[Float][Fiber] Assume stylesheets in document are already loaded (cherrypick #29811 ) (#29835 )

Cherrypick #29811 When we made stylesheets suspend even during high priority updates we exposed a bug in the loading tracking of stylesheets that are loaded as part of the preamble. This allowed these stylesheets to put suspense boundaries into fallback mode more often than expected because cases where a stylesheet was server rendered could now cause a fallback to trigger which was never intended to happen. This fix updates resource construction to evaluate whether the instance exists in the DOM prior to construction and if so marks the resource as loaded and inserted. One ambiguity that needed to be solved still is how to tell whether a stylesheet rendered as part of a late Suspense boundary reveal is already loaded. I updated the instruction to clear out the loading promise after successfully loading. This is useful because later if we encounter this same resource again we can avoid the microtask if it is already loaded. It also means that we can concretely understand that if a stylesheet is in the DOM without this marker then it must have loaded (or errored) already.
2024-06-10 11:41:15 -07:00
2625 changed files with 26414 additions and 43473 deletions
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -0,0 +1,699 @@
+version: 2.1
+
+aliases:
+  - &docker
+    - image: cimg/node:18.20.1-browsers
+
+  - &environment
+    TZ: /usr/share/zoneinfo/America/Los_Angeles
+
+  - &restore_yarn_cache_fixtures_dom
+    restore_cache:
+      name: Restore yarn cache for fixtures/dom
+      keys:
+        - v2-yarn_cache-{{ arch }}-{{ checksum "yarn.lock" }}-fixtures/dom
+
+  - &yarn_install_fixtures_dom
+    run:
+      name: Install dependencies in fixtures/dom
+      working_directory: fixtures/dom
+      command: yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
+
+  - &yarn_install_fixtures_dom_retry
+    run:
+      name: Install dependencies in fixtures/dom (retry)
+      when: on_fail
+      working_directory: fixtures/dom
+      command: yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
+
+  - &save_yarn_cache_fixtures_dom
+    save_cache:
+      name: Save yarn cache for fixtures/dom
+      key: v2-yarn_cache-{{ arch }}-{{ checksum "yarn.lock" }}-fixtures/dom
+      paths:
+        - ~/.cache/yarn
+
+  - &TEST_PARALLELISM 20
+
+  - &attach_workspace
+    at: build
+
+commands:
+  setup_node_modules:
+    description: "Restore node_modules"
+    steps:
+      - restore_cache:
+          name: Restore yarn cache
+          keys:
+            - v2-yarn_cache-{{ arch }}-{{ checksum "yarn.lock" }}
+      - run:
+          name: Install dependencies
+          command: |
+            yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
+            if [ $? -ne 0 ]; then
+              yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
+            fi
+          environment:
+          # If we start needing the Electron binary, please ensure the binary is cached in CI following https://www.electronjs.org/docs/latest/tutorial/installation
+            ELECTRON_SKIP_BINARY_DOWNLOAD: 1
+      - save_cache:
+          name: Save yarn cache
+          key: v2-yarn_cache-{{ arch }}-{{ checksum "yarn.lock" }}
+          paths:
+            - ~/.cache/yarn
+
+# The CircleCI API doesn't yet support triggering a specific workflow, but it
+# does support triggering a pipeline. So as a workaround you can triggger the
+# entire pipeline and use parameters to disable everything except the workflow
+# you want. CircleCI recommends this workaround here:
+# https://support.circleci.com/hc/en-us/articles/360050351292-How-to-trigger-a-workflow-via-CircleCI-API-v2-
+parameters:
+  # This is only set when triggering the CI pipeline via an API request.
+  prerelease_commit_sha:
+    type: string
+    default: ''
+
+jobs:
+  yarn_lint:
+    docker: *docker
+    environment: *environment
+
+    steps:
+      - checkout
+      - setup_node_modules
+      - run: node ./scripts/prettier/index
+      - run: node ./scripts/tasks/eslint
+      - run: ./scripts/circleci/check_license.sh
+      - run: ./scripts/circleci/test_print_warnings.sh
+
+  yarn_flow:
+    docker: *docker
+    environment: *environment
+    parallelism: 5
+
+    steps:
+      - checkout
+      - setup_node_modules
+      - run: node ./scripts/tasks/flow-ci
+
+
+  yarn_flags:
+    docker: *docker
+    environment: *environment
+
+    steps:
+      - checkout
+      - setup_node_modules
+      - run: yarn flags
+
+  scrape_warning_messages:
+    docker: *docker
+    environment: *environment
+
+    steps:
+      - checkout
+      - setup_node_modules
+      - run:
+          command: |
+            mkdir -p ./build/__test_utils__
+            node ./scripts/print-warnings/print-warnings.js > build/__test_utils__/ReactAllWarnings.js
+      - persist_to_workspace:
+          root: .
+          paths:
+            - build
+
+  yarn_build:
+    docker: *docker
+    environment: *environment
+    parallelism: 40
+    steps:
+      - checkout
+      - setup_node_modules
+      - run: yarn build
+      - persist_to_workspace:
+          root: .
+          paths:
+            - build
+
+  download_build:
+    docker: *docker
+    environment: *environment
+    parameters:
+      revision:
+        type: string
+    steps:
+      - checkout
+      - setup_node_modules
+      - run:
+          name: Download artifacts for revision
+          command: |
+              git fetch origin main
+              cd ./scripts/release && yarn && cd ../../
+              scripts/release/download-experimental-build.js --commit=<< parameters.revision >> --allowBrokenCI
+      - persist_to_workspace:
+          root: .
+          paths:
+            - build
+
+  download_base_build_for_sizebot:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - setup_node_modules
+      - run:
+          name: Download artifacts for base revision
+          command: |
+            git fetch origin main
+            cd ./scripts/release && yarn && cd ../../
+            scripts/release/download-experimental-build.js --commit=$(git merge-base HEAD origin/main) --allowBrokenCI
+            mv ./build ./base-build
+
+      - run:
+          # TODO: The `download-experimental-build` script copies the npm
+          # packages into the `node_modules` directory. This is a historical
+          # quirk of how the release script works. Let's pretend they
+          # don't exist.
+          name: Delete extraneous files
+          command: rm -rf ./base-build/node_modules
+
+      - persist_to_workspace:
+          root: .
+          paths:
+            - base-build
+
+  process_artifacts_combined:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - setup_node_modules
+      - run: echo "<< pipeline.git.revision	>>" >> build/COMMIT_SHA
+        # Compress build directory into a single tarball for easy download
+      - run: tar -zcvf ./build.tgz ./build
+        # TODO: Migrate scripts to use `build` directory instead of `build2`
+      - run: cp ./build.tgz ./build2.tgz
+      - store_artifacts:
+          path: ./build2.tgz
+      - store_artifacts:
+          path: ./build.tgz
+
+  sizebot:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - run: echo "<< pipeline.git.revision	>>" >> build/COMMIT_SHA
+      - setup_node_modules
+      - run:
+          command: node ./scripts/tasks/danger
+      - store_artifacts:
+          path: sizebot-message.md
+
+  build_devtools_and_process_artifacts:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - setup_node_modules
+      - run:
+          environment:
+            RELEASE_CHANNEL: experimental
+          command: ./scripts/circleci/pack_and_store_devtools_artifacts.sh
+      - store_artifacts:
+          path: ./build/devtools.tgz
+      # Simplifies getting the extension for local testing
+      - store_artifacts:
+          path: ./build/devtools/chrome-extension.zip
+          destination: react-devtools-chrome-extension.zip
+      - store_artifacts:
+          path: ./build/devtools/firefox-extension.zip
+          destination: react-devtools-firefox-extension.zip
+
+  run_devtools_e2e_tests:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - setup_node_modules
+      - run:
+          name: Playwright install deps
+          command: |
+            npx playwright install
+            sudo npx playwright install-deps
+      - run:
+          environment:
+            RELEASE_CHANNEL: experimental
+          command: ./scripts/circleci/run_devtools_e2e_tests.js
+
+  run_fixtures_flight_tests:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      # Fixture copies some built packages from the workroot after install.
+      # That means dependencies of the built packages are not installed.
+      # We need to install dependencies of the workroot to fulfill all dependency constraints
+      - setup_node_modules
+      - restore_cache:
+          name: Restore yarn cache of fixture
+          keys:
+            - v2-yarn_cache_fixtures_flight-{{ arch }}-{{ checksum "yarn.lock" }}
+      - run:
+          name: Install fixture dependencies
+          working_directory: fixtures/flight
+          command: |
+            yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
+            if [ $? -ne 0 ]; then
+              yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
+            fi
+      - save_cache:
+          name: Save yarn cache of fixture
+          key: v2-yarn_cache_fixtures_flight-{{ arch }}-{{ checksum "yarn.lock" }}
+          paths:
+            - ~/.cache/yarn
+      - run:
+          working_directory: fixtures/flight
+          name: Playwright install deps
+          command: |
+            npx playwright install
+            sudo npx playwright install-deps
+      - run:
+          name: Run tests
+          working_directory: fixtures/flight
+          command: yarn test
+          environment:
+          # Otherwise the webserver is a blackbox
+            DEBUG: pw:webserver
+      - store_artifacts:
+          path: fixtures/flight/playwright-report
+      - store_artifacts:
+          path: fixtures/flight/test-results
+
+  run_devtools_tests_for_versions:
+    docker: *docker
+    environment: *environment
+    parallelism: *TEST_PARALLELISM
+    parameters:
+      version:
+        type: string
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - setup_node_modules
+      - run: ./scripts/circleci/download_devtools_regression_build.js << parameters.version >> --replaceBuild
+      - run: node ./scripts/jest/jest-cli.js --build --project devtools --release-channel=experimental --reactVersion << parameters.version >> --ci
+
+  run_devtools_e2e_tests_for_versions:
+    docker: *docker
+    environment: *environment
+    parallelism: *TEST_PARALLELISM
+    parameters:
+      version:
+        type: string
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - setup_node_modules
+      - run:
+          name: Playwright install deps
+          command: |
+            npx playwright install
+            sudo npx playwright install-deps
+      - run: ./scripts/circleci/download_devtools_regression_build.js << parameters.version >>
+      - run:
+          environment:
+            RELEASE_CHANNEL: experimental
+          command: ./scripts/circleci/run_devtools_e2e_tests.js << parameters.version >>
+      - run:
+          name: Cleanup build regression folder
+          command: rm -r ./build-regression
+      - store_artifacts:
+          path: ./tmp/screenshots
+
+  yarn_lint_build:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - setup_node_modules
+      - run: yarn lint-build
+
+  yarn_check_release_dependencies:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - setup_node_modules
+      - run: yarn check-release-dependencies
+
+
+  check_error_codes:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace: *attach_workspace
+      - setup_node_modules
+      - run:
+          name: Search build artifacts for unminified errors
+          command: |
+            yarn extract-errors
+            git diff --quiet || (echo "Found unminified errors. Either update the error codes map or disable error minification for the affected build, if appropriate." && false)
+
+  check_generated_fizz_runtime:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace: *attach_workspace
+      - setup_node_modules
+      - run:
+          name: Confirm generated inline Fizz runtime is up to date
+          command: |
+            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)
+
+  yarn_test:
+    docker: *docker
+    environment: *environment
+    parallelism: *TEST_PARALLELISM
+    parameters:
+      args:
+        type: string
+    steps:
+      - checkout
+      - setup_node_modules
+      - run: yarn test <<parameters.args>> --ci
+
+  yarn_test_build:
+    docker: *docker
+    environment: *environment
+    parallelism: *TEST_PARALLELISM
+    parameters:
+      args:
+        type: string
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - setup_node_modules
+      - run: yarn test --build <<parameters.args>> --ci
+
+  RELEASE_CHANNEL_stable_yarn_test_dom_fixtures:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace:
+          at: .
+      - setup_node_modules
+      - *restore_yarn_cache_fixtures_dom
+      - *yarn_install_fixtures_dom
+      - *yarn_install_fixtures_dom_retry
+      - *save_yarn_cache_fixtures_dom
+      - run:
+          name: Run DOM fixture tests
+          environment:
+            RELEASE_CHANNEL: stable
+          working_directory: fixtures/dom
+          command: |
+            yarn predev
+            yarn test --maxWorkers=2
+
+  publish_prerelease:
+    parameters:
+      commit_sha:
+        type: string
+      release_channel:
+        type: string
+      dist_tag:
+        type: string
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - setup_node_modules
+      - run:
+          name: Run publish script
+          command: |
+            git fetch origin main
+            cd ./scripts/release && yarn && cd ../../
+            scripts/release/prepare-release-from-ci.js --skipTests -r << parameters.release_channel >> --commit=<< parameters.commit_sha >>
+            cp ./scripts/release/ci-npmrc ~/.npmrc
+            scripts/release/publish.js --ci --tags << parameters.dist_tag >>
+
+workflows:
+
+  build_and_test:
+    unless: << pipeline.parameters.prerelease_commit_sha >>
+    jobs:
+      - yarn_flags:
+          filters:
+            branches:
+              ignore:
+                - builds/facebook-www
+      - yarn_flow:
+          filters:
+            branches:
+              ignore:
+                - builds/facebook-www
+      - check_generated_fizz_runtime:
+          filters:
+            branches:
+              ignore:
+                - builds/facebook-www
+      - yarn_lint:
+          filters:
+            branches:
+              ignore:
+                - builds/facebook-www
+      - yarn_test:
+          filters:
+            branches:
+              ignore:
+                - builds/facebook-www
+          matrix:
+            parameters:
+              args:
+                # Intentionally passing these as strings instead of creating a
+                # separate parameter per CLI argument, since it's easier to
+                # control/see which combinations we want to run.
+                - "-r=stable --env=development"
+                - "-r=stable --env=production"
+                - "-r=experimental --env=development"
+                - "-r=experimental --env=production"
+                - "-r=www-classic --env=development --variant=false"
+                - "-r=www-classic --env=production --variant=false"
+                - "-r=www-classic --env=development --variant=true"
+                - "-r=www-classic --env=production --variant=true"
+                - "-r=www-modern --env=development --variant=false"
+                - "-r=www-modern --env=production --variant=false"
+                - "-r=www-modern --env=development --variant=true"
+                - "-r=www-modern --env=production --variant=true"
+                - "-r=xplat --env=development --variant=false"
+                - "-r=xplat --env=development --variant=true"
+                - "-r=xplat --env=production --variant=false"
+                - "-r=xplat --env=production --variant=true"
+
+                # TODO: Test more persistent configurations?
+                - '-r=stable --env=development --persistent'
+                - '-r=experimental --env=development --persistent'
+      - yarn_build:
+          filters:
+            branches:
+              ignore:
+                - builds/facebook-www
+      - scrape_warning_messages:
+          filters:
+            branches:
+              ignore:
+                - builds/facebook-www
+      - process_artifacts_combined:
+          requires:
+            - scrape_warning_messages
+            - yarn_build
+      - yarn_test_build:
+          requires:
+            - yarn_build
+          matrix:
+            parameters:
+              args:
+                # Intentionally passing these as strings instead of creating a
+                # separate parameter per CLI argument, since it's easier to
+                # control/see which combinations we want to run.
+                - "-r=stable --env=development"
+                - "-r=stable --env=production"
+                - "-r=experimental --env=development"
+                - "-r=experimental --env=production"
+
+                # Dev Tools
+                - "--project=devtools -r=experimental"
+
+                # TODO: Update test config to support www build tests
+                # - "-r=www-classic --env=development --variant=false"
+                # - "-r=www-classic --env=production --variant=false"
+                # - "-r=www-classic --env=development --variant=true"
+                # - "-r=www-classic --env=production --variant=true"
+                # - "-r=www-modern --env=development --variant=false"
+                # - "-r=www-modern --env=production --variant=false"
+                # - "-r=www-modern --env=development --variant=true"
+                # - "-r=www-modern --env=production --variant=true"
+
+                # TODO: Update test config to support xplat build tests
+                # - "-r=xplat --env=development --variant=false"
+                # - "-r=xplat --env=development --variant=true"
+                # - "-r=xplat --env=production --variant=false"
+                # - "-r=xplat --env=production --variant=true"
+
+                # TODO: Test more persistent configurations?
+      - download_base_build_for_sizebot:
+          filters:
+            branches:
+              ignore:
+                - main
+                - builds/facebook-www
+      - sizebot:
+          filters:
+            branches:
+              ignore:
+                - main
+          requires:
+            - download_base_build_for_sizebot
+            - yarn_build
+      - yarn_lint_build:
+          requires:
+            - yarn_build
+      - yarn_check_release_dependencies:
+          requires:
+            - yarn_build
+      - check_error_codes:
+          requires:
+            - yarn_build
+      - RELEASE_CHANNEL_stable_yarn_test_dom_fixtures:
+          requires:
+            - yarn_build
+      - build_devtools_and_process_artifacts:
+          requires:
+            - yarn_build
+      - run_devtools_e2e_tests:
+          requires:
+            - build_devtools_and_process_artifacts
+      - run_fixtures_flight_tests:
+          requires:
+            - yarn_build
+
+  devtools_regression_tests:
+    unless: << pipeline.parameters.prerelease_commit_sha >>
+    triggers:
+      - schedule:
+          # DevTools regression tests run once a day
+          cron: "0 0 * * *"
+          filters:
+            branches:
+              only:
+                - main
+    jobs:
+      - download_build:
+          revision: << pipeline.git.revision >>
+      - build_devtools_and_process_artifacts:
+          requires:
+            - download_build
+      - run_devtools_tests_for_versions:
+          requires:
+            - build_devtools_and_process_artifacts
+          matrix:
+            parameters:
+              version:
+                - "16.0"
+                - "16.5" # schedule package
+                - "16.8" # hooks
+                - "17.0"
+                - "18.0"
+      - run_devtools_e2e_tests_for_versions:
+          requires:
+            - build_devtools_and_process_artifacts
+          matrix:
+            parameters:
+              version:
+                - "16.0"
+                - "16.5" # schedule package
+                - "16.8" # hooks
+                - "17.0"
+                - "18.0"
+
+  # Used to publish a prerelease manually via the command line
+  publish_preleases:
+    when: << pipeline.parameters.prerelease_commit_sha >>
+    jobs:
+      - publish_prerelease:
+          name: Publish to Canary channel
+          commit_sha: << pipeline.parameters.prerelease_commit_sha >>
+          release_channel: stable
+          # The tags to use when publishing canaries. The main one we should
+          # always include is "canary" but we can use multiple (e.g. alpha,
+          # beta, rc). To declare multiple, use a comma-separated string, like
+          # this:
+          #   dist_tag: "canary,alpha,beta,rc"
+          #
+          # TODO: We currently tag canaries with "next" in addition to "canary"
+          # because this used to be called the "next" channel and some
+          # downstream consumers might still expect that tag. We can remove this
+          # after some time has elapsed and the change has been communicated.
+          dist_tag: "canary,next,rc"
+      - publish_prerelease:
+          name: Publish to Experimental channel
+          requires:
+            # NOTE: Intentionally running these jobs sequentially because npm
+            # will sometimes fail if you try to concurrently publish two
+            # different versions of the same package, even if they use different
+            # dist tags.
+            - Publish to Canary channel
+          commit_sha: << pipeline.parameters.prerelease_commit_sha >>
+          release_channel: experimental
+          dist_tag: experimental
+
+  # Publishes on a cron schedule
+  publish_preleases_nightly:
+    unless: << pipeline.parameters.prerelease_commit_sha >>
+    triggers:
+      - schedule:
+          # At 10 minutes past 16:00 on Mon, Tue, Wed, Thu, and Fri
+          cron: "10 16 * * 1,2,3,4,5"
+          filters:
+            branches:
+              only:
+                - main
+    jobs:
+      - publish_prerelease:
+          name: Publish to Canary channel
+          commit_sha: << pipeline.git.revision >>
+          release_channel: stable
+          dist_tag: "canary,next,rc"
+      - publish_prerelease:
+          name: Publish to Experimental channel
+          requires:
+            # NOTE: Intentionally running these jobs sequentially because npm
+            # will sometimes fail if you try to concurrently publish two
+            # different versions of the same package, even if they use different
+            # dist tags.
+            - Publish to Canary channel
+          commit_sha: << pipeline.git.revision >>
+          release_channel: experimental
+          dist_tag: experimental
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -12,13 +12,11 @@ const WARNING = 1;
 const ERROR = 2;

