19.1.6

Co-authored-by: "Sebastian \"Sebbie\" Silbermann" <sebastian.silbermann@vercel.com>

.eslintrc.js

@@ -331,6 +331,7 @@ module.exports = {
         'packages/react-server-dom-turbopack/**/*.js',
         'packages/react-server-dom-parcel/**/*.js',
         'packages/react-server-dom-fb/**/*.js',
+        'packages/react-server-dom-unbundled/**/*.js',
         'packages/react-test-renderer/**/*.js',
         'packages/react-debug-tools/**/*.js',
         'packages/react-devtools-extensions/**/*.js',

.github/workflows/compiler_discord_notify.yml

@@ -1,15 +1,20 @@
 name: (Compiler) Discord Notify
 
 on:
-  pull_request_target:
+  pull_request:
     types: [opened, ready_for_review]
     paths:
       - compiler/**
       - .github/workflows/compiler_**.yml
 
+permissions: {}
+
 jobs:
   check_maintainer:
     uses: facebook/react/.github/workflows/shared_check_maintainer.yml@main
+    permissions:
+      # Used by check_maintainer
+      contents: read
     with:
       actor: ${{ github.event.pull_request.user.login }}
 
@@ -19,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Discord Webhook Action
-        uses: tsickert/discord-webhook@v6.0.0
+        uses: tsickert/discord-webhook@86dc739f3f165f16dadc5666051c367efa1692f4
         with:
           webhook-url: ${{ secrets.COMPILER_DISCORD_WEBHOOK_URL }}
           embed-author-name: ${{ github.event.pull_request.user.login }}

.github/workflows/compiler_playground.yml

@@ -8,6 +8,8 @@ on:
       - compiler/**
       - .github/workflows/compiler_playground.yml
 
+permissions: {}
+
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
@@ -36,10 +38,23 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: compiler-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
       - run: yarn install --frozen-lockfile
+      - name: Check Playwright version
+        id: playwright_version
+        run: echo "playwright_version=$(npm ls @playwright/test | grep @playwright | sed 's/.*@//' | head -1)" >> "$GITHUB_OUTPUT"
+      - name: Cache Playwright Browsers for version ${{ steps.playwright_version.outputs.playwright_version }}
+        id: cache_playwright_browsers
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-browsers-v6-${{ runner.arch }}-${{ runner.os }}-${{ steps.playwright_version.outputs.playwright_version }}
       - run: npx playwright install --with-deps chromium
+        if: steps.cache_playwright_browsers.outputs.cache-hit != 'true'
+      - run: npx playwright install-deps
+        if: steps.cache_playwright_browsers.outputs.cache-hit == 'true'
       - run: CI=true yarn test
       - run: ls -R test-results
         if: '!cancelled()'
@@ -49,3 +64,4 @@ jobs:
         with:
           name: test-results
           path: compiler/apps/playground/test-results
+          if-no-files-found: ignore

.github/workflows/compiler_prereleases.yml

@@ -20,11 +20,12 @@ on:
       NPM_TOKEN:
         required: true
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
   # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
   SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
-  GH_TOKEN: ${{ github.token }}
   NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
 
 defaults:
@@ -46,8 +47,9 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: compiler-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - name: Publish packages to npm
         run: |

.github/workflows/compiler_prereleases_manual.yml

@@ -15,6 +15,8 @@ on:
         required: true
         type: string
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
 

.github/workflows/compiler_prereleases_nightly.yml

@@ -5,6 +5,8 @@ on:
     # At 10 minutes past 16:00 on Mon, Tue, Wed, Thu, and Fri
     - cron: 10 16 * * 1,2,3,4,5
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
 

.github/workflows/compiler_prereleases_weekly.yml

@@ -5,6 +5,8 @@ on:
     # At 10 minutes past 9:00 on Mon
     - cron: 10 9 * * 1
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
 

.github/workflows/compiler_typescript.yml

@@ -8,6 +8,8 @@ on:
       - compiler/**
       - .github/workflows/compiler_typescript.yml
 
+permissions: {}
+
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
@@ -46,8 +48,9 @@ jobs:
       - name: Restore cached node_modules
         uses: actions/cache@v4
         with:
-          path: "**/node_modules"
-          key: compiler-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - run: yarn workspace babel-plugin-react-compiler lint
 
@@ -66,8 +69,9 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: compiler-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - run: yarn workspace babel-plugin-react-compiler jest
 
@@ -90,8 +94,9 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: compiler-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('compiler/**/yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - run: xvfb-run -a yarn workspace ${{ matrix.workspace_name }} test
         if: runner.os == 'Linux' && matrix.workspace_name == 'react-forgive'

.github/workflows/devtools_regression_tests.yml

@@ -9,6 +9,8 @@ on:
         required: false
         type: string
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
   # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
@@ -18,6 +20,9 @@ jobs:
   download_build:
     name: Download base build
     runs-on: ubuntu-latest
+    permissions:
+      # We use github.token to download the build artifact from a previous runtime_build_and_test.yml run
+      actions: read
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
@@ -29,13 +34,13 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-release-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-release-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
-      - run: yarn install --frozen-lockfile
-        working-directory: scripts/release
+      - run: yarn --cwd scripts/release install --frozen-lockfile
       - name: Download react-devtools artifacts for base revision
         run: |
           git fetch origin main
@@ -47,6 +52,7 @@ jobs:
         with:
           name: build
           path: build
+          if-no-files-found: error
 
   build_devtools_and_process_artifacts:
     name: Build DevTools and process artifacts
@@ -63,8 +69,9 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
@@ -83,17 +90,20 @@ jobs:
         with:
           name: react-devtools
           path: build/devtools.tgz
+          if-no-files-found: error
       # Simplifies getting the extension for local testing
       - name: Archive chrome extension
         uses: actions/upload-artifact@v4
         with:
           name: react-devtools-chrome-extension
           path: build/devtools/chrome-extension.zip
+          if-no-files-found: error
       - name: Archive firefox extension
         uses: actions/upload-artifact@v4
         with:
           name: react-devtools-firefox-extension
           path: build/devtools/firefox-extension.zip
+          if-no-files-found: error
 
   run_devtools_tests_for_versions:
     name: Run DevTools tests for versions
@@ -120,8 +130,9 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - name: Restore all archived build artifacts
         uses: actions/download-artifact@v4
@@ -154,8 +165,9 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - name: Restore all archived build artifacts
         uses: actions/download-artifact@v4
@@ -176,3 +188,4 @@ jobs:
         with:
           name: screenshots
           path: ./tmp/screenshots
+          if-no-files-found: warn

.github/workflows/runtime_build_and_test.yml

@@ -3,9 +3,21 @@ name: (Runtime) Build and Test
 on:
   push:
     branches: [main]
+    tags:
+      # To get CI for backport releases.
+      # This will duplicate CI for releases from main which is acceptable
+      - "v*"
   pull_request:
     paths-ignore:
       - compiler/**
+  workflow_dispatch:
+    inputs:
+      commit_sha:
+        required: false
+        type: string
+        default: ''
+
+permissions: {}
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.run_id }}
@@ -17,6 +29,91 @@ env:
   SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
 
 jobs:
+  # ----- NODE_MODULES CACHE -----
+  # Centralize the node_modules cache so it is saved once and each subsequent job only needs to
+  # restore the cache. Prevents race conditions where multiple workflows try to write to the cache.
+  runtime_node_modules_cache:
+    name: Cache Runtime node_modules
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+      - name: Check cache hit
+        uses: actions/cache/restore@v4
+        id: node_modules
+        with:
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          lookup-only: true
+      - uses: actions/setup-node@v4
+        if: steps.node_modules.outputs.cache-hit != 'true'
+        with:
+          node-version-file: '.nvmrc'
+          cache: yarn
+          cache-dependency-path: yarn.lock
+      - name: Warm with old cache
+        if: steps.node_modules.outputs.cache-hit != 'true'
+        uses: actions/cache/restore@v4
+        with:
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+      - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - name: Save cache
+        if: steps.node_modules.outputs.cache-hit != 'true'
+        uses: actions/cache/save@v4
+        with:
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+
+  runtime_compiler_node_modules_cache:
+    name: Cache Runtime, Compiler node_modules
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+      - name: Check cache hit
+        uses: actions/cache/restore@v4
+        id: node_modules
+        with:
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          lookup-only: true
+      - uses: actions/setup-node@v4
+        if: steps.node_modules.outputs.cache-hit != 'true'
+        with:
+          node-version-file: '.nvmrc'
+          cache: yarn
+          cache-dependency-path: |
+            yarn.lock
+            compiler/yarn.lock
+      - name: Warm with old cache
+        if: steps.node_modules.outputs.cache-hit != 'true'
+        uses: actions/cache/restore@v4
+        with:
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+      - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: yarn --cwd compiler install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - name: Save cache
+        if: steps.node_modules.outputs.cache-hit != 'true'
+        uses: actions/cache/save@v4
+        with:
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+
   # ----- FLOW -----
   discover_flow_inline_configs:
     name: Discover flow inline configs
@@ -26,7 +123,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/github-script@v7
         id: set-matrix
         with:
@@ -36,7 +133,7 @@ jobs:
 
   flow:
     name: Flow check ${{ matrix.flow_inline_config_shortname }}
-    needs: discover_flow_inline_configs
+    needs: [discover_flow_inline_configs, runtime_node_modules_cache]
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -45,45 +142,52 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - run: node ./scripts/tasks/flow-ci ${{ matrix.flow_inline_config_shortname }}
 
   # ----- FIZZ -----
   check_generated_fizz_runtime:
     name: Confirm generated inline Fizz runtime is up to date
+    needs: [runtime_node_modules_cache]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - run: |
           yarn generate-inline-fizz-runtime
           git diff --quiet || (echo "There was a change to the Fizz runtime. Run `yarn generate-inline-fizz-runtime` and check in the result." && false)
@@ -91,30 +195,34 @@ jobs:
   # ----- FEATURE FLAGS -----
   flags:
     name: Check flags
+    needs: [runtime_node_modules_cache]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - run: yarn flags
 
   # ----- TESTS -----
   test:
     name: yarn test ${{ matrix.params }} (Shard ${{ matrix.shard }})
+    needs: [runtime_compiler_node_modules_cache]
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -148,56 +256,102 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
-          cache-dependency-path: yarn.lock
+          cache-dependency-path: |
+            yarn.lock
+            compiler/yarn.lock
+      - name: Restore cached node_modules
+        uses: actions/cache/restore@v4
+        id: node_modules
+        with:
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
+      - name: Ensure clean build directory
+        run: rm -rf build
+      - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: yarn --cwd compiler install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: yarn test ${{ matrix.params }} --ci --shard=${{ matrix.shard }}
+
+  # Hardcoded to improve parallelism
+  test-linter:
+    name: Test eslint-plugin-react-hooks
+    needs: [runtime_compiler_node_modules_cache]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version-file: '.nvmrc'
+          cache: yarn
+          cache-dependency-path:  |
+            yarn.lock
+            compiler/yarn.lock
       - name: Restore cached node_modules
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-      - name: Ensure clean build directory
-        run: rm -rf build
-      - run: yarn install --frozen-lockfile
-      - run: yarn test ${{ matrix.params }} --ci --shard=${{ matrix.shard }}
-
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+      - name: Install runtime dependencies
+        run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - name: Install compiler dependencies
+        run: yarn install --frozen-lockfile
+        working-directory: compiler
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: ./scripts/react-compiler/build-compiler.sh && ./scripts/react-compiler/link-compiler.sh
+      - run: yarn workspace eslint-plugin-react-hooks test
+        
   # ----- BUILD -----
   build_and_lint:
     name: yarn build and lint
+    needs: [runtime_compiler_node_modules_cache]
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
         # yml is dumb. update the --total arg to yarn build if you change the number of workers
-        worker_id: [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]
+        worker_id: [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24]
         release_channel: [stable, experimental]
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
-          cache-dependency-path: yarn.lock
+          cache-dependency-path: |
+            yarn.lock
+            compiler/yarn.lock
       - uses: actions/setup-java@v4
         with:
           distribution: temurin
           java-version: 11.0.22
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
-      - run: yarn build --index=${{ matrix.worker_id }} --total=20 --r=${{ matrix.release_channel }} --ci
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: yarn --cwd compiler install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: yarn build --index=${{ matrix.worker_id }} --total=25 --r=${{ matrix.release_channel }} --ci
         env:
           CI: github
           RELEASE_CHANNEL: ${{ matrix.release_channel }}
@@ -211,10 +365,11 @@ jobs:
         with:
           name: _build_${{ matrix.worker_id }}_${{ matrix.release_channel }}
           path: build
+          if-no-files-found: error
 
   test_build:
     name: yarn test-build
-    needs: build_and_lint
+    needs: [build_and_lint, runtime_compiler_node_modules_cache]
     strategy:
       fail-fast: false
       matrix:
@@ -249,28 +404,42 @@ jobs:
           # TODO: Test more persistent configurations?
         ]
         shard:
-          - 1/3
-          - 2/3
-          - 3/3
+          - 1/10
+          - 2/10
+          - 3/10
+          - 4/10
+          - 5/10
+          - 6/10
+          - 7/10
+          - 8/10
+          - 9/10
+          - 10/10
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
-          cache-dependency-path: yarn.lock
+          cache-dependency-path: |
+            yarn.lock
+            compiler/yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: yarn --cwd compiler install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -283,26 +452,29 @@ jobs:
 
   process_artifacts_combined:
     name: Process artifacts combined
-    needs: build_and_lint
+    needs: [build_and_lint, runtime_node_modules_cache]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -311,7 +483,7 @@ jobs:
           merge-multiple: true
       - name: Display structure of build
         run: ls -R build
-      - run: echo ${{ github.sha }} >> build/COMMIT_SHA
+      - run: echo ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
       - name: Scrape warning messages
         run: |
           mkdir -p ./build/__test_utils__
@@ -327,29 +499,33 @@ jobs:
           path: |
             ./build.tgz
             ./build2.tgz
+          if-no-files-found: error
 
   check_error_codes:
     name: Search build artifacts for unminified errors
-    needs: build_and_lint
+    needs: [build_and_lint, runtime_node_modules_cache]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -365,26 +541,29 @@ jobs:
 
   check_release_dependencies:
     name: Check release dependencies
-    needs: build_and_lint
+    needs: [build_and_lint, runtime_node_modules_cache]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -402,22 +581,23 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache@v4 # note: this does not reuse centralized cache since it has unique cache key
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: fixtures_dom-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: fixtures_dom-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'fixtures/dom/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
-      - run: yarn install --frozen-lockfile
-        working-directory: fixtures/dom
+      - run: yarn --cwd fixtures/dom install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -442,7 +622,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -452,14 +632,31 @@ jobs:
       # That means dependencies of the built packages are not installed.
       # We need to install dependencies of the workroot to fulfill all dependency constraints
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache@v4 # note: this does not reuse centralized cache since it has unique cache key
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: fixtures_flight-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: fixtures_flight-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'fixtures/flight/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: yarn --cwd fixtures/flight install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - name: Check Playwright version
+        id: playwright_version
+        run: echo "playwright_version=$(npm ls @playwright/test | grep @playwright | sed 's/.*@//' | head -1)" >> "$GITHUB_OUTPUT"
+      - name: Cache Playwright Browsers for version ${{ steps.playwright_version.outputs.playwright_version }}
+        id: cache_playwright_browsers
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-browsers-v6-${{ runner.arch }}-${{ runner.os }}-${{ steps.playwright_version.outputs.playwright_version }}
+      - name: Playwright install deps
+        if: steps.cache_playwright_browsers.outputs.cache-hit != 'true'
+        working-directory: fixtures/flight
+        run: npx playwright install --with-deps chromium
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -468,16 +665,6 @@ jobs:
           merge-multiple: true
       - name: Display structure of build
         run: ls -R build
-      - name: Install fixture dependencies
-        working-directory: fixtures/flight
-        run: |
-          yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
-          if [ $? -ne 0 ]; then
-            yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
-          fi
-      - name: Playwright install deps
-        working-directory: fixtures/flight
-        run: npx playwright install --with-deps chromium
       - name: Run tests
         working-directory: fixtures/flight
         run: yarn test
@@ -489,16 +676,18 @@ jobs:
         with:
           name: flight-playwright-report
           path: fixtures/flight/playwright-report
+          if-no-files-found: warn
       - name: Archive Flight fixture artifacts
         uses: actions/upload-artifact@v4
         with:
           name: flight-test-results
           path: fixtures/flight/test-results
+          if-no-files-found: ignore
 
   # ----- DEVTOOLS -----
   build_devtools_and_process_artifacts:
     name: Build DevTools and process artifacts
-    needs: build_and_lint
+    needs: [build_and_lint, runtime_node_modules_cache]
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -507,21 +696,24 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -539,6 +731,7 @@ jobs:
         with:
           name: react-devtools-${{ matrix.browser }}-extension
           path: build/devtools/${{ matrix.browser }}-extension.zip
+          if-no-files-found: error
 
   merge_devtools_artifacts:
     name: Merge DevTools artifacts
@@ -553,26 +746,29 @@ jobs:
 
   run_devtools_e2e_tests:
     name: Run DevTools e2e tests
-    needs: build_and_lint
+    needs: [build_and_lint, runtime_node_modules_cache]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -591,26 +787,32 @@ jobs:
     if: ${{ github.event_name == 'pull_request' && github.ref_name != 'main' && github.event.pull_request.base.ref == 'main' }}
     name: Run sizebot
     needs: [build_and_lint]
+    permissions:
+      # We use github.token to download the build artifact from a previous runtime_build_and_test.yml run
+      actions: read
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache@v4 # note: this does not reuse centralized cache since it has unique cache key
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-release-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
-        working-directory: scripts/release
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: yarn --cwd scripts/release install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
       - name: Download artifacts for base revision
         run: |
           GH_TOKEN=${{ github.token }} scripts/release/download-experimental-build.js --commit=$(git rev-parse ${{ github.event.pull_request.base.sha }})
@@ -625,7 +827,6 @@ jobs:
         run: ls -R base-build
       - name: Ensure clean build directory
         run: rm -rf build
-      - run: yarn install --frozen-lockfile
       - name: Restore archived build for PR
         uses: actions/download-artifact@v4
         with:
@@ -638,10 +839,11 @@ jobs:
           node ./scripts/print-warnings/print-warnings.js > build/__test_utils__/ReactAllWarnings.js
       - name: Display structure of build for PR
         run: ls -R build
-      - run: echo ${{ github.sha }} >> build/COMMIT_SHA
+      - run: echo ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
       - run: node ./scripts/tasks/danger
       - name: Archive sizebot results
         uses: actions/upload-artifact@v4
         with:
           name: sizebot-message
           path: sizebot-message.md
+          if-no-files-found: ignore

