reason: Set<ValueReason>};
 // Maintains a mapping of top-level variables to the kind of value they hold
 class InferenceState {
   env: Environment;
-  #isFunctionExpression: boolean;
 
   // The kind of each value, based on its allocation site
   #values: Map<InstructionValue, AbstractValue>;
@@ -271,25 +267,16 @@ class InferenceState {
 
   constructor(
     env: Environment,
-    isFunctionExpression: boolean,
     values: Map<InstructionValue, AbstractValue>,
     variables: Map<IdentifierId, Set<InstructionValue>>,
   ) {
     this.env = env;
-    this.#isFunctionExpression = isFunctionExpression;
     this.#values = values;
     this.#variables = variables;
   }
 
-  static empty(
-    env: Environment,
-    isFunctionExpression: boolean,
-  ): InferenceState {
-    return new InferenceState(env, isFunctionExpression, new Map(), new Map());
-  }
-
-  get isFunctionExpression(): boolean {
-    return this.#isFunctionExpression;
+  static empty(env: Environment): InferenceState {
+    return new InferenceState(env, new Map(), new Map());
   }
 
   // (Re)initializes a @param value with its default @param kind.
@@ -407,14 +394,9 @@ class InferenceState {
 
   freezeValues(values: Set<InstructionValue>, reason: Set<ValueReason>): void {
     for (const value of values) {
-      if (
-        value.kind === 'DeclareContext' ||
-        (value.kind === 'StoreContext' &&
-          (value.lvalue.kind === InstructionKind.Let ||
-            value.lvalue.kind === InstructionKind.Const))
-      ) {
+      if (value.kind === 'DeclareContext') {
         /**
-         * Avoid freezing context variable declarations, hoisted or otherwise
+         * Avoid freezing hoisted context declarations
          * function Component() {
          *   const cb = useBar(() => foo(2)); // produces a hoisted context declaration
          *   const foo = useFoo();            // reassigns to the context variable
@@ -631,7 +613,6 @@ class InferenceState {
     } else {
       return new InferenceState(
         this.env,
-        this.#isFunctionExpression,
         nextValues ?? new Map(this.#values),
         nextVariables ?? new Map(this.#variables),
       );
@@ -646,7 +627,6 @@ class InferenceState {
   clone(): InferenceState {
     return new InferenceState(
       this.env,
-      this.#isFunctionExpression,
       new Map(this.#values),
       new Map(this.#variables),
     );
@@ -1611,14 +1591,6 @@ function inferBlock(
         );
 
         const lvalue = instr.lvalue;
-        if (instrValue.lvalue.kind !== InstructionKind.Reassign) {
-          state.initialize(instrValue, {
-            kind: ValueKind.Mutable,
-            reason: new Set([ValueReason.Other]),
-            context: new Set(),
-          });
-          state.define(instrValue.lvalue.place, instrValue);
-        }
         state.alias(lvalue, instrValue.value);
         lvalue.effect = Effect.Store;
         continuation = {kind: 'funeffects'};
@@ -1809,15 +1781,8 @@ function inferBlock(
     if (block.terminal.kind === 'return' || block.terminal.kind === 'throw') {
       if (
         state.isDefined(operand) &&
-        ((operand.identifier.type.kind === 'Function' &&
-          state.isFunctionExpression) ||
-          state.kind(operand).kind === ValueKind.Context)
+        state.kind(operand).kind === ValueKind.Context
       ) {
-        /**
-         * Returned values should only be typed as 'frozen' if they are both (1)
-         * local and (2) not a function expression which may capture and mutate
-         * this function's outer context.
-         */
         effect = Effect.ConditionallyMutate;
       } else {
         effect = Effect.Freeze;

compiler/packages/babel-plugin-react-compiler/src/Optimization/ConstantPropagation.ts

@@ -327,23 +327,6 @@ function evaluateInstruction(
           }
           return null;
         }
-        case '-': {
-          const operand = read(constants, value.value);
-          if (
-            operand !== null &&
-            operand.kind === 'Primitive' &&
-            typeof operand.value === 'number'
-          ) {
-            const result: Primitive = {
-              kind: 'Primitive',
-              value: operand.value * -1,
-              loc: value.loc,
-            };
-            instr.value = result;
-            return result;
-          }
-          return null;
-        }
         default:
           return null;
       }
@@ -509,73 +492,6 @@ function evaluateInstruction(
       }
       return null;
     }
-    case 'TemplateLiteral': {
-      if (value.subexprs.length === 0) {
-        const result: InstructionValue = {
-          kind: 'Primitive',
-          value: value.quasis.map(q => q.cooked).join(''),
-          loc: value.loc,
-        };
-        instr.value = result;
-        return result;
-      }
-
-      if (value.subexprs.length !== value.quasis.length - 1) {
-        return null;
-      }
-
-      if (value.quasis.some(q => q.cooked === undefined)) {
-        return null;
-      }
-
-      let quasiIndex = 0;
-      let resultString = value.quasis[quasiIndex].cooked as string;
-      ++quasiIndex;
-
-      for (const subExpr of value.subexprs) {
-        const subExprValue = read(constants, subExpr);
-        if (!subExprValue || subExprValue.kind !== 'Primitive') {
-          return null;
-        }
-
-        const expressionValue = subExprValue.value;
-        if (
-          typeof expressionValue !== 'number' &&
-          typeof expressionValue !== 'string' &&
-          typeof expressionValue !== 'boolean' &&
-          !(typeof expressionValue === 'object' && expressionValue === null)
-        ) {
-          // value is not supported (function, object) or invalid (symbol), or something else
-          return null;
-        }
-
-        const suffix = value.quasis[quasiIndex].cooked;
-        ++quasiIndex;
-
-        if (suffix === undefined) {
-          return null;
-        }
-
-        /*
-         * Spec states that concat calls ToString(argument) internally on its parameters
-         * -> we don't have to implement ToString(argument) ourselves and just use the engine implementation
-         * Refs:
-         *  - https://tc39.es/ecma262/2024/#sec-tostring
-         *  - https://tc39.es/ecma262/2024/#sec-string.prototype.concat
-         *  - https://tc39.es/ecma262/2024/#sec-template-literals-runtime-semantics-evaluation
-         */
-        resultString = resultString.concat(expressionValue as string, suffix);
-      }
-
-      const result: InstructionValue = {
-        kind: 'Primitive',
-        value: resultString,
-        loc: value.loc,
-      };
-
-      instr.value = result;
-      return result;
-    }
     case 'LoadLocal': {
       const placeValue = read(constants, value.place);
       if (placeValue !== null) {

compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/CodegenReactiveFunction.ts