 module.exports = {
-  extends: ['prettier', 'plugin:jest/recommended'],
+  extends: ['prettier'],

  // Stop ESLint from looking for a configuration file in parent folders
  root: true,

-  reportUnusedDisableDirectives: true,
-
  plugins: [
    'babel',
    'ft-flow',
@@ -247,7 +245,7 @@ module.exports = {
      },
    ],
    'no-shadow': ERROR,
-    'no-unused-vars': [ERROR, {args: 'none', ignoreRestSiblings: true}],
+    'no-unused-vars': [ERROR, {args: 'none'}],
    'no-use-before-define': OFF,
    'no-useless-concat': OFF,
    quotes: [ERROR, 'single', {avoidEscape: true, allowTemplateLiterals: true}],
@@ -378,49 +376,16 @@ module.exports = {
      files: ['**/__tests__/*.js'],
      rules: {
        // https://github.com/jest-community/eslint-plugin-jest
-        // Meh, who cares.
-        'jest/consistent-test-it': OFF,
-        // Meh, we have a lot of these, who cares.
-        'jest/no-alias-methods': OFF,
-        // We do conditions based on feature flags.
-        'jest/no-conditional-expect': OFF,
-        // We have our own assertion helpers.
-        'jest/expect-expect': OFF,
-        // Lame rule that fires in itRender helpers or in render methods.
-        'jest/no-standalone-expect': OFF,
+        'jest/no-focused-tests': ERROR,
+        'jest/valid-expect': ERROR,
+        'jest/valid-expect-in-promise': ERROR,
      },
    },
    {
-      // Rules specific to test setup helper files.
-      files: [
-        '**/setupTests.js',
-        '**/setupEnv.js',
-        '**/jest/TestFlags.js',
-        '**/dom-event-testing-library/testHelpers.js',
-        '**/utils/ReactDOMServerIntegrationTestUtils.js',
-        '**/babel/transform-react-version-pragma.js',
-        '**/babel/transform-test-gate-pragma.js',
-      ],
+      // disable no focused tests for test setup helper files even if they are inside __tests__ directory
+      files: ['**/setupTests.js'],
      rules: {
-        // Some helpers intentionally focus tests.
        'jest/no-focused-tests': OFF,
-        // Test fn helpers don't use static text names.
-        'jest/valid-title': OFF,
-        // We have our own assertion helpers.
-        'jest/expect-expect': OFF,
-        // Some helpers intentionally disable tests.
-        'jest/no-disabled-tests': OFF,
-        // Helpers export text function helpers.
-        'jest/no-export': OFF,
-        // The examples in comments trigger false errors.
-        'jest/no-commented-out-tests': OFF,
-      },
-    },
-    {
-      files: ['**/jest/TestFlags.js'],
-      rules: {
-        // The examples in comments trigger false errors.
-        'jest/no-commented-out-tests': OFF,
      },
    },
    {
@@ -486,12 +451,7 @@ module.exports = {
      },
    },
    {
-      files: [
-        'packages/react-devtools-extensions/**/*.js',
-        'packages/react-devtools-shared/src/hook.js',
-        'packages/react-devtools-shared/src/backend/console.js',
-        'packages/react-devtools-shared/src/backend/shared/DevToolsComponentStackFrame.js',
-      ],
+      files: ['packages/react-devtools-extensions/**/*.js'],
      globals: {
        __IS_CHROME__: 'readonly',
        __IS_FIREFOX__: 'readonly',
@@ -578,7 +538,6 @@ module.exports = {
    TimeoutID: 'readonly',
    WheelEventHandler: 'readonly',
    FinalizationRegistry: 'readonly',
-    Omit: 'readonly',

    spyOnDev: 'readonly',
    spyOnDevAndProd: 'readonly',
--- a/.git-blame-ignore-revs
+++ b/.git-blame-ignore-revs
@@ -1,2 +1 @@
 c998bb1ed4b3285398c9c7797135d3f060243c6a
-fd2b3e13d330a4559f5aa21462e1cb2cbbcf144b
--- a/.github/workflows/runtime_commit_artifacts.yml
+++ b/.github/workflows/runtime_commit_artifacts.yml
@@ -1,21 +1,8 @@
-name: (Runtime) Commit Artifacts for Meta WWW and fbsource V2
+name: Commit Artifacts for Meta WWW and fbsource

 on:
-  workflow_run:
-    workflows: ["(Runtime) Build and Test"]
-    types: [completed]
-    branches:
-      - main
-  workflow_dispatch:
-    inputs:
-      commit_sha:
-        required: false
-        type: string
-
-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-  # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
-  SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
+  push:
+    branches: [main, meta-www, meta-fbsource]

 jobs:
  download_artifacts:
@@ -59,27 +46,101 @@ jobs:
        run: |
          echo "www_branch_count=$(git ls-remote --heads origin "refs/heads/meta-www" | wc -l)" >> "$GITHUB_OUTPUT"
          echo "fbsource_branch_count=$(git ls-remote --heads origin "refs/heads/meta-fbsource" | wc -l)" >> "$GITHUB_OUTPUT"
-      - uses: actions/setup-node@v4
+      - name: Download and unzip artifacts
+        uses: actions/github-script@v6
+        env:
+          CIRCLECI_TOKEN: ${{secrets.CIRCLECI_TOKEN_DIFFTRAIN}}
        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-        name: yarn install (react)
-      - run: yarn install --frozen-lockfile
-        name: yarn install (scripts/release)
-        working-directory: scripts/release
-      - name: Download artifacts for base revision
-        run: |
-          GH_TOKEN=${{ github.token }} scripts/release/download-experimental-build.js --commit=${{ inputs.commit_sha || github.event.workflow_run.head_sha }}
-      - name: Display structure of build
-        run: ls -R build
+          script: |
+            const cp = require('child_process');
+
+            function sleep(ms) {
+              return new Promise(resolve => setTimeout(resolve, ms));
+            }
+
+            function execHelper(command, options, streamStdout = false) {
+              return new Promise((resolve, reject) => {
+                const proc = cp.exec(
+                  command,
+                  options,
+                  (error, stdout) => (error ? reject(error) : resolve(stdout.trim())),
+                );
+                if (streamStdout) {
+                  proc.stdout.pipe(process.stdout);
+                }
+              });
+            }
+
+            let artifactsUrl = null;
+            // This is a temporary, dirty hack to avoid needing a GitHub auth token in the circleci
+            // workflow to notify this GitHub action. Sorry!
+            let iter = 0;
+            spinloop: while (iter < 15) {
+              const res = await github.rest.repos.listCommitStatusesForRef({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                ref: context.sha
+              });
+              for (const status of res.data) {
+                if (/process_artifacts_combined/.test(status.context)) {
+                  switch (status.state) {
+                    case 'pending': {
+                      console.log(`${status.context} is still pending`);
+                      break;
+                    }
+                    case 'failure':
+                    case 'error': {
+                      throw new Error(`${status.context} has failed or errored`);
+                    }
+                    case 'success': {
+                      // The status does not include a build ID, but we can extract it
+                      // from the URL. I couldn't find a better way to do this.
+                      const ciBuildId = /\/facebook\/react\/([0-9]+)/.exec(
+                        status.target_url,
+                      )[1];
+                      if (Number.parseInt(ciBuildId, 10) + '' === ciBuildId) {
+                        artifactsUrl =
+                          `https://circleci.com/api/v1.1/project/github/facebook/react/${ciBuildId}/artifacts`;
+                        console.log(`Found artifactsUrl: ${artifactsUrl}`);
+                        break spinloop;
+                      } else {
+                        throw new Error(`${ciBuildId} isn't a number`);
+                      }
+                      break;
+                    }
+                    default: {
+                      throw new Error(`Unhandled status state: ${status.state}`);
+                      break;
+                    }
+                  }
+                }
+              }
+              iter++;
+              console.log("Sleeping for 60s...");
+              await sleep(60_000);
+            }
+            if (artifactsUrl != null) {
+              const {CIRCLECI_TOKEN} = process.env;
+              const res = await fetch(artifactsUrl, {
+                headers: {
+                  'Circle-Token': CIRCLECI_TOKEN
+                }
+              });
+              const data = await res.json();
+              if (!Array.isArray(data) && data.message != null) {
+                throw `CircleCI returned: ${data.message}`;
+              }
+              for (const artifact of data) {
+                if (artifact.path === 'build.tgz') {
+                  console.log(`Downloading and unzipping ${artifact.url}`);
+                  await execHelper(
+                    `curl -L ${artifact.url} -H "Circle-Token: ${CIRCLECI_TOKEN}" | tar -xvz`
+                  );
+                }
+              }
+            } else {
+              process.exitCode = 1;
+            }
      - name: Strip @license from eslint plugin and react-refresh
        run: |
          sed -i -e 's/ @license React*//' \
@@ -134,9 +195,9 @@ jobs:
          ls -R ./compiled-rn
      - name: Add REVISION files
        run: |
-          echo ${{ github.event.workflow_run.head_sha }} >> ./compiled/facebook-www/REVISION
+          echo ${{ github.sha }} >> ./compiled/facebook-www/REVISION
          cp ./compiled/facebook-www/REVISION ./compiled/facebook-www/REVISION_TRANSFORMS
-          echo ${{ github.event.workflow_run.head_sha}} >> ./compiled-rn/facebook-fbsource/xplat/js/react-native-github/Libraries/Renderer/REVISION
+          echo ${{ github.sha }} >> ./compiled-rn/facebook-fbsource/xplat/js/react-native-github/Libraries/Renderer/REVISION
      - name: "Get current version string"
        id: get_current_version
        run: |
@@ -149,11 +210,11 @@ jobs:
          echo "current_version_classic=$VERSION_CLASSIC" >> "$GITHUB_OUTPUT"
          echo "current_version_modern=$VERSION_MODERN" >> "$GITHUB_OUTPUT"
          echo "current_version_rn=$VERSION_NATIVE_FB" >> "$GITHUB_OUTPUT"
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v3
        with:
          name: compiled
          path: compiled/
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v3
        with:
          name: compiled-rn
          path: compiled-rn/
@@ -168,7 +229,7 @@ jobs:
          ref: builds/facebook-www
      - name: Ensure clean directory
        run: rm -rf compiled
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@v3
        with:
          name: compiled
          path: compiled/
@@ -189,18 +250,14 @@ jobs:
          grep -rl "$CURRENT_VERSION_MODERN" ./compiled || echo "No files found with $CURRENT_VERSION_MODERN"
          grep -rl "$CURRENT_VERSION_MODERN" ./compiled | xargs -r sed -i -e "s/$CURRENT_VERSION_MODERN/$LAST_VERSION_MODERN/g"
          grep -rl "$CURRENT_VERSION_MODERN" ./compiled || echo "Modern version reverted"
-      - name: Check for changes
+      - name: Check if only the REVISION file has changed
        id: check_should_commit
        run: |
          echo "Full git status"
-          git add .
          git status
          echo "===================="
          if git status --porcelain | grep -qv '/REVISION'; then
            echo "Changes detected"
-            echo "===== Changes ====="
-            git --no-pager diff -U0 | grep '^[+-]' | head -n 50
-            echo "==================="
            echo "should_commit=true" >> "$GITHUB_OUTPUT"
          else
            echo "No Changes detected"
@@ -233,12 +290,12 @@ jobs:
        uses: stefanzweifel/git-auto-commit-action@v4
        with:
          commit_message: |
-            ${{ github.event.workflow_run.head_commit.message }}
+            ${{ github.event.head_commit.message }}

-            DiffTrain build for [${{ github.event.workflow_run.head_sha }}](https://github.com/facebook/react/commit/${{ github.event.workflow_run.head_sha }})
+            DiffTrain build for [${{ github.sha }}](https://github.com/facebook/react/commit/${{ github.sha }})
          branch: builds/facebook-www
-          commit_user_name: ${{ github.event.workflow_run.triggering_actor.login }}
-          commit_user_email: ${{ github.event.workflow_run.triggering_actor.email || format('{0}@users.noreply.github.com', github.event.workflow_run.triggering_actor.login) }}
+          commit_user_name: ${{ github.actor }}
+          commit_user_email: ${{ github.actor }}@users.noreply.github.com
          create_branch: true