.github/workflows/runtime_commit_artifacts.yml

@@ -16,6 +16,13 @@ on:
         required: true
         default: false
         type: boolean
+      dry_run:
+        description: Perform a dry run (run everything except push)
+        required: true
+        default: false
+        type: boolean
+
+permissions: {}
 
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
@@ -25,6 +32,40 @@ env:
 jobs:
   download_artifacts:
     runs-on: ubuntu-latest
+    permissions:
+      # We use github.token to download the build artifact from a previous runtime_build_and_test.yml run
+      actions: read
+    steps:
+      - uses: actions/checkout@v4
+      - name: Restore cached node_modules
+        uses: actions/cache@v4
+        id: node_modules
+        with:
+          path: |
+            **/node_modules
+          key: runtime-release-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
+      - name: Ensure clean build directory
+        run: rm -rf build
+      - run: yarn install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - run: yarn --cwd scripts/release install --frozen-lockfile
+        if: steps.node_modules.outputs.cache-hit != 'true'
+      - name: Download artifacts for base revision
+        run: |
+          GH_TOKEN=${{ github.token }} scripts/release/download-experimental-build.js --commit=${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }}
+      - name: Display structure of build
+        run: ls -R build
+      - name: Archive build
+        uses: actions/upload-artifact@v4
+        with:
+          name: build
+          path: build/
+          if-no-files-found: error
+
+
+  process_artifacts:
+    runs-on: ubuntu-latest
+    needs: [download_artifacts]
     outputs:
       www_branch_count: ${{ steps.check_branches.outputs.www_branch_count }}
       fbsource_branch_count: ${{ steps.check_branches.outputs.fbsource_branch_count }}
@@ -64,27 +105,11 @@ jobs:
         run: |
           echo "www_branch_count=$(git ls-remote --heads origin "refs/heads/meta-www" | wc -l)" >> "$GITHUB_OUTPUT"
           echo "fbsource_branch_count=$(git ls-remote --heads origin "refs/heads/meta-fbsource" | wc -l)" >> "$GITHUB_OUTPUT"
-      - uses: actions/setup-node@v4
+      - name: Restore downloaded build
+        uses: actions/download-artifact@v4
         with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: runtime-release-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
-      - name: Ensure clean build directory
-        run: rm -rf build
-      - run: yarn install --frozen-lockfile
-        name: yarn install (react)
-      - run: yarn install --frozen-lockfile
-        name: yarn install (scripts/release)
-        working-directory: scripts/release
-      - name: Download artifacts for base revision
-        run: |
-          GH_TOKEN=${{ github.token }} scripts/release/download-experimental-build.js --commit=${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }}
+          name: build
+          path: build
       - name: Display structure of build
         run: ls -R build
       - name: Strip @license from eslint plugin and react-refresh
@@ -107,9 +132,10 @@ jobs:
           mkdir ./compiled/facebook-www/__test_utils__
           mv build/__test_utils__/ReactAllWarnings.js ./compiled/facebook-www/__test_utils__/ReactAllWarnings.js
 
-          # Move eslint-plugin-react-hooks into facebook-www
+          # Move eslint-plugin-react-hooks into eslint-plugin-react-hooks
+          mkdir ./compiled/eslint-plugin-react-hooks
           mv build/oss-experimental/eslint-plugin-react-hooks/cjs/eslint-plugin-react-hooks.development.js \
-            ./compiled/facebook-www/eslint-plugin-react-hooks.js
+            ./compiled/eslint-plugin-react-hooks/index.js
 
           # Move unstable_server-external-runtime.js into facebook-www
           mv build/oss-experimental/react-dom/unstable_server-external-runtime.js \
@@ -147,9 +173,9 @@ jobs:
           ls -R ./compiled-rn
       - name: Add REVISION files
         run: |
-          echo ${{ github.sha }} >> ./compiled/facebook-www/REVISION
+          echo ${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }} >> ./compiled/facebook-www/REVISION
           cp ./compiled/facebook-www/REVISION ./compiled/facebook-www/REVISION_TRANSFORMS
-          echo ${{ github.sha}} >> ./compiled-rn/facebook-fbsource/xplat/js/react-native-github/Libraries/Renderer/REVISION
+          echo ${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }} >> ./compiled-rn/facebook-fbsource/xplat/js/react-native-github/Libraries/Renderer/REVISION
       - name: "Get current version string"
         id: get_current_version
         run: |
@@ -166,15 +192,20 @@ jobs:
         with:
           name: compiled
           path: compiled/
+          if-no-files-found: error
       - uses: actions/upload-artifact@v4
         with:
           name: compiled-rn
           path: compiled-rn/
+          if-no-files-found: error
 
   commit_www_artifacts:
-    needs: download_artifacts
-    if: inputs.force == true || (github.ref == 'refs/heads/main' && needs.download_artifacts.outputs.www_branch_count == '0')
+    needs: [download_artifacts, process_artifacts]
+    if: inputs.force == true || (github.ref == 'refs/heads/main' && needs.process_artifacts.outputs.www_branch_count == '0')
     runs-on: ubuntu-latest
+    permissions:
+      # Used to push a commit to builds/facebook-www
+      contents: write
     steps:
       - uses: actions/checkout@v4
         with:
@@ -186,12 +217,12 @@ jobs:
           name: compiled
           path: compiled/
       - name: Revert version changes
-        if: needs.download_artifacts.outputs.last_version_classic != '' && needs.download_artifacts.outputs.last_version_modern != ''
+        if: needs.process_artifacts.outputs.last_version_classic != '' && needs.process_artifacts.outputs.last_version_modern != ''
         env:
-          CURRENT_VERSION_CLASSIC: ${{ needs.download_artifacts.outputs.current_version_classic }}
-          CURRENT_VERSION_MODERN: ${{ needs.download_artifacts.outputs.current_version_modern }}
-          LAST_VERSION_CLASSIC: ${{ needs.download_artifacts.outputs.last_version_classic }}
-          LAST_VERSION_MODERN: ${{ needs.download_artifacts.outputs.last_version_modern }}
+          CURRENT_VERSION_CLASSIC: ${{ needs.process_artifacts.outputs.current_version_classic }}
+          CURRENT_VERSION_MODERN: ${{ needs.process_artifacts.outputs.current_version_modern }}
+          LAST_VERSION_CLASSIC: ${{ needs.process_artifacts.outputs.last_version_classic }}
+          LAST_VERSION_MODERN: ${{ needs.process_artifacts.outputs.last_version_modern }}
         run: |
           echo "Reverting $CURRENT_VERSION_CLASSIC to $LAST_VERSION_CLASSIC"
           grep -rl "$CURRENT_VERSION_CLASSIC" ./compiled || echo "No files found with $CURRENT_VERSION_CLASSIC"
@@ -221,12 +252,12 @@ jobs:
             echo "should_commit=false" >> "$GITHUB_OUTPUT"
           fi
       - name: Re-apply version changes
-        if: inputs.force == true || (steps.check_should_commit.outputs.should_commit == 'true' && needs.download_artifacts.outputs.last_version_classic != '' && needs.download_artifacts.outputs.last_version_modern != '')
+        if: inputs.force == true || (steps.check_should_commit.outputs.should_commit == 'true' && needs.process_artifacts.outputs.last_version_classic != '' && needs.process_artifacts.outputs.last_version_modern != '')
         env:
-          CURRENT_VERSION_CLASSIC: ${{ needs.download_artifacts.outputs.current_version_classic }}
-          CURRENT_VERSION_MODERN: ${{ needs.download_artifacts.outputs.current_version_modern }}
-          LAST_VERSION_CLASSIC: ${{ needs.download_artifacts.outputs.last_version_classic }}
-          LAST_VERSION_MODERN: ${{ needs.download_artifacts.outputs.last_version_modern }}
+          CURRENT_VERSION_CLASSIC: ${{ needs.process_artifacts.outputs.current_version_classic }}
+          CURRENT_VERSION_MODERN: ${{ needs.process_artifacts.outputs.current_version_modern }}
+          LAST_VERSION_CLASSIC: ${{ needs.process_artifacts.outputs.last_version_classic }}
+          LAST_VERSION_MODERN: ${{ needs.process_artifacts.outputs.last_version_modern }}
         run: |
           echo "Re-applying $LAST_VERSION_CLASSIC to $CURRENT_VERSION_CLASSIC"
           grep -rl "$LAST_VERSION_CLASSIC" ./compiled || echo "No files found with $LAST_VERSION_CLASSIC"
@@ -240,24 +271,31 @@ jobs:
       - name: Will commit these changes
         if: inputs.force == true || steps.check_should_commit.outputs.should_commit == 'true'
         run: |
-          echo ":"
-          git status -u
+          git add .
+          git status
+      - name: Check commit message
+        if: inputs.dry_run
+        run: |
+          git fetch origin --quiet
+          git show ${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }} --no-patch --pretty=format:"%B"
       - name: Commit changes to branch
         if: inputs.force == true || steps.check_should_commit.outputs.should_commit == 'true'
-        uses: stefanzweifel/git-auto-commit-action@v5
-        with:
-          commit_message: |
-            ${{ github.event.workflow_run.head_commit.message || format('Manual build of {0}', github.event.workflow_run.head_sha || github.sha) }}
+        run: |
+          git config --global user.email "${{ format('{0}@users.noreply.github.com', github.triggering_actor) }}"
+          git config --global user.name "${{ github.triggering_actor }}"
 
-            DiffTrain build for [${{ github.event.workflow_run.head_sha || github.sha }}](https://github.com/facebook/react/commit/${{ github.event.workflow_run.head_sha || github.sha }})
-          branch: builds/facebook-www
-          commit_user_name: ${{ github.triggering_actor }}
-          commit_user_email: ${{ format('{0}@users.noreply.github.com', github.triggering_actor) }}
-          create_branch: true
+          git fetch origin --quiet
+          git commit -m "$(git show ${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }} --no-patch --pretty=format:'%B%n%nDiffTrain build for [${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }}](https://github.com/facebook/react/commit/${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha}})')" || echo "No changes to commit"
+      - name: Push changes to branch
+        if: inputs.dry_run == false && (inputs.force == true || steps.check_should_commit.outputs.should_commit == 'true')
+        run: git push
 
   commit_fbsource_artifacts:
-    needs: download_artifacts
-    if: inputs.force == true || (github.ref == 'refs/heads/main' && needs.download_artifacts.outputs.fbsource_branch_count == '0')
+    needs: [download_artifacts, process_artifacts]
+    permissions:
+      # Used to push a commit to builds/facebook-fbsource
+      contents: write
+    if: inputs.force == true || (github.ref == 'refs/heads/main' && needs.process_artifacts.outputs.fbsource_branch_count == '0')
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -270,10 +308,10 @@ jobs:
           name: compiled-rn
           path: compiled-rn/
       - name: Revert version changes
-        if: needs.download_artifacts.outputs.last_version_rn != ''
+        if: needs.process_artifacts.outputs.last_version_rn != ''
         env:
-          CURRENT_VERSION: ${{ needs.download_artifacts.outputs.current_version_rn }}
-          LAST_VERSION: ${{ needs.download_artifacts.outputs.last_version_rn }}
+          CURRENT_VERSION: ${{ needs.process_artifacts.outputs.current_version_rn }}
+          LAST_VERSION: ${{ needs.process_artifacts.outputs.last_version_rn }}
         run: |
           echo "Reverting $CURRENT_VERSION to $LAST_VERSION"
           grep -rl "$CURRENT_VERSION" ./compiled-rn || echo "No files found with $CURRENT_VERSION"
@@ -299,10 +337,10 @@ jobs:
             echo "should_commit=false" >> "$GITHUB_OUTPUT"
           fi
       - name: Re-apply version changes
-        if: inputs.force == true || (steps.check_should_commit.outputs.should_commit == 'true' && needs.download_artifacts.outputs.last_version_rn != '')
+        if: inputs.force == true || (steps.check_should_commit.outputs.should_commit == 'true' && needs.process_artifacts.outputs.last_version_rn != '')
         env:
-          CURRENT_VERSION: ${{ needs.download_artifacts.outputs.current_version_rn }}
-          LAST_VERSION: ${{ needs.download_artifacts.outputs.last_version_rn }}
+          CURRENT_VERSION: ${{ needs.process_artifacts.outputs.current_version_rn }}
+          LAST_VERSION: ${{ needs.process_artifacts.outputs.last_version_rn }}
         run: |
           echo "Re-applying $LAST_VERSION to $CURRENT_VERSION"
           grep -rl "$LAST_VERSION" ./compiled-rn || echo "No files found with $LAST_VERSION"
@@ -409,15 +447,19 @@ jobs:
         run: |
           git add .
           git status
+      - name: Check commit message
+        if: inputs.dry_run
+        run: |
+          git fetch origin --quiet
+          git show ${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }} --no-patch --pretty=format:"%B"
       - name: Commit changes to branch
         if: inputs.force == true || steps.check_should_commit.outputs.should_commit == 'true'
-        uses: stefanzweifel/git-auto-commit-action@v5
-        with:
-          commit_message: |
-            ${{ github.event.workflow_run.head_commit.message || format('Manual build of {0}', github.event.workflow_run.head_sha || github.sha) }}
+        run: |
+          git config --global user.email "${{ format('{0}@users.noreply.github.com', github.triggering_actor) }}"
+          git config --global user.name "${{ github.triggering_actor }}"
 
-            DiffTrain build for [${{ github.event.workflow_run.head_sha || github.sha }}](https://github.com/facebook/react/commit/${{ github.event.workflow_run.head_sha || github.sha }})
-          branch: builds/facebook-fbsource
-          commit_user_name: ${{ github.triggering_actor }}
-          commit_user_email: ${{ format('{0}@users.noreply.github.com', github.triggering_actor) }}
-          create_branch: true
+          git fetch origin --quiet
+          git commit -m "$(git show ${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }} --no-patch --pretty=format:'%B%n%nDiffTrain build for [${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha }}](https://github.com/facebook/react/commit/${{ inputs.commit_sha || github.event.workflow_run.head_sha || github.sha}})')" || echo "No changes to commit"
+      - name: Push changes to branch
+        if: inputs.dry_run == false && (inputs.force == true || steps.check_should_commit.outputs.should_commit == 'true')
+        run: git push

.github/workflows/runtime_discord_notify.yml

@@ -1,15 +1,20 @@
 name: (Runtime) Discord Notify
 
 on:
-  pull_request_target:
+  pull_request:
     types: [opened, ready_for_review]
     paths-ignore:
       - compiler/**
       - .github/workflows/compiler_**.yml
 
+permissions: {}
+
 jobs:
   check_maintainer:
     uses: facebook/react/.github/workflows/shared_check_maintainer.yml@main
+    permissions:
+      # Used by check_maintainer
+      contents: read
     with:
       actor: ${{ github.event.pull_request.user.login }}
 
@@ -19,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Discord Webhook Action
-        uses: tsickert/discord-webhook@v6.0.0
+        uses: tsickert/discord-webhook@86dc739f3f165f16dadc5666051c367efa1692f4
         with:
           webhook-url: ${{ secrets.DISCORD_WEBHOOK_URL }}
           embed-author-name: ${{ github.event.pull_request.user.login }}

.github/workflows/runtime_eslint_plugin_e2e.yml

@@ -7,6 +7,8 @@ on:
     paths-ignore:
       - compiler/**
 
+permissions: {}
+
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
@@ -35,16 +37,20 @@ jobs:
         with:
           node-version-file: '.nvmrc'
           cache: yarn
-          cache-dependency-path: yarn.lock
+          cache-dependency-path: |
+            yarn.lock
+            compiler/yarn.lock
       - name: Restore cached node_modules
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "node_modules"
-          key: runtime-eslint_e2e-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-eslint_e2e-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+      - run: yarn --cwd compiler install --frozen-lockfile
       - name: Build plugin
         working-directory: fixtures/eslint-v${{ matrix.eslint_major }}
         run: node build.mjs

.github/workflows/runtime_fuzz_tests.yml

@@ -8,6 +8,8 @@ on:
       - main
   workflow_dispatch:
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
 

.github/workflows/runtime_prereleases.yml

@@ -17,11 +17,12 @@ on:
       NPM_TOKEN:
         required: true
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
   # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
   SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
-  GH_TOKEN: ${{ github.token }}
   NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
 
 jobs:
@@ -39,13 +40,13 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-release-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-release-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
-      - run: yarn install --frozen-lockfile
-        working-directory: scripts/release
+      - run: yarn --cwd scripts/release install --frozen-lockfile
       - run: |
           scripts/release/prepare-release-from-ci.js --skipTests -r ${{ inputs.release_channel }} --commit=${{ inputs.commit_sha }}
           cp ./scripts/release/ci-npmrc ~/.npmrc

.github/workflows/runtime_prereleases_manual.yml

@@ -6,6 +6,8 @@ on:
       prerelease_commit_sha:
         required: true
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
 

.github/workflows/runtime_prereleases_nightly.yml

@@ -5,6 +5,8 @@ on:
     # At 10 minutes past 16:00 on Mon, Tue, Wed, Thu, and Fri
     - cron: 10 16 * * 1,2,3,4,5
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
 

.github/workflows/runtime_releases_from_npm_manual.yml

@@ -31,11 +31,12 @@ on:
         type: boolean
         default: false
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
   # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
   SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
-  GH_TOKEN: ${{ github.token }}
   NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
 
 jobs:
@@ -44,7 +45,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Discord Webhook Action
-        uses: tsickert/discord-webhook@v6.0.0
+        uses: tsickert/discord-webhook@86dc739f3f165f16dadc5666051c367efa1692f4
         with:
           webhook-url: ${{ secrets.DISCORD_WEBHOOK_URL }}
           embed-author-name: ${{ github.event.sender.login }}
@@ -71,13 +72,13 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-release-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-release-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
-      - run: yarn install --frozen-lockfile
-        working-directory: scripts/release
+      - run: yarn --cwd scripts/release install --frozen-lockfile
       - run: cp ./scripts/release/ci-npmrc ~/.npmrc
       - if: '${{ inputs.only_packages }}'
         name: 'Prepare ${{ inputs.only_packages }} from NPM'