@@ -1000,14 +1000,6 @@ function codegenTerminal(
           lval = codegenLValue(cx, iterableItem.value.lvalue.pattern);
           break;
         }
-        case 'StoreContext': {
-          CompilerError.throwTodo({
-            reason: 'Support non-trivial for..in inits',
-            description: null,
-            loc: terminal.init.loc,
-            suggestions: null,
-          });
-        }
         default:
           CompilerError.invariant(false, {
             reason: `Expected a StoreLocal or Destructure to be assigned to the collection`,
@@ -1100,14 +1092,6 @@ function codegenTerminal(
           lval = codegenLValue(cx, iterableItem.value.lvalue.pattern);
           break;
         }
-        case 'StoreContext': {
-          CompilerError.throwTodo({
-            reason: 'Support non-trivial for..of inits',
-            description: null,
-            loc: terminal.init.loc,
-            suggestions: null,
-          });
-        }
         default:
           CompilerError.invariant(false, {
             reason: `Expected a StoreLocal or Destructure to be assigned to the collection`,
@@ -2131,17 +2115,10 @@ function codegenInstructionValue(
     }
     case 'TypeCastExpression': {
       if (t.isTSType(instrValue.typeAnnotation)) {
-        if (instrValue.typeAnnotationKind === 'satisfies') {
-          value = t.tsSatisfiesExpression(
-            codegenPlaceToExpression(cx, instrValue.value),
-            instrValue.typeAnnotation,
-          );
-        } else {
-          value = t.tsAsExpression(
-            codegenPlaceToExpression(cx, instrValue.value),
-            instrValue.typeAnnotation,
-          );
-        }
+        value = t.tsAsExpression(
+          codegenPlaceToExpression(cx, instrValue.value),
+          instrValue.typeAnnotation,
+        );
       } else {
         value = t.typeCastExpression(
           codegenPlaceToExpression(cx, instrValue.value),
@@ -2327,12 +2304,9 @@ function codegenInstructionValue(
  * u0080 to u009F: C1 control codes
  * u00A0 to uFFFF: All non-basic Latin characters
  * https://en.wikipedia.org/wiki/List_of_Unicode_characters#Control_codes
- *
- * u010000 to u10FFFF: Astral plane characters
- * https://mathiasbynens.be/notes/javascript-unicode
  */
 const STRING_REQUIRES_EXPR_CONTAINER_PATTERN =
-  /[\u{0000}-\u{001F}\u{007F}\u{0080}-\u{FFFF}\u{010000}-\u{10FFFF}]|"|\\/u;
+  /[\u{0000}-\u{001F}\u{007F}\u{0080}-\u{FFFF}]|"|\\/u;
 function codegenJsxAttribute(
   cx: Context,
   attribute: JsxAttribute,

compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/PrintReactiveFunction.ts

@@ -255,12 +255,6 @@ function writeReactiveValue(writer: Writer, value: ReactiveValue): void {
   }
 }
 
-export function printReactiveTerminal(terminal: ReactiveTerminal): string {
-  const writer = new Writer();
-  writeTerminal(writer, terminal);
-  return writer.complete();
-}
-
 function writeTerminal(writer: Writer, terminal: ReactiveTerminal): void {
   switch (terminal.kind) {
     case 'break': {

compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/PruneHoistedContexts.ts

@@ -7,17 +7,12 @@
 
 import {CompilerError} from '..';
 import {
-  convertHoistedLValueKind,
-  IdentifierId,
-  InstructionId,
+  DeclarationId,
   InstructionKind,
-  Place,
   ReactiveFunction,
   ReactiveInstruction,
-  ReactiveScopeBlock,
   ReactiveStatement,
 } from '../HIR';
-import {empty, Stack} from '../Utils/Stack';
 import {
   ReactiveFunctionTransform,
   Transformed,
@@ -27,144 +22,138 @@ import {
 /*
  * Prunes DeclareContexts lowered for HoistedConsts, and transforms any references back to its
  * original instruction kind.
- *
- * Also detects and bails out on context variables which are:
- * - function declarations, which are hoisted by JS engines to the nearest block scope
- * - referenced before they are defined (i.e. having a `DeclareContext HoistedConst`)
- * - declared
- *
- * This is because React Compiler converts a `function foo()` function declaration to
- * 1. a `let foo;` declaration before reactive memo blocks
- * 2. a `foo = function foo() {}` assignment within the block
- *
- * This means references before the assignment are invalid (see fixture
- * error.todo-functiondecl-hoisting)
  */
 export function pruneHoistedContexts(fn: ReactiveFunction): void {
-  visitReactiveFunction(fn, new Visitor(), {
-    activeScopes: empty(),
-    uninitialized: new Map(),
-  });
+  const hoistedIdentifiers: HoistedIdentifiers = new Map();
+  visitReactiveFunction(fn, new Visitor(), hoistedIdentifiers);
 }
 
-type VisitorState = {
-  activeScopes: Stack<Set<IdentifierId>>;
-  uninitialized: Map<
-    IdentifierId,
-    | {
-        kind: 'unknown-kind';
-      }
-    | {
-        kind: 'func';
-        definition: Place | null;
-      }
-  >;
-};
+const REWRITTEN_HOISTED_CONST: unique symbol = Symbol(
+  'REWRITTEN_HOISTED_CONST',
+);
+const REWRITTEN_HOISTED_LET: unique symbol = Symbol('REWRITTEN_HOISTED_LET');
 