  commit_fbsource_artifacts:
@@ -251,7 +308,7 @@ jobs:
          ref: builds/facebook-fbsource
      - name: Ensure clean directory
        run: rm -rf compiled-rn
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@v3
        with:
          name: compiled-rn
          path: compiled-rn/
@@ -265,19 +322,17 @@ jobs:
          grep -rl "$CURRENT_VERSION" ./compiled-rn || echo "No files found with $CURRENT_VERSION"
          grep -rl "$CURRENT_VERSION" ./compiled-rn | xargs -r sed -i -e "s/$CURRENT_VERSION/$LAST_VERSION/g"
          grep -rl "$CURRENT_VERSION" ./compiled-rn || echo "Version reverted"
-      - name: Check for changes
+      - name: Check if only the REVISION file has changed
        id: check_should_commit
        run: |
          echo "Full git status"
-          git add .
-          git --no-pager diff -U0 --cached | grep '^[+-]' | head -n 100
+          git status
          echo "===================="
-          # Ignore REVISION or lines removing @generated headers.
-          if git diff --cached ':(exclude)*REVISION' | grep -vE "^(@@|diff|index|\-\-\-|\+\+\+|\- \* @generated SignedSource)" | grep "^[+-]" > /dev/null; then
+          echo "Checking for changes"
+          # Check if there are changes in the files other than REVISION or @generated headers
+          # We also filter out the file name lines with "---" and "+++".
+          if git diff -- . ':(exclude)*REVISION' | grep -vE "^(@@|diff|index|\-\-\-|\+\+\+|@generated SignedSource)" | grep "^[+-]" > /dev/null; then
            echo "Changes detected"
-            echo "===== Changes ====="
-            git --no-pager diff --cached ':(exclude)*REVISION' | grep -vE "^(@@|diff|index|\-\-\-|\+\+\+|\- \* @generated SignedSource)" | grep "^[+-]" | head -n 50
-            echo "==================="
            echo "should_commit=true" >> "$GITHUB_OUTPUT"
          else
            echo "No Changes detected"
@@ -293,108 +348,20 @@ jobs:
          grep -rl "$LAST_VERSION" ./compiled-rn || echo "No files found with $LAST_VERSION"
          grep -rl "$LAST_VERSION" ./compiled-rn | xargs -r sed -i -e "s/$LAST_VERSION/$CURRENT_VERSION/g"
          grep -rl "$LAST_VERSION" ./compiled-rn || echo "Version re-applied"
-      - name: Add files for signing
-        if: steps.check_should_commit.outputs.should_commit == 'true'
-        run: |
-          echo ":"
-          git add .
-      - name: Signing files
-        if: steps.check_should_commit.outputs.should_commit == 'true'
-        uses: actions/github-script@v7
-        with:
-          script: |
-            // TODO: Move this to a script file.
-            // We currently can't call scripts from the repo because
-            // at this point in the workflow, we're on the compiled
-            // artifact branch (so the scripts don't exist).
-            // We can fix this with a composite action in the main repo.
-            // This script is duplicated above.
-            const fs = require('fs');
-            const crypto = require('crypto');
-            const {execSync} = require('child_process');
-
-            // TODO: when we move this to a script, we can use this from npm.
-            // Copy of signedsource since we can't install deps on this branch.
-            const GENERATED = '@' + 'generated';
-            const NEWTOKEN = '<<SignedSource::*O*zOeWoEQle#+L!plEphiEmie@IsG>>';
-            const PATTERN = new RegExp(`${GENERATED} (?:SignedSource<<([a-f0-9]{32})>>)`);
-
-            const TokenNotFoundError = new Error(
-              `SignedSource.signFile(...): Cannot sign file without token: ${NEWTOKEN}`
-            );
-
-            function hash(data, encoding) {
-              const md5sum = crypto.createHash('md5');
-              md5sum.update(data, encoding);
-              return md5sum.digest('hex');
-            }
-
-            const SignedSource = {
-              getSigningToken() {
-                return `${GENERATED} ${NEWTOKEN}`;
-              },
-              isSigned(data) {
-                return PATTERN.exec(data) != null;
-              },
-              signFile(data) {
-                if (!data.includes(NEWTOKEN)) {
-                  if (SignedSource.isSigned(data)) {
-                    // Signing a file that was previously signed.
-                   data = data.replace(PATTERN, SignedSource.getSigningToken());
-                  } else {
-                    throw TokenNotFoundError;
-                  }
-                }
-                return data.replace(NEWTOKEN, `SignedSource<<${hash(data, 'utf8')}>>`);
-              },
-            };
-
-            const directory = './compiled-rn';
-            console.log('Signing files in directory:', directory);
-            try {
-              const result = execSync(`git status --porcelain ${directory}`, {encoding: 'utf8'});
-
-              // Parse the git status output to get file paths
-              const files = result.split('\n').filter(file => file.endsWith('.js'));
-
-              if (files.length === 0) {
-                throw new Error(
-                  'git status returned no files to sign. this job should not have run.'
-                );
-              } else {
-                files.forEach(line => {
-                  const file = line.slice(3).trim();
-                  if (file) {
-                    console.log('  Signing file:', file);
-                    const originalContents = fs.readFileSync(file, 'utf8');
-                    const signedContents = SignedSource.signFile(
-                      originalContents
-                        // Need to add the header in, since it's not inserted at build time.
-                        .replace(' */\n', ` * ${SignedSource.getSigningToken()}\n */\n`)
-                    );
-
-                    fs.writeFileSync(file, signedContents, 'utf8');
-                  }
-                });
-              }
-            } catch (e) {
-              process.exitCode = 1;
-              console.error('Error signing files:', e);
-            }
      - name: Will commit these changes
        if: steps.check_should_commit.outputs.should_commit == 'true'
        run: |
-          git add .
-          git status
+          echo ":"
+          git status -u
      - name: Commit changes to branch
        if: steps.check_should_commit.outputs.should_commit == 'true'
        uses: stefanzweifel/git-auto-commit-action@v4
        with:
          commit_message: |
-            ${{ github.event.workflow_run.head_commit.message }}
+            ${{ github.event.head_commit.message }}

-            DiffTrain build for commit https://github.com/facebook/react/commit/${{ github.event.workflow_run.head_sha }}.
+            DiffTrain build for commit https://github.com/facebook/react/commit/${{ github.sha }}.
          branch: builds/facebook-fbsource
-          commit_user_name: ${{ github.event.workflow_run.triggering_actor.login }}
-          commit_user_email: ${{ github.event.workflow_run.triggering_actor.email || format('{0}@users.noreply.github.com', github.event.workflow_run.triggering_actor.login) }}
+          commit_user_name: ${{ github.actor }}
+          commit_user_email: ${{ github.actor }}@users.noreply.github.com
          create_branch: true
--- a/.github/workflows/compiler-playground.yml
+++ b/.github/workflows/compiler-playground.yml
@@ -1,18 +1,13 @@
-name: (Compiler) Playground
+name: Compiler Playground

 on:
  push:
    branches: [main]
  pull_request:
    paths:
-      - compiler/**
+      - "compiler/**"
      - .github/workflows/compiler-playground.yml

-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-  # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
-  SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
-
 defaults:
  run:
    working-directory: compiler
@@ -25,8 +20,8 @@ jobs:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
+          node-version: 18.x
+          cache: "yarn"
          cache-dependency-path: compiler/yarn.lock
      - name: Restore cached node_modules
        uses: actions/cache@v4
--- a/.github/workflows/compiler-rust.yml
+++ b/.github/workflows/compiler-rust.yml
@@ -1,4 +1,4 @@
-name: (Compiler) Rust
+name: React Compiler (Rust)

 on:
  push:
@@ -18,7 +18,6 @@ on:
 env:
  CARGO_TERM_COLOR: always
  RUSTFLAGS: -Dwarnings
-  TZ: /usr/share/zoneinfo/America/Los_Angeles

 defaults:
  run:
--- a/.github/workflows/compiler-typescript.yml
+++ b/.github/workflows/compiler-typescript.yml
@@ -1,18 +1,13 @@
-name: (Compiler) TypeScript
+name: React Compiler (TypeScript)

 on:
  push:
    branches: [main]
  pull_request:
    paths:
-      - compiler/**
+      - "compiler/**"
      - .github/workflows/compiler-typescript.yml

-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-  # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
-  SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
-
 defaults:
  run:
    working-directory: compiler
@@ -28,6 +23,25 @@ jobs:
      - id: set-matrix
        run: echo "matrix=$(find packages -mindepth 1 -maxdepth 1 -type d | sed 's!packages/!!g' | tr '\n' ',' | sed s/.$// | jq -Rsc '. / "," - [""]')" >> $GITHUB_OUTPUT

