[eprh] Remove __EXPERIMENTAL__

`__EXPERIMENTAL__` flag doesn't have any use outside of the React repo. Let's remove these flags for now.

.eslintrc.js

@@ -336,11 +336,11 @@ module.exports = {
         'packages/react-devtools-extensions/**/*.js',
         'packages/react-devtools-timeline/**/*.js',
         'packages/react-native-renderer/**/*.js',
-        'packages/eslint-plugin-react-hooks/**/*.js',
         'packages/jest-react/**/*.js',
         'packages/internal-test-utils/**/*.js',
         'packages/**/__tests__/*.js',
         'packages/**/npm/*.js',
+        'compiler/packages/eslint-plugin-react-hooks/**/*.js',
       ],
       rules: {
         'react-internal/prod-error-codes': OFF,
@@ -515,7 +515,7 @@ module.exports = {
       },
     },
     {
-      files: ['packages/eslint-plugin-react-hooks/src/**/*'],
+      files: ['compiler/packages/eslint-plugin-react-hooks/src/**/*'],
       extends: ['plugin:@typescript-eslint/recommended'],
       parser: '@typescript-eslint/parser',
       plugins: ['@typescript-eslint', 'eslint-plugin'],

.github/workflows/compiler_discord_notify.yml

@@ -19,7 +19,7 @@ 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

@@ -36,8 +36,9 @@ 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: npx playwright install --with-deps chromium
       - run: CI=true yarn test

.github/workflows/compiler_prereleases.yml

@@ -46,8 +46,9 @@ 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_typescript.yml

@@ -46,8 +46,9 @@ 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 +67,9 @@ 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 +92,9 @@ 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

@@ -29,13 +29,13 @@ 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
@@ -63,8 +63,9 @@ 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
@@ -120,8 +121,9 @@ 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 +156,9 @@ 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

.github/workflows/runtime_build_and_test.yml

@@ -17,6 +17,75 @@ 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: ${{ github.event.pull_request.head.sha || github.sha }}
+      - name: Check cache hit
+        uses: actions/cache/restore@v4
+        id: node_modules
+        with:
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ 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
+      - 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-v6-${{ runner.arch }}-${{ 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: ${{ github.event.pull_request.head.sha || github.sha }}
+      - name: Check cache hit
+        uses: actions/cache/restore@v4
+        id: node_modules
+        with:
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+          lookup-only: true
+      - uses: actions/setup-node@v4
+        if: steps.node_modules.outputs.cache-hit != 'true'
+        with:
+          node-version-file: '.nvmrc'
+          cache: yarn
+          cache-dependency-path: |
+            yarn.lock
+            compiler/yarn.lock
+      - 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-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
+
   # ----- FLOW -----
   discover_flow_inline_configs:
     name: Discover flow inline configs
@@ -36,7 +105,7 @@ jobs:
 
   flow:
     name: Flow check ${{ matrix.flow_inline_config_shortname }}
-    needs: discover_flow_inline_configs
+    needs: [discover_flow_inline_configs, runtime_node_modules_cache]
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -52,19 +121,22 @@ jobs:
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ runner.arch }}-${{ 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: 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
@@ -76,14 +148,16 @@ jobs:
           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 }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ 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 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)
@@ -91,6 +165,7 @@ jobs:
   # ----- FEATURE FLAGS -----
   flags:
     name: Check flags
+    needs: [runtime_node_modules_cache]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -102,19 +177,22 @@ jobs:
           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 }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ 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 ${{ matrix.shard }})
+    needs: [runtime_compiler_node_modules_cache]
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -153,27 +231,34 @@ jobs:
         with:
           node-version-file: '.nvmrc'
           cache: yarn
-          cache-dependency-path: yarn.lock
+          cache-dependency-path: |
+            yarn.lock
+            compiler/yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-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
+        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 }}
 
   # ----- 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
@@ -183,21 +268,27 @@ jobs:
         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 }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v6-${{ 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 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 }}
@@ -214,7 +305,7 @@ jobs:
 
   test_build:
     name: yarn test-build
-    needs: build_and_lint
+    needs: [build_and_lint, runtime_compiler_node_modules_cache]
     strategy:
       fail-fast: false
       matrix:
@@ -261,16 +352,22 @@ 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
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
       - name: Ensure clean build directory
         run: rm -rf build
       - run: yarn install --frozen-lockfile
+        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:
@@ -283,7 +380,7 @@ 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
@@ -295,14 +392,16 @@ jobs:
           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 }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ 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'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -311,7 +410,7 @@ jobs:
           merge-multiple: true
       - name: Display structure of build
         run: ls -R build
-      - run: echo ${{ github.sha }} >> build/COMMIT_SHA
+      - run: echo ${{ github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
       - name: Scrape warning messages
         run: |
           mkdir -p ./build/__test_utils__
@@ -330,7 +429,7 @@ jobs:
 
   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
@@ -342,14 +441,16 @@ jobs:
           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 }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ 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'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -365,7 +466,7 @@ 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
@@ -377,14 +478,16 @@ jobs:
           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 }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ 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'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -409,15 +512,16 @@ jobs:
           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') }}
       - 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:
@@ -452,14 +556,16 @@ 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') }}
       - 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:
@@ -498,7 +604,7 @@ jobs:
   # ----- 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
@@ -514,14 +620,16 @@ jobs:
           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 }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ 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'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -553,7 +661,7 @@ 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
@@ -565,14 +673,16 @@ jobs:
           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 }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-node_modules-v6-${{ 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'
       - name: Restore archived build
         uses: actions/download-artifact@v4
         with:
@@ -590,7 +700,7 @@ jobs:
   sizebot:
     if: ${{ github.event_name == 'pull_request' && github.ref_name != 'main' && github.event.pull_request.base.ref == 'main' }}
     name: Run sizebot
-    needs: [build_and_lint]
+    needs: [build_and_lint, runtime_node_modules_cache]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -602,15 +712,18 @@ jobs:
           cache: yarn
           cache-dependency-path: yarn.lock
       - name: Restore cached node_modules
-        uses: actions/cache@v4
+        uses: actions/cache/restore@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
+          path: |
+            **/node_modules
+          key: runtime-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 }})
@@ -626,6 +739,7 @@ jobs:
       - 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 for PR
         uses: actions/download-artifact@v4
         with:
@@ -638,7 +752,7 @@ jobs:
           node ./scripts/print-warnings/print-warnings.js > build/__test_utils__/ReactAllWarnings.js
       - name: Display structure of build for PR
         run: ls -R build
-      - run: echo ${{ github.sha }} >> build/COMMIT_SHA
+      - run: echo ${{ github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
       - run: node ./scripts/tasks/danger
       - name: Archive sizebot results
         uses: actions/upload-artifact@v4