-class Visitor extends ReactiveFunctionTransform<VisitorState> {
-  override visitScope(scope: ReactiveScopeBlock, state: VisitorState): void {
-    state.activeScopes = state.activeScopes.push(
-      new Set(scope.scope.declarations.keys()),
-    );
-    /**
-     * Add declared but not initialized / assigned variables. This may include
-     * function declarations that escape the memo block.
-     */
-    for (const decl of scope.scope.declarations.values()) {
-      state.uninitialized.set(decl.identifier.id, {kind: 'unknown-kind'});
-    }
-    this.traverseScope(scope, state);
-    state.activeScopes.pop();
-    for (const decl of scope.scope.declarations.values()) {
-      state.uninitialized.delete(decl.identifier.id);
-    }
-  }
-  override visitPlace(
-    _id: InstructionId,
-    place: Place,
-    state: VisitorState,
-  ): void {
-    const maybeHoistedFn = state.uninitialized.get(place.identifier.id);
-    if (
-      maybeHoistedFn?.kind === 'func' &&
-      maybeHoistedFn.definition !== place
-    ) {
-      CompilerError.throwTodo({
-        reason: '[PruneHoistedContexts] Rewrite hoisted function references',
-        loc: place.loc,
-      });
-    }
-  }
+type HoistedIdentifiers = Map<
+  DeclarationId,
+  | InstructionKind
+  | typeof REWRITTEN_HOISTED_CONST
+  | typeof REWRITTEN_HOISTED_LET
+>;
+
+class Visitor extends ReactiveFunctionTransform<HoistedIdentifiers> {
   override transformInstruction(
     instruction: ReactiveInstruction,
-    state: VisitorState,
+    state: HoistedIdentifiers,
   ): Transformed<ReactiveStatement> {
+    this.visitInstruction(instruction, state);
+
     /**
      * Remove hoisted declarations to preserve TDZ
      */
-    if (instruction.value.kind === 'DeclareContext') {
-      const maybeNonHoisted = convertHoistedLValueKind(
-        instruction.value.lvalue.kind,
-      );
-      if (maybeNonHoisted != null) {
-        if (
-          maybeNonHoisted === InstructionKind.Function &&
-          state.uninitialized.has(instruction.value.lvalue.place.identifier.id)
-        ) {
-          state.uninitialized.set(
-            instruction.value.lvalue.place.identifier.id,
-            {
-              kind: 'func',
-              definition: null,
-            },
-          );
-        }
-        return {kind: 'remove'};
-      }
-    }
     if (
-      instruction.value.kind === 'StoreContext' &&
-      instruction.value.lvalue.kind !== InstructionKind.Reassign
+      instruction.value.kind === 'DeclareContext' &&
+      instruction.value.lvalue.kind === 'HoistedConst'
     ) {
-      /**
-       * Rewrite StoreContexts let/const that will be pre-declared in
-       * codegen to reassignments.
-       */
-      const lvalueId = instruction.value.lvalue.place.identifier.id;
-      const isDeclaredByScope = state.activeScopes.find(scope =>
-        scope.has(lvalueId),
+      state.set(
+        instruction.value.lvalue.place.identifier.declarationId,
+        InstructionKind.Const,
       );
-      if (isDeclaredByScope) {
+      return {kind: 'remove'};
+    }
+
+    if (
+      instruction.value.kind === 'DeclareContext' &&
+      instruction.value.lvalue.kind === 'HoistedLet'
+    ) {
+      state.set(
+        instruction.value.lvalue.place.identifier.declarationId,
+        InstructionKind.Let,
+      );
+      return {kind: 'remove'};
+    }
+
+    if (
+      instruction.value.kind === 'DeclareContext' &&
+      instruction.value.lvalue.kind === 'HoistedFunction'
+    ) {
+      state.set(
+        instruction.value.lvalue.place.identifier.declarationId,
+        InstructionKind.Function,
+      );
+      return {kind: 'remove'};
+    }
+
+    if (instruction.value.kind === 'StoreContext') {
+      const kind = state.get(
+        instruction.value.lvalue.place.identifier.declarationId,
+      );
+      if (kind != null) {
+        CompilerError.invariant(kind !== REWRITTEN_HOISTED_CONST, {
+          reason: 'Expected exactly one store to a hoisted const variable',
+          loc: instruction.loc,
+        });
         if (
-          instruction.value.lvalue.kind === InstructionKind.Let ||
-          instruction.value.lvalue.kind === InstructionKind.Const
+          kind === InstructionKind.Const ||
+          kind === InstructionKind.Function
         ) {
-          instruction.value.lvalue.kind = InstructionKind.Reassign;
-        } else if (instruction.value.lvalue.kind === InstructionKind.Function) {
-          const maybeHoistedFn = state.uninitialized.get(lvalueId);
-          if (maybeHoistedFn != null) {
-            CompilerError.invariant(maybeHoistedFn.kind === 'func', {
-              reason: '[PruneHoistedContexts] Unexpected hoisted function',
-              loc: instruction.loc,
-            });
-            maybeHoistedFn.definition = instruction.value.lvalue.place;
-            /**
-             * References to hoisted functions are now "safe" as variable assignments
-             * have finished.
-             */
-            state.uninitialized.delete(lvalueId);
-          }
-        } else {
-          CompilerError.throwTodo({
-            reason: '[PruneHoistedContexts] Unexpected kind',
-            description: `(${instruction.value.lvalue.kind})`,
-            loc: instruction.loc,
-          });
+          state.set(
+            instruction.value.lvalue.place.identifier.declarationId,
+            REWRITTEN_HOISTED_CONST,
+          );
+          return {
+            kind: 'replace',
+            value: {
+              kind: 'instruction',
+              instruction: {
+                ...instruction,
+                value: {
+                  ...instruction.value,
+                  lvalue: {
+                    ...instruction.value.lvalue,
+                    kind,
+                  },
+                  type: null,
+                  kind: 'StoreLocal',
+                },
+              },
+            },
+          };
+        } else if (kind !== REWRITTEN_HOISTED_LET) {
+          /**
+           * Context variables declared with let may have reassignments. Only
+           * insert a `DeclareContext` for the first encountered `StoreContext`
+           * instruction.
+           */
+          state.set(
+            instruction.value.lvalue.place.identifier.declarationId,
+            REWRITTEN_HOISTED_LET,
+          );
+          return {
+            kind: 'replace-many',
+            value: [
+              {
+                kind: 'instruction',
+                instruction: {
+                  id: instruction.id,
+                  lvalue: null,
+                  value: {
+                    kind: 'DeclareContext',
+                    lvalue: {
+                      kind: InstructionKind.Let,
+                      place: {...instruction.value.lvalue.place},
+                    },
+                    loc: instruction.value.loc,
+                  },
+                  loc: instruction.loc,
+                },
+              },
+              {kind: 'instruction', instruction},
+            ],
+          };
         }
       }
     }
 
-    this.visitInstruction(instruction, state);
     return {kind: 'keep'};
   }
 }

compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/StabilizeBlockIds.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 {
   BlockId,
   ReactiveFunction,

compiler/packages/babel-plugin-react-compiler/src/Transform/TransformFire.ts

@@ -34,11 +34,7 @@ import {
 } from '../HIR';
 import {createTemporaryPlace, markInstructionIds} from '../HIR/HIRBuilder';
 import {getOrInsertWith} from '../Utils/utils';
-import {
-  BuiltInFireFunctionId,
-  BuiltInFireId,
-  DefaultNonmutatingHook,
-} from '../HIR/ObjectShape';
+import {BuiltInFireId, DefaultNonmutatingHook} from '../HIR/ObjectShape';
 import {eachInstructionOperand} from '../HIR/visitors';
 import {printSourceLocationLine} from '../HIR/PrintHIR';
 import {USE_FIRE_FUNCTION_NAME} from '../HIR/Environment';
@@ -637,13 +633,6 @@ class Context {
       () => createTemporaryPlace(this.#env, GeneratedSource),
     );
 