+  # Hardcoded to improve parallelism for babel-plugin-react-compiler
+  prettier:
+    name: Run prettier
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 18.x
+          cache: "yarn"
+          cache-dependency-path: compiler/yarn.lock
+      - name: Restore cached node_modules
+        uses: actions/cache@v4
+        with:
+          path: "**/node_modules"
+          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('compiler/**/yarn.lock') }}
+      - run: yarn install --frozen-lockfile
+      - run: yarn prettier:ci
+
  # Hardcoded to improve parallelism
  lint:
    name: Lint babel-plugin-react-compiler
@@ -36,8 +50,8 @@ jobs:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
+          node-version: 18.x
+          cache: "yarn"
          cache-dependency-path: compiler/yarn.lock
      - name: Restore cached node_modules
        uses: actions/cache@v4
@@ -55,8 +69,8 @@ jobs:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
+          node-version: 18.x
+          cache: "yarn"
          cache-dependency-path: compiler/yarn.lock
      - name: Restore cached node_modules
        uses: actions/cache@v4
@@ -79,8 +93,8 @@ jobs:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
+          node-version: 18.x
+          cache: "yarn"
          cache-dependency-path: compiler/yarn.lock
      - name: Restore cached node_modules
        uses: actions/cache@v4
--- a/.github/workflows/devtools_check_repro.yml
+++ b/.github/workflows/devtools_check_repro.yml
@@ -0,0 +1,205 @@
+name: DevTools Check for bug repro
+on:
+  issues:
+    types: [opened, edited]
+  issue_comment:
+    types: [created, edited]
+
+jobs:
+  check-repro:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/github-script@v3
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const URL_REGEXP = /### Website or app[\r\n]+([^#]+)###/m;
+            const REPRO_STEPS_REGEXP = /### Repro steps[\r\n]+([^#]+)###/m;
+            const LABEL_NEEDS_MORE_INFORMATION = "Resolution: Needs More Information";
+            const LABEL_UNCONFIRMED = "Status: Unconfirmed";
+
+            function debug(...args) {
+              core.info(args.map(JSON.stringify).join(' '));
+            }
+
+            if (context.payload.comment) {
+              debug('Ignoring comment update.');
+              return;
+            }
+
+            const user = context.payload.sender.login;
+            const issue = context.payload.issue;
+            const body = issue.body;
+
+            const urlMatch = body.match(URL_REGEXP);
+            const reproStepsMatch = body.match(REPRO_STEPS_REGEXP);
+
+            const url = urlMatch !== null ? urlMatch[1].trim() : null;
+            const reproSteps = reproStepsMatch !== null ? reproStepsMatch[1].trim() : null;
+
+            if (!url || !reproSteps) {
+              debug('This issue is not a DevTools bug report.');
+              return;
+            }
+
+            debug(`found URL "${url}"`);
+            debug(`found repro steps "${reproSteps}"`);
+
+            async function createComment(comment) {
+              // Format
+              comment = comment
+                .split("\n")
+                .map((line) => line.trim())
+                .join("\n")
+                .trim();
+
+              await github.issues.createComment({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                body: comment,
+              });
+            }
+
+            async function getGitHubActionComments() {
+              debug(`Loading existing comments...`);
+
+              const comments = await github.issues.listComments({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+              });
+
+              return comments.data.filter(comment => {
+                debug(`comment by user: "${comment.user.login}"`);
+                return comment.user.login === 'github-actions[bot]';
+              });
+            }
+
+            async function getIssueLabels() {
+              const issues = await github.issues.listLabelsOnIssue({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+              });
+
+              return issues.data;
+            }
+
+            async function updateIssue(state, assignees = []) {
+              await github.issues.update({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                state,
+                assignees,
+              });
+            }
+
+            async function closeWithComment(comment) {
+              if (issue.state !== 'open') {
+                debug(`Issue is not open`);
+                return;
+              }
+
+              const labels = await getIssueLabels();
+              const label = labels.find(label => label.name === LABEL_UNCONFIRMED);
+              if (!label) {
+                debug(`Issue was not opened via DevTools bug report template`);
+                return;
+              }
+
+              const comments = await getGitHubActionComments();
+              if (comments.length > 0) {
+                debug(`Already commented on issue; won't comment again`);
+                return;
+              }
+
+              debug(`Missing required information`);
+
+              await github.issues.addLabels({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                labels: [LABEL_NEEDS_MORE_INFORMATION],
+              });
+
+              await createComment(comment);
+              await updateIssue('closed', [user]);
+            }
+
+            async function openWithComment(comment) {
+              if (issue.state !== 'closed') {
+                debug(`Issue is already open`);
+                return;
+              }
+
+              const labels = await getIssueLabels();
+              const label = labels.find(label => label.name === LABEL_NEEDS_MORE_INFORMATION);
+              if (!label) {
+                debug(`Issue was not tagged as needs information`);
+                return;
+              }
+
+              const comments = await getGitHubActionComments();
+              if (comments.length === 0) {
+                debug(`Issue was closed by someone else; won't reopen`);
+                return;
+              }
+
+              debug(`Re-opening closed issue`);
+
+              await github.issues.removeLabel({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                name: LABEL_NEEDS_MORE_INFORMATION,
+              });
+
+              await createComment(comment);
+              await updateIssue('open');
+            }
+
+            const PROBABLY_NOT_A_URL_REGEX = /(^Chrome$|^Firefox$| Website)/i;
+
+            const COMMENT_HEADER = `
+              @${user}: We're sorry you've seen this error. ❤️
+            `.trim();
+
+            const COMMENT_FOOTER = `
+              Please help us by providing a link to a CodeSandbox (https://codesandbox.io/s/new), a repository on GitHub, or a minimal code example that reproduces the problem. (Screenshots or videos can also be helpful if they help provide context on how to repro the bug.)
+
+              Here are some tips for providing a minimal example: https://stackoverflow.com/help/mcve
+
+              Issues without repros are automatically closed but we will re-open if you update with repro info.
+            `.trim();
+
+            if (url.includes("localhost")) {
+              closeWithComment(`
+                ${COMMENT_HEADER}
+
+                Unfortunately the URL you provided ("localhost") is not publicly accessible. (This means that we will not be able to reproduce the problem you're reporting.)
+
+                ${COMMENT_FOOTER}
+              `);
+            } else if (url.length < 10 || url.match(PROBABLY_NOT_A_URL_REGEX)) {
+              closeWithComment(`
+                ${COMMENT_HEADER}
+
+                It looks like you forgot to specify a valid URL. (This means that we will not be able to reproduce the problem you're reporting.)
+
+                ${COMMENT_FOOTER}
+              `);
+            } else if (reproSteps.length < 25) {
+              closeWithComment(`
+                ${COMMENT_HEADER}
+
+                Unfortunately, it doesn't look like this issue has enough info for one of us to reproduce and fix it though.
+
+                ${COMMENT_FOOTER}
+              `);
+            } else {
+              openWithComment(`
+                Thank you for providing repro steps! Re-opening issue now for triage.
+              `);
+            }
--- a/.github/workflows/devtools_regression_tests.yml
+++ b/.github/workflows/devtools_regression_tests.yml
@@ -1,173 +0,0 @@
-name: (DevTools) Regression Tests
-
-on:
-  schedule:
-    - cron: 0 0 * * *
-  workflow_dispatch:
-    inputs:
-      commit_sha:
-        required: false
-        type: string
-
-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-  # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
-  SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
-
-jobs:
-  download_build:
-    name: Download base build
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: yarn install --frozen-lockfile
-        working-directory: scripts/release
-      - name: Download react-devtools artifacts for base revision
-        run: |
-          git fetch origin main
-          GH_TOKEN=${{ github.token }} scripts/release/download-experimental-build.js --commit=${{ inputs.commit_sha || '$(git rev-parse origin/main)' }}
-      - name: Display structure of build
-        run: ls -R build
-      - name: Archive build
-        uses: actions/upload-artifact@v4
-        with:
-          name: build
-          path: build
-
-  build_devtools_and_process_artifacts:
-    name: Build DevTools and process artifacts
-    needs: download_build
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          name: build
-          path: build
-      - run: ./scripts/ci/pack_and_store_devtools_artifacts.sh
-        env:
-          RELEASE_CHANNEL: experimental
-      - name: Display structure of build
-        run: ls -R build
-      - name: Archive devtools build
-        uses: actions/upload-artifact@v4
-        with:
-          name: react-devtools
-          path: build/devtools.tgz
-      # Simplifies getting the extension for local testing
-      - name: Archive chrome extension
-        uses: actions/upload-artifact@v4
-        with:
-          name: react-devtools-chrome-extension
-          path: build/devtools/chrome-extension.zip
-      - name: Archive firefox extension
-        uses: actions/upload-artifact@v4
-        with:
-          name: react-devtools-firefox-extension
-          path: build/devtools/firefox-extension.zip
-
-  run_devtools_tests_for_versions:
-    name: Run DevTools tests for versions
-    needs: build_devtools_and_process_artifacts
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        version:
-          - "16.0"
-          - "16.5" # schedule package
-          - "16.8" # hooks
-          - "17.0"
-          - "18.0"
-    continue-on-error: true
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore all archived build artifacts
-        uses: actions/download-artifact@v4
-      - name: Display structure of build
-        run: ls -R build
-      - run: ./scripts/ci/download_devtools_regression_build.js ${{ matrix.version }} --replaceBuild
-      - run: node ./scripts/jest/jest-cli.js --build --project devtools --release-channel=experimental --reactVersion ${{ matrix.version }} --ci
-
-  run_devtools_e2e_tests_for_versions:
-    name: Run DevTools e2e tests for versions
-    needs: build_devtools_and_process_artifacts
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        version:
-          - "16.0"
-          - "16.5" # schedule package
-          - "16.8" # hooks
-          - "17.0"
-          - "18.0"
-    continue-on-error: true
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore all archived build artifacts
-        uses: actions/download-artifact@v4
-      - name: Display structure of build
-        run: ls -R build
-      - name: Playwright install deps
-        run: |
-          npx playwright install
-          sudo npx playwright install-deps
-      - run: ./scripts/ci/download_devtools_regression_build.js ${{ matrix.version }}
-      - run: ls -R build-regression
-      - run: ./scripts/ci/run_devtools_e2e_tests.js ${{ matrix.version }}
-        env:
-          RELEASE_CHANNEL: experimental
-      - name: Cleanup build regression folder
-        run: rm -r ./build-regression
-      - uses: actions/upload-artifact@v4
-        with:
-          name: screenshots
-          path: ./tmp/screenshots
--- a/.github/workflows/runtime_fuzz_tests.yml
+++ b/.github/workflows/runtime_fuzz_tests.yml
@@ -1,19 +1,20 @@
-name: (Runtime) Fuzz tests
-
+name: facebook/react/fuzz_tests
 on:
  schedule:
-    - cron: 0 * * * *
+  - cron: 0 * * * *
  push:
    branches:
      - main
  workflow_dispatch:
-
-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-
+    inputs:
+      prerelease_commit_sha:
+        required: false
 jobs:
  test_fuzz:
+    if: inputs.prerelease_commit_sha == ''
    runs-on: ubuntu-latest
+    env:
+      TZ: "/usr/share/zoneinfo/America/Los_Angeles"
    steps:
    - uses: actions/checkout@v4.1.0
    - uses: actions/setup-node@v4
--- a/.github/workflows/runtime_build_and_test.yml
+++ b/.github/workflows/runtime_build_and_test.yml
@@ -1,611 +0,0 @@
-name: (Runtime) Build and Test
-
-on:
-  push:
-    branches: [main]
-  pull_request:
-    paths-ignore:
-      - compiler/**
-
-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-  # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
-  SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
-
-jobs:
-  # ----- FLOW -----
-  discover_flow_inline_configs:
-    name: Discover flow inline configs
-    runs-on: ubuntu-latest
-    outputs:
-      matrix: ${{ steps.set-matrix.outputs.result }}
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/github-script@v7
-        id: set-matrix
-        with:
-          script: |
-            const inlinedHostConfigs = require('./scripts/shared/inlinedHostConfigs.js');
-            return inlinedHostConfigs.map(config => config.shortName);
-
-  flow:
-    name: Flow check ${{ matrix.flow_inline_config_shortname }}
-    needs: discover_flow_inline_configs
-    runs-on: ubuntu-latest
-    continue-on-error: true
-    strategy:
-      matrix:
-        flow_inline_config_shortname: ${{ fromJSON(needs.discover_flow_inline_configs.outputs.matrix) }}
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - 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
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - 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)
-
-  # ----- FEATURE FLAGS -----
-  flags:
-    name: Check flags
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: yarn flags
-
-  # ----- TESTS -----
-  test:
-    name: yarn test ${{ matrix.params }} (Shard ${{ matrix.shard }})
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        params:
-          - "-r=stable --env=development"
-          - "-r=stable --env=production"
-          - "-r=experimental --env=development"
-          - "-r=experimental --env=production"
-          - "-r=www-classic --env=development --variant=false"
-          - "-r=www-classic --env=production --variant=false"
-          - "-r=www-classic --env=development --variant=true"
-          - "-r=www-classic --env=production --variant=true"
-          - "-r=www-modern --env=development --variant=false"
-          - "-r=www-modern --env=production --variant=false"
-          - "-r=www-modern --env=development --variant=true"
-          - "-r=www-modern --env=production --variant=true"
-          - "-r=xplat --env=development --variant=false"
-          - "-r=xplat --env=development --variant=true"
-          - "-r=xplat --env=production --variant=false"
-          - "-r=xplat --env=production --variant=true"
-          # TODO: Test more persistent configurations?
-          - "-r=stable --env=development --persistent"
-          - "-r=experimental --env=development --persistent"
-        shard:
-          - 1/5
-          - 2/5
-          - 3/5
-          - 4/5
-          - 5/5
-    continue-on-error: true
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: yarn test ${{ matrix.params }} --ci --shard=${{ matrix.shard }}
-
-  # ----- BUILD -----
-  build_and_lint:
-    name: yarn build and lint
-    runs-on: ubuntu-latest
-    strategy:
-      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]
-        release_channel: [stable, experimental]
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - uses: actions/setup-java@v4
-        with:
-          distribution: temurin
-          java-version: 11.0.22
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: yarn build --index=${{ matrix.worker_id }} --total=20 --r=${{ matrix.release_channel }} --ci
-        env:
-          CI: github
-          RELEASE_CHANNEL: ${{ matrix.release_channel }}
-          NODE_INDEX: ${{ matrix.worker_id }}
-      - name: Lint build
-        run: yarn lint-build
-      - name: Display structure of build
-        run: ls -R build
-      - name: Archive build
-        uses: actions/upload-artifact@v4
-        with:
-          name: _build_${{ matrix.worker_id }}_${{ matrix.release_channel }}
-          path: build
-
-  test_build:
-    name: yarn test-build
-    needs: build_and_lint
-    strategy:
-      matrix:
-        test_params: [
-          # Intentionally passing these as strings instead of creating a
-          # separate parameter per CLI argument, since it's easier to
-          # control/see which combinations we want to run.
-          -r=stable --env=development,
-          -r=stable --env=production,
-          -r=experimental --env=development,
-          -r=experimental --env=production,
-
-          # Dev Tools
-          --project=devtools -r=experimental,
-
-          # TODO: Update test config to support www build tests
-          # - "-r=www-classic --env=development --variant=false"
-          # - "-r=www-classic --env=production --variant=false"
-          # - "-r=www-classic --env=development --variant=true"
-          # - "-r=www-classic --env=production --variant=true"
-          # - "-r=www-modern --env=development --variant=false"
-          # - "-r=www-modern --env=production --variant=false"
-          # - "-r=www-modern --env=development --variant=true"
-          # - "-r=www-modern --env=production --variant=true"
-
-          # TODO: Update test config to support xplat build tests
-          # - "-r=xplat --env=development --variant=false"
-          # - "-r=xplat --env=development --variant=true"
-          # - "-r=xplat --env=production --variant=false"
-          # - "-r=xplat --env=production --variant=true"
-
-          # TODO: Test more persistent configurations?
-        ]
-        shard:
-          - 1/3
-          - 2/3
-          - 3/3
-    continue-on-error: true
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - name: Display structure of build
-        run: ls -R build
-      - run: yarn test --build ${{ matrix.test_params }} --shard=${{ matrix.shard }} --ci
-
-  process_artifacts_combined:
-    name: Process artifacts combined
-    needs: build_and_lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - name: Display structure of build
-        run: ls -R build
-      - run: echo ${{ github.sha }} >> build/COMMIT_SHA
-      - name: Scrape warning messages
-        run: |
-          mkdir -p ./build/__test_utils__
-          node ./scripts/print-warnings/print-warnings.js > build/__test_utils__/ReactAllWarnings.js
-        # Compress build directory into a single tarball for easy download
-      - run: tar -zcvf ./build.tgz ./build
-        # TODO: Migrate scripts to use `build` directory instead of `build2`
-      - run: cp ./build.tgz ./build2.tgz
-      - name: Archive build artifacts
-        uses: actions/upload-artifact@v4
-        with:
-          name: artifacts_combined
-          path: |
-            ./build.tgz
-            ./build2.tgz
-
-  check_error_codes:
-    name: Search build artifacts for unminified errors
-    needs: build_and_lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - name: Display structure of build
-        run: ls -R build
-      - name: Search build artifacts for unminified errors
-        run: |
-          yarn extract-errors
-          git diff --quiet || (echo "Found unminified errors. Either update the error codes map or disable error minification for the affected build, if appropriate." && false)
-
-  check_release_dependencies:
-    name: Check release dependencies
-    needs: build_and_lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - name: Display structure of build
-        run: ls -R build
-      - run: yarn check-release-dependencies
-
-  RELEASE_CHANNEL_stable_yarn_test_dom_fixtures:
-    name: Check fixtures DOM (stable)
-    needs: build_and_lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: v2-yarn_cache_fixtures_dom-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
-        working-directory: fixtures/dom
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - name: Display structure of build
-        run: ls -R build
-      - name: Run DOM fixture tests
-        run: |
-          yarn predev
-          yarn test
-        working-directory: fixtures/dom
-        env:
-          RELEASE_CHANNEL: stable
-
-  # ----- FLIGHT -----
-  run_fixtures_flight_tests:
-    name: Run fixtures Flight tests
-    needs: build_and_lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      # Fixture copies some built packages from the workroot after install.
-      # 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
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: v2-yarn_cache_fixtures_flight-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - name: Display structure of build
-        run: ls -R build
-      - name: Install fixture dependencies
-        working-directory: fixtures/flight
-        run: |
-          yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
-          if [ $? -ne 0 ]; then
-            yarn install --frozen-lockfile --cache-folder ~/.cache/yarn
-          fi
-      - name: Playwright install deps
-        working-directory: fixtures/flight
-        run: |
-          npx playwright install
-          sudo npx playwright install-deps
-      - name: Run tests
-        working-directory: fixtures/flight
-        run: yarn test
-        env:
-          # Otherwise the webserver is a blackbox
-          DEBUG: pw:webserver
-      - name: Archive Flight fixture artifacts
-        uses: actions/upload-artifact@v4
-        with:
-          name: flight-playwright-report
-          path: fixtures/flight/playwright-report
-      - name: Archive Flight fixture artifacts
-        uses: actions/upload-artifact@v4
-        with:
-          name: flight-test-results
-          path: fixtures/flight/test-results
-
-  # ----- DEVTOOLS -----
-  build_devtools_and_process_artifacts:
-    name: Build DevTools and process artifacts
-    needs: build_and_lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - run: ./scripts/ci/pack_and_store_devtools_artifacts.sh
-        env:
-          RELEASE_CHANNEL: experimental
-      - name: Display structure of build
-        run: ls -R build
-      - name: Archive devtools build
-        uses: actions/upload-artifact@v4
-        with:
-          name: react-devtools
-          path: build/devtools.tgz
-      # Simplifies getting the extension for local testing
-      - name: Archive chrome extension
-        uses: actions/upload-artifact@v4
-        with:
-          name: react-devtools-chrome-extension
-          path: build/devtools/chrome-extension.zip
-      - name: Archive firefox extension
-        uses: actions/upload-artifact@v4
-        with:
-          name: react-devtools-firefox-extension
-          path: build/devtools/firefox-extension.zip
-
-  run_devtools_e2e_tests:
-    name: Run DevTools e2e tests
-    needs: build_devtools_and_process_artifacts
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - run: |
-          npx playwright install
-          sudo npx playwright install-deps
-      - run: ./scripts/ci/run_devtools_e2e_tests.js
-        env:
-          RELEASE_CHANNEL: experimental
-
-  # ----- SIZEBOT -----
-  download_base_build_for_sizebot:
-    if: ${{ github.event_name == 'pull_request' && github.ref_name != 'main' }}
-    name: Download base build for sizebot
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: yarn install --frozen-lockfile
-        working-directory: scripts/release
-      - name: Download artifacts for base revision
-        run: |
-          git fetch origin main
-          GH_TOKEN=${{ github.token }} scripts/release/download-experimental-build.js --commit=$(git rev-parse origin/main)
-          mv ./build ./base-build
-      # TODO: The `download-experimental-build` script copies the npm
-      # packages into the `node_modules` directory. This is a historical
-      # quirk of how the release script works. Let's pretend they
-      # don't exist.
-      - name: Delete extraneous files
-        run: rm -rf ./base-build/node_modules
-      - name: Display structure of base-build
-        run: ls -R base-build
-      - name: Archive base-build
-        uses: actions/upload-artifact@v4
-        with:
-          name: base-build
-          path: base-build
-
-  sizebot:
-    name: Run sizebot
-    needs: [build_and_lint, download_base_build_for_sizebot]
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - name: Restore archived build for PR
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - name: Scrape warning messages
-        run: |
-          mkdir -p ./build/__test_utils__
-          node ./scripts/print-warnings/print-warnings.js > build/__test_utils__/ReactAllWarnings.js
-      - name: Display structure of build for PR
-        run: ls -R build
-      - name: Restore archived base-build from origin/main
-        uses: actions/download-artifact@v4
-        with:
-          name: base-build
-          path: base-build
-      - name: Display structure of base-build from origin/main
-        run: ls -R base-build
-      - run: echo ${{ github.sha }} >> build/COMMIT_SHA
-      - run: node ./scripts/tasks/danger
-      - name: Archive sizebot results
-        uses: actions/upload-artifact@v4
-        with:
-          name: sizebot-message
-          path: sizebot-message.md
--- a/.github/workflows/runtime_prereleases.yml
+++ b/.github/workflows/runtime_prereleases.yml
@@ -1,50 +0,0 @@
-name: (Runtime) Publish Prereleases
-
-on:
-  workflow_call:
-    inputs:
-      commit_sha:
-        required: true
-        default: ''
-        type: string
-      release_channel:
-        required: true
-        type: string
-      dist_tag:
-        required: true
-        type: string
-    secrets:
-      NPM_TOKEN:
-        required: true
-
-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-  # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
-  SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
-  GH_TOKEN: ${{ github.token }}
-  NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
-
-jobs:
-  publish_prerelease:
-    name: Publish prelease (${{ inputs.release_channel }}) ${{ inputs.commit_sha }} @${{ inputs.dist_tag }}
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        id: node_modules
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock', 'scripts/release/yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: yarn install --frozen-lockfile
-        working-directory: scripts/release
-      - run: |
-          scripts/release/prepare-release-from-ci.js --skipTests -r ${{ inputs.release_channel }} --commit=${{ inputs.commit_sha }}
-          cp ./scripts/release/ci-npmrc ~/.npmrc
-          scripts/release/publish.js --ci --tags ${{ inputs.dist_tag }}
--- a/.github/workflows/runtime_prereleases_manual.yml
+++ b/.github/workflows/runtime_prereleases_manual.yml
@@ -1,47 +0,0 @@
-name: (Runtime) Publish Prereleases Manual
-
-on:
-  workflow_dispatch:
-    inputs:
-      prerelease_commit_sha:
-        required: true
-
-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-
-jobs:
-
-  publish_prerelease_canary:
-    name: Publish to Canary channel
-    uses: facebook/react/.github/workflows/runtime_prereleases.yml@main
-    with:
-      commit_sha: ${{ inputs.prerelease_commit_sha }}
-      release_channel: stable
-      # The tags to use when publishing canaries. The main one we should
-      # always include is "canary" but we can use multiple (e.g. alpha,
-      # beta, rc). To declare multiple, use a comma-separated string, like
-      # this:
-      #   dist_tag: "canary,alpha,beta,rc"
-      #
-      # TODO: We currently tag canaries with "next" in addition to "canary"
-      # because this used to be called the "next" channel and some
-      # downstream consumers might still expect that tag. We can remove this
-      # after some time has elapsed and the change has been communicated.
-      dist_tag: canary,next,rc
-    secrets:
-      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
-
-  publish_prerelease_experimental:
-    name: Publish to Experimental channel
-    uses: facebook/react/.github/workflows/runtime_prereleases.yml@main
-    # NOTE: Intentionally running these jobs sequentially because npm
-    # will sometimes fail if you try to concurrently publish two
-    # different versions of the same package, even if they use different
-    # dist tags.
-    needs: publish_prerelease_canary
-    with:
-      commit_sha: ${{ inputs.prerelease_commit_sha }}
-      release_channel: experimental
-      dist_tag: experimental
-    secrets:
-      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
--- a/.github/workflows/runtime_prereleases_nightly.yml
+++ b/.github/workflows/runtime_prereleases_nightly.yml
@@ -1,35 +0,0 @@
-name: (Runtime) Publish Prereleases Nightly
-
-on:
-  schedule:
-    # At 10 minutes past 16:00 on Mon, Tue, Wed, Thu, and Fri
-    - cron: 10 16 * * 1,2,3,4,5
-
-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-
-jobs:
-  publish_prerelease_canary:
-    name: Publish to Canary channel
-    uses: facebook/react/.github/workflows/runtime_prereleases.yml@main
-    with:
-      commit_sha: ${{ github.sha }}
-      release_channel: stable
-      dist_tag: canary,next,rc
-    secrets:
-      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
-
-  publish_prerelease_experimental:
-    name: Publish to Experimental channel
-    uses: facebook/react/.github/workflows/runtime_prereleases.yml@main
-    # NOTE: Intentionally running these jobs sequentially because npm
-    # will sometimes fail if you try to concurrently publish two
-    # different versions of the same package, even if they use different
-    # dist tags.
-    needs: publish_prerelease_canary
-    with:
-      commit_sha: ${{ github.sha }}
-      release_channel: experimental
-      dist_tag: experimental
-    secrets:
-      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
--- a/.github/workflows/shared_lint.yml
+++ b/.github/workflows/shared_lint.yml
@@ -1,84 +0,0 @@
-name: (Shared) Lint
-
-on:
-  push:
-    branches: [main]
-  pull_request:
-
-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles
-  # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
-  SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
-
-jobs:
-  prettier:
-    name: Run prettier
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('**/yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: yarn prettier-check
-
-  eslint:
-    name: Run eslint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: node ./scripts/tasks/eslint
-
-  check_license:
-    name: Check license
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: ./scripts/ci/check_license.sh
-
-  test_print_warnings:
-    name: Test print warnings
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache@v4
-        with:
-          path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
-      - run: yarn install --frozen-lockfile
-      - run: ./scripts/ci/test_print_warnings.sh
--- a/.github/workflows/shared_stale.yml
+++ b/.github/workflows/shared_stale.yml
@@ -1,13 +1,9 @@
 # Configuration for stale action workflow - https://github.com/actions/stale
-name: (Shared) Manage stale issues and PRs
+name: 'Manage stale issues and PRs'
 on:
  schedule:
    # Run hourly
    - cron: '0 * * * *'
-  workflow_dispatch:
-
-env:
-  TZ: /usr/share/zoneinfo/America/Los_Angeles

 jobs:
  stale:
--- a/.nvmrc
+++ b/.nvmrc
@@ -1 +1 @@
-v18.20.1
+v18.20.0
--- a/.prettierignore
+++ b/.prettierignore
@@ -1,6 +1,6 @@
-# react runtime
 build