.github/workflows/runtime_commit_artifacts.yml

@@ -16,6 +16,11 @@ on:
         required: true
         default: false
         type: boolean
+      dry_run:
+        description: Perform a dry run (run everything except push)
+        required: true
+        default: false
+        type: boolean
 
 env:
   TZ: /usr/share/zoneinfo/America/Los_Angeles
@@ -73,15 +78,13 @@ 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
-        name: yarn install (react)
-      - run: yarn install --frozen-lockfile
-        name: yarn install (scripts/release)
-        working-directory: scripts/release
+      - run: yarn --cwd scripts/release install --frozen-lockfile
       - 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 }}
@@ -107,9 +110,10 @@ 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 \
@@ -242,18 +246,22 @@ jobs:
         run: |
           echo ":"
           git status -u
+      - 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
@@ -409,15 +417,19 @@ 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

@@ -19,7 +19,7 @@ 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

@@ -35,16 +35,20 @@ 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_prereleases.yml

@@ -39,13 +39,13 @@ 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_releases_from_npm_manual.yml

@@ -44,7 +44,7 @@ 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: ${{ github.event.sender.login }}
@@ -71,13 +71,13 @@ jobs:
         uses: actions/cache@v4
         id: node_modules
         with:
-          path: "**/node_modules"
-          key: runtime-release-node_modules-${{ 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_cleanup_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 Branch Caches
+on:
+  pull_request:
+    types:
+      - closed
+  workflow_dispatch:
+
+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
+          echo "Deleting caches..."
+          for cacheKey in $cacheKeysForPR
+          do
+              gh cache delete $cacheKey
+          done
+          echo "Done"
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_REPO: ${{ github.repository }}
+          BRANCH: refs/pull/${{ github.event.pull_request.number }}/merge

.github/workflows/shared_lint.yml

@@ -28,8 +28,9 @@ 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 +49,9 @@ 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 +70,9 @@ 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 +91,9 @@ 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

ReactVersions.js

@@ -33,7 +33,6 @@ const canaryChannelLabel = 'canary';
 const rcNumber = 0;
 
 const stablePackages = {
-  'eslint-plugin-react-hooks': '5.2.0',
   'jest-react': '0.17.0',
   react: ReactVersion,
   'react-art': ReactVersion,

babel.config-react-compiler.js

@@ -1,19 +0,0 @@
-'use strict';
-
-/**
- * HACK: @poteto React Compiler inlines Zod in its build artifact. Zod spreads values passed to .map
- * which causes issues in @babel/plugin-transform-spread in loose mode, as it will result in
- * {undefined: undefined} which fails to parse.
- *
- * [@babel/plugin-transform-block-scoping', {throwIfClosureRequired: true}] also causes issues with
- * the built version of the compiler. The minimal set of plugins needed for this file is reexported
- * from babel.config-ts.
- *
- * I will remove this hack later when we move eslint-plugin-react-hooks into the compiler directory.
- **/
-
-const baseConfig = require('./babel.config-ts');
-
-module.exports = {
-  plugins: baseConfig.plugins,
-};

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/package.json

@@ -16,7 +16,7 @@
     "snap:build": "yarn workspace snap run build",
     "snap:ci": "yarn snap:build && yarn snap",
     "ts:analyze-trace": "scripts/ts-analyze-trace.sh",
-    "lint": "yarn eslint src",
+    "lint": "../../node_modules/eslint-v8/bin/eslint.js src",
     "watch": "yarn build --watch"
   },
   "dependencies": {
@@ -43,7 +43,7 @@
     "babel-jest": "^29.0.3",
     "babel-plugin-fbt": "^1.0.0",
     "babel-plugin-fbt-runtime": "^1.0.0",
-    "eslint": "^8.57.1",
+    "eslint-v8": "npm:eslint@^8.57.1",
     "invariant": "^2.2.4",
     "jest": "^29.0.3",
     "jest-environment-jsdom": "^29.0.3",

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

@@ -181,6 +181,7 @@ function ReactForgetFunctionTransform() {
         fn,
         forgetOptions,
         'Other',
+        'all_features',
         '_c',
         null,
         null,

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/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,
@@ -100,6 +101,7 @@ import {outlineJSX} from '../Optimization/OutlineJsx';
 import {optimizePropsMethodCalls} from '../Optimization/OptimizePropsMethodCalls';
 import {transformFire} from '../Transform';
 import {validateNoImpureFunctionsInRender} from '../Validation/ValiateNoImpureFunctionsInRender';
+import {CompilerError} from '..';
 
 export type CompilerPipelineValue =
   | {kind: 'ast'; name: string; value: CodegenFunction}
@@ -113,6 +115,7 @@ function run(
   >,
   config: EnvironmentConfig,
   fnType: ReactFunctionType,
+  mode: CompilerMode,
   useMemoCacheIdentifier: string,
   logger: Logger | null,
   filename: string | null,
@@ -122,6 +125,7 @@ function run(
   const env = new Environment(
     func.scope,
     fnType,
+    mode,
     config,
     contextIdentifiers,
     logger,
@@ -160,10 +164,10 @@ function runWithEnvironment(
   validateUseMemo(hir);
 
   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 +200,13 @@ 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);
+    }
+    if (env.config.validateNoCapitalizedCalls) {
+      validateNoCapitalizedCalls(hir);
+    }
   }
 
   if (env.config.enableFire) {
@@ -205,10 +214,6 @@ 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 +224,12 @@ 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 +249,30 @@ 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);
+    }
 
-  if (env.config.validateNoSetStateInRender) {
-    validateNoSetStateInRender(hir);
-  }
+    if (env.config.validateNoSetStateInRender) {
+      validateNoSetStateInRender(hir);
+    }
 
-  if (env.config.validateNoSetStateInPassiveEffects) {
-    validateNoSetStateInPassiveEffects(hir);
-  }
+    if (env.config.validateNoSetStateInPassiveEffects) {
+      validateNoSetStateInPassiveEffects(hir);
+    }
 
-  if (env.config.validateNoJSXInTryStatements) {
-    validateNoJSXInTryStatement(hir);
-  }
+    if (env.config.validateNoJSXInTryStatements) {
+      validateNoJSXInTryStatement(hir);
+    }
 
-  if (env.config.validateNoImpureFunctionsInRender) {
-    validateNoImpureFunctionsInRender(hir);
+    if (env.config.validateNoImpureFunctionsInRender) {
+      validateNoImpureFunctionsInRender(hir);
+    }
   }
 
   inferReactivePlaces(hir);
@@ -280,7 +292,12 @@ function runWithEnvironment(
     value: hir,
   });
 