.github/workflows/shared_check_maintainer.yml

@@ -14,6 +14,8 @@ on:
       is_core_team:
         value: ${{ jobs.check_maintainer.outputs.is_core_team }}
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
   # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
@@ -22,6 +24,9 @@ env:
 jobs:
   check_maintainer:
     runs-on: ubuntu-latest
+    permissions:
+      # We fetch the contents of the MAINTAINERS file
+      contents: read
     outputs:
       is_core_team: ${{ steps.check_if_actor_is_maintainer.outputs.result }}
     steps:

.github/workflows/shared_cleanup_merged_branch_caches.yml

@@ -0,0 +1,41 @@
+# https://github.com/actions/cache/blob/main/tips-and-workarounds.md#force-deletion-of-caches-overriding-default-cache-eviction-policy
+
+name: (Shared) Cleanup Merged Branch Caches
+on:
+  pull_request:
+    types:
+      - closed
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        required: true
+        type: string
+
+permissions: {}
+
+jobs:
+  cleanup:
+    runs-on: ubuntu-latest
+    permissions:
+      # `actions:write` permission is required to delete caches
+      #   See also: https://docs.github.com/en/rest/actions/cache?apiVersion=2022-11-28#delete-a-github-actions-cache-for-a-repository-using-a-cache-id
+      actions: write
+      contents: read
+    steps:
+      - name: Cleanup
+        run: |
+          echo "Fetching list of cache key"
+          cacheKeysForPR=$(gh cache list --ref $BRANCH --limit 100 --json id --jq '.[].id')
+
+          ## Setting this to not fail the workflow while deleting cache keys.
+          set +e
+          for cacheKey in $cacheKeysForPR
+          do
+              gh cache delete $cacheKey
+              echo "Deleting $cacheKey"
+          done
+          echo "Done"
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_REPO: ${{ github.repository }}
+          BRANCH: refs/pull/${{ inputs.pr_number || github.event.pull_request.number }}/merge

.github/workflows/shared_cleanup_stale_branch_caches.yml

@@ -0,0 +1,35 @@
+# https://github.com/actions/cache/blob/main/tips-and-workarounds.md#force-deletion-of-caches-overriding-default-cache-eviction-policy
+
+name: (Shared) Cleanup Stale Branch Caches
+on:
+  schedule:
+    - cron: 0 0 * * *
+  workflow_dispatch:
+
+permissions: {}
+
+jobs:
+  cleanup:
+    runs-on: ubuntu-latest
+    permissions:
+      # `actions:write` permission is required to delete caches
+      #   See also: https://docs.github.com/en/rest/actions/cache?apiVersion=2022-11-28#delete-a-github-actions-cache-for-a-repository-using-a-cache-id
+      actions: write
+      contents: read
+    steps:
+      - name: Cleanup
+        run: |
+          echo "Fetching list of cache keys"
+          cacheKeysForPR=$(gh cache list --limit 100 --json id,ref --jq '.[] | select(.ref != "refs/heads/main") | .id')
+
+          ## Setting this to not fail the workflow while deleting cache keys.
+          set +e
+          for cacheKey in $cacheKeysForPR
+          do
+              gh cache delete $cacheKey
+              echo "Deleting $cacheKey"
+          done
+          echo "Done"
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_REPO: ${{ github.repository }}

.github/workflows/shared_close_direct_sync_branch_prs.yml

@@ -5,6 +5,8 @@ on:
     branches:
       - 'builds/facebook-**'
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
   # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
@@ -13,6 +15,9 @@ env:
 jobs:
   close_pr:
     runs-on: ubuntu-latest
+    permissions:
+      # Used to create a review and close PRs
+      pull-requests: write
     steps:
       - name: Close PR
         uses: actions/github-script@v7

.github/workflows/shared_label_core_team_prs.yml

@@ -1,7 +1,9 @@
 name: (Shared) Label Core Team PRs
 
 on:
-  pull_request_target:
+  pull_request:
+
+permissions: {}
 
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
@@ -11,6 +13,9 @@ env:
 jobs:
   check_maintainer:
     uses: facebook/react/.github/workflows/shared_check_maintainer.yml@main
+    permissions:
+      # Used by check_maintainer
+      contents: read
     with:
       actor: ${{ github.event.pull_request.user.login }}
 
@@ -18,6 +23,11 @@ jobs:
     if: ${{ needs.check_maintainer.outputs.is_core_team == 'true' }}
     runs-on: ubuntu-latest
     needs: check_maintainer
+    permissions:
+      # Used to add labels on issues
+      issues: write
+      # Used to add labels on PRs
+      pull-requests: write
     steps:
       - name: Label PR as React Core Team
         uses: actions/github-script@v7

.github/workflows/shared_lint.yml

@@ -5,6 +5,8 @@ on:
     branches: [main]
   pull_request:
 
+permissions: {}
+
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
@@ -28,8 +30,9 @@ jobs:
       - name: Restore cached node_modules
         uses: actions/cache@v4
         with:
-          path: "**/node_modules"
-          key: shared-lint-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: shared-lint-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
@@ -48,8 +51,9 @@ jobs:
       - name: Restore cached node_modules
         uses: actions/cache@v4
         with:
-          path: "**/node_modules"
-          key: shared-lint-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: shared-lint-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
@@ -68,8 +72,9 @@ jobs:
       - name: Restore cached node_modules
         uses: actions/cache@v4
         with:
-          path: "**/node_modules"
-          key: shared-lint-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: shared-lint-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
@@ -88,8 +93,9 @@ jobs:
       - name: Restore cached node_modules
         uses: actions/cache@v4
         with:
-          path: "**/node_modules"
-          key: shared-lint-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
+          path: |
+            **/node_modules
+          key: shared-lint-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile

.github/workflows/shared_stale.yml

@@ -6,6 +6,8 @@ on:
     - cron: '0 * * * *'
   workflow_dispatch:
 
+permissions: {}
+
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
 

ReactVersions.js

@@ -7,18 +7,18 @@
 //
 // The @latest channel uses the version as-is, e.g.:
 //
-//   19.1.0
+//   19.1.6
 //
 // The @canary channel appends additional information, with the scheme
 // <version>-<label>-<commit_sha>, e.g.:
 //
-//   19.1.0-canary-a1c2d3e4
+//   19.1.6-canary-a1c2d3e4
 //
 // The @experimental channel doesn't include a version, only a date and a sha, e.g.:
 //
 //   0.0.0-experimental-241c4467e-20200129
 
-const ReactVersion = '19.1.0';
+const ReactVersion = '19.1.6';
 
 // 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
@@ -34,7 +34,7 @@ const rcNumber = 0;
 
 const stablePackages = {
   'eslint-plugin-react-hooks': '5.2.0',
-  'jest-react': '0.17.0',
+  'jest-react': '0.16.0',
   react: ReactVersion,
   'react-art': ReactVersion,
   'react-dom': ReactVersion,

babel.config.js

@@ -4,8 +4,7 @@ module.exports = {
   plugins: [
     '@babel/plugin-syntax-jsx',
     '@babel/plugin-transform-flow-strip-types',
-    ['@babel/plugin-transform-class-properties', {loose: true}],
-    '@babel/plugin-transform-classes',
+    ['@babel/plugin-proposal-class-properties', {loose: true}],
     'syntax-trailing-function-commas',
     [
       '@babel/plugin-proposal-object-rest-spread',

compiler/packages/babel-plugin-react-compiler/scripts/jest/e2e-forget.config.js

@@ -7,7 +7,4 @@
 
 const makeE2EConfig = require('../jest/makeE2EConfig');
 
-const config = makeE2EConfig('e2e with forget', true);
-config.setupFilesAfterEnv = ['<rootDir>/../scripts/jest/setupEnvE2E.js'];
-
-module.exports = config;
+module.exports = makeE2EConfig('e2e with forget', true);

compiler/packages/babel-plugin-react-compiler/scripts/jest/makeTransform.ts

@@ -5,19 +5,16 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {jsx} from '@babel/plugin-syntax-jsx';
 import babelJest from 'babel-jest';
-import {compile} from 'babel-plugin-react-compiler';
+import {
+  validateEnvironmentConfig,
+  EnvironmentConfig,
+} from 'babel-plugin-react-compiler';
 import {execSync} from 'child_process';
 
 import type {NodePath, Visitor} from '@babel/traverse';
-import type {CallExpression, FunctionDeclaration} from '@babel/types';
-import * as t from '@babel/types';
-import {
-  EnvironmentConfig,
-  validateEnvironmentConfig,
-} from 'babel-plugin-react-compiler';
-import {basename} from 'path';
+import type {CallExpression} from '@babel/types';
+import BabelPluginReactCompiler from 'babel-plugin-react-compiler';
 
 /**
  * -- IMPORTANT --
@@ -28,10 +25,19 @@ import {basename} from 'path';
 const e2eTransformerCacheKey = 1;
 const forgetOptions: EnvironmentConfig = validateEnvironmentConfig({
   enableAssumeHooksFollowRulesOfReact: true,
-  enableFunctionOutlining: false,
 });
 const debugMode = process.env['DEBUG_FORGET_COMPILER'] != null;
 
+const compilerCacheKey = execSync(
+  'yarn --silent --cwd ../.. hash packages/babel-plugin-react-compiler/dist',
+)
+  .toString()
+  .trim();
+
+if (debugMode) {
+  console.log('cachebreaker', compilerCacheKey);
+}
+
 module.exports = (useForget: boolean) => {
   function createTransformer() {
     return babelJest.createTransformer({
@@ -42,15 +48,14 @@ module.exports = (useForget: boolean) => {
           plugins: [
             useForget
               ? [
-                  ReactForgetFunctionTransform,
+                  BabelPluginReactCompiler,
                   {
+                    environment: forgetOptions,
                     /*
                      * Jest hashes the babel config as a cache breaker.
                      * (see https://github.com/jestjs/jest/blob/v29.6.2/packages/babel-jest/src/index.ts#L84)
                      */
-                    compilerCacheKey: execSync(
-                      'yarn --silent --cwd ../.. hash packages/babel-plugin-react-compiler/dist',
-                    ).toString(),
+                    compilerCacheKey,
                     transformOptionsCacheKey: forgetOptions,
                     e2eTransformerCacheKey,
                   },
@@ -105,103 +110,3 @@ module.exports = (useForget: boolean) => {
     createTransformer,
   };
 };
-
-// Mostly copied from react/scripts/babel/transform-forget.js
-function isReactComponentLike(fn: NodePath<FunctionDeclaration>): boolean {
-  let isReactComponent = false;
-  let hasNoUseForgetDirective = false;
-
-  /*
-   * React components start with an upper case letter,
-   * React hooks start with `use`
-   */
-  if (
-    fn.node.id == null ||
-    (fn.node.id.name[0].toUpperCase() !== fn.node.id.name[0] &&
-      !/^use[A-Z0-9]/.test(fn.node.id.name))
-  ) {
-    return false;
-  }
-
-  fn.traverse({
-    DirectiveLiteral(path) {
-      if (path.node.value === 'use no forget') {
-        hasNoUseForgetDirective = true;
-      }
-    },
-
-    JSX(path) {
-      // Is there is a JSX node created in the current function context?
-      if (path.scope.getFunctionParent()?.path.node === fn.node) {
-        isReactComponent = true;
-      }
-    },
-
-    CallExpression(path) {
-      // Is there hook usage?
-      if (
-        path.node.callee.type === 'Identifier' &&
-        !/^use[A-Z0-9]/.test(path.node.callee.name)
-      ) {
-        isReactComponent = true;
-      }
-    },
-  });
-
-  if (hasNoUseForgetDirective) {
-    return false;
-  }
-
-  return isReactComponent;
-}
-
-function ReactForgetFunctionTransform() {
-  const compiledFns = new Set();
-  const visitor = {
-    FunctionDeclaration(fn: NodePath<FunctionDeclaration>, state: any): void {
-      if (compiledFns.has(fn.node)) {
-        return;
-      }
-
-      if (!isReactComponentLike(fn)) {
-        return;
-      }
-      if (debugMode) {
-        const filename = basename(state.file.opts.filename);
-        if (fn.node.loc && fn.node.id) {
-          console.log(
-            ` Compiling ${filename}:${fn.node.loc.start.line}:${fn.node.loc.start.column}  ${fn.node.id.name}`,
-          );
-        } else {
-          console.log(` Compiling ${filename} ${fn.node.id?.name}`);
-        }
-      }
-
-      const compiled = compile(
-        fn,
-        forgetOptions,
-        'Other',
-        '_c',
-        null,
-        null,
-        null,
-      );
-      compiledFns.add(compiled);
-
-      const fun = t.functionDeclaration(
-        compiled.id,
-        compiled.params,
-        compiled.body,
-        compiled.generator,
-        compiled.async,
-      );
-      fn.replaceWith(fun);
-      fn.skip();
-    },
-  };
-  return {
-    name: 'react-forget-e2e',
-    inherits: jsx,
-    visitor,
-  };
-}

compiler/packages/babel-plugin-react-compiler/scripts/jest/setupEnvE2E.js

@@ -1,16 +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.
- */
-
-const ReactCompilerRuntime = require('react/compiler-runtime');
-
-/*
- * Our e2e babel transform currently only compiles functions, not programs.
- * As a result, our e2e transpiled code does not contain an import for the
- * memo cache function. As a temporary hack, we add a `_c` global, which is
- * the name that is used for the import by default.
- */
-globalThis._c = ReactCompilerRuntime.c;

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

@@ -11,6 +11,7 @@ import {
   injectReanimatedFlag,
   pipelineUsesReanimatedPlugin,
 } from '../Entrypoint/Reanimated';
+import validateNoUntransformedReferences from '../Entrypoint/ValidateNoUntransformedReferences';
 
 const ENABLE_REACT_COMPILER_TIMINGS =
   process.env['ENABLE_REACT_COMPILER_TIMINGS'] === '1';
@@ -61,12 +62,19 @@ export default function BabelPluginReactCompiler(
               },
             };
           }
-          compileProgram(prog, {
+          const result = compileProgram(prog, {
             opts,
             filename: pass.filename ?? null,
             comments: pass.file.ast.comments ?? [],
             code: pass.file.code,
           });
+          validateNoUntransformedReferences(
+            prog,
+            pass.filename ?? null,
+            opts.logger,
+            opts.environment,
+            result?.retryErrors ?? [],
+          );
           if (ENABLE_REACT_COMPILER_TIMINGS === true) {
             performance.mark(`${filename}:end`, {
               detail: 'BabelPlugin:Program:end',

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

@@ -6,6 +6,7 @@
  */
 
 import type {SourceLocation} from './HIR';
+import {Err, Ok, Result} from './Utils/Result';
 import {assertExhaustive} from './Utils/utils';
 
 export enum ErrorSeverity {
@@ -224,6 +225,10 @@ export class CompilerError extends Error {
     return this.details.length > 0;
   }
 
+  asResult(): Result<void, CompilerError> {
+    return this.hasErrors() ? Err(this) : Ok(undefined);
+  }
+
   /*
    * An error is critical if it means the compiler has entered into a broken state and cannot
    * continue safely. Other expected errors such as Todos mean that we can skip over that component

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

@@ -8,7 +8,119 @@
 import {NodePath} from '@babel/core';
 import * as t from '@babel/types';
 import {PluginOptions} from './Options';
+import {CompilerError} from '../CompilerError';
 