+compiler
 packages/react-devtools-core/dist
 packages/react-devtools-extensions/chrome/build
 packages/react-devtools-extensions/firefox/build
@@ -14,27 +14,3 @@ packages/react-devtools-shared/src/hooks/__tests__/__source__/__untransformed__/
 packages/react-devtools-shell/dist
 packages/react-devtools-timeline/dist
 packages/react-devtools-timeline/static
-
-# react compiler
-compiler/**/dist
-compiler/**/__tests__/fixtures/**/*.expect.md
-compiler/**/.next
-
-# contains invalid graphql`...` which results in a promise rejection error from `yarn prettier-all`.
-compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-kitchensink.js
-
-compiler/crates
-compiler/apps/playground/public
-
-compiler/**/LICENSE
-compiler/*.md*
-compiler/*.json
-compiler/*.css
-compiler/*.webmanifest
-compiler/*.map
-compiler/*.sh
-compiler/*.txt
-compiler/*.ico
-compiler/*.svg
-compiler/*.lock
-compiler/*.toml
--- a/.prettierrc.js
+++ b/.prettierrc.js
@@ -1,23 +1,19 @@
 'use strict';

-const {esNextPaths} = require('./scripts/shared/pathsByLanguageVersion');
+const {
+  esNextPaths,
+  typescriptPaths,
+} = require('./scripts/shared/pathsByLanguageVersion');

 module.exports = {
-  plugins: ['prettier-plugin-hermes-parser'],
  bracketSpacing: false,
  singleQuote: true,
  bracketSameLine: true,
  trailingComma: 'es5',
  printWidth: 80,
-  parser: 'hermes',
+  parser: 'flow',
  arrowParens: 'avoid',
  overrides: [
-    {
-      files: ['*.code-workspace'],
-      options: {
-        parser: 'json-stringify',
-      },
-    },
    {
      files: esNextPaths,
      options: {
@@ -25,7 +21,7 @@ module.exports = {
      },
    },
    {
-      files: ['*.ts', '*.tsx'],
+      files: typescriptPaths,
      options: {
        trailingComma: 'all',
        parser: 'typescript',
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# [React](https://react.dev/) &middot; [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/facebook/react/blob/main/LICENSE) [![npm version](https://img.shields.io/npm/v/react.svg?style=flat)](https://www.npmjs.com/package/react) [![(Runtime) Build and Test](https://github.com/facebook/react/actions/workflows/runtime_build_and_test.yml/badge.svg)](https://github.com/facebook/react/actions/workflows/runtime_build_and_test.yml) [![(Compiler) TypeScript](https://github.com/facebook/react/actions/workflows/compiler_typescript.yml/badge.svg?branch=main)](https://github.com/facebook/react/actions/workflows/compiler_typescript.yml) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](https://legacy.reactjs.org/docs/how-to-contribute.html#your-first-pull-request)
+# [React](https://react.dev/) &middot; [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/facebook/react/blob/main/LICENSE) [![npm version](https://img.shields.io/npm/v/react.svg?style=flat)](https://www.npmjs.com/package/react) [![CircleCI Status](https://circleci.com/gh/facebook/react.svg?style=shield)](https://circleci.com/gh/facebook/react) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](https://legacy.reactjs.org/docs/how-to-contribute.html#your-first-pull-request)

 React is a JavaScript library for building user interfaces.

@@ -18,7 +18,7 @@ React has been designed for gradual adoption from the start, and **you can use a

 ## Documentation

-You can find the React documentation [on the website](https://react.dev/).
+You can find the React documentation [on the website](https://react.dev/).  

 Check out the [Getting Started](https://react.dev/learn) page for a quick overview.

@@ -55,7 +55,7 @@ root.render(<HelloMessage name="Taylor" />);

 This example will render "Hello Taylor" into a container on the page.

-You'll notice that we used an HTML-like syntax; [we call it JSX](https://react.dev/learn#writing-markup-with-jsx). JSX is not required to use React, but it makes code more readable, and writing it feels like writing HTML.
+You'll notice that we used an HTML-like syntax; [we call it JSX](https://react.dev/learn#writing-markup-with-jsx). JSX is not required to use React, but it makes code more readable, and writing it feels like writing HTML. 

 ## Contributing

--- a/ReactVersions.js
+++ b/ReactVersions.js
@@ -25,7 +25,7 @@ const ReactVersion = '19.0.0';
 // choose to change it to "alpha", "beta", "rc", etc.
 //
 // It only affects the label used in the version string. To customize the
-// npm dist tags used during publish, refer to .github/workflows/runtime_prereleases_*.yml.
+// npm dist tags used during publish, refer to .circleci/config.yml.
 const canaryChannelLabel = 'rc';

 // If the canaryChannelLabel is "rc", the build pipeline will use this to build
--- a/compiler/.eslintrc.js
+++ b/compiler/.eslintrc.js
@@ -43,12 +43,6 @@ module.exports = {

    "multiline-comment-style": ["error", "starred-block"],

-    /**
-     * We sometimes need to check for control characters in regexes for things like preserving input
-     * strings
-     */
-    "no-control-regex": "off",
-
    "@typescript-eslint/no-empty-function": "off",

    /*
@@ -88,7 +82,7 @@ module.exports = {
    ],
    "@typescript-eslint/array-type": ["error", { default: "generic" }],
    "@typescript-eslint/triple-slash-reference": "off",
-    "@typescript-eslint/no-var-requires": "off",
+    "@typescript-eslint/no-var-requires": "off"
  },
  parser: "@typescript-eslint/parser",
  plugins: ["@typescript-eslint"],
--- a/compiler/.prettierignore
+++ b/compiler/.prettierignore
@@ -0,0 +1,21 @@
+**/dist
+**/__tests__/fixtures/**/*.expect.md
+**/__tests__/fixtures/**/*.flow.js
+**/.next
+
+crates
+apps/playground/public
+
+**/LICENSE
+.*
+*.md*
+*.json
+*.css
+*.webmanifest
+*.map
+*.sh
+*.txt
+*.ico
+*.svg
+*.lock
+*.toml
--- a/compiler/.prettierrc.js
+++ b/compiler/.prettierrc.js
@@ -0,0 +1,9 @@
+const config = {
+  requirePragma: false,
+  parser: "babel-ts",
+  semi: true,
+  singleQuote: false,
+  trailingComma: "es5"
+}
+
+module.exports = config;
--- a/compiler/.vscode/settings.json
+++ b/compiler/.vscode/settings.json
@@ -0,0 +1,8 @@
+{
+  "editor.formatOnSave": true,
+  "[typescript][typescriptreact]": {
+    "editor.codeActionsOnSave": {
+      "source.organizeImports": "explicit"
+    }
+  }
+}
--- a/compiler/apps/playground/tests/e2e/page.spec.ts
+++ b/compiler/apps/playground/tests/e2e/page.spec.ts
@@ -5,8 +5,8 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {expect, test} from '@playwright/test';
-import {encodeStore, type Store} from '../../lib/stores';
+import { expect, test } from "@playwright/test";
+import { encodeStore, type Store } from "../../lib/stores";

 const STORE: Store = {
  source: `export default function TestComponent({ x }) {
@@ -17,33 +17,33 @@ const STORE: Store = {
 const HASH = encodeStore(STORE);

 function concat(data: Array<string>): string {
-  return data.join('');
+  return data.join("");
 }

-test('editor should compile successfully', async ({page}) => {
-  await page.goto(`/#${HASH}`, {waitUntil: 'networkidle'});
+test("editor should compile successfully", async ({ page }) => {
+  await page.goto(`/#${HASH}`, { waitUntil: "networkidle" });
  await page.screenshot({
    fullPage: true,
-    path: 'test-results/00-on-networkidle.png',
+    path: "test-results/00-on-networkidle.png",
  });

  // User input from hash compiles
  await page.screenshot({
    fullPage: true,
-    path: 'test-results/01-show-js-before.png',
+    path: "test-results/01-show-js-before.png",
  });
  const userInput =
-    (await page.locator('.monaco-editor').nth(2).allInnerTexts()) ?? [];
-  expect(concat(userInput)).toMatchSnapshot('user-input.txt');
+    (await page.locator(".monaco-editor").nth(2).allInnerTexts()) ?? [];
+  expect(concat(userInput)).toMatchSnapshot("user-input.txt");

  // Reset button works
-  page.on('dialog', dialog => dialog.accept());
-  await page.getByRole('button', {name: 'Reset'}).click();
+  page.on("dialog", (dialog) => dialog.accept());
+  await page.getByRole("button", { name: "Reset" }).click();
  await page.screenshot({
    fullPage: true,
-    path: 'test-results/02-show-js-after.png',
+    path: "test-results/02-show-js-after.png",
  });
  const defaultInput =
-    (await page.locator('.monaco-editor').nth(2).allInnerTexts()) ?? [];
-  expect(concat(defaultInput)).toMatchSnapshot('default-input.txt');
+    (await page.locator(".monaco-editor").nth(2).allInnerTexts()) ?? [];
+  expect(concat(defaultInput)).toMatchSnapshot("default-input.txt");
 });
--- a/compiler/apps/playground/app/index.tsx
+++ b/compiler/apps/playground/app/index.tsx
@@ -5,24 +5,25 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type {NextPage} from 'next';
-import Head from 'next/head';
-import {SnackbarProvider} from 'notistack';
-import {Editor, Header, StoreProvider} from '../components';
-import MessageSnackbar from '../components/Message';
+import type { NextPage } from "next";
+import Head from "next/head";
+import { SnackbarProvider } from "notistack";
+import { Editor, Header, StoreProvider } from "../components";
+import MessageSnackbar from "../components/Message";

 const Home: NextPage = () => {
  return (
    <div className="flex flex-col w-screen h-screen font-light">
      <Head>
        <title>
-          {process.env.NODE_ENV === 'development'
-            ? '[DEV] React Compiler Playground'
-            : 'React Compiler Playground'}
+          {process.env.NODE_ENV === "development"
+            ? "[DEV] React Compiler Playground"
+            : "React Compiler Playground"}
        </title>
        <meta
          name="viewport"
-          content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0"></meta>
+          content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0"
+        ></meta>
        <link rel="icon" href="/favicon.ico" />
        <link rel="manifest" href="/site.webmanifest" />
        <link
@@ -44,7 +45,8 @@ const Home: NextPage = () => {
        <SnackbarProvider
          preventDuplicate
          maxSnack={10}
-          Components={{message: MessageSnackbar}}>
+          Components={{ message: MessageSnackbar }}
+        >
          <Header />
          <Editor />
        </SnackbarProvider>
--- a/compiler/apps/playground/app/layout.tsx
+++ b/compiler/apps/playground/app/layout.tsx
@@ -5,21 +5,26 @@
 * LICENSE file in the root directory of this source tree.
 */

-import '../styles/globals.css';
+import "../styles/globals.css";

-export default function RootLayout({children}: {children: React.ReactNode}) {
-  'use no memo';
+export default function RootLayout({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  "use no memo";
  return (
    <html lang="en">
      <head>
        <title>
-          {process.env.NODE_ENV === 'development'
-            ? '[DEV] React Compiler Playground'
-            : 'React Compiler Playground'}
+          {process.env.NODE_ENV === "development"
+            ? "[DEV] React Compiler Playground"
+            : "React Compiler Playground"}
        </title>
        <meta
          name="viewport"
-          content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0"></meta>
+          content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0"
+        ></meta>
        <link rel="icon" href="/favicon.ico" />
        <link rel="manifest" href="/site.webmanifest" />
        <link
--- a/compiler/apps/playground/app/page.tsx
+++ b/compiler/apps/playground/app/page.tsx
@@ -5,11 +5,11 @@
 * LICENSE file in the root directory of this source tree.
 */

-'use client';
+"use client";

-import {SnackbarProvider} from 'notistack';
-import {Editor, Header, StoreProvider} from '../components';
-import MessageSnackbar from '../components/Message';
+import { SnackbarProvider } from "notistack";
+import { Editor, Header, StoreProvider } from "../components";
+import MessageSnackbar from "../components/Message";

 export default function Hoot() {
  return (
@@ -17,7 +17,8 @@ export default function Hoot() {
      <SnackbarProvider
        preventDuplicate
        maxSnack={10}
-        Components={{message: MessageSnackbar}}>
+        Components={{ message: MessageSnackbar }}
+      >
        <Header />
        <Editor />
      </SnackbarProvider>
--- a/compiler/apps/playground/babel.config.js
+++ b/compiler/apps/playground/babel.config.js
@@ -8,12 +8,12 @@
 module.exports = function (api) {
  api.cache(true);
  return {
-    presets: ['next/babel'],
+    presets: ["next/babel"],
    plugins: [
      [
-        'babel-plugin-react-compiler',
+        "babel-plugin-react-compiler",
        {
-          runtimeModule: 'react-compiler-runtime',
+          runtimeModule: "react-compiler-runtime",
        },
      ],
    ],
--- a/compiler/apps/playground/colors.js
+++ b/compiler/apps/playground/colors.js
@@ -11,86 +11,86 @@

 module.exports = {
  // Text colors
-  primary: '#23272F', // gray-90
-  'primary-dark': '#F6F7F9', // gray-5
-  secondary: '#404756', // gray-70
-  'secondary-dark': '#EBECF0', // gray-10
-  link: '#087EA4', // blue-50
-  'link-dark': '#149ECA', // blue-40
-  syntax: '#EBECF0', // gray-10
-  wash: '#FFFFFF',
-  'wash-dark': '#23272F', // gray-90
-  card: '#F6F7F9', // gray-05
-  'card-dark': '#343A46', // gray-80
-  highlight: '#E6F7FF', // blue-10
-  'highlight-dark': 'rgba(88,175,223,.1)',
-  border: '#EBECF0', // gray-10
-  'border-dark': '#343A46', // gray-80
-  'secondary-button': '#EBECF0', // gray-10
-  'secondary-button-dark': '#404756', // gray-70
+  primary: "#23272F", // gray-90
+  "primary-dark": "#F6F7F9", // gray-5
+  secondary: "#404756", // gray-70
+  "secondary-dark": "#EBECF0", // gray-10
+  link: "#087EA4", // blue-50
+  "link-dark": "#149ECA", // blue-40
+  syntax: "#EBECF0", // gray-10
+  wash: "#FFFFFF",
+  "wash-dark": "#23272F", // gray-90
+  card: "#F6F7F9", // gray-05
+  "card-dark": "#343A46", // gray-80
+  highlight: "#E6F7FF", // blue-10
+  "highlight-dark": "rgba(88,175,223,.1)",
+  border: "#EBECF0", // gray-10
+  "border-dark": "#343A46", // gray-80
+  "secondary-button": "#EBECF0", // gray-10
+  "secondary-button-dark": "#404756", // gray-70

  // Gray
-  'gray-95': '#16181D',
-  'gray-90': '#23272F',
-  'gray-80': '#343A46',
-  'gray-70': '#404756',
-  'gray-60': '#4E5769',
-  'gray-50': '#5E687E', // unused
-  'gray-40': '#78839B',
-  'gray-30': '#99A1B3',
-  'gray-20': '#BCC1CD',
-  'gray-10': '#EBECF0',
-  'gray-5': '#F6F7F9',
+  "gray-95": "#16181D",
+  "gray-90": "#23272F",
+  "gray-80": "#343A46",
+  "gray-70": "#404756",
+  "gray-60": "#4E5769",
+  "gray-50": "#5E687E", // unused
+  "gray-40": "#78839B",
+  "gray-30": "#99A1B3",
+  "gray-20": "#BCC1CD",
+  "gray-10": "#EBECF0",
+  "gray-5": "#F6F7F9",

  // Blue
-  'blue-60': '#045975',
-  'blue-50': '#087EA4',
-  'blue-40': '#149ECA', // Brand Blue
-  'blue-30': '#58C4DC', // unused
-  'blue-20': '#ABE2ED',
-  'blue-10': '#E6F7FF', // todo: doesn't match illustrations
-  'blue-5': '#E6F6FA',
+  "blue-60": "#045975",
+  "blue-50": "#087EA4",
+  "blue-40": "#149ECA", // Brand Blue
+  "blue-30": "#58C4DC", // unused
+  "blue-20": "#ABE2ED",
+  "blue-10": "#E6F7FF", // todo: doesn't match illustrations
+  "blue-5": "#E6F6FA",

  // Yellow
-  'yellow-60': '#B65700',
-  'yellow-50': '#C76A15',
-  'yellow-40': '#DB7D27', // unused
-  'yellow-30': '#FABD62', // unused
-  'yellow-20': '#FCDEB0', // unused
-  'yellow-10': '#FDE7C7',
-  'yellow-5': '#FEF5E7',
+  "yellow-60": "#B65700",
+  "yellow-50": "#C76A15",
+  "yellow-40": "#DB7D27", // unused
+  "yellow-30": "#FABD62", // unused
+  "yellow-20": "#FCDEB0", // unused
+  "yellow-10": "#FDE7C7",
+  "yellow-5": "#FEF5E7",