-  if (!env.config.enableMinimalTransformsForRetry) {
+  if (env.isInferredMemoEnabled) {
+    /**
+     * 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});
   }
@@ -529,6 +546,7 @@ export function compileFn(
   >,
   config: EnvironmentConfig,
   fnType: ReactFunctionType,
+  mode: CompilerMode,
   useMemoCacheIdentifier: string,
   logger: Logger | null,
   filename: string | null,
@@ -538,6 +556,7 @@ 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 +431,33 @@ 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,
+          ),
+        };
+      } 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 +546,28 @@ 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 +604,7 @@ export function compileProgram(
     }
   } catch (err) {
     handleError(err, pass, null);
-    return;
+    return null;
   }
 
   /*
@@ -613,7 +616,12 @@ 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 +646,7 @@ export function compileProgram(
     }
     addImportsToProgram(program, externalFunctions);
   }
+  return {retryErrors};
 }
 
 function shouldSkipCompilation(
@@ -1093,20 +1102,23 @@ 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 +1144,7 @@ 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 +1154,13 @@ 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>;
 
@@ -550,8 +552,6 @@ 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 +626,6 @@ 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 +652,7 @@ const testComplexConfigDefaults: PartialEnvironmentConfig = {
       source: 'react-compiler-runtime',
       importSpecifierName: 'shouldInstrument',
     },
-    globalGating: '__DEV__',
+    globalGating: 'DEV',
   },
   enableEmitHookGuards: {
     source: 'react-compiler-runtime',
@@ -851,6 +840,7 @@ export class Environment {
   code: string | null;
   config: EnvironmentConfig;
   fnType: ReactFunctionType;
+  compilerMode: CompilerMode;
   useMemoCacheIdentifier: string;
   hasLoweredContextAccess: boolean;
   hasFireRewrite: boolean;
@@ -861,6 +851,7 @@ export class Environment {
   constructor(
     scope: BabelScope,
     fnType: ReactFunctionType,
+    compilerMode: CompilerMode,
     config: EnvironmentConfig,
     contextIdentifiers: Set<t.Identifier>,
     logger: Logger | null,
@@ -870,6 +861,7 @@ export class Environment {
   ) {
     this.#scope = scope;
     this.fnType = fnType;
+    this.compilerMode = compilerMode;
     this.config = config;
     this.filename = filename;
     this.code = code;
@@ -924,6 +916,10 @@ export class Environment {
     this.#hoistedIdentifiers = new Set();
   }
 
+  get isInferredMemoEnabled(): boolean {
+    return this.compilerMode !== 'no_inferred_memo';
+  }
+
   get nextIdentifierId(): IdentifierId {
     return makeIdentifierId(this.#nextIdentifer++);
   }
@@ -1125,10 +1121,34 @@ export class Environment {
       moduleName.toLowerCase() === 'react-dom'
     );
   }
+  static knownReactModules: ReadonlyArray<string> = ['react', 'react-dom'];
+
+  getFallthroughPropertyType(
+    receiver: Type,
+    _property: Type,
+  ): BuiltInType | PolyType | null {
+    let shapeId = null;
+    if (receiver.kind === 'Object' || receiver.kind === 'Function') {
+      shapeId = receiver.shapeId;
+    }
+
+    if (shapeId !== null) {
+      const shape = this.#shapes.get(shapeId);
+
+      CompilerError.invariant(shape !== undefined, {
+        reason: `[HIR] Forget internal error: cannot resolve shape ${shapeId}`,
+        description: null,
+        loc: null,
+        suggestions: null,
+      });
+      return shape.properties.get('*') ?? null;
+    }
+    return null;
+  }
 
   getPropertyType(
     receiver: Type,
-    property: string,
+    property: string | number,
   ): BuiltInType | PolyType | null {
     let shapeId = null;
     if (receiver.kind === 'Object' || receiver.kind === 'Function') {
@@ -1146,17 +1166,19 @@ export class Environment {
         loc: null,
         suggestions: null,
       });
-      let value =
-        shape.properties.get(property) ?? shape.properties.get('*') ?? null;
-      if (value === null && isHookName(property)) {
-        value = this.#getCustomHookType();
+      if (typeof property === 'string') {
+        return (
+          shape.properties.get(property) ??
+          shape.properties.get('*') ??
+          (isHookName(property) ? this.#getCustomHookType() : null)
+        );
+      } else {
+        return shape.properties.get('*') ?? null;
       }
-      return value;
-    } else if (isHookName(property)) {
+    } else if (typeof property === 'string' && isHookName(property)) {
       return this.#getCustomHookType();
-    } else {
-      return null;
     }
+    return null;
   }
 
   getFunctionSignature(type: FunctionType): FunctionSignature | null {

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

@@ -119,8 +119,8 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
       ],
       /*
        * https://tc39.es/ecma262/multipage/indexed-collections.html#sec-array.from
-       * Array.from(arrayLike, optionalFn, optionalThis) not added because
-       * the Effect of `arrayLike` is polymorphic i.e.
+       * Array.from(arrayLike, optionalFn, optionalThis)
+       * Note that the Effect of `arrayLike` is polymorphic i.e.
        *  - Effect.read if
        *     - it does not have an @iterator property and is array-like
        *       (i.e. has a length property)
@@ -128,6 +128,20 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
        *  - Effect.mutate if it is a self-mutative iterator (e.g. a generator
        *    function)
        */
+      [
+        'from',
+        addFunction(DEFAULT_SHAPES, [], {
+          positionalParams: [
+            Effect.ConditionallyMutate,
+            Effect.ConditionallyMutate,
+            Effect.ConditionallyMutate,
+          ],
+          restParam: Effect.Read,
+          returnType: {kind: 'Object', shapeId: BuiltInArrayId},
+          calleeEffect: Effect.Read,
+          returnValueKind: ValueKind.Mutable,
+        }),
+      ],
       [
         'of',
         // Array.of(element0, ..., elementN)

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/ObjectShape.ts

@@ -535,6 +535,30 @@ addObject(BUILTIN_SHAPES, BuiltInRefValueId, [
   ['*', {kind: 'Object', shapeId: BuiltInRefValueId}],
 ]);
 