+/**
+ * Gating rewrite for function declarations which are referenced before their
+ * declaration site.
+ *
+ * ```js
+ * // original
+ * export default React.memo(Foo);
+ * function Foo() { ... }
+ *
+ * // React compiler optimized + gated
+ * import {gating} from 'myGating';
+ * export default React.memo(Foo);
+ * const gating_result = gating();  <- inserted
+ * function Foo_optimized() {}      <- inserted
+ * function Foo_unoptimized() {}    <- renamed from Foo
+ * function Foo() {                 <- inserted function, which can be hoisted by JS engines
+ *   if (gating_result) return Foo_optimized();
+ *   else return Foo_unoptimized();
+ * }
+ * ```
+ */
+function insertAdditionalFunctionDeclaration(
+  fnPath: NodePath<t.FunctionDeclaration>,
+  compiled: t.FunctionDeclaration,
+  gating: NonNullable<PluginOptions['gating']>,
+): void {
+  const originalFnName = fnPath.node.id;
+  const originalFnParams = fnPath.node.params;
+  const compiledParams = fnPath.node.params;
+  /**
+   * Note that other than `export default function() {}`, all other function
+   * declarations must have a binding identifier. Since default exports cannot
+   * be referenced, it's safe to assume that all function declarations passed
+   * here will have an identifier.
+   * https://tc39.es/ecma262/multipage/ecmascript-language-functions-and-classes.html#sec-function-definitions
+   */
+  CompilerError.invariant(originalFnName != null && compiled.id != null, {
+    reason:
+      'Expected function declarations that are referenced elsewhere to have a named identifier',
+    loc: fnPath.node.loc ?? null,
+  });
+  CompilerError.invariant(originalFnParams.length === compiledParams.length, {
+    reason:
+      'Expected React Compiler optimized function declarations to have the same number of parameters as source',
+    loc: fnPath.node.loc ?? null,
+  });
+
+  const gatingCondition = fnPath.scope.generateUidIdentifier(
+    `${gating.importSpecifierName}_result`,
+  );
+  const unoptimizedFnName = fnPath.scope.generateUidIdentifier(
+    `${originalFnName.name}_unoptimized`,
+  );
+  const optimizedFnName = fnPath.scope.generateUidIdentifier(
+    `${originalFnName.name}_optimized`,
+  );
+  /**
+   * Step 1: rename existing functions
+   */
+  compiled.id.name = optimizedFnName.name;
+  fnPath.get('id').replaceInline(unoptimizedFnName);
+
+  /**
+   * Step 2: insert new function declaration
+   */
+  const newParams: Array<t.Identifier | t.RestElement> = [];
+  const genNewArgs: Array<() => t.Identifier | t.SpreadElement> = [];
+  for (let i = 0; i < originalFnParams.length; i++) {
+    const argName = `arg${i}`;
+    if (originalFnParams[i].type === 'RestElement') {
+      newParams.push(t.restElement(t.identifier(argName)));
+      genNewArgs.push(() => t.spreadElement(t.identifier(argName)));
+    } else {
+      newParams.push(t.identifier(argName));
+      genNewArgs.push(() => t.identifier(argName));
+    }
+  }
+  // insertAfter called in reverse order of how nodes should appear in program
+  fnPath.insertAfter(
+    t.functionDeclaration(
+      originalFnName,
+      newParams,
+      t.blockStatement([
+        t.ifStatement(
+          gatingCondition,
+          t.returnStatement(
+            t.callExpression(
+              compiled.id,
+              genNewArgs.map(fn => fn()),
+            ),
+          ),
+          t.returnStatement(
+            t.callExpression(
+              unoptimizedFnName,
+              genNewArgs.map(fn => fn()),
+            ),
+          ),
+        ),
+      ]),
+    ),
+  );
+  fnPath.insertBefore(
+    t.variableDeclaration('const', [
+      t.variableDeclarator(
+        gatingCondition,
+        t.callExpression(t.identifier(gating.importSpecifierName), []),
+      ),
+    ]),
+  );
+  fnPath.insertBefore(compiled);
+}
 export function insertGatedFunctionDeclaration(
   fnPath: NodePath<
     t.FunctionDeclaration | t.ArrowFunctionExpression | t.FunctionExpression
@@ -18,47 +130,57 @@ export function insertGatedFunctionDeclaration(
     | t.ArrowFunctionExpression
     | t.FunctionExpression,
   gating: NonNullable<PluginOptions['gating']>,
+  referencedBeforeDeclaration: boolean,
 ): void {
-  const gatingExpression = t.conditionalExpression(
-    t.callExpression(t.identifier(gating.importSpecifierName), []),
-    buildFunctionExpression(compiled),
-    buildFunctionExpression(fnPath.node),
-  );
-
-  /*
-   * Convert function declarations to named variables *unless* this is an
-   * `export default function ...` since `export default const ...` is
-   * not supported. For that case we fall through to replacing w the raw
-   * conditional expression
-   */
-  if (
-    fnPath.parentPath.node.type !== 'ExportDefaultDeclaration' &&
-    fnPath.node.type === 'FunctionDeclaration' &&
-    fnPath.node.id != null
-  ) {
-    fnPath.replaceWith(
-      t.variableDeclaration('const', [
-        t.variableDeclarator(fnPath.node.id, gatingExpression),
-      ]),
-    );
-  } else if (
-    fnPath.parentPath.node.type === 'ExportDefaultDeclaration' &&
-    fnPath.node.type !== 'ArrowFunctionExpression' &&
-    fnPath.node.id != null
-  ) {
-    fnPath.insertAfter(
-      t.exportDefaultDeclaration(t.identifier(fnPath.node.id.name)),
-    );
-    fnPath.parentPath.replaceWith(
-      t.variableDeclaration('const', [
-        t.variableDeclarator(
-          t.identifier(fnPath.node.id.name),
-          gatingExpression,
-        ),
-      ]),
-    );
+  if (referencedBeforeDeclaration && fnPath.isFunctionDeclaration()) {
+    CompilerError.invariant(compiled.type === 'FunctionDeclaration', {
+      reason: 'Expected compiled node type to match input type',
+      description: `Got ${compiled.type} but expected FunctionDeclaration`,
+      loc: fnPath.node.loc ?? null,
+    });
+    insertAdditionalFunctionDeclaration(fnPath, compiled, gating);
   } else {
-    fnPath.replaceWith(gatingExpression);
+    const gatingExpression = t.conditionalExpression(
+      t.callExpression(t.identifier(gating.importSpecifierName), []),
+      buildFunctionExpression(compiled),
+      buildFunctionExpression(fnPath.node),
+    );
+
+    /*
+     * Convert function declarations to named variables *unless* this is an
+     * `export default function ...` since `export default const ...` is
+     * not supported. For that case we fall through to replacing w the raw
+     * conditional expression
+     */
+    if (
+      fnPath.parentPath.node.type !== 'ExportDefaultDeclaration' &&
+      fnPath.node.type === 'FunctionDeclaration' &&
+      fnPath.node.id != null
+    ) {
+      fnPath.replaceWith(
+        t.variableDeclaration('const', [
+          t.variableDeclarator(fnPath.node.id, gatingExpression),
+        ]),
+      );
+    } else if (
+      fnPath.parentPath.node.type === 'ExportDefaultDeclaration' &&
+      fnPath.node.type !== 'ArrowFunctionExpression' &&
+      fnPath.node.id != null
+    ) {
+      fnPath.insertAfter(
+        t.exportDefaultDeclaration(t.identifier(fnPath.node.id.name)),
+      );
+      fnPath.parentPath.replaceWith(
+        t.variableDeclaration('const', [
+          t.variableDeclarator(
+            t.identifier(fnPath.node.id.name),
+            gatingExpression,
+          ),
+        ]),
+      );
+    } else {
+      fnPath.replaceWith(gatingExpression);
+    }
   }
 }
 

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

@@ -12,6 +12,7 @@ import {
   EnvironmentConfig,
   ExternalFunction,
   parseEnvironmentConfig,
+  tryParseExternalFunction,
 } from '../HIR/Environment';
 import {hasOwnProperty} from '../Utils/utils';
 import {fromZodError} from 'zod-validation-error';
@@ -271,6 +272,14 @@ export function parsePluginOptions(obj: unknown): PluginOptions {
           parsedOptions[key] = parseTargetConfig(value);
           break;
         }
+        case 'gating': {
+          if (value == null) {
+            parsedOptions[key] = null;
+          } else {
+            parsedOptions[key] = tryParseExternalFunction(value);
+          }
+          break;
+        }
         default: {
           parsedOptions[key] = value;
         }

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

@@ -24,6 +24,7 @@ import {
   pruneUnusedLabelsHIR,
 } from '../HIR';
 import {
+  CompilerMode,
   Environment,
   EnvironmentConfig,
   ReactFunctionType,
@@ -99,7 +100,9 @@ import {propagateScopeDependenciesHIR} from '../HIR/PropagateScopeDependenciesHI
 import {outlineJSX} from '../Optimization/OutlineJsx';
 import {optimizePropsMethodCalls} from '../Optimization/OptimizePropsMethodCalls';
 import {transformFire} from '../Transform';
-import {validateNoImpureFunctionsInRender} from '../Validation/ValiateNoImpureFunctionsInRender';
+import {validateNoImpureFunctionsInRender} from '../Validation/ValidateNoImpureFunctionsInRender';
+import {CompilerError} from '..';
+import {validateStaticComponents} from '../Validation/ValidateStaticComponents';
 
 export type CompilerPipelineValue =
   | {kind: 'ast'; name: string; value: CodegenFunction}
@@ -113,6 +116,7 @@ function run(
   >,
   config: EnvironmentConfig,
   fnType: ReactFunctionType,
+  mode: CompilerMode,
   useMemoCacheIdentifier: string,
   logger: Logger | null,
   filename: string | null,
@@ -122,6 +126,7 @@ function run(
   const env = new Environment(
     func.scope,
     fnType,
+    mode,
     config,
     contextIdentifiers,
     logger,
@@ -157,13 +162,13 @@ function runWithEnvironment(
   log({kind: 'hir', name: 'PruneMaybeThrows', value: hir});
 
   validateContextVariableLValues(hir);
-  validateUseMemo(hir);
+  validateUseMemo(hir).unwrap();
 
   if (
+    env.isInferredMemoEnabled &&
     !env.config.enablePreserveExistingManualUseMemo &&
     !env.config.disableMemoizationForDebugging &&
-    !env.config.enableChangeDetectionForDebugging &&
-    !env.config.enableMinimalTransformsForRetry
+    !env.config.enableChangeDetectionForDebugging
   ) {
     dropManualMemoization(hir);
     log({kind: 'hir', name: 'DropManualMemoization', value: hir});
@@ -196,8 +201,13 @@ function runWithEnvironment(
   inferTypes(hir);
   log({kind: 'hir', name: 'InferTypes', value: hir});
 
-  if (env.config.validateHooksUsage) {
-    validateHooksUsage(hir);
+  if (env.isInferredMemoEnabled) {
+    if (env.config.validateHooksUsage) {
+      validateHooksUsage(hir).unwrap();
+    }
+    if (env.config.validateNoCapitalizedCalls) {
+      validateNoCapitalizedCalls(hir).unwrap();
+    }
   }
 
   if (env.config.enableFire) {
@@ -205,10 +215,6 @@ function runWithEnvironment(
     log({kind: 'hir', name: 'TransformFire', value: hir});
   }
 
-  if (env.config.validateNoCapitalizedCalls) {
-    validateNoCapitalizedCalls(hir);
-  }
-
   if (env.config.lowerContextAccess) {
     lowerContextAccess(hir, env.config.lowerContextAccess);
   }
@@ -219,7 +225,12 @@ function runWithEnvironment(
   analyseFunctions(hir);
   log({kind: 'hir', name: 'AnalyseFunctions', value: hir});
 
-  inferReferenceEffects(hir);
+  const fnEffectErrors = inferReferenceEffects(hir);
+  if (env.isInferredMemoEnabled) {
+    if (fnEffectErrors.length > 0) {
+      CompilerError.throw(fnEffectErrors[0]);
+    }
+  }
   log({kind: 'hir', name: 'InferReferenceEffects', value: hir});
 
   validateLocalsNotReassignedAfterRender(hir);
@@ -239,28 +250,30 @@ function runWithEnvironment(
   inferMutableRanges(hir);
   log({kind: 'hir', name: 'InferMutableRanges', value: hir});
 
-  if (env.config.assertValidMutableRanges) {
-    assertValidMutableRanges(hir);
-  }
+  if (env.isInferredMemoEnabled) {
+    if (env.config.assertValidMutableRanges) {
+      assertValidMutableRanges(hir);
+    }
 
-  if (env.config.validateRefAccessDuringRender) {
-    validateNoRefAccessInRender(hir);
-  }
+    if (env.config.validateRefAccessDuringRender) {
+      validateNoRefAccessInRender(hir).unwrap();
+    }
 
-  if (env.config.validateNoSetStateInRender) {
-    validateNoSetStateInRender(hir);
-  }
+    if (env.config.validateNoSetStateInRender) {
+      validateNoSetStateInRender(hir).unwrap();
+    }
 
-  if (env.config.validateNoSetStateInPassiveEffects) {
-    validateNoSetStateInPassiveEffects(hir);
-  }
+    if (env.config.validateNoSetStateInPassiveEffects) {
+      env.logErrors(validateNoSetStateInPassiveEffects(hir));
+    }
 
-  if (env.config.validateNoJSXInTryStatements) {
-    validateNoJSXInTryStatement(hir);
-  }
+    if (env.config.validateNoJSXInTryStatements) {
+      env.logErrors(validateNoJSXInTryStatement(hir));
+    }
 
-  if (env.config.validateNoImpureFunctionsInRender) {
-    validateNoImpureFunctionsInRender(hir);
+    if (env.config.validateNoImpureFunctionsInRender) {
+      validateNoImpureFunctionsInRender(hir).unwrap();
+    }
   }
 
   inferReactivePlaces(hir);
@@ -280,7 +293,16 @@ function runWithEnvironment(
     value: hir,
   });
 
-  if (!env.config.enableMinimalTransformsForRetry) {
+  if (env.isInferredMemoEnabled) {
+    if (env.config.validateStaticComponents) {
+      env.logErrors(validateStaticComponents(hir));
+    }
+
+    /**
+     * Only create reactive scopes (which directly map to generated memo blocks)
+     * if inferred memoization is enabled. This makes all later passes which
+     * transform reactive-scope labeled instructions no-ops.
+     */
     inferReactiveScopeVariables(hir);
     log({kind: 'hir', name: 'InferReactiveScopeVariables', value: hir});
   }
@@ -492,14 +514,14 @@ function runWithEnvironment(
   });
 
   if (env.config.validateMemoizedEffectDependencies) {
-    validateMemoizedEffectDependencies(reactiveFunction);
+    validateMemoizedEffectDependencies(reactiveFunction).unwrap();
   }
 
   if (
     env.config.enablePreserveExistingMemoizationGuarantees ||
     env.config.validatePreserveExistingMemoizationGuarantees
   ) {
-    validatePreservedManualMemoization(reactiveFunction);
+    validatePreservedManualMemoization(reactiveFunction).unwrap();
   }
 
   const ast = codegenFunction(reactiveFunction, {
@@ -529,6 +551,7 @@ export function compileFn(
   >,
   config: EnvironmentConfig,
   fnType: ReactFunctionType,
+  mode: CompilerMode,
   useMemoCacheIdentifier: string,
   logger: Logger | null,
   filename: string | null,
@@ -538,6 +561,7 @@ export function compileFn(
     func,
     config,
     fnType,
+    mode,
     useMemoCacheIdentifier,
     logger,
     filename,

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

@@ -16,8 +16,6 @@ import {
   EnvironmentConfig,
   ExternalFunction,
   ReactFunctionType,
-  MINIMAL_RETRY_CONFIG,
-  tryParseExternalFunction,
 } from '../HIR/Environment';
 import {CodegenFunction} from '../ReactiveScopes';
 import {isComponentDeclaration} from '../Utils/ComponentDeclaration';
@@ -273,6 +271,9 @@ function isFilePartOfSources(
   return false;
 }
 
+type CompileProgramResult = {
+  retryErrors: Array<{fn: BabelFn; error: CompilerError}>;
+};
 /**
  * `compileProgram` is directly invoked by the react-compiler babel plugin, so
  * exceptions thrown by this function will fail the babel build.
@@ -287,16 +288,16 @@ function isFilePartOfSources(
 export function compileProgram(
   program: NodePath<t.Program>,
   pass: CompilerPass,
-): void {
+): CompileProgramResult | null {
   if (shouldSkipCompilation(program, pass)) {
-    return;
+    return null;
   }
 
   const environment = pass.opts.environment;
   const restrictedImportsErr = validateRestrictedImports(program, environment);
   if (restrictedImportsErr) {
     handleError(restrictedImportsErr, pass, null);
-    return;
+    return null;
   }
   const useMemoCacheIdentifier = program.scope.generateUidIdentifier('c');
 
@@ -367,7 +368,7 @@ export function compileProgram(
       filename: pass.filename ?? null,
     },
   );
-
+  const retryErrors: Array<{fn: BabelFn; error: CompilerError}> = [];
   const processFn = (
     fn: BabelFn,
     fnType: ReactFunctionType,
@@ -408,6 +409,7 @@ export function compileProgram(
             fn,
             environment,
             fnType,
+            'all_features',
             useMemoCacheIdentifier.name,
             pass.opts.logger,
             pass.filename,
@@ -418,28 +420,7 @@ export function compileProgram(
         compileResult = {kind: 'error', error: err};
       }
     }
-    // If non-memoization features are enabled, retry regardless of error kind
-    if (compileResult.kind === 'error' && environment.enableFire) {
-      try {
-        compileResult = {
-          kind: 'compile',
-          compiledFn: compileFn(
-            fn,
-            {
-              ...environment,
-              ...MINIMAL_RETRY_CONFIG,
-            },
-            fnType,
-            useMemoCacheIdentifier.name,
-            pass.opts.logger,
-            pass.filename,
-            pass.code,
-          ),
-        };
-      } catch (err) {
-        compileResult = {kind: 'error', error: err};
-      }
-    }
+
     if (compileResult.kind === 'error') {
       /**
        * If an opt out directive is present, log only instead of throwing and don't mark as
@@ -450,7 +431,39 @@ export function compileProgram(
       } else {
         handleError(compileResult.error, pass, fn.node.loc ?? null);
       }
-      return 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',
+            useMemoCacheIdentifier.name,
+            pass.opts.logger,
+            pass.filename,
+            pass.code,
+          ),
+        };
+        if (
+          !compileResult.compiledFn.hasFireRewrite &&
+          !compileResult.compiledFn.hasLoweredContextAccess
+        ) {
+          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, {
@@ -539,32 +552,28 @@ export function compileProgram(
     program.node.directives,
   );
   if (moduleScopeOptOutDirectives.length > 0) {
-    return;
+    return null;
   }
-
+  let gating: null | {
+    gatingFn: ExternalFunction;
+    referencedBeforeDeclared: Set<CompileResult>;
+  } = null;
   if (pass.opts.gating != null) {
-    const error = checkFunctionReferencedBeforeDeclarationAtTopLevel(
-      program,
-      compiledFns.map(result => {
-        return result.originalFn;
-      }),
-    );
-    if (error) {
-      handleError(error, pass, null);
-      return;
-    }
+    gating = {
+      gatingFn: pass.opts.gating,
+      referencedBeforeDeclared:
+        getFunctionReferencedBeforeDeclarationAtTopLevel(program, compiledFns),
+    };
   }
 
   const hasLoweredContextAccess = compiledFns.some(
     c => c.compiledFn.hasLoweredContextAccess,
   );
   const externalFunctions: Array<ExternalFunction> = [];
-  let gating: null | ExternalFunction = null;
   try {
     // TODO: check for duplicate import specifiers
-    if (pass.opts.gating != null) {
-      gating = tryParseExternalFunction(pass.opts.gating);
-      externalFunctions.push(gating);
+    if (gating != null) {
+      externalFunctions.push(gating.gatingFn);
     }
 
     const lowerContextAccess = environment.lowerContextAccess;
@@ -601,7 +610,7 @@ export function compileProgram(
     }
   } catch (err) {
     handleError(err, pass, null);
-    return;
+    return null;
   }
 
   /*
@@ -613,7 +622,12 @@ export function compileProgram(
     const transformedFn = createNewFunctionNode(originalFn, compiledFn);
 
     if (gating != null && kind === 'original') {
-      insertGatedFunctionDeclaration(originalFn, transformedFn, gating);
+      insertGatedFunctionDeclaration(
+        originalFn,
+        transformedFn,
+        gating.gatingFn,
+        gating.referencedBeforeDeclared.has(result),
+      );
     } else {
       originalFn.replaceWith(transformedFn);
     }
@@ -638,6 +652,7 @@ export function compileProgram(
     }
     addImportsToProgram(program, externalFunctions);
   }
+  return {retryErrors};
 }
 
 function shouldSkipCompilation(
@@ -993,31 +1008,39 @@ function callsHooksOrCreatesJsx(
   return invokesHooks || createsJsx;
 }
 