-    fireFunctionBinding.identifier.type = {
-      kind: 'Function',
-      shapeId: BuiltInFireFunctionId,
-      return: {kind: 'Poly'},
-      isConstructor: false,
-    };
-
     this.#capturedCalleeIdentifierIds.set(callee.identifier.id, {
       fireFunctionBinding,
       capturedCalleeIdentifier: callee.identifier,

compiler/packages/babel-plugin-react-compiler/src/Transform/index.ts

@@ -4,5 +4,4 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
-
 export {transformFire} from './TransformFire';

compiler/packages/babel-plugin-react-compiler/src/Utils/TestUtils.ts

@@ -1,210 +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 {fromZodError} from 'zod-validation-error';
-import {CompilerError} from '../CompilerError';
-import {
-  CompilationMode,
-  defaultOptions,
-  parsePluginOptions,
-  PluginOptions,
-} from '../Entrypoint';
-import {EnvironmentConfig} from '..';
-import {
-  EnvironmentConfigSchema,
-  PartialEnvironmentConfig,
-} from '../HIR/Environment';
-import {Err, Ok, Result} from './Result';
-import {hasOwnProperty} from './utils';
-
-function tryParseTestPragmaValue(val: string): Result<unknown, unknown> {
-  try {
-    let parsedVal: unknown;
-    const stringMatch = /^"([^"]*)"$/.exec(val);
-    if (stringMatch && stringMatch.length > 1) {
-      parsedVal = stringMatch[1];
-    } else {
-      parsedVal = JSON.parse(val);
-    }
-    return Ok(parsedVal);
-  } catch (e) {
-    return Err(e);
-  }
-}
-
-const testComplexConfigDefaults: PartialEnvironmentConfig = {
-  validateNoCapitalizedCalls: [],
-  enableChangeDetectionForDebugging: {
-    source: 'react-compiler-runtime',
-    importSpecifierName: '$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: Partial<Record<keyof EnvironmentConfig, unknown>> = {};
-
-  for (const token of pragma.split(' ')) {
-    if (!token.startsWith('@')) {
-      continue;
-    }
-    const keyVal = token.slice(1);
-    const valIdx = keyVal.indexOf(':');
-    const key = valIdx === -1 ? keyVal : keyVal.slice(0, valIdx);
-    const val = valIdx === -1 ? undefined : keyVal.slice(valIdx + 1);
-    const isSet = val === undefined || val === 'true';
-    if (!hasOwnProperty(EnvironmentConfigSchema.shape, key)) {
-      continue;
-    }
-
-    if (isSet && key in testComplexConfigDefaults) {
-      maybeConfig[key] = testComplexConfigDefaults[key];
-    } else if (isSet) {
-      maybeConfig[key] = true;
-    } else if (val === 'false') {
-      maybeConfig[key] = false;
-    } else if (val) {
-      const parsedVal = tryParseTestPragmaValue(val).unwrap();
-      if (key === 'customMacros' && typeof parsedVal === 'string') {
-        const valSplit = parsedVal.split('.');
-        const props = [];
-        for (const elt of valSplit.slice(1)) {
-          if (elt === '*') {
-            props.push({type: 'wildcard'});
-          } else if (elt.length > 0) {
-            props.push({type: 'name', name: elt});
-          }
-        }
-        maybeConfig[key] = [[valSplit[0], props]];
-        continue;
-      }
-      maybeConfig[key] = parsedVal;
-    }
-  }
-  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,
-  });
-}
-
-const testComplexPluginOptionDefaults: Partial<PluginOptions> = {
-  gating: {
-    source: 'ReactForgetFeatureFlag',
-    importSpecifierName: 'isForgetEnabled_Fixtures',
-  },
-};
-export function parseConfigPragmaForTests(
-  pragma: string,
-  defaults: {
-    compilationMode: CompilationMode;
-  },
-): PluginOptions {
-  const environment = parseConfigPragmaEnvironmentForTest(pragma);
-  const options: Record<keyof PluginOptions, unknown> = {
-    ...defaultOptions,
-    panicThreshold: 'all_errors',
-    compilationMode: defaults.compilationMode,
-    environment,
-  };
-  for (const token of pragma.split(' ')) {
-    if (!token.startsWith('@')) {
-      continue;
-    }
-    const keyVal = token.slice(1);
-    const idx = keyVal.indexOf(':');
-    const key = idx === -1 ? keyVal : keyVal.slice(0, idx);
-    const val = idx === -1 ? undefined : keyVal.slice(idx + 1);
-    if (!hasOwnProperty(defaultOptions, key)) {
-      continue;
-    }
-    const isSet = val === undefined || val === 'true';
-    if (isSet && key in testComplexPluginOptionDefaults) {
-      options[key] = testComplexPluginOptionDefaults[key];
-    } else if (isSet) {
-      options[key] = true;
-    } else if (val === 'false') {
-      options[key] = false;
-    } else if (val != null) {
-      const parsedVal = tryParseTestPragmaValue(val).unwrap();
-      if (key === 'target' && parsedVal === 'donotuse_meta_internal') {
-        options[key] = {
-          kind: parsedVal,
-          runtimeModule: 'react',
-        };
-      } else {
-        options[key] = parsedVal;
-      }
-    }
-  }
-  return parsePluginOptions(options);
-}

compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoCapitalizedCalls.ts

@@ -4,7 +4,6 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
-
 import {CompilerError, EnvironmentConfig, ErrorSeverity} from '..';
 import {HIRFunction, IdentifierId} from '../HIR';
 import {DEFAULT_GLOBALS} from '../HIR/Globals';

compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoFreezingKnownMutableFunctions.ts

@@ -1,130 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {CompilerError, Effect, ErrorSeverity} from '..';
-import {
-  FunctionEffect,
-  HIRFunction,
-  IdentifierId,
-  isMutableEffect,
-  isRefOrRefLikeMutableType,
-  Place,
-} from '../HIR';
-import {
-  eachInstructionValueOperand,
-  eachTerminalOperand,
-} from '../HIR/visitors';
-import {Result} from '../Utils/Result';
-import {Iterable_some} from '../Utils/utils';
-
-/**
- * Validates that functions with known mutations (ie due to types) cannot be passed
- * where a frozen value is expected. Example:
- *
- * ```
- * function Component() {
- *   const cache = new Map();
- *   const onClick = () => {
- *     cache.set(...);
- *   }
- *   useHook(onClick); // ERROR: cannot pass a mutable value
- *   return <Foo onClick={onClick} /> // ERROR: cannot pass a mutable value
- * }
- * ```
- *
- * Because `onClick` function mutates `cache` when called, `onClick` is equivalent to a mutable
- * variables. But unlike other mutables values like an array, the receiver of the function has
- * no way to avoid mutation — for example, a function can receive an array and choose not to mutate
- * it, but there's no way to know that a function is mutable and avoid calling it.
- *
- * This pass detects functions with *known* mutations (Store or Mutate, not ConditionallyMutate)
- * that are passed where a frozen value is expected and rejects them.
- */
-export function validateNoFreezingKnownMutableFunctions(
-  fn: HIRFunction,
-): Result<void, CompilerError> {
-  const errors = new CompilerError();
-  const contextMutationEffects: Map<
-    IdentifierId,
-    Extract<FunctionEffect, {kind: 'ContextMutation'}>
-  > = new Map();
-
-  function visitOperand(operand: Place): void {
-    if (operand.effect === Effect.Freeze) {
-      const effect = contextMutationEffects.get(operand.identifier.id);
-      if (effect != null) {
-        errors.push({
-          reason: `This argument is a function which modifies local variables when called, which can bypass memoization and cause the UI not to update`,
-          description: `Functions that are returned from hooks, passed as arguments to hooks, or passed as props to components may not mutate local variables`,
-          loc: operand.loc,
-          severity: ErrorSeverity.InvalidReact,
-        });
-        errors.push({
-          reason: `The function modifies a local variable here`,
-          loc: effect.loc,
-          severity: ErrorSeverity.InvalidReact,
-        });
-      }
-    }
-  }
-
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const {lvalue, value} = instr;
-      switch (value.kind) {
-        case 'LoadLocal': {
-          const effect = contextMutationEffects.get(value.place.identifier.id);
-          if (effect != null) {
-            contextMutationEffects.set(lvalue.identifier.id, effect);
-          }
-          break;
-        }
-        case 'StoreLocal': {
-          const effect = contextMutationEffects.get(value.value.identifier.id);
-          if (effect != null) {
-            contextMutationEffects.set(lvalue.identifier.id, effect);
-            contextMutationEffects.set(
-              value.lvalue.place.identifier.id,
-              effect,
-            );
-          }
-          break;
-        }
-        case 'FunctionExpression': {
-          const knownMutation = (value.loweredFunc.func.effects ?? []).find(
-            effect => {
-              return (
-                effect.kind === 'ContextMutation' &&
-                (effect.effect === Effect.Store ||
-                  effect.effect === Effect.Mutate) &&
-                Iterable_some(effect.places, place => {
-                  return (
-                    isMutableEffect(place.effect, place.loc) &&
-                    !isRefOrRefLikeMutableType(place.identifier.type)
-                  );
-                })
-              );
-            },
-          );
-          if (knownMutation && knownMutation.kind === 'ContextMutation') {
-            contextMutationEffects.set(lvalue.identifier.id, knownMutation);
-          }
-          break;
-        }
-        default: {
-          for (const operand of eachInstructionValueOperand(value)) {
-            visitOperand(operand);
-          }
-        }
-      }
-    }
-    for (const operand of eachTerminalOperand(block.terminal)) {
-      visitOperand(operand);
-    }
-  }
-  return errors.asResult();
-}