+/**
+ * MixedReadOnly =
+ *   | primitive
+ *   | simple objects (Record<string, MixedReadOnly>)
+ *   | Array<MixedReadOnly>
+ *
+ * APIs such as Relay — but also Flux and other data stores — often return a
+ * union of types with some interesting properties in terms of analysis.
+ *
+ * Given this constraint, if data came from Relay, then we should be able to
+ * infer things like `data.items.map(): Array`. That may seem like a leap at
+ * first but remember, we assume you're not patching builtins. Thus the only way
+ * data.items.map can exist and be a function, given the above set of data types
+ * and builtin JS methods, is if `data.items` was an Array, and `data.items.map`
+ * is therefore calling Array.prototype.map. Then we know that function returns
+ * an Array as well. This relies on the fact that map() is being called, so if
+ * data.items was some other type it would error at runtime - so it's sound.
+ *
+ * Note that this shape is currently only used for hook return values, which
+ * means that it's safe to type aliasing method-call return kinds as `Frozen`.
+ *
+ * Also note that all newly created arrays from method-calls (e.g. `.map`)
+ * have the appropriate mutable `BuiltInArray` shape
+ */
 addObject(BUILTIN_SHAPES, BuiltInMixedReadonlyId, [
   [
     'toString',
@@ -546,6 +570,36 @@ addObject(BUILTIN_SHAPES, BuiltInMixedReadonlyId, [
       returnValueKind: ValueKind.Primitive,
     }),
   ],
+  [
+    'indexOf',
+    addFunction(BUILTIN_SHAPES, [], {
+      positionalParams: [],
+      restParam: Effect.Read,
+      returnType: {kind: 'Primitive'},
+      calleeEffect: Effect.Read,
+      returnValueKind: ValueKind.Primitive,
+    }),
+  ],
+  [
+    'includes',
+    addFunction(BUILTIN_SHAPES, [], {
+      positionalParams: [],
+      restParam: Effect.Read,
+      returnType: {kind: 'Primitive'},
+      calleeEffect: Effect.Read,
+      returnValueKind: ValueKind.Primitive,
+    }),
+  ],
+  [
+    'at',
+    addFunction(BUILTIN_SHAPES, [], {
+      positionalParams: [Effect.Read],
+      restParam: null,
+      returnType: {kind: 'Object', shapeId: BuiltInMixedReadonlyId},
+      calleeEffect: Effect.Capture,
+      returnValueKind: ValueKind.Frozen,
+    }),
+  ],
   [
     'map',
     addFunction(BUILTIN_SHAPES, [], {
@@ -642,9 +696,9 @@ addObject(BUILTIN_SHAPES, BuiltInMixedReadonlyId, [
     addFunction(BUILTIN_SHAPES, [], {
       positionalParams: [],
       restParam: Effect.ConditionallyMutate,
-      returnType: {kind: 'Poly'},
+      returnType: {kind: 'Object', shapeId: BuiltInMixedReadonlyId},
       calleeEffect: Effect.ConditionallyMutate,
-      returnValueKind: ValueKind.Mutable,
+      returnValueKind: ValueKind.Frozen,
       noAlias: true,
       mutableOnlyIfOperandsAreMutable: true,
     }),

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/HIR/Types.ts

@@ -60,7 +60,15 @@ export type PropType = {
   kind: 'Property';
   objectType: Type;
   objectName: string;
-  propertyName: PropertyLiteral;
+  propertyName:
+    | {
+        kind: 'literal';
+        value: PropertyLiteral;
+      }
+    | {
+        kind: 'computed';
+        value: Type;
+      };
 };
 
 export type ObjectMethod = {

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);
   }
 }
 
@@ -872,11 +873,33 @@ function inferBlock(
                 reason: new Set([ValueReason.Other]),
                 context: new Set(),
               };
+
+        for (const element of instrValue.elements) {
+          if (element.kind === 'Spread') {
+            state.referenceAndRecordEffects(
+              freezeActions,
+              element.place,
+              isArrayType(element.place.identifier)
+                ? Effect.Capture
+                : Effect.ConditionallyMutate,
+              ValueReason.Other,
+            );
+          } else if (element.kind === 'Identifier') {
+            state.referenceAndRecordEffects(
+              freezeActions,
+              element,
+              Effect.Capture,
+              ValueReason.Other,
+            );
+          } else {
+            let _: 'Hole' = element.kind;
+          }
+        }
+        state.initialize(instrValue, valueKind);
+        state.define(instr.lvalue, instrValue);
+        instr.lvalue.effect = Effect.Store;
         continuation = {
-          kind: 'initialize',
-          valueKind,
-          effect: {kind: Effect.Capture, reason: ValueReason.Other},
-          lvalueEffect: Effect.Store,
+          kind: 'funeffects',
         };
         break;
       }
@@ -1241,21 +1264,12 @@ function inferBlock(
         for (let i = 0; i < instrValue.args.length; i++) {
           const arg = instrValue.args[i];
           const place = arg.kind === 'Identifier' ? arg : arg.place;
-          if (effects !== null) {
-            state.referenceAndRecordEffects(
-              freezeActions,
-              place,
-              effects[i],
-              ValueReason.Other,
-            );
-          } else {
-            state.referenceAndRecordEffects(
-              freezeActions,
-              place,
-              Effect.ConditionallyMutate,
-              ValueReason.Other,
-            );
-          }
+          state.referenceAndRecordEffects(
+            freezeActions,
+            place,
+            getArgumentEffect(effects != null ? effects[i] : null, arg),
+            ValueReason.Other,
+          );
           hasCaptureArgument ||= place.effect === Effect.Capture;
         }
         if (signature !== null) {
@@ -1307,7 +1321,10 @@ function inferBlock(
           signature !== null
             ? {
                 kind: signature.returnValueKind,
-                reason: new Set([ValueReason.Other]),
+                reason: new Set([
+                  signature.returnValueReason ??
+                    ValueReason.KnownReturnSignature,
+                ]),
                 context: new Set(),
               }
             : {
@@ -1356,25 +1373,16 @@ function inferBlock(
         for (let i = 0; i < instrValue.args.length; i++) {
           const arg = instrValue.args[i];
           const place = arg.kind === 'Identifier' ? arg : arg.place;
-          if (effects !== null) {
-            /*
-             * If effects are inferred for an argument, we should fail invalid
-             * mutating effects
-             */
-            state.referenceAndRecordEffects(
-              freezeActions,
-              place,
-              effects[i],
-              ValueReason.Other,
-            );
-          } else {
-            state.referenceAndRecordEffects(
-              freezeActions,
-              place,
-              Effect.ConditionallyMutate,
-              ValueReason.Other,
-            );
-          }
+          /*
+           * If effects are inferred for an argument, we should fail invalid
+           * mutating effects
+           */
+          state.referenceAndRecordEffects(
+            freezeActions,
+            place,
+            getArgumentEffect(effects != null ? effects[i] : null, arg),
+            ValueReason.Other,
+          );
           hasCaptureArgument ||= place.effect === Effect.Capture;
         }
         if (signature !== null) {
@@ -2049,3 +2057,31 @@ function areArgumentsImmutableAndNonMutating(
   }
   return true;
 }
+
+function getArgumentEffect(
+  signatureEffect: Effect | null,
+  arg: Place | SpreadPattern,
+): Effect {
+  if (signatureEffect != null) {
+    if (arg.kind === 'Identifier') {
+      return signatureEffect;
+    } else if (
+      signatureEffect === Effect.Mutate ||
+      signatureEffect === Effect.ConditionallyMutate
+    ) {
+      return signatureEffect;
+    } else {
+      // see call-spread-argument-mutable-iterator test fixture
+      if (signatureEffect === Effect.Freeze) {
+        CompilerError.throwTodo({
+          reason: 'Support spread syntax for hook arguments',
+          loc: arg.place.loc,
+        });
+      }
+      // effects[i] is Effect.Capture | Effect.Read | Effect.Store
+      return Effect.ConditionallyMutate;
+    }
+  } else {
+    return Effect.ConditionallyMutate;
+  }
+}