+function isNonNode(node?: t.Expression | null): boolean {
+  if (!node) {
+    return true;
+  }
+  switch (node.type) {
+    case 'ObjectExpression':
+    case 'ArrowFunctionExpression':
+    case 'FunctionExpression':
+    case 'BigIntLiteral':
+    case 'ClassExpression':
+    case 'NewExpression': // technically `new Array()` is legit, but unlikely
+      return true;
+  }
+  return false;
+}
+
 function returnsNonNode(
   node: NodePath<
     t.FunctionDeclaration | t.ArrowFunctionExpression | t.FunctionExpression
   >,
 ): boolean {
-  let hasReturn = false;
   let returnsNonNode = false;
+  if (
+    // node.traverse#ArrowFunctionExpression isn't called for the root node
+    node.type === 'ArrowFunctionExpression' &&
+    node.node.body.type !== 'BlockStatement'
+  ) {
+    returnsNonNode = isNonNode(node.node.body);
+  }
 
   node.traverse({
     ReturnStatement(ret) {
-      hasReturn = true;
-      const argument = ret.node.argument;
-      if (argument == null) {
-        returnsNonNode = true;
-      } else {
-        switch (argument.type) {
-          case 'ObjectExpression':
-          case 'ArrowFunctionExpression':
-          case 'FunctionExpression':
-          case 'BigIntLiteral':
-          case 'ClassExpression':
-          case 'NewExpression': // technically `new Array()` is legit, but unlikely
-            returnsNonNode = true;
-        }
-      }
+      returnsNonNode = isNonNode(ret.node.argument);
     },
     // Skip traversing all nested functions and their return statements
     ArrowFunctionExpression: skipNestedFunctions(node),
@@ -1026,7 +1049,7 @@ function returnsNonNode(
     ObjectMethod: node => node.skip(),
   });
 
-  return !hasReturn || returnsNonNode;
+  return returnsNonNode;
 }
 
 /*
@@ -1093,20 +1116,23 @@ function getFunctionName(
   }
 }
 
-function checkFunctionReferencedBeforeDeclarationAtTopLevel(
+function getFunctionReferencedBeforeDeclarationAtTopLevel(
   program: NodePath<t.Program>,
-  fns: Array<BabelFn>,
-): CompilerError | null {
-  const fnIds = new Set(
+  fns: Array<CompileResult>,
+): Set<CompileResult> {
+  const fnNames = new Map<string, {id: t.Identifier; fn: CompileResult}>(
     fns
-      .map(fn => getFunctionName(fn))
+      .map<[NodePath<t.Expression> | null, CompileResult]>(fn => [
+        getFunctionName(fn.originalFn),
+        fn,
+      ])
       .filter(
-        (name): name is NodePath<t.Identifier> => !!name && name.isIdentifier(),
+        (entry): entry is [NodePath<t.Identifier>, CompileResult] =>
+          !!entry[0] && entry[0].isIdentifier(),
       )
-      .map(name => name.node),
+      .map(entry => [entry[0].node.name, {id: entry[0].node, fn: entry[1]}]),
   );
-  const fnNames = new Map([...fnIds].map(id => [id.name, id]));
-  const errors = new CompilerError();
+  const referencedBeforeDeclaration = new Set<CompileResult>();
 
   program.traverse({
     TypeAnnotation(path) {
@@ -1132,8 +1158,7 @@ function checkFunctionReferencedBeforeDeclarationAtTopLevel(
        * We've reached the declaration, hoisting is no longer possible, stop
        * checking for this component name.
        */
-      if (fnIds.has(id.node)) {
-        fnIds.delete(id.node);
+      if (id.node === fn.id) {
         fnNames.delete(id.node.name);
         return;
       }
@@ -1143,21 +1168,13 @@ function checkFunctionReferencedBeforeDeclarationAtTopLevel(
        * A null scope means there's no function scope, which means we're at the
        * top level scope.
        */
-      if (scope === null) {
-        errors.pushErrorDetail(
-          new CompilerErrorDetail({
-            reason: `Encountered a function used before its declaration, which breaks Forget's gating codegen due to hoisting`,
-            description: `Rewrite the reference to ${fn.name} to not rely on hoisting to fix this issue`,
-            loc: fn.loc ?? null,
-            suggestions: null,
-            severity: ErrorSeverity.Invariant,
-          }),
-        );
+      if (scope === null && id.isReferencedIdentifier()) {
+        referencedBeforeDeclaration.add(fn.fn);
       }
     },
   });
 
-  return errors.details.length > 0 ? errors : null;
+  return referencedBeforeDeclaration;
 }
 
 function getReactCompilerRuntimeModule(opts: PluginOptions): string {

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

@@ -0,0 +1,275 @@
+import {NodePath} from '@babel/core';
+import * as t from '@babel/types';
+
+import {
+  CompilerError,
+  CompilerErrorDetailOptions,
+  EnvironmentConfig,
+  ErrorSeverity,
+  Logger,
+} from '..';
+import {getOrInsertWith} from '../Utils/utils';
+import {Environment} from '../HIR';
+import {DEFAULT_EXPORT} from '../HIR/Environment';
+
+function throwInvalidReact(
+  options: Omit<CompilerErrorDetailOptions, 'severity'>,
+  {logger, filename}: TraversalState,
+): never {
+  const detail: CompilerErrorDetailOptions = {
+    ...options,
+    severity: ErrorSeverity.InvalidReact,
+  };
+  logger?.logEvent(filename, {
+    kind: 'CompileError',
+    fnLoc: null,
+    detail,
+  });
+  CompilerError.throw(detail);
+}
+function assertValidEffectImportReference(
+  numArgs: number,
+  paths: Array<NodePath<t.Node>>,
+  context: TraversalState,
+): void {
+  for (const path of paths) {
+    const parent = path.parentPath;
+    if (parent != null && parent.isCallExpression()) {
+      const args = parent.get('arguments');
+      /**
+       * Only error on untransformed references of the form `useMyEffect(...)`
+       * or `moduleNamespace.useMyEffect(...)`, with matching argument counts.
+       * TODO: do we also want a mode to also hard error on non-call references?
+       */
+      if (args.length === numArgs) {
+        const maybeErrorDiagnostic = matchCompilerDiagnostic(
+          path,
+          context.transformErrors,
+        );
+        /**
+         * Note that we cannot easily check the type of the first argument here,
+         * as it may have already been transformed by the compiler (and not
+         * memoized).
+         */
+        throwInvalidReact(
+          {
+            reason:
+              '[InferEffectDependencies] React Compiler is unable to infer dependencies of this effect. ' +
+              'This will break your build! ' +
+              'To resolve, either pass your own dependency array or fix reported compiler bailout diagnostics.',
+            description: maybeErrorDiagnostic
+              ? `(Bailout reason: ${maybeErrorDiagnostic})`
+              : null,
+            loc: parent.node.loc ?? null,
+          },
+          context,
+        );
+      }
+    }
+  }
+}
+
+function assertValidFireImportReference(
+  paths: Array<NodePath<t.Node>>,
+  context: TraversalState,
+): void {
+  if (paths.length > 0) {
+    const maybeErrorDiagnostic = matchCompilerDiagnostic(
+      paths[0],
+      context.transformErrors,
+    );
+    throwInvalidReact(
+      {
+        reason:
+          '[Fire] Untransformed reference to compiler-required feature. ' +
+          'Either remove this `fire` call or ensure it is successfully transformed by the compiler',
+        description: maybeErrorDiagnostic
+          ? `(Bailout reason: ${maybeErrorDiagnostic})`
+          : null,
+        loc: paths[0].node.loc ?? null,
+      },
+      context,
+    );
+  }
+}
+export default function validateNoUntransformedReferences(
+  path: NodePath<t.Program>,
+  filename: string | null,
+  logger: Logger | null,
+  env: EnvironmentConfig,
+  transformErrors: Array<{fn: NodePath<t.Node>; error: CompilerError}>,
+): void {
+  const moduleLoadChecks = new Map<
+    string,
+    Map<string, CheckInvalidReferenceFn>
+  >();
+  if (env.enableFire) {
+    /**
+     * Error on any untransformed references to `fire` (e.g. including non-call
+     * expressions)
+     */
+    for (const module of Environment.knownReactModules) {
+      const react = getOrInsertWith(moduleLoadChecks, module, () => new Map());
+      react.set('fire', assertValidFireImportReference);
+    }
+  }
+  if (env.inferEffectDependencies) {
+    for (const {
+      function: {source, importSpecifierName},
+      numRequiredArgs,
+    } of env.inferEffectDependencies) {
+      const module = getOrInsertWith(moduleLoadChecks, source, () => new Map());
+      module.set(
+        importSpecifierName,
+        assertValidEffectImportReference.bind(null, numRequiredArgs),
+      );
+    }
+  }
+  if (moduleLoadChecks.size > 0) {
+    transformProgram(path, moduleLoadChecks, filename, logger, transformErrors);
+  }
+}
+
+type TraversalState = {
+  shouldInvalidateScopes: boolean;
+  program: NodePath<t.Program>;
+  logger: Logger | null;
+  filename: string | null;
+  transformErrors: Array<{fn: NodePath<t.Node>; error: CompilerError}>;
+};
+type CheckInvalidReferenceFn = (
+  paths: Array<NodePath<t.Node>>,
+  context: TraversalState,
+) => void;
+
+function validateImportSpecifier(
+  specifier: NodePath<t.ImportSpecifier>,
+  importSpecifierChecks: Map<string, CheckInvalidReferenceFn>,
+  state: TraversalState,
+): void {
+  const imported = specifier.get('imported');
+  const specifierName: string =
+    imported.node.type === 'Identifier'
+      ? imported.node.name
+      : imported.node.value;
+  const checkFn = importSpecifierChecks.get(specifierName);
+  if (checkFn == null) {
+    return;
+  }
+  if (state.shouldInvalidateScopes) {
+    state.shouldInvalidateScopes = false;
+    state.program.scope.crawl();
+  }
+
+  const local = specifier.get('local');
+  const binding = local.scope.getBinding(local.node.name);
+  CompilerError.invariant(binding != null, {
+    reason: 'Expected binding to be found for import specifier',
+    loc: local.node.loc ?? null,
+  });
+  checkFn(binding.referencePaths, state);
+}
+
+function validateNamespacedImport(
+  specifier: NodePath<t.ImportNamespaceSpecifier | t.ImportDefaultSpecifier>,
+  importSpecifierChecks: Map<string, CheckInvalidReferenceFn>,
+  state: TraversalState,
+): void {
+  if (state.shouldInvalidateScopes) {
+    state.shouldInvalidateScopes = false;
+    state.program.scope.crawl();
+  }
+  const local = specifier.get('local');
+  const binding = local.scope.getBinding(local.node.name);
+  const defaultCheckFn = importSpecifierChecks.get(DEFAULT_EXPORT);
+
+  CompilerError.invariant(binding != null, {
+    reason: 'Expected binding to be found for import specifier',
+    loc: local.node.loc ?? null,
+  });
+  const filteredReferences = new Map<
+    CheckInvalidReferenceFn,
+    Array<NodePath<t.Node>>
+  >();
+  for (const reference of binding.referencePaths) {
+    if (defaultCheckFn != null) {
+      getOrInsertWith(filteredReferences, defaultCheckFn, () => []).push(
+        reference,
+      );
+    }
+    const parent = reference.parentPath;
+    if (
+      parent != null &&
+      parent.isMemberExpression() &&
+      parent.get('object') === reference
+    ) {
+      if (parent.node.computed || parent.node.property.type !== 'Identifier') {
+        continue;
+      }
+      const checkFn = importSpecifierChecks.get(parent.node.property.name);
+      if (checkFn != null) {
+        getOrInsertWith(filteredReferences, checkFn, () => []).push(parent);
+      }
+    }
+  }
+
+  for (const [checkFn, references] of filteredReferences) {
+    checkFn(references, state);
+  }
+}
+function transformProgram(
+  path: NodePath<t.Program>,
+
+  moduleLoadChecks: Map<string, Map<string, CheckInvalidReferenceFn>>,
+  filename: string | null,
+  logger: Logger | null,
+  transformErrors: Array<{fn: NodePath<t.Node>; error: CompilerError}>,
+): void {
+  const traversalState: TraversalState = {
+    shouldInvalidateScopes: true,
+    program: path,
+    filename,
+    logger,
+    transformErrors,
+  };
+  path.traverse({
+    ImportDeclaration(path: NodePath<t.ImportDeclaration>) {
+      const importSpecifierChecks = moduleLoadChecks.get(
+        path.node.source.value,
+      );
+      if (importSpecifierChecks == null) {
+        return;
+      }
+      const specifiers = path.get('specifiers');
+      for (const specifier of specifiers) {
+        if (specifier.isImportSpecifier()) {
+          validateImportSpecifier(
+            specifier,
+            importSpecifierChecks,
+            traversalState,
+          );
+        } else {
+          validateNamespacedImport(
+            specifier as NodePath<
+              t.ImportNamespaceSpecifier | t.ImportDefaultSpecifier
+            >,
+            importSpecifierChecks,
+            traversalState,
+          );
+        }
+      }
+    },
+  });
+}
+
+function matchCompilerDiagnostic(
+  badReference: NodePath<t.Node>,
+  transformErrors: Array<{fn: NodePath<t.Node>; error: CompilerError}>,
+): string | null {
+  for (const {fn, error} of transformErrors) {
+    if (fn.isAncestor(badReference)) {
+      return error.toString();
+    }
+  }
+  return null;
+}

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

@@ -1455,6 +1455,11 @@ function lowerObjectPropertyKey(
       kind: 'identifier',
       name: key.node.name,
     };
+  } else if (key.isNumericLiteral()) {
+    return {
+      kind: 'identifier',
+      name: String(key.node.value),
+    };
   }
 
   builder.errors.push({

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

@@ -13,11 +13,13 @@ import {
   BlockId,
   DependencyPathEntry,
   GeneratedSource,
+  getHookKind,
   HIRFunction,
   Identifier,
   IdentifierId,
   InstructionId,
   InstructionValue,
+  LoweredFunction,
   PropertyLiteral,
   ReactiveScopeDependency,
   ScopeId,
@@ -112,6 +114,9 @@ export function collectHoistablePropertyLoads(
     hoistableFromOptionals,
     registry,
     nestedFnImmutableContext: null,
+    assumedInvokedFns: fn.env.config.enableTreatFunctionDepsAsConditional
+      ? new Set()
+      : getAssumedInvokedFunctions(fn),
   });
 }
 
@@ -127,6 +132,11 @@ type CollectHoistablePropertyLoadsContext = {
    * but are currently kept separate for readability.
    */
   nestedFnImmutableContext: ReadonlySet<IdentifierId> | null;
+  /**
+   * Functions which are assumed to be eventually called (as opposed to ones which might
+   * not be called, e.g. the 0th argument of Array.map)
+   */
+  assumedInvokedFns: ReadonlySet<LoweredFunction>;
 };
 function collectHoistablePropertyLoadsImpl(
   fn: HIRFunction,
@@ -338,7 +348,13 @@ function collectNonNullsInBlocks(
       context.registry.getOrCreateIdentifier(identifier),
     );
   }
-  const nodes = new Map<BlockId, BlockInfo>();
+  const nodes = new Map<
+    BlockId,
+    {
+      block: BasicBlock;
+      assumedNonNullObjects: Set<PropertyPathNode>;
+    }
+  >();
   for (const [_, block] of fn.body.blocks) {
     const assumedNonNullObjects = new Set<PropertyPathNode>(
       knownNonNullIdentifiers,
@@ -358,32 +374,30 @@ function collectNonNullsInBlocks(
       ) {
         assumedNonNullObjects.add(maybeNonNull);
       }
-      if (
-        (instr.value.kind === 'FunctionExpression' ||
-          instr.value.kind === 'ObjectMethod') &&
-        !fn.env.config.enableTreatFunctionDepsAsConditional
-      ) {
+      if (instr.value.kind === 'FunctionExpression') {
         const innerFn = instr.value.loweredFunc;
-        const innerHoistableMap = collectHoistablePropertyLoadsImpl(
-          innerFn.func,
-          {
-            ...context,
-            nestedFnImmutableContext:
-              context.nestedFnImmutableContext ??
-              new Set(
-                innerFn.func.context
-                  .filter(place =>
-                    isImmutableAtInstr(place.identifier, instr.id, context),
-                  )
-                  .map(place => place.identifier.id),
-              ),
-          },
-        );
-        const innerHoistables = assertNonNull(
-          innerHoistableMap.get(innerFn.func.body.entry),
-        );
-        for (const entry of innerHoistables.assumedNonNullObjects) {
-          assumedNonNullObjects.add(entry);
+        if (context.assumedInvokedFns.has(innerFn)) {
+          const innerHoistableMap = collectHoistablePropertyLoadsImpl(
+            innerFn.func,
+            {
+              ...context,
+              nestedFnImmutableContext:
+                context.nestedFnImmutableContext ??
+                new Set(
+                  innerFn.func.context
+                    .filter(place =>
+                      isImmutableAtInstr(place.identifier, instr.id, context),
+                    )
+                    .map(place => place.identifier.id),
+                ),
+            },
+          );
+          const innerHoistables = assertNonNull(
+            innerHoistableMap.get(innerFn.func.body.entry),
+          );
+          for (const entry of innerHoistables.assumedNonNullObjects) {
+            assumedNonNullObjects.add(entry);
+          }
         }
       }
     }
@@ -591,3 +605,130 @@ function reduceMaybeOptionalChains(
     }
   } while (changed);
 }
+
+function getAssumedInvokedFunctions(
+  fn: HIRFunction,
+  temporaries: Map<
+    IdentifierId,
+    {fn: LoweredFunction; mayInvoke: Set<LoweredFunction>}
+  > = new Map(),
+): ReadonlySet<LoweredFunction> {
+  const hoistableFunctions = new Set<LoweredFunction>();
+  /**
+   * Step 1: Conservatively collect identifier to function expression mappings
+   */
+  for (const block of fn.body.blocks.values()) {
+    for (const {lvalue, value} of block.instructions) {
+      /**
+       * Conservatively only match function expressions which can have guaranteed ssa.
+       * ObjectMethods and ObjectProperties do not.
+       */
+      if (value.kind === 'FunctionExpression') {
+        temporaries.set(lvalue.identifier.id, {
+          fn: value.loweredFunc,
+          mayInvoke: new Set(),
+        });
+      } else if (value.kind === 'StoreLocal') {
+        const lvalue = value.lvalue.place.identifier;
+        const maybeLoweredFunc = temporaries.get(value.value.identifier.id);
+        if (maybeLoweredFunc != null) {
+          temporaries.set(lvalue.id, maybeLoweredFunc);
+        }
+      } else if (value.kind === 'LoadLocal') {
+        const maybeLoweredFunc = temporaries.get(value.place.identifier.id);
+        if (maybeLoweredFunc != null) {
+          temporaries.set(lvalue.identifier.id, maybeLoweredFunc);
+        }
+      }
+    }
+  }
+  /**
+   * Step 2: Forward pass to do analysis of assumed function calls. Note that
+   * this is conservative and does not count indirect references through
+   * containers (e.g. `return {cb: () => {...}})`).
+   */
+  for (const block of fn.body.blocks.values()) {
+    for (const {lvalue, value} of block.instructions) {
+      if (value.kind === 'CallExpression') {
+        const callee = value.callee;
+        const maybeHook = getHookKind(fn.env, callee.identifier);
+        const maybeLoweredFunc = temporaries.get(callee.identifier.id);
+        if (maybeLoweredFunc != null) {
+          // Direct calls
+          hoistableFunctions.add(maybeLoweredFunc.fn);
+        } else if (maybeHook != null) {
+          /**
+           * Assume arguments to all hooks are safe to invoke
+           */
+          for (const arg of value.args) {
+            if (arg.kind === 'Identifier') {
+              const maybeLoweredFunc = temporaries.get(arg.identifier.id);
+              if (maybeLoweredFunc != null) {
+                hoistableFunctions.add(maybeLoweredFunc.fn);
+              }
+            }
+          }
+        }
+      } else if (value.kind === 'JsxExpression') {
+        /**
+         * Assume JSX attributes and children are safe to invoke
+         */
+        for (const attr of value.props) {
+          if (attr.kind === 'JsxSpreadAttribute') {
+            continue;
+          }
+          const maybeLoweredFunc = temporaries.get(attr.place.identifier.id);
+          if (maybeLoweredFunc != null) {
+            hoistableFunctions.add(maybeLoweredFunc.fn);
+          }
+        }
+        for (const child of value.children ?? []) {
+          const maybeLoweredFunc = temporaries.get(child.identifier.id);
+          if (maybeLoweredFunc != null) {
+            hoistableFunctions.add(maybeLoweredFunc.fn);
+          }
+        }
+      } else if (value.kind === 'FunctionExpression') {
+        /**
+         * Recursively traverse into other function expressions which may invoke
+         * or pass already declared functions to react (e.g. as JSXAttributes).
+         *
+         * If lambda A calls lambda B, we assume lambda B is safe to invoke if
+         * lambda A is -- even if lambda B is conditionally called. (see
+         * `conditional-call-chain` fixture for example).
+         */
+        const loweredFunc = value.loweredFunc.func;
+        const lambdasCalled = getAssumedInvokedFunctions(
+          loweredFunc,
+          temporaries,
+        );
+        const maybeLoweredFunc = temporaries.get(lvalue.identifier.id);
+        if (maybeLoweredFunc != null) {
+          for (const called of lambdasCalled) {
+            maybeLoweredFunc.mayInvoke.add(called);
+          }
+        }
+      }
+    }
+    if (block.terminal.kind === 'return') {
+      /**
+       * Assume directly returned functions are safe to call
+       */
+      const maybeLoweredFunc = temporaries.get(
+        block.terminal.value.identifier.id,
+      );
+      if (maybeLoweredFunc != null) {
+        hoistableFunctions.add(maybeLoweredFunc.fn);
+      }
+    }
+  }
+
+  for (const [_, {fn, mayInvoke}] of temporaries) {
+    if (hoistableFunctions.has(fn)) {
+      for (const called of mayInvoke) {
+        hoistableFunctions.add(called);
+      }
+    }
+  }
+  return hoistableFunctions;
+}