compiler/packages/babel-plugin-react-compiler/src/Validation/ValidatePreservedManualMemoization.ts

@@ -141,14 +141,14 @@ function getCompareDependencyResultDescription(
 ): string {
   switch (result) {
     case CompareDependencyResult.Ok:
-      return 'Dependencies equal';
+      return 'dependencies equal';
     case CompareDependencyResult.RootDifference:
     case CompareDependencyResult.PathDifference:
-      return 'Inferred different dependency than source';
+      return 'inferred different dependency than source';
     case CompareDependencyResult.RefAccessDifference:
-      return 'Differences in ref.current access';
+      return 'differences in ref.current access';
     case CompareDependencyResult.Subpath:
-      return 'Inferred less specific property than source';
+      return 'inferred less specific property than source';
   }
 }
 
@@ -279,20 +279,17 @@ function validateInferredDep(
     severity: ErrorSeverity.CannotPreserveMemoization,
     reason:
       'React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected',
-    description:
-      DEBUG ||
-      // If the dependency is a named variable then we can report it. Otherwise only print in debug mode
-      (dep.identifier.name != null && dep.identifier.name.kind === 'named')
-        ? `The inferred dependency was \`${prettyPrintScopeDependency(
-            dep,
-          )}\`, but the source dependencies were [${validDepsInMemoBlock
-            .map(dep => printManualMemoDependency(dep, true))
-            .join(', ')}]. ${
-            errorDiagnostic
-              ? getCompareDependencyResultDescription(errorDiagnostic)
-              : 'Inferred dependency not present in source'
-          }`
-        : null,
+    description: DEBUG
+      ? `The inferred dependency was \`${prettyPrintScopeDependency(
+          dep,
+        )}\`, but the source dependencies were [${validDepsInMemoBlock
+          .map(dep => printManualMemoDependency(dep, true))
+          .join(', ')}]. Detail: ${
+          errorDiagnostic
+            ? getCompareDependencyResultDescription(errorDiagnostic)
+            : 'none'
+        }`
+      : null,
     loc: memoLocation,
     suggestions: null,
   });

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/arrow-function-with-implicit-return.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @compilationMode:"infer"
+// @compilationMode(infer)
 const Test = () => <div />;
 
 export const FIXTURE_ENTRYPOINT = {
@@ -15,7 +15,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-import { c as _c } from "react/compiler-runtime"; // @compilationMode:"infer"
+import { c as _c } from "react/compiler-runtime"; // @compilationMode(infer)
 const Test = () => {
   const $ = _c(1);
   let t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/arrow-function-with-implicit-return.js

@@ -1,4 +1,4 @@
-// @compilationMode:"infer"
+// @compilationMode(infer)
 const Test = () => <div />;
 
 export const FIXTURE_ENTRYPOINT = {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-functiondecl-hoisting.expect.md

@@ -0,0 +1,79 @@
+
+## Input
+
+```javascript
+import {Stringify} from 'shared-runtime';
+
+/**
+ * Fixture currently fails with
+ * Found differences in evaluator results
+ *   Non-forget (expected):
+ *   (kind: ok) <div>{"result":{"value":2},"fn":{"kind":"Function","result":{"value":2}},"shouldInvokeFns":true}</div>
+ *   Forget:
+ *   (kind: exception) bar is not a function
+ */
+function Foo({value}) {
+  const result = bar();
+  function bar() {
+    return {value};
+  }
+  return <Stringify result={result} fn={bar} shouldInvokeFns={true} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Foo,
+  params: [{value: 2}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { Stringify } from "shared-runtime";
+
+/**
+ * Fixture currently fails with
+ * Found differences in evaluator results
+ *   Non-forget (expected):
+ *   (kind: ok) <div>{"result":{"value":2},"fn":{"kind":"Function","result":{"value":2}},"shouldInvokeFns":true}</div>
+ *   Forget:
+ *   (kind: exception) bar is not a function
+ */
+function Foo(t0) {
+  const $ = _c(6);
+  const { value } = t0;
+  let bar;
+  let result;
+  if ($[0] !== value) {
+    result = bar();
+    bar = function bar() {
+      return { value };
+    };
+    $[0] = value;
+    $[1] = bar;
+    $[2] = result;
+  } else {
+    bar = $[1];
+    result = $[2];
+  }
+  let t1;
+  if ($[3] !== bar || $[4] !== result) {
+    t1 = <Stringify result={result} fn={bar} shouldInvokeFns={true} />;
+    $[3] = bar;
+    $[4] = result;
+    $[5] = t1;
+  } else {
+    t1 = $[5];
+  }
+  return t1;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Foo,
+  params: [{ value: 2 }],
+};
+
+```
+      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/capturing-function-alias-computed-load-3-iife.expect.md

@@ -34,7 +34,8 @@ function bar(a, b) {
   if ($[0] !== a || $[1] !== b) {
     const x = [a, b];
     y = {};
-    let t = {};
+    let t;
+    t = {};
 
     y = x[0][1];
     t = x[1][0];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/capturing-function-alias-computed-load-3.expect.md