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

@@ -2429,6 +2429,9 @@ function codegenObjectPropertyKey(
       });
       return expr;
     }
+    case 'number': {
+      return t.numericLiteral(key.name);
+    }
   }
 }
 

compiler/packages/babel-plugin-react-compiler/src/TypeInference/InferTypes.ts

@@ -307,11 +307,26 @@ function* generateInstructionTypes(
         kind: 'Property',
         objectType: value.object.identifier.type,
         objectName: getName(names, value.object.identifier.id),
-        propertyName: value.property,
+        propertyName: {
+          kind: 'literal',
+          value: value.property,
+        },
       });
       break;
     }
 
+    case 'ComputedLoad': {
+      yield equation(left, {
+        kind: 'Property',
+        objectType: value.object.identifier.type,
+        objectName: getName(names, value.object.identifier.id),
+        propertyName: {
+          kind: 'computed',
+          value: value.property.identifier.type,
+        },
+      });
+      break;
+    }
     case 'MethodCall': {
       const returnType = makeType();
       yield equation(value.property.identifier.type, {
@@ -336,7 +351,10 @@ function* generateInstructionTypes(
               kind: 'Property',
               objectType: value.value.identifier.type,
               objectName: getName(names, value.value.identifier.id),
-              propertyName: makePropertyLiteral(propertyName),
+              propertyName: {
+                kind: 'literal',
+                value: makePropertyLiteral(propertyName),
+              },
             });
           } else {
             break;
@@ -353,7 +371,10 @@ function* generateInstructionTypes(
                 kind: 'Property',
                 objectType: value.value.identifier.type,
                 objectName: getName(names, value.value.identifier.id),
-                propertyName: makePropertyLiteral(property.key.name),
+                propertyName: {
+                  kind: 'literal',
+                  value: makePropertyLiteral(property.key.name),
+                },
               });
             }
           }
@@ -410,7 +431,6 @@ function* generateInstructionTypes(
     case 'RegExpLiteral':
     case 'MetaProperty':
     case 'ComputedStore':
-    case 'ComputedLoad':
     case 'Await':
     case 'GetIterator':
     case 'IteratorNext':
@@ -454,12 +474,13 @@ class Unifier {
         return;
       }
       const objectType = this.get(tB.objectType);
-      let propertyType;
-      if (typeof tB.propertyName === 'number') {
-        propertyType = null;
-      } else {
-        propertyType = this.env.getPropertyType(objectType, tB.propertyName);
-      }
+      const propertyType =
+        tB.propertyName.kind === 'literal'
+          ? this.env.getPropertyType(objectType, tB.propertyName.value)
+          : this.env.getFallthroughPropertyType(
+              objectType,
+              tB.propertyName.value,
+            );
       if (propertyType !== null) {
         this.unify(tA, propertyType);
       }
@@ -677,7 +698,11 @@ class Unifier {
 const RefLikeNameRE = /^(?:[a-zA-Z$_][a-zA-Z$_0-9]*)Ref$|^ref$/;
 
 function isRefLikeName(t: PropType): boolean {
-  return RefLikeNameRE.test(t.objectName) && t.propertyName === 'current';
+  return (
+    t.propertyName.kind === 'literal' &&
+    RefLikeNameRE.test(t.objectName) &&
+    t.propertyName.value === 'current'
+  );
 }
 
 function tryUnionTypes(ty1: Type, ty2: Type): Type | null {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-arg1-captures-arg0.expect.md

@@ -0,0 +1,91 @@
+
+## Input
+
+```javascript
+import {useIdentity, Stringify} from 'shared-runtime';
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism).
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr, (x, idx) => ({...x, id: idx}));
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { useIdentity, Stringify } from "shared-runtime";
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism).
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component(t0) {
+  const $ = _c(4);
+  const { value } = t0;
+  const arr = [{ value: "foo" }, { value: "bar" }, { value }];
+  useIdentity();
+  const derived = Array.from(arr, _temp);
+  let t1;
+  if ($[0] !== derived) {
+    t1 = derived.at(-1);
+    $[0] = derived;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  let t2;
+  if ($[2] !== t1) {
+    t2 = <Stringify>{t1}</Stringify>;
+    $[2] = t1;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
+}
+function _temp(x, idx) {
+  return { ...x, id: idx };
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 5 }],
+  sequentialRenders: [{ value: 5 }, { value: 6 }, { value: 6 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"children":{"value":5,"id":2}}</div>
+<div>{"children":{"value":6,"id":2}}</div>
+<div>{"children":{"value":6,"id":2}}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-arg1-captures-arg0.js

@@ -0,0 +1,26 @@
+import {useIdentity, Stringify} from 'shared-runtime';
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism).
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr, (x, idx) => ({...x, id: idx}));
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-captures-arg0.expect.md

@@ -0,0 +1,88 @@
+
+## Input
+
+```javascript
+import {useIdentity, Stringify} from 'shared-runtime';
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism)
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr);
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { useIdentity, Stringify } from "shared-runtime";
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism)
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component(t0) {
+  const $ = _c(4);
+  const { value } = t0;
+  const arr = [{ value: "foo" }, { value: "bar" }, { value }];
+  useIdentity();
+  const derived = Array.from(arr);
+  let t1;
+  if ($[0] !== derived) {
+    t1 = derived.at(-1);
+    $[0] = derived;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  let t2;
+  if ($[2] !== t1) {
+    t2 = <Stringify>{t1}</Stringify>;
+    $[2] = t1;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 5 }],
+  sequentialRenders: [{ value: 5 }, { value: 6 }, { value: 6 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"children":{"value":5}}</div>
+<div>{"children":{"value":6}}</div>
+<div>{"children":{"value":6}}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-captures-arg0.js