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

@@ -96,6 +96,8 @@ export const MacroSchema = z.union([
   z.tuple([z.string(), z.array(MacroMethodSchema)]),
 ]);
 
+export type CompilerMode = 'all_features' | 'no_inferred_memo';
+
 export type Macro = z.infer<typeof MacroSchema>;
 export type MacroMethod = z.infer<typeof MacroMethodSchema>;
 
@@ -328,6 +330,11 @@ const EnvironmentConfigSchema = z.object({
    */
   validateNoJSXInTryStatements: z.boolean().default(false),
 
+  /**
+   * Validates against dynamically creating components during render.
+   */
+  validateStaticComponents: z.boolean().default(false),
+
   /**
    * Validates that the dependencies of all effect hooks are memoized. This helps ensure
    * that Forget does not introduce infinite renders caused by a dependency changing,
@@ -550,8 +557,6 @@ const EnvironmentConfigSchema = z.object({
    */
   disableMemoizationForDebugging: z.boolean().default(false),
 
-  enableMinimalTransformsForRetry: z.boolean().default(false),
-
   /**
    * When true, rather using memoized values, the compiler will always re-compute
    * values, and then use a heuristic to compare the memoized value to the newly
@@ -626,17 +631,6 @@ const EnvironmentConfigSchema = z.object({
 
 export type EnvironmentConfig = z.infer<typeof EnvironmentConfigSchema>;
 
-export const MINIMAL_RETRY_CONFIG: PartialEnvironmentConfig = {
-  validateHooksUsage: false,
-  validateRefAccessDuringRender: false,
-  validateNoSetStateInRender: false,
-  validateNoSetStateInPassiveEffects: false,
-  validateNoJSXInTryStatements: false,
-  validateMemoizedEffectDependencies: false,
-  validateNoCapitalizedCalls: null,
-  validateBlocklistedImports: null,
-  enableMinimalTransformsForRetry: true,
-};
 /**
  * For test fixtures and playground only.
  *
@@ -663,7 +657,7 @@ const testComplexConfigDefaults: PartialEnvironmentConfig = {
       source: 'react-compiler-runtime',
       importSpecifierName: 'shouldInstrument',
     },
-    globalGating: '__DEV__',
+    globalGating: 'DEV',
   },
   enableEmitHookGuards: {
     source: 'react-compiler-runtime',
@@ -851,6 +845,7 @@ export class Environment {
   code: string | null;
   config: EnvironmentConfig;
   fnType: ReactFunctionType;
+  compilerMode: CompilerMode;
   useMemoCacheIdentifier: string;
   hasLoweredContextAccess: boolean;
   hasFireRewrite: boolean;
@@ -861,6 +856,7 @@ export class Environment {
   constructor(
     scope: BabelScope,
     fnType: ReactFunctionType,
+    compilerMode: CompilerMode,
     config: EnvironmentConfig,
     contextIdentifiers: Set<t.Identifier>,
     logger: Logger | null,
@@ -870,6 +866,7 @@ export class Environment {
   ) {
     this.#scope = scope;
     this.fnType = fnType;
+    this.compilerMode = compilerMode;
     this.config = config;
     this.filename = filename;
     this.code = code;
@@ -924,6 +921,10 @@ export class Environment {
     this.#hoistedIdentifiers = new Set();
   }
 
+  get isInferredMemoEnabled(): boolean {
+    return this.compilerMode !== 'no_inferred_memo';
+  }
+
   get nextIdentifierId(): IdentifierId {
     return makeIdentifierId(this.#nextIdentifer++);
   }
@@ -936,6 +937,19 @@ export class Environment {
     return makeScopeId(this.#nextScope++);
   }
 
+  logErrors(errors: Result<void, CompilerError>): void {
+    if (errors.isOk() || this.logger == null) {
+      return;
+    }
+    for (const error of errors.unwrapErr().details) {
+      this.logger.logEvent(this.filename, {
+        kind: 'CompileError',
+        detail: error,
+        fnLoc: null,
+      });
+    }
+  }
+
   isContextIdentifier(node: t.Identifier): boolean {
     return this.#contextIdentifiers.has(node);
   }
@@ -1125,6 +1139,7 @@ export class Environment {
       moduleName.toLowerCase() === 'react-dom'
     );
   }
+  static knownReactModules: ReadonlyArray<string> = ['react', 'react-dom'];
 
   getFallthroughPropertyType(
     receiver: Type,

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

@@ -703,6 +703,10 @@ export type ObjectPropertyKey =
   | {
       kind: 'computed';
       name: Place;
+    }
+  | {
+      kind: 'number';
+      name: number;
     };
 
 export type ObjectProperty = {

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

@@ -330,6 +330,9 @@ function printObjectPropertyKey(key: ObjectPropertyKey): string {
     case 'computed': {
       return `[${printPlace(key.name)}]`;
     }
+    case 'number': {
+      return String(key.name);
+    }
   }
 }
 

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

@@ -5,7 +5,12 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {CompilerError, ErrorSeverity, ValueKind} from '..';
+import {
+  CompilerError,
+  CompilerErrorDetailOptions,
+  ErrorSeverity,
+  ValueKind,
+} from '..';
 import {
   AbstractValue,
   BasicBlock,
@@ -290,21 +295,21 @@ export function inferTerminalFunctionEffects(
   return functionEffects;
 }
 
-export function raiseFunctionEffectErrors(
+export function transformFunctionEffectErrors(
   functionEffects: Array<FunctionEffect>,
-): void {
-  functionEffects.forEach(eff => {
+): Array<CompilerErrorDetailOptions> {
+  return functionEffects.map(eff => {
     switch (eff.kind) {
       case 'ReactMutation':
       case 'GlobalMutation': {
-        CompilerError.throw(eff.error);
+        return eff.error;
       }
       case 'ContextMutation': {
-        CompilerError.throw({
+        return {
           severity: ErrorSeverity.Invariant,
           reason: `Unexpected ContextMutation in top-level function effects`,
           loc: eff.loc,
-        });
+        };
       }
       default:
         assertExhaustive(

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

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {CompilerError} from '../CompilerError';
+import {CompilerError, CompilerErrorDetailOptions} from '../CompilerError';
 import {Environment} from '../HIR';
 import {
   AbstractValue,
@@ -49,7 +49,7 @@ import {assertExhaustive} from '../Utils/utils';
 import {
   inferTerminalFunctionEffects,
   inferInstructionFunctionEffects,
-  raiseFunctionEffectErrors,
+  transformFunctionEffectErrors,
 } from './InferFunctionEffects';
 
 const UndefinedValue: InstructionValue = {
@@ -103,7 +103,7 @@ const UndefinedValue: InstructionValue = {
 export default function inferReferenceEffects(
   fn: HIRFunction,
   options: {isFunctionExpression: boolean} = {isFunctionExpression: false},
-): void {
+): Array<CompilerErrorDetailOptions> {
   /*
    * Initial state contains function params
    * TODO: include module declarations here as well
@@ -241,8 +241,9 @@ export default function inferReferenceEffects(
 
   if (options.isFunctionExpression) {
     fn.effects = functionEffects;
-  } else if (!fn.env.config.enableMinimalTransformsForRetry) {
-    raiseFunctionEffectErrors(functionEffects);
+    return [];
+  } else {
+    return transformFunctionEffectErrors(functionEffects);
   }
 }
 

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

@@ -14,7 +14,7 @@ import {
   renameVariables,
 } from '.';
 import {CompilerError, ErrorSeverity} from '../CompilerError';
-import {Environment, EnvironmentConfig, ExternalFunction} from '../HIR';
+import {Environment, ExternalFunction} from '../HIR';
 import {
   ArrayPattern,
   BlockId,
@@ -156,7 +156,7 @@ export function codegenFunction(
   const compiled = compileResult.unwrap();
 
   const hookGuard = fn.env.config.enableEmitHookGuards;
-  if (hookGuard != null) {
+  if (hookGuard != null && fn.env.isInferredMemoEnabled) {
     compiled.body = t.blockStatement([
       createHookGuard(
         hookGuard,
@@ -250,7 +250,11 @@ export function codegenFunction(
   }
 
   const emitInstrumentForget = fn.env.config.enableEmitInstrumentForget;
-  if (emitInstrumentForget != null && fn.id != null) {
+  if (
+    emitInstrumentForget != null &&
+    fn.id != null &&
+    fn.env.isInferredMemoEnabled
+  ) {
     /*
      * Technically, this is a conditional hook call. However, we expect
      * __DEV__ and gating identifier to be runtime constants
@@ -548,7 +552,7 @@ function codegenBlockNoReset(
 }
 
 function wrapCacheDep(cx: Context, value: t.Expression): t.Expression {
-  if (cx.env.config.enableEmitFreeze != null) {
+  if (cx.env.config.enableEmitFreeze != null && cx.env.isInferredMemoEnabled) {
     // The import declaration for emitFreeze is inserted in the Babel plugin
     return t.conditionalExpression(
       t.identifier('__DEV__'),
@@ -1553,7 +1557,7 @@ function createHookGuard(
  * ```
  */
 function createCallExpression(
-  config: EnvironmentConfig,
+  env: Environment,
   callee: t.Expression,
   args: Array<t.Expression | t.SpreadElement>,
   loc: SourceLocation | null,
@@ -1564,8 +1568,8 @@ function createCallExpression(
     callExpr.loc = loc;
   }
 
-  const hookGuard = config.enableEmitHookGuards;
-  if (hookGuard != null && isHook) {
+  const hookGuard = env.config.enableEmitHookGuards;
+  if (hookGuard != null && isHook && env.isInferredMemoEnabled) {
     const iife = t.functionExpression(
       null,
       [],
@@ -1701,7 +1705,7 @@ function codegenInstructionValue(
       const callee = codegenPlaceToExpression(cx, instrValue.callee);
       const args = instrValue.args.map(arg => codegenArgument(cx, arg));
       value = createCallExpression(
-        cx.env.config,
+        cx.env,
         callee,
         args,
         instrValue.loc,
@@ -1791,7 +1795,7 @@ function codegenInstructionValue(
       );
       const args = instrValue.args.map(arg => codegenArgument(cx, arg));
       value = createCallExpression(
-        cx.env.config,
+        cx.env,
         memberExpr,
         args,
         instrValue.loc,
@@ -2429,6 +2433,9 @@ function codegenObjectPropertyKey(
       });
       return expr;
     }
+    case 'number': {
+      return t.numericLiteral(key.name);
+    }
   }
 }
 

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

@@ -26,6 +26,7 @@ import {
   eachTerminalOperand,
 } from '../HIR/visitors';
 import {assertExhaustive} from '../Utils/utils';
+import {Result} from '../Utils/Result';
 
 /**
  * Represents the possible kinds of value which may be stored at a given Place during
@@ -87,7 +88,9 @@ function joinKinds(a: Kind, b: Kind): Kind {
  *   may not appear as the callee of a conditional call.
  *   See the note for Kind.PotentialHook for sources of potential hooks
  */
-export function validateHooksUsage(fn: HIRFunction): void {
+export function validateHooksUsage(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
   const unconditionalBlocks = computeUnconditionalBlocks(fn);
 
   const errors = new CompilerError();
@@ -423,9 +426,7 @@ export function validateHooksUsage(fn: HIRFunction): void {
   for (const [, error] of errorsByPlace) {
     errors.push(error);
   }
-  if (errors.hasErrors()) {
-    throw errors;
-  }
+  return errors.asResult();
 }
 
 function visitFunctionExpression(errors: CompilerError, fn: HIRFunction): void {

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

@@ -22,6 +22,7 @@ import {
   ReactiveFunctionVisitor,
   visitReactiveFunction,
 } from '../ReactiveScopes/visitors';
+import {Result} from '../Utils/Result';
 
 /**
  * Validates that all known effect dependencies are memoized. The algorithm checks two things:
@@ -47,12 +48,12 @@ import {
  * mutate(object); // ... mutable range ends here after this mutation
  * ```
  */
-export function validateMemoizedEffectDependencies(fn: ReactiveFunction): void {
+export function validateMemoizedEffectDependencies(
+  fn: ReactiveFunction,
+): Result<void, CompilerError> {
   const errors = new CompilerError();
   visitReactiveFunction(fn, new Visitor(), errors);
-  if (errors.hasErrors()) {
-    throw errors;
-  }
+  return errors.asResult();
 }
 
 class Visitor extends ReactiveFunctionVisitor<CompilerError> {

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

@@ -4,11 +4,14 @@
  * 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} from '..';
+import {CompilerError, EnvironmentConfig, ErrorSeverity} from '..';
 import {HIRFunction, IdentifierId} from '../HIR';
 import {DEFAULT_GLOBALS} from '../HIR/Globals';
+import {Result} from '../Utils/Result';
 
-export function validateNoCapitalizedCalls(fn: HIRFunction): void {
+export function validateNoCapitalizedCalls(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
   const envConfig: EnvironmentConfig = fn.env.config;
   const ALLOW_LIST = new Set([
     ...DEFAULT_GLOBALS.keys(),
@@ -26,6 +29,7 @@ export function validateNoCapitalizedCalls(fn: HIRFunction): void {
     );
   };
 
+  const errors = new CompilerError();
   const capitalLoadGlobals = new Map<IdentifierId, string>();
   const capitalizedProperties = new Map<IdentifierId, string>();
   const reason =
@@ -73,7 +77,8 @@ export function validateNoCapitalizedCalls(fn: HIRFunction): void {
           const propertyIdentifier = value.property.identifier.id;
           const propertyName = capitalizedProperties.get(propertyIdentifier);
           if (propertyName != null) {
-            CompilerError.throwInvalidReact({
+            errors.push({
+              severity: ErrorSeverity.InvalidReact,
               reason,
               description: `${propertyName} may be a component.`,
               loc: value.loc,
@@ -85,4 +90,5 @@ export function validateNoCapitalizedCalls(fn: HIRFunction): void {
       }
     }
   }
+  return errors.asResult();
 }

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

@@ -8,6 +8,7 @@
 import {CompilerError, ErrorSeverity} from '..';
 import {HIRFunction} from '../HIR';
 import {getFunctionCallSignature} from '../Inference/InferReferenceEffects';
+import {Result} from '../Utils/Result';
 
 /**
  * Checks that known-impure functions are not called during render. Examples of invalid functions to
@@ -18,7 +19,9 @@ import {getFunctionCallSignature} from '../Inference/InferReferenceEffects';
  * this in several of our validation passes and should unify those analyses into a reusable helper
  * and use it here.
  */
-export function validateNoImpureFunctionsInRender(fn: HIRFunction): void {
+export function validateNoImpureFunctionsInRender(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
   const errors = new CompilerError();
   for (const [, block] of fn.body.blocks) {
     for (const instr of block.instructions) {
@@ -46,7 +49,5 @@ export function validateNoImpureFunctionsInRender(fn: HIRFunction): void {
       }
     }
   }
-  if (errors.hasErrors()) {
-    throw errors;
-  }
+  return errors.asResult();
 }