  // Purple
-  'purple-60': '#2B3491', // unused
-  'purple-50': '#575FB7',
-  'purple-40': '#6B75DB',
-  'purple-30': '#8891EC',
-  'purple-20': '#C3C8F5', // unused
-  'purple-10': '#E7E9FB',
-  'purple-5': '#F3F4FD',
+  "purple-60": "#2B3491", // unused
+  "purple-50": "#575FB7",
+  "purple-40": "#6B75DB",
+  "purple-30": "#8891EC",
+  "purple-20": "#C3C8F5", // unused
+  "purple-10": "#E7E9FB",
+  "purple-5": "#F3F4FD",

  // Green
-  'green-60': '#2B6E62',
-  'green-50': '#388F7F',
-  'green-40': '#44AC99',
-  'green-30': '#7FCCBF',
-  'green-20': '#ABDED5',
-  'green-10': '#E5F5F2',
-  'green-5': '#F4FBF9',
+  "green-60": "#2B6E62",
+  "green-50": "#388F7F",
+  "green-40": "#44AC99",
+  "green-30": "#7FCCBF",
+  "green-20": "#ABDED5",
+  "green-10": "#E5F5F2",
+  "green-5": "#F4FBF9",

  // RED
-  'red-60': '#712D28',
-  'red-50': '#A6423A', // unused
-  'red-40': '#C1554D',
-  'red-30': '#D07D77',
-  'red-20': '#E5B7B3', // unused
-  'red-10': '#F2DBD9', // unused
-  'red-5': '#FAF1F0',
+  "red-60": "#712D28",
+  "red-50": "#A6423A", // unused
+  "red-40": "#C1554D",
+  "red-30": "#D07D77",
+  "red-20": "#E5B7B3", // unused
+  "red-10": "#F2DBD9", // unused
+  "red-5": "#FAF1F0",

  // MISC
-  'code-block': '#99a1b30f', // gray-30 @ 6%
-  'gradient-blue': '#58C4DC', // Only used for the landing gradient for now.
+  "code-block": "#99a1b30f", // gray-30 @ 6%
+  "gradient-blue": "#58C4DC", // Only used for the landing gradient for now.
  github: {
-    highlight: '#fffbdd',
+    highlight: "#fffbdd",
  },
 };
--- a/compiler/apps/playground/components/Editor/EditorImpl.tsx
+++ b/compiler/apps/playground/components/Editor/EditorImpl.tsx
@@ -5,10 +5,9 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {parse as babelParse, ParserPlugin} from '@babel/parser';
-import * as HermesParser from 'hermes-parser';
-import traverse, {NodePath} from '@babel/traverse';
-import * as t from '@babel/types';
+import { parse, ParserPlugin } from "@babel/parser";
+import traverse, { NodePath } from "@babel/traverse";
+import * as t from "@babel/types";
 import {
  CompilerError,
  CompilerErrorDetail,
@@ -20,51 +19,31 @@ import {
  run,
  ValueKind,
  type Hook,
-} from 'babel-plugin-react-compiler/src';
-import {type ReactFunctionType} from 'babel-plugin-react-compiler/src/HIR/Environment';
-import clsx from 'clsx';
-import invariant from 'invariant';
-import {useSnackbar} from 'notistack';
-import {useDeferredValue, useMemo} from 'react';
-import {useMountEffect} from '../../hooks';
-import {defaultStore} from '../../lib/defaultStore';
+} from "babel-plugin-react-compiler/src";
+import { type ReactFunctionType } from "babel-plugin-react-compiler/src/HIR/Environment";
+import clsx from "clsx";
+import invariant from "invariant";
+import { useSnackbar } from "notistack";
+import { useDeferredValue, useMemo } from "react";
+import { useMountEffect } from "../../hooks";
+import { defaultStore } from "../../lib/defaultStore";
 import {
  createMessage,
  initStoreFromUrlOrLocalStorage,
  MessageLevel,
  MessageSource,
  type Store,
-} from '../../lib/stores';
-import {useStore, useStoreDispatch} from '../StoreContext';
-import Input from './Input';
+} from "../../lib/stores";
+import { useStore, useStoreDispatch } from "../StoreContext";
+import Input from "./Input";
 import {
  CompilerOutput,
  default as Output,
  PrintedCompilerPipelineValue,
-} from './Output';
-import {printFunctionWithOutlined} from 'babel-plugin-react-compiler/src/HIR/PrintHIR';
-import {printReactiveFunctionWithOutlined} from 'babel-plugin-react-compiler/src/ReactiveScopes/PrintReactiveFunction';
-
-function parseInput(input: string, language: 'flow' | 'typescript') {
-  // Extract the first line to quickly check for custom test directives
-  if (language === 'flow') {
-    return HermesParser.parse(input, {
-      babel: true,
-      flow: 'all',
-      sourceType: 'module',
-      enableExperimentalComponentSyntax: true,
-    });
-  } else {
-    return babelParse(input, {
-      plugins: ['typescript', 'jsx'],
-      sourceType: 'module',
-    });
-  }
-}
+} from "./Output";

 function parseFunctions(
-  source: string,
-  language: 'flow' | 'typescript',
+  source: string
 ): Array<
  NodePath<
    t.FunctionDeclaration | t.ArrowFunctionExpression | t.FunctionExpression
@@ -76,7 +55,20 @@ function parseFunctions(
    >
  > = [];
  try {
-    const ast = parseInput(source, language);
+    const isFlow = source
+      .trim()
+      .split("\n", 1)[0]
+      .match(/\s*\/\/\s*\@flow\s*/);
+    let type_transform: ParserPlugin;
+    if (isFlow) {
+      type_transform = "flow";
+    } else {
+      type_transform = "typescript";
+    }
+    const ast = parse(source, {
+      plugins: [type_transform, "jsx"],
+      sourceType: "module",
+    });
    traverse(ast, {
      FunctionDeclaration(nodePath) {
        items.push(nodePath);
@@ -105,7 +97,7 @@ function parseFunctions(

 const COMMON_HOOKS: Array<[string, Hook]> = [
  [
-    'useFragment',
+    "useFragment",
    {
      valueKind: ValueKind.Frozen,
      effectKind: Effect.Freeze,
@@ -114,7 +106,7 @@ const COMMON_HOOKS: Array<[string, Hook]> = [
    },
  ],
  [
-    'usePaginationFragment',
+    "usePaginationFragment",
    {
      valueKind: ValueKind.Frozen,
      effectKind: Effect.Freeze,
@@ -123,7 +115,7 @@ const COMMON_HOOKS: Array<[string, Hook]> = [
    },
  ],
  [
-    'useRefetchableFragment',
+    "useRefetchableFragment",
    {
      valueKind: ValueKind.Frozen,
      effectKind: Effect.Freeze,
@@ -132,7 +124,7 @@ const COMMON_HOOKS: Array<[string, Hook]> = [
    },
  ],
  [
-    'useLazyLoadQuery',
+    "useLazyLoadQuery",
    {
      valueKind: ValueKind.Frozen,
      effectKind: Effect.Freeze,
@@ -141,7 +133,7 @@ const COMMON_HOOKS: Array<[string, Hook]> = [
    },
  ],
  [
-    'usePreloadedQuery',
+    "usePreloadedQuery",
    {
      valueKind: ValueKind.Frozen,
      effectKind: Effect.Freeze,
@@ -156,22 +148,22 @@ function isHookName(s: string): boolean {
 }

 function getReactFunctionType(
-  id: NodePath<t.Identifier | null | undefined>,
+  id: NodePath<t.Identifier | null | undefined>
 ): ReactFunctionType {
  if (id && id.node && id.isIdentifier()) {
    if (isHookName(id.node.name)) {
-      return 'Hook';
+      return "Hook";
    }

    const isPascalCaseNameSpace = /^[A-Z].*/;
    if (isPascalCaseNameSpace.test(id.node.name)) {
-      return 'Component';
+      return "Component";
    }
  }
-  return 'Other';
+  return "Other";
 }

-function compile(source: string): [CompilerOutput, 'flow' | 'typescript'] {
+function compile(source: string): CompilerOutput {
  const results = new Map<string, PrintedCompilerPipelineValue[]>();
  const error = new CompilerError();
  const upsert = (result: PrintedCompilerPipelineValue) => {
@@ -182,33 +174,27 @@ function compile(source: string): [CompilerOutput, 'flow' | 'typescript'] {
      results.set(result.name, [result]);
    }
  };
-  let language: 'flow' | 'typescript';
-  if (source.match(/\@flow/)) {
-    language = 'flow';
-  } else {
-    language = 'typescript';
-  }
  try {
    // Extract the first line to quickly check for custom test directives
-    const pragma = source.substring(0, source.indexOf('\n'));
+    const pragma = source.substring(0, source.indexOf("\n"));
    const config = parseConfigPragma(pragma);

-    for (const fn of parseFunctions(source, language)) {
+    for (const fn of parseFunctions(source)) {
      if (!fn.isFunctionDeclaration()) {
        error.pushErrorDetail(
          new CompilerErrorDetail({
            reason: `Unexpected function type ${fn.node.type}`,
            description:
-              'Playground only supports parsing function declarations',
+              "Playground only supports parsing function declarations",
            severity: ErrorSeverity.Todo,
            loc: fn.node.loc ?? null,
            suggestions: null,
-          }),
+          })
        );
        continue;
      }

-      const id = fn.get('id');
+      const id = fn.get("id");
      for (const result of run(
        fn,
        {
@@ -216,20 +202,20 @@ function compile(source: string): [CompilerOutput, 'flow' | 'typescript'] {
          customHooks: new Map([...COMMON_HOOKS]),
        },
        getReactFunctionType(id),
-        '_c',
-        null,
+        "_c",
        null,
        null,
+        null
      )) {
        const fnName = fn.node.id?.name ?? null;
        switch (result.kind) {
-          case 'ast': {
+          case "ast": {
            upsert({
-              kind: 'ast',
+              kind: "ast",
              fnName,
              name: result.name,
              value: {
-                type: 'FunctionDeclaration',
+                type: "FunctionDeclaration",
                id: result.value.id,
                async: result.value.async,
                generator: result.value.generator,
@@ -239,27 +225,27 @@ function compile(source: string): [CompilerOutput, 'flow' | 'typescript'] {
            });
            break;
          }
-          case 'hir': {
+          case "hir": {
            upsert({
-              kind: 'hir',
+              kind: "hir",
              fnName,
              name: result.name,
-              value: printFunctionWithOutlined(result.value),
+              value: printHIR(result.value.body),
            });
            break;
          }
-          case 'reactive': {
+          case "reactive": {
            upsert({
-              kind: 'reactive',
+              kind: "reactive",
              fnName,
              name: result.name,
-              value: printReactiveFunctionWithOutlined(result.value),
+              value: printReactiveFunction(result.value),
            });
            break;
          }
-          case 'debug': {
+          case "debug": {
            upsert({
-              kind: 'debug',
+              kind: "debug",
              fnName,
              name: result.name,
              value: result.value,
@@ -288,24 +274,24 @@ function compile(source: string): [CompilerOutput, 'flow' | 'typescript'] {
          reason: `Unexpected failure when transforming input! ${err}`,
          loc: null,
          suggestions: null,
-        }),
+        })
      );
    }
  }
  if (error.hasErrors()) {
-    return [{kind: 'err', results, error: error}, language];
+    return { kind: "err", results, error: error };
  }
-  return [{kind: 'ok', results}, language];
+  return { kind: "ok", results };
 }

 export default function Editor() {
  const store = useStore();
  const deferredStore = useDeferredValue(store);
  const dispatchStore = useStoreDispatch();
-  const {enqueueSnackbar} = useSnackbar();
-  const [compilerOutput, language] = useMemo(
+  const { enqueueSnackbar } = useSnackbar();
+  const compilerOutput = useMemo(
    () => compile(deferredStore.source),
-    [deferredStore.source],
+    [deferredStore.source]
  );

  useMountEffect(() => {
@@ -313,35 +299,34 @@ export default function Editor() {
    try {
      mountStore = initStoreFromUrlOrLocalStorage();
    } catch (e) {
-      invariant(e instanceof Error, 'Only Error may be caught.');
+      invariant(e instanceof Error, "Only Error may be caught.");
      enqueueSnackbar(e.message, {
-        variant: 'message',
+        variant: "message",
        ...createMessage(
-          'Bad URL - fell back to the default Playground.',
+          "Bad URL - fell back to the default Playground.",
          MessageLevel.Info,
-          MessageSource.Playground,
+          MessageSource.Playground
        ),
      });
      mountStore = defaultStore;
    }
    dispatchStore({
-      type: 'setStore',
-      payload: {store: mountStore},
+      type: "setStore",
+      payload: { store: mountStore },
    });
  });

  return (
    <>
      <div className="relative flex basis top-14">
-        <div className={clsx('relative sm:basis-1/4')}>
+        <div className={clsx("relative sm:basis-1/4")}>
          <Input
-            language={language}
            errors={
-              compilerOutput.kind === 'err' ? compilerOutput.error.details : []
+              compilerOutput.kind === "err" ? compilerOutput.error.details : []
            }
          />
        </div>
-        <div className={clsx('flex sm:flex flex-wrap')}>
+        <div className={clsx("flex sm:flex flex-wrap")}>
          <Output store={deferredStore} compilerOutput={compilerOutput} />
        </div>
      </div>
--- a/compiler/apps/playground/components/Editor/Input.tsx
+++ b/compiler/apps/playground/components/Editor/Input.tsx
@@ -5,28 +5,27 @@
 * LICENSE file in the root directory of this source tree.
 */

-import MonacoEditor, {loader, type Monaco} from '@monaco-editor/react';
-import {CompilerErrorDetail} from 'babel-plugin-react-compiler/src';
-import invariant from 'invariant';
-import type {editor} from 'monaco-editor';
-import * as monaco from 'monaco-editor';
-import {Resizable} from 're-resizable';
-import {useEffect, useState} from 'react';
-import {renderReactCompilerMarkers} from '../../lib/reactCompilerMonacoDiagnostics';
-import {useStore, useStoreDispatch} from '../StoreContext';
-import {monacoOptions} from './monacoOptions';
+import MonacoEditor, { loader, type Monaco } from "@monaco-editor/react";
+import { CompilerErrorDetail } from "babel-plugin-react-compiler/src";
+import invariant from "invariant";
+import type { editor } from "monaco-editor";
+import * as monaco from "monaco-editor";
+import { Resizable } from "re-resizable";
+import { useEffect, useState } from "react";
+import { renderReactCompilerMarkers } from "../../lib/reactCompilerMonacoDiagnostics";
+import { useStore, useStoreDispatch } from "../StoreContext";
+import { monacoOptions } from "./monacoOptions";
 // TODO: Make TS recognize .d.ts files, in addition to loading them with webpack.
 // @ts-ignore
-import React$Types from '../../node_modules/@types/react/index.d.ts';
+import React$Types from "../../node_modules/@types/react/index.d.ts";

-loader.config({monaco});
+loader.config({ monaco });

 type Props = {
  errors: CompilerErrorDetail[];
-  language: 'flow' | 'typescript';
 };

-export default function Input({errors, language}: Props) {
+export default function Input({ errors }: Props) {
  const [monaco, setMonaco] = useState<Monaco | null>(null);
  const store = useStore();
  const dispatchStore = useStoreDispatch();
@@ -36,47 +35,18 @@ export default function Input({errors, language}: Props) {
    if (!monaco) return;
    const uri = monaco.Uri.parse(`file:///index.js`);
    const model = monaco.editor.getModel(uri);
-    invariant(model, 'Model must exist for the selected input file.');
-    renderReactCompilerMarkers({monaco, model, details: errors});
+    invariant(model, "Model must exist for the selected input file.");
+    renderReactCompilerMarkers({ monaco, model, details: errors });
    // N.B. that `tabSize` is a model property, not an editor property.
    // So, the tab size has to be set per model.
-    model.updateOptions({tabSize: 2});
+    model.updateOptions({ tabSize: 2 });
  }, [monaco, errors]);

-  const flowDiagnosticDisable = [
-    7028 /* unused label */, 6133 /* var declared but not read */,
-  ];
-  useEffect(() => {
-    // Ignore "can only be used in TypeScript files." errors, since
-    // we want to support syntax highlighting for Flow (*.js) files
-    // and Flow is not a built-in language.
-    if (!monaco) return;
-    monaco.languages.typescript.javascriptDefaults.setDiagnosticsOptions({
-      diagnosticCodesToIgnore: [
-        8002,
-        8003,
-        8004,
-        8005,
-        8006,
-        8008,
-        8009,
-        8010,
-        8011,
-        8012,
-        8013,
-        ...(language === 'flow' ? flowDiagnosticDisable : []),
-      ],
-      noSemanticValidation: true,
-      // Monaco can't validate Flow component syntax
-      noSyntaxValidation: language === 'flow',
-    });
-  }, [monaco, language]);
-
  const handleChange = (value: string | undefined) => {
    if (!value) return;

    dispatchStore({
-      type: 'updateFile',
+      type: "updateFile",
      payload: {
        source: value,
      },
@@ -86,16 +56,27 @@ export default function Input({errors, language}: Props) {
  const handleMount = (_: editor.IStandaloneCodeEditor, monaco: Monaco) => {
    setMonaco(monaco);