@@ -0,0 +1,26 @@
+import {useIdentity, Stringify} from 'shared-runtime';
+
+/**
+ * TODO: Note that this `Array.from` is inferred to be mutating its first
+ * argument. This is because React Compiler's typing system does not yet support
+ * annotating a function with a set of argument match cases + distinct
+ * definitions (polymorphism)
+ *
+ * In this case, we should be able to infer that the `Array.from` call is
+ * not mutating its 0th argument.
+ * The 0th argument should be typed as having `effect:Mutate` only when
+ * (1) it might be a mutable iterable or
+ * (2) the 1st argument might mutate its callee
+ */
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr);
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-maybemutates-arg0.expect.md

@@ -0,0 +1,64 @@
+
+## Input
+
+```javascript
+import {mutateAndReturn, Stringify, useIdentity} from 'shared-runtime';
+
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr, mutateAndReturn);
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { mutateAndReturn, Stringify, useIdentity } from "shared-runtime";
+
+function Component(t0) {
+  const $ = _c(4);
+  const { value } = t0;
+  const arr = [{ value: "foo" }, { value: "bar" }, { value }];
+  useIdentity();
+  const derived = Array.from(arr, mutateAndReturn);
+  let t1;
+  if ($[0] !== derived) {
+    t1 = derived.at(-1);
+    $[0] = derived;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  let t2;
+  if ($[2] !== t1) {
+    t2 = <Stringify>{t1}</Stringify>;
+    $[2] = t1;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 5 }],
+  sequentialRenders: [{ value: 5 }, { value: 6 }, { value: 6 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"children":{"value":5,"wat0":"joe"}}</div>
+<div>{"children":{"value":6,"wat0":"joe"}}</div>
+<div>{"children":{"value":6,"wat0":"joe"}}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-from-maybemutates-arg0.js

@@ -0,0 +1,14 @@
+import {mutateAndReturn, Stringify, useIdentity} from 'shared-runtime';
+
+function Component({value}) {
+  const arr = [{value: 'foo'}, {value: 'bar'}, {value}];
+  useIdentity();
+  const derived = Array.from(arr, mutateAndReturn);
+  return <Stringify>{derived.at(-1)}</Stringify>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 5}],
+  sequentialRenders: [{value: 5}, {value: 6}, {value: 6}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-spread-later-mutated.expect.md

@@ -0,0 +1,62 @@
+
+## Input
+
+```javascript
+function useBar({arg}) {
+  /**
+   * Note that mutableIterator is mutated by the later object spread. Therefore,
+   * `s.values()` should be memoized within the same block as the object spread.
+   * In terms of compiler internals, they should have the same reactive scope.
+   */
+  const obj = {};
+  const s = new Set([obj, 5, 4]);
+  const mutableIterator = s.values();
+  const arr = [...mutableIterator];
+
+  obj.x = arg;
+  return arr;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useBar,
+  params: [{arg: 3}],
+  sequentialRenders: [{arg: 3}, {arg: 3}, {arg: 4}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+function useBar(t0) {
+  const $ = _c(2);
+  const { arg } = t0;
+  let arr;
+  if ($[0] !== arg) {
+    const obj = {};
+    const s = new Set([obj, 5, 4]);
+    const mutableIterator = s.values();
+    arr = [...mutableIterator];
+
+    obj.x = arg;
+    $[0] = arg;
+    $[1] = arr;
+  } else {
+    arr = $[1];
+  }
+  return arr;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useBar,
+  params: [{ arg: 3 }],
+  sequentialRenders: [{ arg: 3 }, { arg: 3 }, { arg: 4 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) [{"x":3},5,4]
+[{"x":3},5,4]
+[{"x":4},5,4]

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-spread-later-mutated.js

@@ -0,0 +1,20 @@
+function useBar({arg}) {
+  /**
+   * Note that mutableIterator is mutated by the later object spread. Therefore,
+   * `s.values()` should be memoized within the same block as the object spread.
+   * In terms of compiler internals, they should have the same reactive scope.
+   */
+  const obj = {};
+  const s = new Set([obj, 5, 4]);
+  const mutableIterator = s.values();
+  const arr = [...mutableIterator];
+
+  obj.x = arg;
+  return arr;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useBar,
+  params: [{arg: 3}],
+  sequentialRenders: [{arg: 3}, {arg: 3}, {arg: 4}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-spread-mutable-iterator.expect.md

@@ -55,26 +55,20 @@ import { c as _c } from "react/compiler-runtime"; /**
 
 function useBar(t0) {
   "use memo";
-  const $ = _c(3);
+  const $ = _c(2);
   const { arg } = t0;
   let t1;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+  if ($[0] !== arg) {
     const s = new Set([1, 5, 4]);
-    t1 = s.values();
-    $[0] = t1;
+    const mutableIterator = s.values();
+
+    t1 = [arg, ...mutableIterator];
+    $[0] = arg;
+    $[1] = t1;
   } else {
-    t1 = $[0];
+    t1 = $[1];
   }
-  const mutableIterator = t1;
-  let t2;
-  if ($[1] !== arg) {
-    t2 = [arg, ...mutableIterator];
-    $[1] = arg;
-    $[2] = t2;
-  } else {
-    t2 = $[2];
-  }
-  return t2;
+  return t1;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -84,4 +78,8 @@ export const FIXTURE_ENTRYPOINT = {
 };
 
 ```
-      
+      
+### Eval output
+(kind: ok) [3,1,5,4]
+[3,1,5,4]
+[4,1,5,4]

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/call-spread-argument-mutable-iterator.expect.md

@@ -0,0 +1,42 @@
+
+## Input
+
+```javascript
+import {useIdentity} from 'shared-runtime';
+
+function useFoo() {
+  const it = new Set([1, 2]).values();
+  useIdentity();
+  return Math.max(...it);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [{}],
+  sequentialRenders: [{}, {}],
+};
+
+```
+
+## Code
+
+```javascript
+import { useIdentity } from "shared-runtime";
+
+function useFoo() {
+  const it = new Set([1, 2]).values();
+  useIdentity();
+  return Math.max(...it);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [{}],
+  sequentialRenders: [{}, {}],
+};
+
+```
+      
+### Eval output
+(kind: ok) 2
+2

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/call-spread-argument-mutable-iterator.js

@@ -0,0 +1,13 @@
+import {useIdentity} from 'shared-runtime';
+
+function useFoo() {
+  const it = new Set([1, 2]).values();
+  useIdentity();
+  return Math.max(...it);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [{}],
+  sequentialRenders: [{}, {}],
+};

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.todo-hook-call-spreads-mutable-iterator.expect.md

@@ -0,0 +1,33 @@
+
+## Input
+
+```javascript
+import {useIdentity} from 'shared-runtime';
+
+function Component() {
+  const items = makeArray(0, 1, 2, null, 4, false, 6);
+  return useIdentity(...items.values());
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [],
+  sequentialRenders: [{}, {}],
+};
+
+```
+
+
+## Error
+
+```
+  3 | function Component() {
+  4 |   const items = makeArray(0, 1, 2, null, 4, false, 6);
+> 5 |   return useIdentity(...items.values());
+    |                         ^^^^^^^^^^^^^^ Todo: Support spread syntax for hook arguments (5:5)
+  6 | }
+  7 |
+  8 | export const FIXTURE_ENTRYPOINT = {
+```
+          
+      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-hook-call-spreads-mutable-iterator.js

@@ -0,0 +1,12 @@
+import {useIdentity} from 'shared-runtime';
+
+function Component() {
+  const items = makeArray(0, 1, 2, null, 4, false, 6);
+  return useIdentity(...items.values());
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [],
+  sequentialRenders: [{}, {}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-nested-method-calls-lower-property-load-into-temporary.expect.md

@@ -4,9 +4,10 @@
 ```javascript
 import {makeArray} from 'shared-runtime';
 