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

@@ -7,6 +7,7 @@
 
 import {CompilerError, ErrorSeverity} from '..';
 import {BlockId, HIRFunction} from '../HIR';
+import {Result} from '../Utils/Result';
 import {retainWhere} from '../Utils/utils';
 
 /**
@@ -19,7 +20,9 @@ import {retainWhere} from '../Utils/utils';
  * created within a try block. JSX is allowed within a catch statement, unless that catch
  * is itself nested inside an outer try.
  */
-export function validateNoJSXInTryStatement(fn: HIRFunction): void {
+export function validateNoJSXInTryStatement(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
   const activeTryBlocks: Array<BlockId> = [];
   const errors = new CompilerError();
   for (const [, block] of fn.body.blocks) {
@@ -46,7 +49,5 @@ export function validateNoJSXInTryStatement(fn: HIRFunction): void {
       activeTryBlocks.push(block.terminal.handler);
     }
   }
-  if (errors.hasErrors()) {
-    throw errors;
-  }
+  return errors.asResult();
 }

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

@@ -99,9 +99,11 @@ class Env extends Map<IdentifierId, RefAccessType> {
   }
 }
 
-export function validateNoRefAccessInRender(fn: HIRFunction): void {
+export function validateNoRefAccessInRender(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
   const env = new Env();
-  validateNoRefAccessInRenderImpl(fn, env).unwrap();
+  return validateNoRefAccessInRenderImpl(fn, env).map(_ => undefined);
 }
 
 function refTypeOfType(place: Place): RefAccessType {

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

@@ -14,6 +14,7 @@ import {
   Place,
 } from '../HIR';
 import {eachInstructionValueOperand} from '../HIR/visitors';
+import {Result} from '../Utils/Result';
 
 /**
  * Validates against calling setState in the body of a *passive* effect (useEffect),
@@ -23,7 +24,9 @@ import {eachInstructionValueOperand} from '../HIR/visitors';
  * often bad for performance and frequently has more efficient and straightforward
  * alternatives. See https://react.dev/learn/you-might-not-need-an-effect for examples.
  */
-export function validateNoSetStateInPassiveEffects(fn: HIRFunction): void {
+export function validateNoSetStateInPassiveEffects(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
   const setStateFunctions: Map<IdentifierId, Place> = new Map();
   const errors = new CompilerError();
   for (const [, block] of fn.body.blocks) {
@@ -98,9 +101,7 @@ export function validateNoSetStateInPassiveEffects(fn: HIRFunction): void {
     }
   }
 
-  if (errors.hasErrors()) {
-    throw errors;
-  }
+  return errors.asResult();
 }
 
 function getSetStateCall(

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

@@ -9,7 +9,7 @@ import {CompilerError, ErrorSeverity} from '../CompilerError';
 import {HIRFunction, IdentifierId, isSetStateType} from '../HIR';
 import {computeUnconditionalBlocks} from '../HIR/ComputeUnconditionalBlocks';
 import {eachInstructionValueOperand} from '../HIR/visitors';
-import {Err, Ok, Result} from '../Utils/Result';
+import {Result} from '../Utils/Result';
 
 /**
  * Validates that the given function does not have an infinite update loop
@@ -39,9 +39,11 @@ import {Err, Ok, Result} from '../Utils/Result';
  * y();
  * ```
  */
-export function validateNoSetStateInRender(fn: HIRFunction): void {
+export function validateNoSetStateInRender(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
   const unconditionalSetStateFunctions: Set<IdentifierId> = new Set();
-  validateNoSetStateInRenderImpl(fn, unconditionalSetStateFunctions).unwrap();
+  return validateNoSetStateInRenderImpl(fn, unconditionalSetStateFunctions);
 }
 
 function validateNoSetStateInRenderImpl(
@@ -145,9 +147,5 @@ function validateNoSetStateInRenderImpl(
     }
   }
 
-  if (errors.hasErrors()) {
-    return Err(errors);
-  } else {
-    return Ok(undefined);
-  }
+  return errors.asResult();
 }

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

@@ -5,9 +5,10 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {CompilerError, Effect, ErrorSeverity} from '..';
+import {CompilerError, ErrorSeverity} from '../CompilerError';
 import {
   DeclarationId,
+  Effect,
   GeneratedSource,
   Identifier,
   IdentifierId,
@@ -30,6 +31,7 @@ import {
   ReactiveFunctionVisitor,
   visitReactiveFunction,
 } from '../ReactiveScopes/visitors';
+import {Result} from '../Utils/Result';
 import {getOrInsertDefault} from '../Utils/utils';
 
 /**
@@ -39,15 +41,15 @@ import {getOrInsertDefault} from '../Utils/utils';
  * This can occur if a value's mutable range somehow extended to include a hook and
  * was pruned.
  */
-export function validatePreservedManualMemoization(fn: ReactiveFunction): void {
+export function validatePreservedManualMemoization(
+  fn: ReactiveFunction,
+): Result<void, CompilerError> {
   const state = {
     errors: new CompilerError(),
     manualMemoState: null,
   };
   visitReactiveFunction(fn, new Visitor(), state);
-  if (state.errors.hasErrors()) {
-    throw state.errors;
-  }
+  return state.errors.asResult();
 }
 
 const DEBUG = false;

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

@@ -0,0 +1,83 @@
+/**
+ * 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, ErrorSeverity} from '../CompilerError';
+import {HIRFunction, IdentifierId, SourceLocation} from '../HIR';
+import {Result} from '../Utils/Result';
+
+/**
+ * Validates against components that are created dynamically and whose identity is not guaranteed
+ * to be stable (which would cause the component to reset on each re-render).
+ */
+export function validateStaticComponents(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
+  const error = new CompilerError();
+  const knownDynamicComponents = new Map<IdentifierId, SourceLocation>();
+  for (const block of fn.body.blocks.values()) {
+    phis: for (const phi of block.phis) {
+      for (const operand of phi.operands.values()) {
+        const loc = knownDynamicComponents.get(operand.identifier.id);
+        if (loc != null) {
+          knownDynamicComponents.set(phi.place.identifier.id, loc);
+          continue phis;
+        }
+      }
+    }
+    for (const instr of block.instructions) {
+      const {lvalue, value} = instr;
+      switch (value.kind) {
+        case 'FunctionExpression':
+        case 'NewExpression':
+        case 'MethodCall':
+        case 'CallExpression': {
+          knownDynamicComponents.set(lvalue.identifier.id, value.loc);
+          break;
+        }
+        case 'LoadLocal': {
+          const loc = knownDynamicComponents.get(value.place.identifier.id);
+          if (loc != null) {
+            knownDynamicComponents.set(lvalue.identifier.id, loc);
+          }
+          break;
+        }
+        case 'StoreLocal': {
+          const loc = knownDynamicComponents.get(value.value.identifier.id);
+          if (loc != null) {
+            knownDynamicComponents.set(lvalue.identifier.id, loc);
+            knownDynamicComponents.set(value.lvalue.place.identifier.id, loc);
+          }
+          break;
+        }
+        case 'JsxExpression': {
+          if (value.tag.kind === 'Identifier') {
+            const location = knownDynamicComponents.get(
+              value.tag.identifier.id,
+            );
+            if (location != null) {
+              error.push({
+                reason: `Components created during render will reset their state each time they are created. Declare components outside of render. `,
+                severity: ErrorSeverity.InvalidReact,
+                loc: value.tag.loc,
+                description: null,
+                suggestions: null,
+              });
+              error.push({
+                reason: `The component may be created during render`,
+                severity: ErrorSeverity.InvalidReact,
+                loc: location,
+                description: null,
+                suggestions: null,
+              });
+            }
+          }
+        }
+      }
+    }
+  }
+  return error.asResult();
+}

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

@@ -5,10 +5,12 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {CompilerError} from '..';
+import {CompilerError, ErrorSeverity} from '..';
 import {FunctionExpression, HIRFunction, IdentifierId} from '../HIR';
+import {Result} from '../Utils/Result';
 
-export function validateUseMemo(fn: HIRFunction): void {
+export function validateUseMemo(fn: HIRFunction): Result<void, CompilerError> {
+  const errors = new CompilerError();
   const useMemos = new Set<IdentifierId>();
   const react = new Set<IdentifierId>();
   const functions = new Map<IdentifierId, FunctionExpression>();
@@ -61,7 +63,8 @@ export function validateUseMemo(fn: HIRFunction): void {
           }
 
           if (body.loweredFunc.func.params.length > 0) {
-            CompilerError.throwInvalidReact({
+            errors.push({
+              severity: ErrorSeverity.InvalidReact,
               reason: 'useMemo callbacks may not accept any arguments',
               description: null,
               loc: body.loc,
@@ -70,7 +73,8 @@ export function validateUseMemo(fn: HIRFunction): void {
           }
 
           if (body.loweredFunc.func.async || body.loweredFunc.func.generator) {
-            CompilerError.throwInvalidReact({
+            errors.push({
+              severity: ErrorSeverity.InvalidReact,
               reason:
                 'useMemo callbacks may not be async or generator functions',
               description: null,
@@ -84,4 +88,5 @@ export function validateUseMemo(fn: HIRFunction): void {
       }
     }
   }
+  return errors.asResult();
 }

compiler/packages/babel-plugin-react-compiler/src/__tests__/e2e/constant-prop.e2e.js

@@ -12,6 +12,7 @@ globalThis.constantValue = 'global test value';
 
 test('literal-constant-propagation', () => {
   function Component() {
+    'use memo';
     const x = 'test value 1';
     return <div>{x}</div>;
   }
@@ -38,6 +39,7 @@ test('literal-constant-propagation', () => {
 
 test('global-constant-propagation', () => {
   function Component() {
+    'use memo';
     const x = constantValue;
 
     return <div>{x}</div>;
@@ -65,6 +67,7 @@ test('global-constant-propagation', () => {
 
 test('lambda-constant-propagation', () => {
   function Component() {
+    'use memo';
     const x = 'test value 1';
     const getDiv = () => <div>{x}</div>;
     return getDiv();
@@ -92,6 +95,7 @@ test('lambda-constant-propagation', () => {
 
 test('lambda-constant-propagation-of-phi-node', () => {
   function Component({noopCallback}) {
+    'use memo';
     const x = 'test value 1';
     if (constantValue) {
       noopCallback();

compiler/packages/babel-plugin-react-compiler/src/__tests__/e2e/update-button.e2e.js

@@ -16,6 +16,7 @@ function Button({label}) {
 
 let currentTheme = 'light';
 function useTheme() {
+  'use memo';
   return currentTheme;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/e2e/update-expressions.e2e.js

@@ -10,6 +10,7 @@ import * as React from 'react';
 import {expectLogsAndClear, log} from './expectLogs';
 
 function Counter(props) {
+  'use memo';
   let value = props.value;
   let a = value++;
   expect(a).toBe(props.value); // postfix

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/arrow-function-expr-gating-test.expect.md

@@ -1,35 +0,0 @@
-
-## Input
-
-```javascript
-// @gating
-const ErrorView = (error, _retry) => <MessageBox error={error}></MessageBox>;
-
-export default ErrorView;
-
-```
-
-## Code
-
-```javascript
-import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
-import { c as _c } from "react/compiler-runtime"; // @gating
-const ErrorView = isForgetEnabled_Fixtures()
-  ? (error, _retry) => {
-      const $ = _c(2);
-      let t0;
-      if ($[0] !== error) {
-        t0 = <MessageBox error={error} />;
-        $[0] = error;
-        $[1] = t0;
-      } else {
-        t0 = $[1];
-      }
-      return t0;
-    }
-  : (error, _retry) => <MessageBox error={error}></MessageBox>;
-
-export default ErrorView;
-
-```
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/arrow-function-expr-gating-test.js

@@ -1,4 +0,0 @@
-// @gating
-const ErrorView = (error, _retry) => <MessageBox error={error}></MessageBox>;
-
-export default ErrorView;

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

@@ -0,0 +1,39 @@
+
+## Input
+
+```javascript
+// @compilationMode(infer)
+const Test = () => <div />;
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Test,
+  params: [{}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime"; // @compilationMode(infer)
+const Test = () => {
+  const $ = _c(1);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = <div />;
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  return t0;
+};
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Test,
+  params: [{}],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div></div>

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

@@ -0,0 +1,7 @@
+// @compilationMode(infer)
+const Test = () => <div />;
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Test,
+  params: [{}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/codegen-emit-imports-same-source.expect.md

@@ -21,7 +21,7 @@ import {
 import { c as _c } from "react/compiler-runtime"; // @enableEmitFreeze @enableEmitInstrumentForget
 
 function useFoo(props) {
-  if (__DEV__ && shouldInstrument)
+  if (DEV && shouldInstrument)
     useRenderCounter("useFoo", "/codegen-emit-imports-same-source.ts");
   const $ = _c(2);
   let t0;

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

@@ -28,7 +28,7 @@ import { c as _c } from "react/compiler-runtime"; // @enableEmitInstrumentForget
 
 function Bar(props) {
   "use forget";
-  if (__DEV__ && shouldInstrument)
+  if (DEV && shouldInstrument)
     useRenderCounter("Bar", "/codegen-instrument-forget-test.ts");
   const $ = _c(2);
   let t0;
@@ -48,7 +48,7 @@ function NoForget(props) {
 
 function Foo(props) {
   "use forget";
-  if (__DEV__ && shouldInstrument)
+  if (DEV && shouldInstrument)
     useRenderCounter("Foo", "/codegen-instrument-forget-test.ts");
   const $ = _c(2);
   let t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.component-syntax-ref-gating.flow.expect.md

@@ -1,24 +0,0 @@
-
-## Input
-
-```javascript
-// @flow @gating
-component Foo(ref: React.RefSetter<Controls>) {
-  return <Bar ref={ref} />;
-}
-
-```
-
-
-## Error
-
-```
-  1 | // @flow @gating
-> 2 | component Foo(ref: React.RefSetter<Controls>) {
-    |           ^^^ Invariant: Encountered a function used before its declaration, which breaks Forget's gating codegen due to hoisting. Rewrite the reference to Foo_withRef to not rely on hoisting to fix this issue (2:2)
-  3 |   return <Bar ref={ref} />;
-  4 | }
-  5 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.component-syntax-ref-gating.flow.js

@@ -1,4 +0,0 @@
-// @flow @gating
-component Foo(ref: React.RefSetter<Controls>) {
-  return <Bar ref={ref} />;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.gating-hoisting.expect.md

@@ -1,26 +0,0 @@
-
-## Input
-
-```javascript
-// @gating
-const Foo = React.forwardRef(Foo_withRef);
-function Foo_withRef(props, ref) {
-  return <Bar ref={ref} {...props}></Bar>;
-}
-
-```
-
-
-## Error
-
-```
-  1 | // @gating
-  2 | const Foo = React.forwardRef(Foo_withRef);
-> 3 | function Foo_withRef(props, ref) {
-    |          ^^^^^^^^^^^ Invariant: Encountered a function used before its declaration, which breaks Forget's gating codegen due to hoisting. Rewrite the reference to Foo_withRef to not rely on hoisting to fix this issue (3:3)
-  4 |   return <Bar ref={ref} {...props}></Bar>;
-  5 | }
-  6 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.gating-hoisting.js

@@ -1,5 +0,0 @@
-// @gating
-const Foo = React.forwardRef(Foo_withRef);
-function Foo_withRef(props, ref) {
-  return <Bar ref={ref} {...props}></Bar>;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.gating-use-before-decl.expect.md

@@ -1,24 +0,0 @@
-
-## Input
-
-```javascript
-// @gating
-import {memo} from 'react';
-
-export default memo(Foo);
-function Foo() {}
-
-```
-
-
-## Error
-
-```
-  3 |
-  4 | export default memo(Foo);
-> 5 | function Foo() {}
-    |          ^^^ Invariant: Encountered a function used before its declaration, which breaks Forget's gating codegen due to hoisting. Rewrite the reference to Foo to not rely on hoisting to fix this issue (5:5)
-  6 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.gating-use-before-decl.js

@@ -1,5 +0,0 @@
-// @gating
-import {memo} from 'react';
-
-export default memo(Foo);
-function Foo() {}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-jsx-in-catch-in-outer-try-with-catch.expect.md

@@ -1,38 +0,0 @@
-
-## Input
-
-```javascript
-// @validateNoJSXInTryStatements
-import {identity} from 'shared-runtime';
-
-function Component(props) {
-  let el;
-  try {
-    let value;
-    try {
-      value = identity(props.foo);
-    } catch {
-      el = <div value={value} />;
-    }
-  } catch {
-    return null;
-  }
-  return el;
-}
-
-```
-
-
-## Error
-
-```
-   9 |       value = identity(props.foo);
-  10 |     } catch {
-> 11 |       el = <div value={value} />;
-     |            ^^^^^^^^^^^^^^^^^^^^^ InvalidReact: Unexpected JSX element within a try statement. To catch errors in rendering a given component, wrap that component in an error boundary. (https://react.dev/reference/react/Component#catching-rendering-errors-with-an-error-boundary) (11:11)
-  12 |     }
-  13 |   } catch {
-  14 |     return null;
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-jsx-in-try-with-catch.expect.md

@@ -1,31 +0,0 @@
-
-## Input
-
-```javascript
-// @validateNoJSXInTryStatements
-function Component(props) {
-  let el;
-  try {
-    el = <div />;
-  } catch {
-    return null;
-  }
-  return el;
-}
-
-```
-
-
-## Error
-
-```
-  3 |   let el;
-  4 |   try {
-> 5 |     el = <div />;
-    |          ^^^^^^^ InvalidReact: Unexpected JSX element within a try statement. To catch errors in rendering a given component, wrap that component in an error boundary. (https://react.dev/reference/react/Component#catching-rendering-errors-with-an-error-boundary) (5:5)
-  6 |   } catch {
-  7 |     return null;
-  8 |   }
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-setState-in-useEffect-transitive.expect.md

@@ -1,37 +0,0 @@
-
-## Input
-
-```javascript
-// @validateNoSetStateInPassiveEffects
-import {useEffect, useState} from 'react';
-
-function Component() {
-  const [state, setState] = useState(0);
-  const f = () => {
-    setState(s => s + 1);
-  };
-  const g = () => {
-    f();
-  };
-  useEffect(() => {
-    g();
-  });
-  return state;
-}
-
-```
-
-
-## Error
-
-```
-  11 |   };
-  12 |   useEffect(() => {
-> 13 |     g();
-     |     ^ InvalidReact: Calling setState directly within a useEffect causes cascading renders and is not recommended. Consider alternatives to useEffect. (https://react.dev/learn/you-might-not-need-an-effect) (13:13)
-  14 |   });
-  15 |   return state;
-  16 | }
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-setState-in-useEffect.expect.md

@@ -1,31 +0,0 @@
-
-## Input
-
-```javascript
-// @validateNoSetStateInPassiveEffects
-import {useEffect, useState} from 'react';
-
-function Component() {
-  const [state, setState] = useState(0);
-  useEffect(() => {
-    setState(s => s + 1);
-  });
-  return state;
-}
-
-```
-
-
-## Error
-
-```
-   5 |   const [state, setState] = useState(0);
-   6 |   useEffect(() => {
->  7 |     setState(s => s + 1);
-     |     ^^^^^^^^ InvalidReact: Calling setState directly within a useEffect causes cascading renders and is not recommended. Consider alternatives to useEffect. (https://react.dev/learn/you-might-not-need-an-effect) (7:7)
-   8 |   });
-   9 |   return state;
-  10 | }
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/function-expression-prototype-call.expect.md

@@ -23,11 +23,11 @@ import { c as _c } from "react/compiler-runtime";
 function Component(props) {
   const $ = _c(4);
   let t0;
-  if ($[0] !== props.name) {
+  if ($[0] !== props) {
     t0 = function () {
       return <div>{props.name}</div>;
     };
-    $[0] = props.name;
+    $[0] = props;
     $[1] = t0;
   } else {
     t0 = $[1];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating-test-export-function-and-default.js

@@ -1,14 +0,0 @@
-// @gating @compilationMode(annotation)
-export default function Bar(props) {
-  'use forget';
-  return <div>{props.bar}</div>;
-}
-
-function NoForget(props) {
-  return <Bar>{props.noForget}</Bar>;
-}
-
-export function Foo(props) {
-  'use forget';
-  return <Foo>{props.bar}</Foo>;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/arrow-function-expr-gating-test.expect.md

@@ -0,0 +1,50 @@
+
+## Input
+
+```javascript
+// @gating
+import {Stringify} from 'shared-runtime';
+const ErrorView = ({error, _retry}) => <Stringify error={error}></Stringify>;
+
+export default ErrorView;
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('ErrorView'),
+  params: [{}],
+};
+
+```
+
+## Code
+
+```javascript
+import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
+import { c as _c } from "react/compiler-runtime"; // @gating
+import { Stringify } from "shared-runtime";
+const ErrorView = isForgetEnabled_Fixtures()
+  ? (t0) => {
+      const $ = _c(2);
+      const { error } = t0;
+      let t1;
+      if ($[0] !== error) {
+        t1 = <Stringify error={error} />;
+        $[0] = error;
+        $[1] = t1;
+      } else {
+        t1 = $[1];
+      }
+      return t1;
+    }
+  : ({ error, _retry }) => <Stringify error={error}></Stringify>;
+
+export default ErrorView;
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("ErrorView"),
+  params: [{}],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/arrow-function-expr-gating-test.js

@@ -0,0 +1,10 @@
+// @gating
+import {Stringify} from 'shared-runtime';
+const ErrorView = ({error, _retry}) => <Stringify error={error}></Stringify>;
+
+export default ErrorView;
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('ErrorView'),
+  params: [{}],
+};

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

@@ -15,9 +15,22 @@ function NoForget(props) {
 
 function Foo(props) {
   'use forget';
-  return <Foo>{props.bar}</Foo>;
+  if (props.bar < 0) {
+    return props.children;
+  }
+  return (
+    <Foo bar={props.bar - 1}>
+      <NoForget />
+    </Foo>
+  );
 }
 
+global.DEV = true;
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Foo'),
+  params: [{bar: 2}],
+};
+
 ```
 