@@ -35,7 +35,8 @@ function bar(a, b) {
   if ($[0] !== a || $[1] !== b) {
     const x = [a, b];
     y = {};
-    let t = {};
+    let t;
+    t = {};
     const f0 = function () {
       y = x[0][1];
       t = x[1][0];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/class-component-with-render-helper.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @compilationMode:"infer"
+// @compilationMode(infer)
 class Component {
   _renderMessage = () => {
     const Message = () => {
@@ -22,7 +22,7 @@ class Component {
 ## Code
 
 ```javascript
-// @compilationMode:"infer"
+// @compilationMode(infer)
 class Component {
   _renderMessage = () => {
     const Message = () => {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/class-component-with-render-helper.js

@@ -1,4 +1,4 @@
-// @compilationMode:"infer"
+// @compilationMode(infer)
 class Component {
   _renderMessage = () => {
     const Message = () => {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/codegen-inline-iife-reassign.expect.md

@@ -33,7 +33,8 @@ function useTest() {
   const $ = _c(1);
   let t0;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    let w = {};
+    let w;
+    w = {};
 
     const t1 = (w = 42);
     const t2 = w;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/codegen-instrument-forget-test.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @enableEmitInstrumentForget @compilationMode:"annotation"
+// @enableEmitInstrumentForget @compilationMode(annotation)
 
 function Bar(props) {
   'use forget';
@@ -24,7 +24,7 @@ function Foo(props) {
 
 ```javascript
 import { shouldInstrument, useRenderCounter } from "react-compiler-runtime";
-import { c as _c } from "react/compiler-runtime"; // @enableEmitInstrumentForget @compilationMode:"annotation"
+import { c as _c } from "react/compiler-runtime"; // @enableEmitInstrumentForget @compilationMode(annotation)
 
 function Bar(props) {
   "use forget";

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/codegen-instrument-forget-test.js

@@ -1,4 +1,4 @@
-// @enableEmitInstrumentForget @compilationMode:"annotation"
+// @enableEmitInstrumentForget @compilationMode(annotation)
 
 function Bar(props) {
   'use forget';

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/component-declaration-basic.flow.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @flow @compilationMode:"infer"
+// @flow @compilationMode(infer)
 export default component Foo(bar: number) {
   return <Bar bar={bar} />;
 }

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/component-declaration-basic.flow.js

@@ -1,4 +1,4 @@
-// @flow @compilationMode:"infer"
+// @flow @compilationMode(infer)
 export default component Foo(bar: number) {
   return <Bar bar={bar} />;
 }

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/conflict-codegen-instrument-forget.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @enableEmitInstrumentForget @compilationMode:"annotation"
+// @enableEmitInstrumentForget @compilationMode(annotation)
 
 import {identity} from 'shared-runtime';
 
@@ -35,7 +35,7 @@ import {
   shouldInstrument as _shouldInstrument3,
   useRenderCounter,
 } from "react-compiler-runtime";
-import { c as _c } from "react/compiler-runtime"; // @enableEmitInstrumentForget @compilationMode:"annotation"
+import { c as _c } from "react/compiler-runtime"; // @enableEmitInstrumentForget @compilationMode(annotation)
 
 import { identity } from "shared-runtime";
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/conflict-codegen-instrument-forget.js

@@ -1,4 +1,4 @@
-// @enableEmitInstrumentForget @compilationMode:"annotation"
+// @enableEmitInstrumentForget @compilationMode(annotation)
 
 import {identity} from 'shared-runtime';
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/constant-propagation-template-literal.expect.md

@@ -1,136 +0,0 @@
-
-## Input
-
-```javascript
-import {Stringify, identity} from 'shared-runtime';
-
-function foo() {
-  try {
-    identity(`${Symbol('0')}`); // Uncaught TypeError: Cannot convert a Symbol value to a string (leave as is)
-  } catch {}
-
-  return (
-    <Stringify
-      value={[
-        `` === '',
-        `\n` === '\n',
-        `a\nb`,
-        `\n`,
-        `a${1}b`,
-        ` abc \u0041\n\u000a\ŧ`,
-        `abc${1}def`,
-        `abc${1}def${2}`,
-        `abc${1}def${2}ghi`,
-        `a${1 + 3}b${``}c${'d' + `e${2 + 4}f`}`,
-        `1${2}${Math.sin(0)}`,
-        `${NaN}`,
-        `${Infinity}`,
-        `${-Infinity}`,
-        `${Number.MAX_SAFE_INTEGER}`,
-        `${Number.MIN_SAFE_INTEGER}`,
-        `${Number.MAX_VALUE}`,
-        `${Number.MIN_VALUE}`,
-        `${-0}`,
-        `
-        `,
-        `${{}}`,
-        `${[1, 2, 3]}`,
-        `${true}`,
-        `${false}`,
-        `${null}`,
-        `${undefined}`,
-        `123456789${0}`,
-        `${0}123456789`,
-        `${0}123456789${0}`,
-        `${0}1234${5}6789${0}`,
-        `${0}1234${`${0}123456789${`${0}123456789${0}`}`}6789${0}`,
-        `${0}1234${`${0}123456789${`${identity(0)}`}`}6789${0}`,
-        `${`${`${`${0}`}`}`}`,
-        `${`${`${`${''}`}`}`}`,
-        `${`${`${`${identity('')}`}`}`}`,
-      ]}
-    />
-  );
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: foo,
-  params: [],
-  isComponent: false,
-};
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime";
-import { Stringify, identity } from "shared-runtime";
-
-function foo() {
-  const $ = _c(1);
-  try {
-    identity(`${Symbol("0")}`);
-  } catch {}
-  let t0;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t0 = (
-      <Stringify
-        value={[
-          true,
-          true,
-
-          "a\nb",
-          "\n",
-          "a1b",
-          " abc A\n\n\u0167",
-          "abc1def",
-          "abc1def2",
-          "abc1def2ghi",
-          "a4bcde6f",
-          `1${2}${Math.sin(0)}`,
-          `${NaN}`,
-          `${Infinity}`,
-          `${-Infinity}`,
-          `${Number.MAX_SAFE_INTEGER}`,
-          `${Number.MIN_SAFE_INTEGER}`,
-          `${Number.MAX_VALUE}`,
-          `${Number.MIN_VALUE}`,
-          "0",
-          "\n        ",
-
-          `${{}}`,
-          `${[1, 2, 3]}`,
-          "true",
-          "false",
-          "null",
-          `${undefined}`,
-          "1234567890",
-          "0123456789",
-          "01234567890",
-          "01234567890",
-          "0123401234567890123456789067890",
-          `${0}1234${`${0}123456789${`${identity(0)}`}`}6789${0}`,
-          "0",
-          "",
-          `${`${`${`${identity("")}`}`}`}`,
-        ]}
-      />
-    );
-    $[0] = t0;
-  } else {
-    t0 = $[0];
-  }
-  return t0;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: foo,
-  params: [],
-  isComponent: false,
-};
-
-```
-      
-### Eval output
-(kind: ok) <div>{"value":[true,true,"a\nb","\n","a1b"," abc A\n\nŧ","abc1def","abc1def2","abc1def2ghi","a4bcde6f","120","NaN","Infinity","-Infinity","9007199254740991","-9007199254740991","1.7976931348623157e+308","5e-324","0","\n        ","[object Object]","1,2,3","true","false","null","undefined","1234567890","0123456789","01234567890","01234567890","0123401234567890123456789067890","012340123456789067890","0","",""]}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/constant-propagation-template-literal.js