-function Component(props) {
+const other = [0, 1];
+function Component({}) {
   const items = makeArray(0, 1, 2, null, 4, false, 6);
-  const max = Math.max(...items.filter(Boolean));
+  const max = Math.max(2, items.push(5), ...other);
   return max;
 }
 
@@ -21,13 +22,13 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-  3 | function Component(props) {
-  4 |   const items = makeArray(0, 1, 2, null, 4, false, 6);
-> 5 |   const max = Math.max(...items.filter(Boolean));
-    |               ^^^^^^^^ Invariant: [Codegen] Internal error: MethodCall::property must be an unpromoted + unmemoized MemberExpression. Got a `Identifier` (5:5)
-  6 |   return max;
-  7 | }
-  8 |
+  4 | function Component({}) {
+  5 |   const items = makeArray(0, 1, 2, null, 4, false, 6);
+> 6 |   const max = Math.max(2, items.push(5), ...other);
+    |               ^^^^^^^^ Invariant: [Codegen] Internal error: MethodCall::property must be an unpromoted + unmemoized MemberExpression. Got a `Identifier` (6:6)
+  7 |   return max;
+  8 | }
+  9 |
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-nested-method-calls-lower-property-load-into-temporary.js

@@ -1,8 +1,9 @@
 import {makeArray} from 'shared-runtime';
 
-function Component(props) {
+const other = [0, 1];
+function Component({}) {
   const items = makeArray(0, 1, 2, null, 4, false, 6);
-  const max = Math.max(...items.filter(Boolean));
+  const max = Math.max(2, items.push(5), ...other);
   return max;
 }
 

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>

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

@@ -0,0 +1,14 @@
+// @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}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-with-hoisted-type-reference.flow.expect.md

@@ -13,6 +13,11 @@ component Component(value: string) {
 
 export default memo<Props>(Component);
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Component'),
+  params: [{value: 'foo'}],
+};
+
 ```
 
 ## Code
@@ -43,5 +48,12 @@ const Component = isForgetEnabled_Fixtures()
 
 export default memo<Props>(Component);
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("Component"),
+  params: [{ value: "foo" }],
+};
+
 ```
-      
+      
+### Eval output
+(kind: ok) <div>foo</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/gating-with-hoisted-type-reference.flow.js

@@ -8,3 +8,8 @@ component Component(value: string) {
 }
 
 export default memo<Props>(Component);
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Component'),
+  params: [{value: 'foo'}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/infer-function-expression-React-memo-gating.expect.md

@@ -35,4 +35,7 @@ export default React.forwardRef(
 );
 
 ```
-      
+      
+### Eval output
+(kind: exception) Fixture not implemented
+logs: ['forwardRef render functions accept exactly two parameters: props and ref. %s','Did you forget to use the ref parameter?']

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/invalid-fnexpr-reference.expect.md

@@ -0,0 +1,59 @@
+
+## Input
+
+```javascript
+// @gating
+import * as React from 'react';
+
+let Foo;
+const MemoFoo = React.memo(Foo);
+Foo = () => <div>hello world!</div>;
+
+/**
+ * Evaluate this fixture module to assert that compiler + original have the same
+ * runtime error message.
+ */
+export const FIXTURE_ENTRYPOINT = {
+  fn: () => {},
+  params: [],
+};
+
+```
+
+## Code
+
+```javascript
+import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
+import { c as _c } from "react/compiler-runtime"; // @gating
+import * as React from "react";
+
+let Foo;
+const MemoFoo = React.memo(Foo);
+Foo = isForgetEnabled_Fixtures()
+  ? () => {
+      const $ = _c(1);
+      let t0;
+      if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+        t0 = <div>hello world!</div>;
+        $[0] = t0;
+      } else {
+        t0 = $[0];
+      }
+      return t0;
+    }
+  : () => <div>hello world!</div>;
+
+/**
+ * Evaluate this fixture module to assert that compiler + original have the same
+ * runtime error message.
+ */
+export const FIXTURE_ENTRYPOINT = {
+  fn: isForgetEnabled_Fixtures() ? () => {} : () => {},
+  params: [],
+};
+
+```
+      
+### Eval output
+(kind: ok) 
+logs: ['memo: The first argument must be a component. Instead received: %s','undefined']

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/invalid-fnexpr-reference.js

@@ -0,0 +1,15 @@
+// @gating
+import * as React from 'react';
+
+let Foo;
+const MemoFoo = React.memo(Foo);
+Foo = () => <div>hello world!</div>;
+
+/**
+ * Evaluate this fixture module to assert that compiler + original have the same
+ * runtime error message.
+ */
+export const FIXTURE_ENTRYPOINT = {
+  fn: () => {},
+  params: [],
+};

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

@@ -3,17 +3,17 @@
 
 ```javascript
 // @gating
-const ErrorView = (error, _retry) => <MessageBox error={error}></MessageBox>;
+import {Stringify} from 'shared-runtime';
 
-const Renderer = props => (
+const ErrorView = (error, _retry) => <Stringify error={error}></Stringify>;
+
+export default props => (
   <Foo>
     <Bar></Bar>
     <ErrorView></ErrorView>
   </Foo>
 );
 