+    // Ignore "can only be used in TypeScript files." errors, since
+    // we want to support syntax highlighting for Flow (*.js) files
+    // and Flow is not a built-in language.
+    monaco.languages.typescript.javascriptDefaults.setDiagnosticsOptions({
+      diagnosticCodesToIgnore: [
+        8002, 8003, 8004, 8005, 8006, 8008, 8009, 8010, 8011, 8012, 8013,
+      ],
+      noSemanticValidation: true,
+      noSyntaxValidation: false,
+    });
+
    const tscOptions = {
      allowNonTsExtensions: true,
      target: monaco.languages.typescript.ScriptTarget.ES2015,
      moduleResolution: monaco.languages.typescript.ModuleResolutionKind.NodeJs,
      jsx: monaco.languages.typescript.JsxEmit.Preserve,
-      typeRoots: ['node_modules/@types'],
+      typeRoots: ["node_modules/@types"],
      allowSyntheticDefaultImports: true,
    };
    monaco.languages.typescript.javascriptDefaults.setCompilerOptions(
-      tscOptions,
+      tscOptions
    );
    monaco.languages.typescript.typescriptDefaults.setCompilerOptions({
      ...tscOptions,
@@ -106,7 +87,7 @@ export default function Input({errors, language}: Props) {
    // Add React type declarations to Monaco
    const reactLib = [
      React$Types,
-      'file:///node_modules/@types/react/index.d.ts',
+      "file:///node_modules/@types/react/index.d.ts",
    ] as [any, string];
    monaco.languages.typescript.javascriptDefaults.addExtraLib(...reactLib);
    monaco.languages.typescript.typescriptDefaults.addExtraLib(...reactLib);
@@ -124,16 +105,17 @@ export default function Input({errors, language}: Props) {
    <div className="relative flex flex-col flex-none border-r border-gray-200">
      <Resizable
        minWidth={650}
-        enable={{right: true}}
+        enable={{ right: true }}
        // Restrict MonacoEditor's height, since the config autoLayout:true
        // will grow the editor to fit within parent element
-        className="!h-[calc(100vh_-_3.5rem)]">
+        className="!h-[calc(100vh_-_3.5rem)]"
+      >
        <MonacoEditor
-          path={'index.js'}
+          path={"index.js"}
          // .js and .jsx files are specified to be TS so that Monaco can actually
          // check their syntax using its TS language service. They are still JS files
          // due to their extensions, so TS language features don't work.
-          language={'javascript'}
+          language={"javascript"}
          value={store.source}
          onMount={handleMount}
          onChange={handleChange}
--- a/compiler/apps/playground/components/Editor/Output.tsx
+++ b/compiler/apps/playground/components/Editor/Output.tsx
@@ -5,46 +5,46 @@
 * LICENSE file in the root directory of this source tree.
 */

-import generate from '@babel/generator';
-import * as t from '@babel/types';
+import generate from "@babel/generator";
+import * as t from "@babel/types";
 import {
  CodeIcon,
  DocumentAddIcon,
  InformationCircleIcon,
-} from '@heroicons/react/outline';
-import MonacoEditor, {DiffEditor} from '@monaco-editor/react';
-import {type CompilerError} from 'babel-plugin-react-compiler/src';
-import parserBabel from 'prettier/plugins/babel';
-import * as prettierPluginEstree from 'prettier/plugins/estree';
-import * as prettier from 'prettier/standalone';
-import {memo, useEffect, useState} from 'react';
-import {type Store} from '../../lib/stores';
-import TabbedWindow from '../TabbedWindow';
-import {monacoOptions} from './monacoOptions';
+} from "@heroicons/react/outline";
+import MonacoEditor, { DiffEditor } from "@monaco-editor/react";
+import { type CompilerError } from "babel-plugin-react-compiler/src";
+import parserBabel from "prettier/plugins/babel";
+import * as prettierPluginEstree from "prettier/plugins/estree";
+import * as prettier from "prettier/standalone";
+import { memo, useEffect, useState } from "react";
+import { type Store } from "../../lib/stores";
+import TabbedWindow from "../TabbedWindow";
+import { monacoOptions } from "./monacoOptions";
 const MemoizedOutput = memo(Output);

 export default MemoizedOutput;

 export type PrintedCompilerPipelineValue =
  | {
-      kind: 'ast';
+      kind: "ast";
      name: string;
      fnName: string | null;
      value: t.FunctionDeclaration;
    }
  | {
-      kind: 'hir';
+      kind: "hir";
      name: string;
      fnName: string | null;
      value: string;
    }
-  | {kind: 'reactive'; name: string; fnName: string | null; value: string}
-  | {kind: 'debug'; name: string; fnName: string | null; value: string};
+  | { kind: "reactive"; name: string; fnName: string | null; value: string }
+  | { kind: "debug"; name: string; fnName: string | null; value: string };

 export type CompilerOutput =
-  | {kind: 'ok'; results: Map<string, PrintedCompilerPipelineValue[]>}
+  | { kind: "ok"; results: Map<string, PrintedCompilerPipelineValue[]> }
  | {
-      kind: 'err';
+      kind: "err";
      results: Map<string, PrintedCompilerPipelineValue[]>;
      error: CompilerError;
    };
@@ -63,7 +63,7 @@ async function tabify(source: string, compilerOutput: CompilerOutput) {
  for (const [passName, results] of compilerOutput.results) {
    for (const result of results) {
      switch (result.kind) {
-        case 'hir': {
+        case "hir": {
          const prev = concattedResults.get(result.name);
          const next = result.value;
          const identName = `function ${result.fnName}`;
@@ -74,7 +74,7 @@ async function tabify(source: string, compilerOutput: CompilerOutput) {
          }
          break;
        }
-        case 'reactive': {
+        case "reactive": {
          const prev = concattedResults.get(passName);
          const next = result.value;
          if (prev != null) {
@@ -84,29 +84,29 @@ async function tabify(source: string, compilerOutput: CompilerOutput) {
          }
          break;
        }
-        case 'ast':
+        case "ast":
          topLevelFnDecls.push(result.value);
          break;
-        case 'debug': {
+        case "debug": {
          concattedResults.set(passName, result.value);
          break;
        }
        default: {
          const _: never = result;
-          throw new Error('Unexpected result kind');
+          throw new Error("Unexpected result kind");
        }
      }
    }
  }
  let lastPassOutput: string | null = null;
-  let nonDiffPasses = ['HIR', 'BuildReactiveFunction', 'EnvironmentConfig'];
  for (const [passName, text] of concattedResults) {
    tabs.set(
      passName,
      <TextTabContent
        output={text}
-        diff={lastPassOutput}
-        showInfoPanel={!nonDiffPasses.includes(passName)}></TextTabContent>,
+        diff={lastPassOutput ?? null}
+        showInfoPanel={true}
+      ></TextTabContent>
    );
    lastPassOutput = text;
  }
@@ -115,24 +115,25 @@ async function tabify(source: string, compilerOutput: CompilerOutput) {
    // Make a synthetic Program so we can have a single AST with all the top level
    // FunctionDeclarations
    const ast = t.program(topLevelFnDecls);
-    const {code, sourceMapUrl} = await codegen(ast, source);
+    const { code, sourceMapUrl } = await codegen(ast, source);
    reorderedTabs.set(
-      'JS',
+      "JS",
      <TextTabContent
        output={code}
        diff={null}
-        showInfoPanel={false}></TextTabContent>,
+        showInfoPanel={false}
+      ></TextTabContent>
    );
    if (sourceMapUrl) {
      reorderedTabs.set(
-        'SourceMap',
+        "SourceMap",
        <>
          <iframe
            src={sourceMapUrl}
            className="w-full h-monaco_small sm:h-monaco"
            title="Generated Code"
          />
-        </>,
+        </>
      );
    }
  }
@@ -144,23 +145,23 @@ async function tabify(source: string, compilerOutput: CompilerOutput) {

 async function codegen(
  ast: t.Program,
-  source: string,
-): Promise<{code: any; sourceMapUrl: string | null}> {
+  source: string
+): Promise<{ code: any; sourceMapUrl: string | null }> {
  const generated = generate(
    ast,
-    {sourceMaps: true, sourceFileName: 'input.js'},
-    source,
+    { sourceMaps: true, sourceFileName: "input.js" },
+    source
  );
  const sourceMapUrl = getSourceMapUrl(
    generated.code,
-    JSON.stringify(generated.map),
+    JSON.stringify(generated.map)
  );
  const codegenOutput = await prettier.format(generated.code, {
    semi: true,
-    parser: 'babel',
+    parser: "babel",
    plugins: [parserBabel, prettierPluginEstree],
  });
-  return {code: codegenOutput, sourceMapUrl};
+  return { code: codegenOutput, sourceMapUrl };
 }

 function utf16ToUTF8(s: string): string {
@@ -171,27 +172,27 @@ function getSourceMapUrl(code: string, map: string): string | null {
  code = utf16ToUTF8(code);
  map = utf16ToUTF8(map);
  return `https://evanw.github.io/source-map-visualization/#${btoa(
-    `${code.length}\0${code}${map.length}\0${map}`,
+    `${code.length}\0${code}${map.length}\0${map}`
  )}`;
 }

-function Output({store, compilerOutput}: Props) {
-  const [tabsOpen, setTabsOpen] = useState<Set<string>>(() => new Set(['JS']));
+function Output({ store, compilerOutput }: Props) {
+  const [tabsOpen, setTabsOpen] = useState<Set<string>>(() => new Set(["JS"]));
  const [tabs, setTabs] = useState<Map<string, React.ReactNode>>(
-    () => new Map(),
+    () => new Map()
  );
  useEffect(() => {
-    tabify(store.source, compilerOutput).then(tabs => {
+    tabify(store.source, compilerOutput).then((tabs) => {
      setTabs(tabs);
    });
  }, [store.source, compilerOutput]);

-  const changedPasses: Set<string> = new Set(['JS', 'HIR']); // Initial and final passes should always be bold
-  let lastResult: string = '';
+  const changedPasses: Set<string> = new Set();
+  let lastResult: string = "";
  for (const [passName, results] of compilerOutput.results) {
    for (const result of results) {
-      let currResult = '';
-      if (result.kind === 'hir' || result.kind === 'reactive') {
+      let currResult = "";
+      if (result.kind === "hir" || result.kind === "reactive") {
        currResult += `function ${result.fnName}\n\n${result.value}`;
      }
      if (currResult !== lastResult) {
@@ -210,16 +211,18 @@ function Output({store, compilerOutput}: Props) {
        tabs={tabs}
        changedPasses={changedPasses}
      />
-      {compilerOutput.kind === 'err' ? (
+      {compilerOutput.kind === "err" ? (
        <div
          className="flex flex-wrap absolute bottom-0 bg-white grow border-y border-grey-200 transition-all ease-in"
-          style={{width: 'calc(100vw - 650px)'}}>
+          style={{ width: "calc(100vw - 650px)" }}
+        >
          <div className="w-full p-4 basis-full border-b">
            <h2>COMPILER ERRORS</h2>
          </div>
          <pre
            className="p-4 basis-full text-red-600 overflow-y-scroll whitespace-pre-wrap"
-            style={{width: 'calc(100vw - 650px)', height: '150px'}}>
+            style={{ width: "calc(100vw - 650px)", height: "150px" }}
+          >
            <code>{compilerOutput.error.toString()}</code>
          </pre>
        </div>
@@ -247,7 +250,8 @@ function TextTabContent({
          {diff != null && output !== diff ? (
            <button
              className="flex items-center gap-1 transition-colors duration-150 ease-in text-secondary hover:text-link"
-              onClick={() => setDiffMode(diffMode => !diffMode)}>
+              onClick={() => setDiffMode((diffMode) => !diffMode)}
+            >
              {!diffMode ? (
                <>
                  <DocumentAddIcon className="w-5 h-5" /> Show Diff
@@ -275,7 +279,7 @@ function TextTabContent({
          options={{
            ...monacoOptions,
            readOnly: true,
-            lineNumbers: 'off',
+            lineNumbers: "off",
            glyphMargin: false,
            // Undocumented see https://github.com/Microsoft/vscode/issues/30795#issuecomment-410998882
            lineDecorationsWidth: 0,
@@ -289,7 +293,7 @@ function TextTabContent({
          options={{
            ...monacoOptions,
            readOnly: true,
-            lineNumbers: 'off',
+            lineNumbers: "off",
            glyphMargin: false,
            // Undocumented see https://github.com/Microsoft/vscode/issues/30795#issuecomment-410998882
            lineDecorationsWidth: 0,
--- a/compiler/apps/playground/components/Editor/index.tsx
+++ b/compiler/apps/playground/components/Editor/index.tsx
@@ -5,11 +5,11 @@
 * LICENSE file in the root directory of this source tree.
 */

-import dynamic from 'next/dynamic';
+import dynamic from "next/dynamic";

 // monaco-editor is currently not compatible with ssr
 // https://github.com/vercel/next.js/issues/31692
-const Editor = dynamic(() => import('./EditorImpl'), {
+const Editor = dynamic(() => import("./EditorImpl"), {
  ssr: false,
 });

--- a/compiler/apps/playground/components/Editor/monacoOptions.ts
+++ b/compiler/apps/playground/components/Editor/monacoOptions.ts
@@ -5,11 +5,11 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type {EditorProps} from '@monaco-editor/react';
+import type { EditorProps } from "@monaco-editor/react";

-export const monacoOptions: Partial<EditorProps['options']> = {
+export const monacoOptions: Partial<EditorProps["options"]> = {
  fontSize: 14,
-  padding: {top: 8},
+  padding: { top: 8 },
  scrollbar: {
    verticalScrollbarSize: 10,
    alwaysConsumeMouseWheel: false,
@@ -22,11 +22,11 @@ export const monacoOptions: Partial<EditorProps['options']> = {
  fontFamily: '"Source Code Pro", monospace',
  glyphMargin: true,

-  autoClosingBrackets: 'languageDefined',
-  autoClosingDelete: 'always',
-  autoClosingOvertype: 'always',
+  autoClosingBrackets: "languageDefined",
+  autoClosingDelete: "always",
+  autoClosingOvertype: "always",

  automaticLayout: true,
-  wordWrap: 'on',
-  wrappingIndent: 'deepIndent',
+  wordWrap: "on",
+  wrappingIndent: "deepIndent",
 };
--- a/compiler/apps/playground/components/Header.tsx
+++ b/compiler/apps/playground/components/Header.tsx
@@ -5,24 +5,24 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {RefreshIcon, ShareIcon} from '@heroicons/react/outline';
-import {CheckIcon} from '@heroicons/react/solid';
-import clsx from 'clsx';
-import Link from 'next/link';
-import {useSnackbar} from 'notistack';
-import {useState} from 'react';
-import {defaultStore} from '../lib/defaultStore';
-import {IconGitHub} from './Icons/IconGitHub';
-import Logo from './Logo';
-import {useStoreDispatch} from './StoreContext';
+import { RefreshIcon, ShareIcon } from "@heroicons/react/outline";
+import { CheckIcon } from "@heroicons/react/solid";
+import clsx from "clsx";
+import Link from "next/link";
+import { useSnackbar } from "notistack";
+import { useState } from "react";
+import { defaultStore } from "../lib/defaultStore";
+import { IconGitHub } from "./Icons/IconGitHub";
+import Logo from "./Logo";
+import { useStoreDispatch } from "./StoreContext";

 export default function Header() {
  const [showCheck, setShowCheck] = useState(false);
  const dispatchStore = useStoreDispatch();
-  const {enqueueSnackbar, closeSnackbar} = useSnackbar();
+  const { enqueueSnackbar, closeSnackbar } = useSnackbar();

  const handleReset = () => {
-    if (confirm('Are you sure you want to reset the playground?')) {
+    if (confirm("Are you sure you want to reset the playground?")) {
      /*
        Close open snackbars if any. This is necessary because when displaying
        outputs (Preview or not), we only close previous snackbars if we received
@@ -31,13 +31,13 @@ export default function Header() {
        such as "Bad URL" will be closed by the outputs calling `closeSnackbar`.
      */
      closeSnackbar();
-      dispatchStore({type: 'setStore', payload: {store: defaultStore}});
+      dispatchStore({ type: "setStore", payload: { store: defaultStore } });
    }
  };

  const handleShare = () => {
    navigator.clipboard.writeText(location.href).then(() => {
-      enqueueSnackbar('URL copied to clipboard');
+      enqueueSnackbar("URL copied to clipboard");
      setShowCheck(true);
      // Show the check mark icon briefly after URL is copied
      setTimeout(() => setShowCheck(false), 1000);
@@ -49,8 +49,8 @@ export default function Header() {
      <div className="flex items-center flex-none h-full gap-2 text-lg">
        <Logo
          className={clsx(
-            'w-8 h-8 text-link',
-            process.env.NODE_ENV === 'development' && 'text-yellow-600',
+            "w-8 h-8 text-link",
+            process.env.NODE_ENV === "development" && "text-yellow-600"
          )}
        />
        <p className="hidden select-none sm:block">React Compiler Playground</p>
@@ -60,7 +60,8 @@ export default function Header() {
          title="Reset Playground"
          aria-label="Reset Playground"
          className="flex items-center gap-1 transition-colors duration-150 ease-in text-secondary hover:text-link"
-          onClick={handleReset}>
+          onClick={handleReset}
+        >
          <RefreshIcon className="w-5 h-5" />
          <p className="hidden sm:block">Reset</p>
        </button>
@@ -69,7 +70,8 @@ export default function Header() {
          aria-label="Copy sharable URL"
          className="flex items-center gap-1 transition-colors duration-150 ease-in text-secondary hover:text-link"
          onClick={handleShare}
-          disabled={showCheck}>
+          disabled={showCheck}
+        >
          {!showCheck ? (
            <ShareIcon className="w-5 h-5" />
          ) : (
@@ -82,7 +84,8 @@ export default function Header() {
          target="_blank"
          rel="noreferrer noopener"
          aria-label="Open on GitHub"
-          className="flex items-center gap-1 transition-colors duration-150 ease-in text-secondary hover:text-link">
+          className="flex items-center gap-1 transition-colors duration-150 ease-in text-secondary hover:text-link"
+        >
          <IconGitHub />
        </Link>
      </div>
--- a/compiler/apps/playground/components/Icons/IconGitHub.tsx
+++ b/compiler/apps/playground/components/Icons/IconGitHub.tsx
@@ -5,9 +5,9 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {memo} from 'react';
+import { memo } from "react";