@@ -1,56 +0,0 @@
-import {Stringify, identity} from 'shared-runtime';
-
-function foo() {
-  try {
-    identity(`${Symbol('0')}`); // Uncaught TypeError: Cannot convert a Symbol value to a string (leave as is)
-  } catch {}
-
-  return (
-    <Stringify
-      value={[
-        `` === '',
-        `\n` === '\n',
-        `a\nb`,
-        `\n`,
-        `a${1}b`,
-        ` abc \u0041\n\u000a\ŧ`,
-        `abc${1}def`,
-        `abc${1}def${2}`,
-        `abc${1}def${2}ghi`,
-        `a${1 + 3}b${``}c${'d' + `e${2 + 4}f`}`,
-        `1${2}${Math.sin(0)}`,
-        `${NaN}`,
-        `${Infinity}`,
-        `${-Infinity}`,
-        `${Number.MAX_SAFE_INTEGER}`,
-        `${Number.MIN_SAFE_INTEGER}`,
-        `${Number.MAX_VALUE}`,
-        `${Number.MIN_VALUE}`,
-        `${-0}`,
-        `
-        `,
-        `${{}}`,
-        `${[1, 2, 3]}`,
-        `${true}`,
-        `${false}`,
-        `${null}`,
-        `${undefined}`,
-        `123456789${0}`,
-        `${0}123456789`,
-        `${0}123456789${0}`,
-        `${0}1234${5}6789${0}`,
-        `${0}1234${`${0}123456789${`${0}123456789${0}`}`}6789${0}`,
-        `${0}1234${`${0}123456789${`${identity(0)}`}`}6789${0}`,
-        `${`${`${`${0}`}`}`}`,
-        `${`${`${`${''}`}`}`}`,
-        `${`${`${`${identity('')}`}`}`}`,
-      ]}
-    />
-  );
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: foo,
-  params: [],
-  isComponent: false,
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/constant-propagation-unary-number.expect.md

@@ -1,74 +0,0 @@
-
-## Input
-
-```javascript
-import {Stringify} from 'shared-runtime';
-
-function foo() {
-  const a = -1;
-  return (
-    <Stringify
-      value={[
-        2 * a,
-        -0,
-        0 === -0,
-        -Infinity,
-        -NaN,
-        a * NaN,
-        a * Infinity,
-        a * -Infinity,
-      ]}
-    />
-  );
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: foo,
-  params: [],
-  isComponent: false,
-};
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime";
-import { Stringify } from "shared-runtime";
-
-function foo() {
-  const $ = _c(1);
-  let t0;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t0 = (
-      <Stringify
-        value={[
-          -2,
-          0,
-          true,
-          -Infinity,
-          -NaN,
-
-          -1 * NaN,
-          -1 * Infinity,
-          -1 * -Infinity,
-        ]}
-      />
-    );
-    $[0] = t0;
-  } else {
-    t0 = $[0];
-  }
-  return t0;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: foo,
-  params: [],
-  isComponent: false,
-};
-
-```
-      
-### Eval output
-(kind: ok) <div>{"value":[-2,0,true,null,null,null,null,null]}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/constant-propagation-unary-number.js

@@ -1,25 +0,0 @@
-import {Stringify} from 'shared-runtime';
-
-function foo() {
-  const a = -1;
-  return (
-    <Stringify
-      value={[
-        2 * a,
-        -0,
-        0 === -0,
-        -Infinity,
-        -NaN,
-        a * NaN,
-        a * Infinity,
-        a * -Infinity,
-      ]}
-    />
-  );
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: foo,
-  params: [],
-  isComponent: false,
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/constant-propagation-unary.expect.md

@@ -58,7 +58,7 @@ function foo() {
           n0: true,
           n1: false,
           n2: false,
-          n3: false,
+          n3: !-1,
           s0: true,
           s1: false,
           s2: false,

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/context-variable-reassigned-outside-of-lambda.expect.md

@@ -30,7 +30,8 @@ function Component(props) {
   const $ = _c(1);
   let t0;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    let x = null;
+    let x;
+    x = null;
     const callback = () => {
       console.log(x);
     };

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bailout-on-suppression-of-custom-rule.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @eslintSuppressionRules:["my-app","react-rule"]
+// @eslintSuppressionRules(my-app/react-rule)
 