-export default Renderer;
-
 ```
 
 ## Code
@@ -21,12 +21,14 @@ export default Renderer;
 ```javascript
 import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
 import { c as _c } from "react/compiler-runtime"; // @gating
+import { Stringify } from "shared-runtime";
+
 const ErrorView = isForgetEnabled_Fixtures()
   ? (error, _retry) => {
       const $ = _c(2);
       let t0;
       if ($[0] !== error) {
-        t0 = <MessageBox error={error} />;
+        t0 = <Stringify error={error} />;
         $[0] = error;
         $[1] = t0;
       } else {
@@ -34,9 +36,9 @@ const ErrorView = isForgetEnabled_Fixtures()
       }
       return t0;
     }
-  : (error, _retry) => <MessageBox error={error}></MessageBox>;
+  : (error, _retry) => <Stringify error={error}></Stringify>;
 
-const Renderer = isForgetEnabled_Fixtures()
+export default isForgetEnabled_Fixtures()
   ? (props) => {
       const $ = _c(1);
       let t0;
@@ -59,7 +61,8 @@ const Renderer = isForgetEnabled_Fixtures()
         <ErrorView></ErrorView>
       </Foo>
     );
-export default Renderer;
 
 ```
-      
+      
+### Eval output
+(kind: exception) Fixture not implemented

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

@@ -0,0 +1,11 @@
+// @gating
+import {Stringify} from 'shared-runtime';
+
+const ErrorView = (error, _retry) => <Stringify error={error}></Stringify>;
+
+export default props => (
+  <Foo>
+    <Bar></Bar>
+    <ErrorView></ErrorView>
+  </Foo>
+);

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

@@ -3,15 +3,22 @@
 
 ```javascript
 // @gating
-const ErrorView = (error, _retry) => <MessageBox error={error}></MessageBox>;
+import {Stringify} from 'shared-runtime';
+
+const ErrorView = (error, _retry) => <Stringify error={error}></Stringify>;
 
 export const Renderer = props => (
-  <Foo>
-    <Bar></Bar>
+  <div>
+    <span></span>
     <ErrorView></ErrorView>
-  </Foo>
+  </div>
 );
 
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Renderer'),
+  params: [{}],
+};
+
 ```
 
 ## Code
@@ -19,12 +26,14 @@ export const Renderer = props => (
 ```javascript
 import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
 import { c as _c } from "react/compiler-runtime"; // @gating
+import { Stringify } from "shared-runtime";
+
 const ErrorView = isForgetEnabled_Fixtures()
   ? (error, _retry) => {
       const $ = _c(2);
       let t0;
       if ($[0] !== error) {
-        t0 = <MessageBox error={error} />;
+        t0 = <Stringify error={error} />;
         $[0] = error;
         $[1] = t0;
       } else {
@@ -32,7 +41,7 @@ const ErrorView = isForgetEnabled_Fixtures()
       }
       return t0;
     }
-  : (error, _retry) => <MessageBox error={error}></MessageBox>;
+  : (error, _retry) => <Stringify error={error}></Stringify>;
 
 export const Renderer = isForgetEnabled_Fixtures()
   ? (props) => {
@@ -40,10 +49,10 @@ export const Renderer = isForgetEnabled_Fixtures()
       let t0;
       if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
         t0 = (
-          <Foo>
-            <Bar />
+          <div>
+            <span />
             <ErrorView />
-          </Foo>
+          </div>
         );
         $[0] = t0;
       } else {
@@ -52,11 +61,17 @@ export const Renderer = isForgetEnabled_Fixtures()
       return t0;
     }
   : (props) => (
-      <Foo>
-        <Bar></Bar>
+      <div>
+        <span></span>
         <ErrorView></ErrorView>
-      </Foo>
+      </div>
     );
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("Renderer"),
+  params: [{}],
+};
 
 ```
-      
+      
+### Eval output
+(kind: ok) <div><span></span><div>{"error":{}}</div></div>

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

@@ -0,0 +1,16 @@
+// @gating
+import {Stringify} from 'shared-runtime';
+
+const ErrorView = (error, _retry) => <Stringify error={error}></Stringify>;
+
+export const Renderer = props => (
+  <div>
+    <span></span>
+    <ErrorView></ErrorView>
+  </div>
+);
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Renderer'),
+  params: [{}],
+};

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

@@ -3,15 +3,24 @@
 
 ```javascript
 // @gating
-const ErrorView = (error, _retry) => <MessageBox error={error}></MessageBox>;
+import {Stringify} from 'shared-runtime';
 
-export default Renderer = props => (
-  <Foo>
-    <Bar></Bar>
+const ErrorView = (error, _retry) => <Stringify error={error}></Stringify>;
+
+const Renderer = props => (
+  <div>
+    <span></span>
     <ErrorView></ErrorView>
-  </Foo>
+  </div>
 );
 
+export default Renderer;
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval('Renderer'),
+  params: [{}],
+};
+
 ```
 
 ## Code
@@ -19,12 +28,14 @@ export default Renderer = props => (
 ```javascript
 import { isForgetEnabled_Fixtures } from "ReactForgetFeatureFlag";
 import { c as _c } from "react/compiler-runtime"; // @gating
+import { Stringify } from "shared-runtime";
+
 const ErrorView = isForgetEnabled_Fixtures()
   ? (error, _retry) => {
       const $ = _c(2);
       let t0;
       if ($[0] !== error) {
-        t0 = <MessageBox error={error} />;
+        t0 = <Stringify error={error} />;
         $[0] = error;
         $[1] = t0;
       } else {
@@ -32,18 +43,18 @@ const ErrorView = isForgetEnabled_Fixtures()
       }
       return t0;
     }
-  : (error, _retry) => <MessageBox error={error}></MessageBox>;
+  : (error, _retry) => <Stringify error={error}></Stringify>;
 
-export default Renderer = isForgetEnabled_Fixtures()
+const Renderer = isForgetEnabled_Fixtures()
   ? (props) => {
       const $ = _c(1);
       let t0;
       if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
         t0 = (
-          <Foo>
-            <Bar />
+          <div>
+            <span />
             <ErrorView />
-          </Foo>
+          </div>
         );
         $[0] = t0;
       } else {
@@ -52,11 +63,19 @@ export default Renderer = isForgetEnabled_Fixtures()
       return t0;
     }
   : (props) => (
-      <Foo>
-        <Bar></Bar>
+      <div>
+        <span></span>
         <ErrorView></ErrorView>
-      </Foo>
+      </div>
     );
+export default Renderer;
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: eval("Renderer"),
+  params: [{}],
+};
 
 ```
-      
+      
+### Eval output
+(kind: ok) <div><span></span><div>{"error":{}}</div></div>