 ## Code
@@ -29,7 +42,7 @@ import { c as _c } from "react/compiler-runtime"; // @enableEmitInstrumentForget
 const Bar = isForgetEnabled_Fixtures()
   ? function Bar(props) {
       "use forget";
-      if (__DEV__ && shouldInstrument)
+      if (DEV && shouldInstrument)
         useRenderCounter("Bar", "/codegen-instrument-forget-gating-test.ts");
       const $ = _c(2);
       let t0;
@@ -53,23 +66,50 @@ function NoForget(props) {
 const Foo = isForgetEnabled_Fixtures()
   ? function Foo(props) {
       "use forget";
-      if (__DEV__ && shouldInstrument)
+      if (DEV && shouldInstrument)
         useRenderCounter("Foo", "/codegen-instrument-forget-gating-test.ts");
-      const $ = _c(2);
-      let t0;
-      if ($[0] !== props.bar) {
-        t0 = <Foo>{props.bar}</Foo>;
-        $[0] = props.bar;
-        $[1] = t0;
-      } else {
-        t0 = $[1];
+      const $ = _c(3);
+      if (props.bar < 0) {
+        return props.children;
       }
-      return t0;
+
+      const t0 = props.bar - 1;
+      let t1;
+      if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+        t1 = <NoForget />;
+        $[0] = t1;
+      } else {
+        t1 = $[0];
+      }
+      let t2;
+      if ($[1] !== t0) {
+        t2 = <Foo bar={t0}>{t1}</Foo>;
+        $[1] = t0;
+        $[2] = t2;
+      } else {
+        t2 = $[2];
+      }
+      return t2;
     }
   : function Foo(props) {
       "use forget";
-      return <Foo>{props.bar}</Foo>;
+      if (props.bar < 0) {
+        return props.children;
+      }
+      return (
+        <Foo bar={props.bar - 1}>
+          <NoForget />
+        </Foo>
+      );
     };
 
+global.DEV = true;
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("Foo"),
+  params: [{ bar: 2 }],
+};
+
 ```
-      
+      
+### Eval output
+(kind: ok) <div></div>

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

@@ -11,5 +11,18 @@ function NoForget(props) {
 
 function Foo(props) {
   'use forget';
-  return <Foo>{props.bar}</Foo>;
+  if (props.bar < 0) {
+    return props.children;
+  }
+  return (
+    <Foo bar={props.bar - 1}>
+      <NoForget />
+    </Foo>
+  );
 }
+
+global.DEV = true;
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Foo'),
+  params: [{bar: 2}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/component-syntax-ref-gating.flow.expect.md

@@ -0,0 +1,62 @@
+
+## Input
+
+```javascript
+// @flow @gating
+import {Stringify} from 'shared-runtime';
+import * as React from 'react';
+
+component Foo(ref: React.RefSetter<Controls>) {
+  return <Stringify ref={ref} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('(...args) => React.createElement(Foo, args)'),
+  params: [{ref: React.createRef()}],
+};
+
+```
+
+## Code
+
+```javascript
+import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
+import { c as _c } from "react/compiler-runtime";
+import { Stringify } from "shared-runtime";
+import * as React from "react";
+
+const Foo = React.forwardRef(Foo_withRef);
+const _isForgetEnabled_Fixtures_result = isForgetEnabled_Fixtures();
+function _Foo_withRef_optimized(_$$empty_props_placeholder$$, ref) {
+  const $ = _c(2);
+  let t0;
+  if ($[0] !== ref) {
+    t0 = <Stringify ref={ref} />;
+    $[0] = ref;
+    $[1] = t0;
+  } else {
+    t0 = $[1];
+  }
+  return t0;
+}
+function _Foo_withRef_unoptimized(
+  _$$empty_props_placeholder$$: $ReadOnly<{}>,
+  ref: React.RefSetter<Controls>,
+): React.Node {
+  return <Stringify ref={ref} />;
+}
+function Foo_withRef(arg0, arg1) {
+  if (_isForgetEnabled_Fixtures_result)
+    return _Foo_withRef_optimized(arg0, arg1);
+  else return _Foo_withRef_unoptimized(arg0, arg1);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("(...args) => React.createElement(Foo, args)"),
+  params: [{ ref: React.createRef() }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"ref":null}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/component-syntax-ref-gating.flow.js

@@ -0,0 +1,12 @@
+// @flow @gating
+import {Stringify} from 'shared-runtime';
+import * as React from 'react';
+
+component Foo(ref: React.RefSetter<Controls>) {
+  return <Stringify ref={ref} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('(...args) => React.createElement(Foo, args)'),
+  params: [{ref: React.createRef()}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-nonreferenced-identifier-collision.expect.md

@@ -0,0 +1,60 @@
+
+## Input
+
+```javascript
+// @gating
+import {identity, useHook as useRenamed} from 'shared-runtime';
+const _ = {
+  useHook: () => {},
+};
+identity(_.useHook);
+
+function useHook() {
+  useRenamed();
+  return <div>hello world!</div>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useHook,
+  params: [{}],
+};
+
+```
+
+## Code
+
+```javascript
+import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
+import { c as _c } from "react/compiler-runtime"; // @gating
+import { identity, useHook as useRenamed } from "shared-runtime";
+const _ = {
+  useHook: isForgetEnabled_Fixtures() ? () => {} : () => {},
+};
+identity(_.useHook);
+const useHook = isForgetEnabled_Fixtures()
+  ? function useHook() {
+      const $ = _c(1);
+      useRenamed();
+      let t0;
+      if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+        t0 = <div>hello world!</div>;
+        $[0] = t0;
+      } else {
+        t0 = $[0];
+      }
+      return t0;
+    }
+  : function useHook() {
+      useRenamed();
+      return <div>hello world!</div>;
+    };
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useHook,
+  params: [{}],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>hello world!</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-nonreferenced-identifier-collision.js

@@ -0,0 +1,16 @@
+// @gating
+import {identity, useHook as useRenamed} from 'shared-runtime';
+const _ = {
+  useHook: () => {},
+};
+identity(_.useHook);
+
+function useHook() {
+  useRenamed();
+  return <div>hello world!</div>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useHook,
+  params: [{}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-test-export-default-function.expect.md

@@ -17,6 +17,11 @@ function Foo(props) {
   return <Foo>{props.bar}</Foo>;
 }
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Bar'),
+  params: [{bar: 2}],
+};
+
 ```
 
 ## Code
@@ -66,5 +71,12 @@ const Foo = isForgetEnabled_Fixtures()
       return <Foo>{props.bar}</Foo>;
     };
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("Bar"),
+  params: [{ bar: 2 }],
+};
+
 ```
-      
+      
+### Eval output
+(kind: ok) <div>2</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-test-export-default-function.js

@@ -12,3 +12,8 @@ function Foo(props) {
   'use forget';
   return <Foo>{props.bar}</Foo>;
 }
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Bar'),
+  params: [{bar: 2}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-test-export-function-and-default.expect.md

@@ -12,11 +12,23 @@ function NoForget(props) {
   return <Bar>{props.noForget}</Bar>;
 }
 
-export function Foo(props) {
+function Foo(props) {
   'use forget';
-  return <Foo>{props.bar}</Foo>;
+  if (props.bar < 0) {
+    return props.children;
+  }
+  return (
+    <Foo bar={props.bar - 1}>
+      <NoForget />
+    </Foo>
+  );
 }
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Bar'),
+  params: [{bar: 2}],
+};
+
 ```
 
 ## Code
@@ -47,25 +59,50 @@ export default Bar;
 function NoForget(props) {
   return <Bar>{props.noForget}</Bar>;
 }
-
-export const Foo = isForgetEnabled_Fixtures()
+const Foo = isForgetEnabled_Fixtures()
   ? function Foo(props) {
       "use forget";
-      const $ = _c(2);
-      let t0;
-      if ($[0] !== props.bar) {
-        t0 = <Foo>{props.bar}</Foo>;
-        $[0] = props.bar;
-        $[1] = t0;
-      } else {
-        t0 = $[1];
+      const $ = _c(3);
+      if (props.bar < 0) {
+        return props.children;
       }
-      return t0;
+
+      const t0 = props.bar - 1;
+      let t1;
+      if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+        t1 = <NoForget />;
+        $[0] = t1;
+      } else {
+        t1 = $[0];
+      }
+      let t2;
+      if ($[1] !== t0) {
+        t2 = <Foo bar={t0}>{t1}</Foo>;
+        $[1] = t0;
+        $[2] = t2;
+      } else {
+        t2 = $[2];
+      }
+      return t2;
     }
   : function Foo(props) {
       "use forget";
-      return <Foo>{props.bar}</Foo>;
+      if (props.bar < 0) {
+        return props.children;
+      }
+      return (
+        <Foo bar={props.bar - 1}>
+          <NoForget />
+        </Foo>
+      );
     };
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("Bar"),
+  params: [{ bar: 2 }],
+};
+
 ```
-      
+      
+### Eval output
+(kind: ok) <div>2</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-test-export-function-and-default.js

@@ -0,0 +1,26 @@
+// @gating @compilationMode(annotation)
+export default function Bar(props) {
+  'use forget';
+  return <div>{props.bar}</div>;
+}
+
+function NoForget(props) {
+  return <Bar>{props.noForget}</Bar>;
+}
+
+function Foo(props) {
+  'use forget';
+  if (props.bar < 0) {
+    return props.children;
+  }
+  return (
+    <Foo bar={props.bar - 1}>
+      <NoForget />
+    </Foo>
+  );
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Bar'),
+  params: [{bar: 2}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-test-export-function.expect.md

@@ -17,6 +17,11 @@ export function Foo(props) {
   return <Foo>{props.bar}</Foo>;
 }
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Bar'),
+  params: [{bar: 2}],
+};
+
 ```
 
 ## Code
@@ -66,5 +71,12 @@ export const Foo = isForgetEnabled_Fixtures()
       return <Foo>{props.bar}</Foo>;
     };
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("Bar"),
+  params: [{ bar: 2 }],
+};
+
 ```
-      
+      
+### Eval output
+(kind: ok) <div>2</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-test-export-function.js

@@ -12,3 +12,8 @@ export function Foo(props) {
   'use forget';
   return <Foo>{props.bar}</Foo>;
 }
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Bar'),
+  params: [{bar: 2}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-test.expect.md

@@ -17,6 +17,11 @@ function Foo(props) {
   return <Foo>{props.bar}</Foo>;
 }
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Bar'),
+  params: [{bar: 2}],
+};
+
 ```
 
 ## Code
@@ -65,5 +70,12 @@ const Foo = isForgetEnabled_Fixtures()
       return <Foo>{props.bar}</Foo>;
     };
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("Bar"),
+  params: [{ bar: 2 }],
+};
+
 ```
-      
+      
+### Eval output
+(kind: ok) <div>2</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-test.js

@@ -12,3 +12,8 @@ function Foo(props) {
   'use forget';
   return <Foo>{props.bar}</Foo>;
 }
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Bar'),
+  params: [{bar: 2}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-use-before-decl-ref.expect.md

@@ -0,0 +1,61 @@
+
+## Input
+
+```javascript
+// @gating
+import {createRef, forwardRef} from 'react';
+import {Stringify} from 'shared-runtime';
+
+const Foo = forwardRef(Foo_withRef);
+function Foo_withRef(props, ref) {
+  return <Stringify ref={ref} {...props} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('(...args) => React.createElement(Foo, args)'),
+  params: [{prop1: 1, prop2: 2, ref: createRef()}],
+};
+
+```
+
+## Code
+
+```javascript
+import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
+import { c as _c } from "react/compiler-runtime"; // @gating
+import { createRef, forwardRef } from "react";
+import { Stringify } from "shared-runtime";
+
+const Foo = forwardRef(Foo_withRef);
+const _isForgetEnabled_Fixtures_result = isForgetEnabled_Fixtures();
+function _Foo_withRef_optimized(props, ref) {
+  const $ = _c(3);
+  let t0;
+  if ($[0] !== props || $[1] !== ref) {
+    t0 = <Stringify ref={ref} {...props} />;
+    $[0] = props;
+    $[1] = ref;
+    $[2] = t0;
+  } else {
+    t0 = $[2];
+  }
+  return t0;
+}
+function _Foo_withRef_unoptimized(props, ref) {
+  return <Stringify ref={ref} {...props} />;
+}
+function Foo_withRef(arg0, arg1) {
+  if (_isForgetEnabled_Fixtures_result)
+    return _Foo_withRef_optimized(arg0, arg1);
+  else return _Foo_withRef_unoptimized(arg0, arg1);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("(...args) => React.createElement(Foo, args)"),
+  params: [{ prop1: 1, prop2: 2, ref: createRef() }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"0":{"prop1":1,"prop2":2,"ref":{"current":null}},"ref":"[[ cyclic ref *3 ]]"}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-use-before-decl-ref.js

@@ -0,0 +1,13 @@
+// @gating
+import {createRef, forwardRef} from 'react';
+import {Stringify} from 'shared-runtime';
+
+const Foo = forwardRef(Foo_withRef);
+function Foo_withRef(props, ref) {
+  return <Stringify ref={ref} {...props} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('(...args) => React.createElement(Foo, args)'),
+  params: [{prop1: 1, prop2: 2, ref: createRef()}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-use-before-decl.expect.md

@@ -0,0 +1,64 @@
+
+## Input
+
+```javascript
+// @gating
+import {memo} from 'react';
+import {Stringify} from 'shared-runtime';
+
+export default memo(Foo);
+function Foo({prop1, prop2}) {
+  'use memo';
+  return <Stringify prop1={prop1} prop2={prop2} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Foo'),
+  params: [{prop1: 1, prop2: 2}],
+};
+
+```
+
+## Code
+
+```javascript
+import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
+import { c as _c } from "react/compiler-runtime"; // @gating
+import { memo } from "react";
+import { Stringify } from "shared-runtime";
+
+export default memo(Foo);
+const _isForgetEnabled_Fixtures_result = isForgetEnabled_Fixtures();
+function _Foo_optimized(t0) {
+  "use memo";
+  const $ = _c(3);
+  const { prop1, prop2 } = t0;
+  let t1;
+  if ($[0] !== prop1 || $[1] !== prop2) {
+    t1 = <Stringify prop1={prop1} prop2={prop2} />;
+    $[0] = prop1;
+    $[1] = prop2;
+    $[2] = t1;
+  } else {
+    t1 = $[2];
+  }
+  return t1;
+}
+function _Foo_unoptimized({ prop1, prop2 }) {
+  "use memo";
+  return <Stringify prop1={prop1} prop2={prop2} />;
+}
+function Foo(arg0) {
+  if (_isForgetEnabled_Fixtures_result) return _Foo_optimized(arg0);
+  else return _Foo_unoptimized(arg0);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("Foo"),
+  params: [{ prop1: 1, prop2: 2 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"prop1":1,"prop2":2}</div>