 /* eslint-disable my-app/react-rule */
 function lowercasecomponent() {
@@ -19,7 +19,7 @@ function lowercasecomponent() {
 ## Error
 
 ```
-  1 | // @eslintSuppressionRules:["my-app","react-rule"]
+  1 | // @eslintSuppressionRules(my-app/react-rule)
   2 |
 > 3 | /* eslint-disable my-app/react-rule */
     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ InvalidReact: React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior. eslint-disable my-app/react-rule (3:3)

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bailout-on-suppression-of-custom-rule.js

@@ -1,4 +1,4 @@
-// @eslintSuppressionRules:["my-app","react-rule"]
+// @eslintSuppressionRules(my-app/react-rule)
 
 /* eslint-disable my-app/react-rule */
 function lowercasecomponent() {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.hoist-optional-member-expression-with-conditional-optional.expect.md

@@ -41,7 +41,7 @@ function Component(props) {
 > 10 |     return x;
      | ^^^^^^^^^^^^^^^^^
 > 11 |   }, [props?.items, props.cond]);
-     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items`, but the source dependencies were [props?.items, props.cond]. Inferred different dependency than source (4:11)
+     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (4:11)
   12 |   return (
   13 |     <ValidateMemoization inputs={[props?.items, props.cond]} output={data} />
   14 |   );

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.hoist-optional-member-expression-with-conditional.expect.md

@@ -41,7 +41,7 @@ function Component(props) {
 > 10 |     return x;
      | ^^^^^^^^^^^^^^^^^
 > 11 |   }, [props?.items, props.cond]);
-     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items`, but the source dependencies were [props?.items, props.cond]. Inferred different dependency than source (4:11)
+     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (4:11)
   12 |   return (
   13 |     <ValidateMemoization inputs={[props?.items, props.cond]} output={data} />
   14 |   );

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-hook-function-argument-mutates-local-variable.expect.md

@@ -1,34 +0,0 @@
-
-## Input
-
-```javascript
-// @validateNoFreezingKnownMutableFunctions
-
-function useFoo() {
-  const cache = new Map();
-  useHook(() => {
-    cache.set('key', 'value');
-  });
-}
-
-```
-
-
-## Error
-
-```
-  3 | function useFoo() {
-  4 |   const cache = new Map();
-> 5 |   useHook(() => {
-    |           ^^^^^^^
-> 6 |     cache.set('key', 'value');
-    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-> 7 |   });
-    | ^^^^ InvalidReact: This argument is a function which modifies local variables when called, which can bypass memoization and cause the UI not to update. Functions that are returned from hooks, passed as arguments to hooks, or passed as props to components may not mutate local variables (5:7)
-
-InvalidReact: The function modifies a local variable here (6:6)
-  8 | }
-  9 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-hook-function-argument-mutates-local-variable.js

@@ -1,8 +0,0 @@
-// @validateNoFreezingKnownMutableFunctions
-
-function useFoo() {
-  const cache = new Map();
-  useHook(() => {
-    cache.set('key', 'value');
-  });
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-optional-member-expression-as-memo-dep-non-optional-in-body.expect.md

@@ -29,7 +29,7 @@ function Component(props) {
 >  6 |     // deps are optional
      | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 >  7 |   }, [props.items?.edges?.nodes]);
-     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items.edges.nodes`, but the source dependencies were [props.items?.edges?.nodes]. Inferred different dependency than source (3:7)
+     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (3:7)
    8 |   return <Foo data={data} />;
    9 | }
   10 |

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-pass-mutable-function-as-prop.expect.md

@@ -1,30 +0,0 @@
-
-## Input
-
-```javascript
-// @validateNoFreezingKnownMutableFunctions
-function Component() {
-  const cache = new Map();
-  const fn = () => {
-    cache.set('key', 'value');
-  };
-  return <Foo fn={fn} />;
-}
-
-```
-
-
-## Error
-
-```
-  5 |     cache.set('key', 'value');
-  6 |   };
-> 7 |   return <Foo fn={fn} />;
-    |                   ^^ InvalidReact: This argument is a function which modifies local variables when called, which can bypass memoization and cause the UI not to update. Functions that are returned from hooks, passed as arguments to hooks, or passed as props to components may not mutate local variables (7:7)
-
-InvalidReact: The function modifies a local variable here (5:5)
-  8 | }
-  9 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-pass-mutable-function-as-prop.js

@@ -1,8 +0,0 @@
-// @validateNoFreezingKnownMutableFunctions
-function Component() {
-  const cache = new Map();
-  const fn = () => {
-    cache.set('key', 'value');
-  };
-  return <Foo fn={fn} />;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-read-ref-prop-in-render-destructure.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateRefAccessDuringRender @compilationMode:"infer"
+// @validateRefAccessDuringRender @compilationMode(infer)
 function Component({ref}) {
   const value = ref.current;
   return <div>{value}</div>;
@@ -14,7 +14,7 @@ function Component({ref}) {
 ## Error
 
 ```
-  1 | // @validateRefAccessDuringRender @compilationMode:"infer"
+  1 | // @validateRefAccessDuringRender @compilationMode(infer)
   2 | function Component({ref}) {
 > 3 |   const value = ref.current;
     |                 ^^^^^^^^^^^ InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (3:3)

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-read-ref-prop-in-render-destructure.js

@@ -1,4 +1,4 @@
-// @validateRefAccessDuringRender @compilationMode:"infer"
+// @validateRefAccessDuringRender @compilationMode(infer)
 function Component({ref}) {
   const value = ref.current;
   return <div>{value}</div>;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-read-ref-prop-in-render-property-load.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateRefAccessDuringRender @compilationMode:"infer"
+// @validateRefAccessDuringRender @compilationMode(infer)
 function Component(props) {
   const value = props.ref.current;
   return <div>{value}</div>;
@@ -14,7 +14,7 @@ function Component(props) {
 ## Error
 
 ```
-  1 | // @validateRefAccessDuringRender @compilationMode:"infer"
+  1 | // @validateRefAccessDuringRender @compilationMode(infer)
   2 | function Component(props) {
 > 3 |   const value = props.ref.current;
     |                 ^^^^^^^^^^^^^^^^^ InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (3:3)

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-read-ref-prop-in-render-property-load.js

@@ -1,4 +1,4 @@
-// @validateRefAccessDuringRender @compilationMode:"infer"
+// @validateRefAccessDuringRender @compilationMode(infer)
 function Component(props) {
   const value = props.ref.current;
   return <div>{value}</div>;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-return-mutable-function-from-hook.expect.md

@@ -1,36 +0,0 @@
-
-## Input
-
-```javascript
-// @validateNoFreezingKnownMutableFunctions
-import {useHook} from 'shared-runtime';
-
-function useFoo() {
-  useHook(); // for inference to kick in
-  const cache = new Map();
-  return () => {
-    cache.set('key', 'value');
-  };
-}
-
-```
-
-
-## Error
-
-```
-   5 |   useHook(); // for inference to kick in
-   6 |   const cache = new Map();
->  7 |   return () => {
-     |          ^^^^^^^
->  8 |     cache.set('key', 'value');
-     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
->  9 |   };
-     | ^^^^ InvalidReact: This argument is a function which modifies local variables when called, which can bypass memoization and cause the UI not to update. Functions that are returned from hooks, passed as arguments to hooks, or passed as props to components may not mutate local variables (7:9)
-
-InvalidReact: The function modifies a local variable here (8:8)
-  10 | }
-  11 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-return-mutable-function-from-hook.js

@@ -1,10 +0,0 @@
-// @validateNoFreezingKnownMutableFunctions
-import {useHook} from 'shared-runtime';
-
-function useFoo() {
-  useHook(); // for inference to kick in
-  const cache = new Map();
-  return () => {
-    cache.set('key', 'value');
-  };
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-write-ref-prop-in-render.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateRefAccessDuringRender @compilationMode:"infer"
+// @validateRefAccessDuringRender @compilationMode(infer)
 function Component(props) {
   const ref = props.ref;
   ref.current = true;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-write-ref-prop-in-render.js

@@ -1,4 +1,4 @@
-// @validateRefAccessDuringRender @compilationMode:"infer"
+// @validateRefAccessDuringRender @compilationMode(infer)
 function Component(props) {
   const ref = props.ref;
   ref.current = true;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.ref-like-name-not-Ref.expect.md

@@ -38,7 +38,7 @@ export const FIXTURE_ENTRYPOINT = {
 > 12 |     Ref.current?.click();
      | ^^^^^^^^^^^^^^^^^^^^^^^^^
 > 13 |   }, []);
-     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `Ref.current`, but the source dependencies were []. Inferred dependency not present in source (11:13)
+     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (11:13)
   14 |
   15 |   return <button onClick={onClick} />;
   16 | }

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.ref-like-name-not-a-ref.expect.md

@@ -38,7 +38,7 @@ export const FIXTURE_ENTRYPOINT = {
 > 12 |     notaref.current?.click();
      | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 > 13 |   }, []);
-     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `notaref.current`, but the source dependencies were []. Inferred dependency not present in source (11:13)
+     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (11:13)
   14 |
   15 |   return <button onClick={onClick} />;
   16 | }