-export const IconGitHub = memo<JSX.IntrinsicElements['svg']>(
+export const IconGitHub = memo<JSX.IntrinsicElements["svg"]>(
  function IconGitHub(props) {
    return (
      <svg
@@ -16,9 +16,10 @@ export const IconGitHub = memo<JSX.IntrinsicElements['svg']>(
        height="1.5em"
        viewBox="0 -2 24 24"
        fill="currentColor"
-        {...props}>
+        {...props}
+      >
        <path d="M10 0a10 10 0 0 0-3.16 19.49c.5.1.68-.22.68-.48l-.01-1.7c-2.78.6-3.37-1.34-3.37-1.34-.46-1.16-1.11-1.47-1.11-1.47-.9-.62.07-.6.07-.6 1 .07 1.53 1.03 1.53 1.03.9 1.52 2.34 1.08 2.91.83.1-.65.35-1.09.63-1.34-2.22-.25-4.55-1.11-4.55-4.94 0-1.1.39-1.99 1.03-2.69a3.6 3.6 0 0 1 .1-2.64s.84-.27 2.75 1.02a9.58 9.58 0 0 1 5 0c1.91-1.3 2.75-1.02 2.75-1.02.55 1.37.2 2.4.1 2.64.64.7 1.03 1.6 1.03 2.69 0 3.84-2.34 4.68-4.57 4.93.36.31.68.92.68 1.85l-.01 2.75c0 .26.18.58.69.48A10 10 0 0 0 10 0"></path>
      </svg>
    );
-  },
+  }
 );
--- a/compiler/apps/playground/components/Logo.tsx
+++ b/compiler/apps/playground/components/Logo.tsx
@@ -7,13 +7,14 @@

 // https://github.com/reactjs/reactjs.org/blob/main/beta/src/components/Logo.tsx

-export default function Logo(props: JSX.IntrinsicElements['svg']) {
+export default function Logo(props: JSX.IntrinsicElements["svg"]) {
  return (
    <svg
      viewBox="0 0 410 369"
      fill="none"
      xmlns="http://www.w3.org/2000/svg"
-      {...props}>
+      {...props}
+    >
      <path
        d="M204.995 224.552C226.56 224.552 244.042 207.07 244.042 185.506C244.042 163.941 226.56 146.459 204.995 146.459C183.43 146.459 165.948 163.941 165.948 185.506C165.948 207.07 183.43 224.552 204.995 224.552Z"
        fill="currentColor"
--- a/compiler/apps/playground/components/Message.tsx
+++ b/compiler/apps/playground/components/Message.tsx
@@ -10,13 +10,13 @@ import {
  ExclamationIcon,
  InformationCircleIcon,
  XIcon,
-} from '@heroicons/react/solid';
-import {CustomContentProps, SnackbarContent, useSnackbar} from 'notistack';
-import {forwardRef} from 'react';
-import {MessageLevel, MessageSource} from '../lib/stores';
+} from "@heroicons/react/solid";
+import { CustomContentProps, SnackbarContent, useSnackbar } from "notistack";
+import { forwardRef } from "react";
+import { MessageLevel, MessageSource } from "../lib/stores";

 // https://notistack.com/examples/advanced/custom-component#custom-variant-(typescript)
-declare module 'notistack' {
+declare module "notistack" {
  interface VariantOverrides {
    message: {
      title: string;
@@ -34,14 +34,15 @@ interface MessageProps extends CustomContentProps {
 }

 const Message = forwardRef<HTMLDivElement, MessageProps>(
-  ({id, title, level, source, codeframe}, ref) => {
-    const {closeSnackbar} = useSnackbar();
+  ({ id, title, level, source, codeframe }, ref) => {
+    const { closeSnackbar } = useSnackbar();
    const isDismissible = source !== MessageSource.Playground;

    return (
      <SnackbarContent
        ref={ref}
-        className="flex items-start justify-between gap-3 px-4 py-3 text-sm bg-white border rounded-md shadow w-toast">
+        className="flex items-start justify-between gap-3 px-4 py-3 text-sm bg-white border rounded-md shadow w-toast"
+      >
        <div className="flex gap-3 w-toast-body">
          {level === MessageLevel.Warning ? (
            <div className="flex items-center justify-center flex-none rounded-md w-7 h-7 bg-amber-100">
@@ -68,15 +69,16 @@ const Message = forwardRef<HTMLDivElement, MessageProps>(
        {isDismissible ? (
          <button
            className="flex items-center justify-center flex-none transition-colors duration-150 ease-in rounded-md justify-self-end group w-7 h-7 hover:bg-gray-200"
-            onClick={() => closeSnackbar(id)}>
+            onClick={() => closeSnackbar(id)}
+          >
            <XIcon className="w-5 h-5 fill-gray-500 group-hover:fill-gray-800" />
          </button>
        ) : null}
      </SnackbarContent>
    );
-  },
+  }
 );

-Message.displayName = 'MessageComponent';
+Message.displayName = "MessageComponent";

 export default Message;
--- a/compiler/apps/playground/components/StoreContext.tsx
+++ b/compiler/apps/playground/components/StoreContext.tsx
@@ -5,12 +5,12 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type {Dispatch, ReactNode} from 'react';
-import {useReducer} from 'react';
-import createContext from '../lib/createContext';
-import {emptyStore} from '../lib/defaultStore';
-import type {Store} from '../lib/stores';
-import {saveStore} from '../lib/stores';
+import type { Dispatch, ReactNode } from "react";
+import { useReducer } from "react";
+import createContext from "../lib/createContext";
+import { emptyStore } from "../lib/defaultStore";
+import type { Store } from "../lib/stores";
+import { saveStore } from "../lib/stores";

 const StoreContext = createContext<Store>();

@@ -29,7 +29,7 @@ export const useStoreDispatch = StoreDispatchContext.useContext;
 /**
 * Make Store and dispatch function available to all sub-components in children.
 */
-export function StoreProvider({children}: {children: ReactNode}) {
+export function StoreProvider({ children }: { children: ReactNode }) {
  const [store, dispatch] = useReducer(storeReducer, emptyStore);

  return (
@@ -43,13 +43,13 @@ export function StoreProvider({children}: {children: ReactNode}) {

 type ReducerAction =
  | {
-      type: 'setStore';
+      type: "setStore";
      payload: {
        store: Store;
      };
    }
  | {
-      type: 'updateFile';
+      type: "updateFile";
      payload: {
        source: string;
      };
@@ -57,14 +57,14 @@ type ReducerAction =

 function storeReducer(store: Store, action: ReducerAction): Store {
  switch (action.type) {
-    case 'setStore': {
+    case "setStore": {
      const newStore = action.payload.store;

      saveStore(newStore);
      return newStore;
    }
-    case 'updateFile': {
-      const {source} = action.payload;
+    case "updateFile": {
+      const { source } = action.payload;

      const newStore = {
        ...store,
--- a/compiler/apps/playground/components/TabbedWindow.tsx
+++ b/compiler/apps/playground/components/TabbedWindow.tsx
@@ -5,8 +5,8 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {Resizable} from 're-resizable';
-import React, {useCallback} from 'react';
+import { Resizable } from "re-resizable";
+import React, { useCallback } from "react";

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

@@ -21,14 +21,15 @@ export default function TabbedWindow(props: {
    return (
      <div
        className="flex items-center justify-center"
-        style={{width: 'calc(100vw - 650px)'}}>
+        style={{ width: "calc(100vw - 650px)" }}
+      >
        No compiler output detected, see errors below
      </div>
    );
  }
  return (
    <div className="flex flex-row">
-      {Array.from(props.tabs.keys()).map(name => {
+      {Array.from(props.tabs.keys()).map((name) => {
        return (
          <TabbedWindowItem
            name={name}
@@ -72,14 +73,13 @@ function TabbedWindowItem({
  return (
    <div key={name} className="flex flex-row">
      {isShow ? (
-        <Resizable className="border-r" minWidth={550} enable={{right: true}}>
+        <Resizable className="border-r" minWidth={550} enable={{ right: true }}>
          <h2
            title="Minimize tab"
            aria-label="Minimize tab"
            onClick={toggleTabs}
-            className={`p-4 duration-150 ease-in border-b cursor-pointer border-grey-200 ${
-              hasChanged ? 'font-bold' : 'font-light'
-            } text-secondary hover:text-link`}>
+            className={`p-4 duration-150 ease-in border-b cursor-pointer border-grey-200 ${hasChanged ? "font-bold" : "font-light"} text-secondary hover:text-link`}
+          >
            - {name}
          </h2>
          {tabs.get(name) ?? <div>No output for {name}</div>}
@@ -89,11 +89,10 @@ function TabbedWindowItem({
          <button
            title={`Expand compiler tab: ${name}`}
            aria-label={`Expand compiler tab: ${name}`}
-            style={{transform: 'rotate(90deg) translate(-50%)'}}
+            style={{ transform: "rotate(90deg) translate(-50%)" }}
            onClick={toggleTabs}
-            className={`flex-grow-0 w-5 transition-colors duration-150 ease-in ${
-              hasChanged ? 'font-bold' : 'font-light'
-            } text-secondary hover:text-link`}>
+            className={`flex-grow-0 w-5 transition-colors duration-150 ease-in ${hasChanged ? "font-bold" : "font-light"} text-secondary hover:text-link`}
+          >
            {name}
          </button>
        </div>
--- a/compiler/apps/playground/components/index.ts
+++ b/compiler/apps/playground/components/index.ts
@@ -5,6 +5,6 @@
 * LICENSE file in the root directory of this source tree.
 */

-export {default as Editor} from './Editor';
-export {default as Header} from './Header';
-export {StoreProvider} from './StoreContext';
+export { default as Editor } from "./Editor";
+export { default as Header } from "./Header";
+export { StoreProvider } from "./StoreContext";
--- a/compiler/apps/playground/hooks/index.ts
+++ b/compiler/apps/playground/hooks/index.ts
@@ -5,4 +5,4 @@
 * LICENSE file in the root directory of this source tree.
 */

-export {default as useMountEffect} from './useMountEffect';
+export { default as useMountEffect } from "./useMountEffect";
--- a/compiler/apps/playground/hooks/useMountEffect.ts
+++ b/compiler/apps/playground/hooks/useMountEffect.ts
@@ -5,8 +5,8 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type {EffectCallback} from 'react';
-import {useEffect} from 'react';
+import type { EffectCallback } from "react";
+import { useEffect } from "react";

 export default function useMountEffect(effect: EffectCallback) {
  return useEffect(effect, []);
--- a/compiler/apps/playground/lib/createContext.ts
+++ b/compiler/apps/playground/lib/createContext.ts
@@ -5,7 +5,7 @@
 * LICENSE file in the root directory of this source tree.
 */

-import React from 'react';
+import React from "react";

 /**
 * Replacement to React.createContext.
@@ -29,9 +29,9 @@ export default function createContext<T>() {
  function useContext() {
    const c = React.useContext(context);
    if (!c)
-      throw new Error('useContext must be within a Provider with a value');
+      throw new Error("useContext must be within a Provider with a value");
    return c;
  }

-  return {useContext, Provider: context.Provider};
+  return { useContext, Provider: context.Provider };
 }
--- a/compiler/apps/playground/lib/defaultStore.ts
+++ b/compiler/apps/playground/lib/defaultStore.ts
@@ -5,7 +5,7 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type {Store} from './stores';
+import type { Store } from "./stores";

 const index = `\
 export default function MyApp() {
@@ -18,5 +18,5 @@ export const defaultStore: Store = {
 };

 export const emptyStore: Store = {
-  source: '',
+  source: "",
 };
--- a/compiler/apps/playground/lib/reactCompilerMonacoDiagnostics.ts
+++ b/compiler/apps/playground/lib/reactCompilerMonacoDiagnostics.ts
@@ -5,16 +5,16 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {Monaco} from '@monaco-editor/react';
+import { Monaco } from "@monaco-editor/react";
 import {
  CompilerErrorDetail,
  ErrorSeverity,
-} from 'babel-plugin-react-compiler/src';
-import {MarkerSeverity, type editor} from 'monaco-editor';
+} from "babel-plugin-react-compiler/src";
+import { MarkerSeverity, type editor } from "monaco-editor";

 function mapReactCompilerSeverityToMonaco(
  level: ErrorSeverity,
-  monaco: Monaco,
+  monaco: Monaco
 ): MarkerSeverity {
  switch (level) {
    case ErrorSeverity.Todo:
@@ -26,9 +26,9 @@ function mapReactCompilerSeverityToMonaco(

 function mapReactCompilerDiagnosticToMonacoMarker(
  detail: CompilerErrorDetail,
-  monaco: Monaco,
+  monaco: Monaco
 ): editor.IMarkerData | null {
-  if (detail.loc == null || typeof detail.loc === 'symbol') {
+  if (detail.loc == null || typeof detail.loc === "symbol") {
    return null;
  }
  const severity = mapReactCompilerSeverityToMonaco(detail.severity, monaco);
@@ -63,27 +63,27 @@ export function renderReactCompilerMarkers({
    markers.push(marker);
  }
  if (markers.length > 0) {
-    monaco.editor.setModelMarkers(model, 'owner', markers);
-    const newDecorations = markers.map(marker => {
+    monaco.editor.setModelMarkers(model, "owner", markers);
+    const newDecorations = markers.map((marker) => {
      return {
        range: new monaco.Range(
          marker.startLineNumber,
          marker.startColumn,
          marker.endLineNumber,
-          marker.endColumn,
+          marker.endColumn
        ),
        options: {
          isWholeLine: true,
-          glyphMarginClassName: 'bg-red-300',
+          glyphMarginClassName: "bg-red-300",
        },
      };
    });
    decorations = model.deltaDecorations(decorations, newDecorations);
  } else {
-    monaco.editor.setModelMarkers(model, 'owner', []);
+    monaco.editor.setModelMarkers(model, "owner", []);
    decorations = model.deltaDecorations(
-      model.getAllDecorations().map(d => d.id),
-      [],
+      model.getAllDecorations().map((d) => d.id),
+      []
    );
  }
 }
--- a/compiler/apps/playground/lib/stores/index.ts
+++ b/compiler/apps/playground/lib/stores/index.ts
@@ -5,5 +5,5 @@
 * LICENSE file in the root directory of this source tree.
 */

-export * from './messages';
-export * from './store';
+export * from "./messages";
+export * from "./store";
--- a/compiler/apps/playground/lib/stores/messages.ts
+++ b/compiler/apps/playground/lib/stores/messages.ts
@@ -27,10 +27,10 @@ export interface Message {
 export function createMessage(
  message: string,
  level: MessageLevel,
-  source: MessageSource,
+  source: MessageSource
 ): Message {
-  const [title, ...body] = message.split('\n');
-  const codeframe = body.length > 0 ? body.join('\n') : undefined;
+  const [title, ...body] = message.split("\n");
+  const codeframe = body.length > 0 ? body.join("\n") : undefined;

  return {
    source,
--- a/compiler/apps/playground/lib/stores/store.ts
+++ b/compiler/apps/playground/lib/stores/store.ts
@@ -5,12 +5,12 @@
 * LICENSE file in the root directory of this source tree.
 */

-import invariant from 'invariant';
+import invariant from "invariant";
 import {
  compressToEncodedURIComponent,
  decompressFromEncodedURIComponent,
-} from 'lz-string';
-import {defaultStore} from '../defaultStore';
+} from "lz-string";
+import { defaultStore } from "../defaultStore";

 /**
 * Global Store for Playground
@@ -30,8 +30,8 @@ export function decodeStore(hash: string): Store {
 */
 export function saveStore(store: Store) {
  const hash = encodeStore(store);
-  localStorage.setItem('playgroundStore', hash);
-  history.replaceState({}, '', `#${hash}`);
+  localStorage.setItem("playgroundStore", hash);
+  history.replaceState({}, "", `#${hash}`);
 }

 /**
@@ -41,9 +41,9 @@ export function saveStore(store: Store) {
 function isValidStore(raw: unknown): raw is Store {
  return (
    raw != null &&
-    typeof raw == 'object' &&
-    'source' in raw &&
-    typeof raw['source'] === 'string'
+    typeof raw == "object" &&
+    "source" in raw &&
+    typeof raw["source"] === "string"
  );
 }

@@ -53,7 +53,7 @@ function isValidStore(raw: unknown): raw is Store {
 */
 export function initStoreFromUrlOrLocalStorage(): Store {
  const encodedSourceFromUrl = location.hash.slice(1);
-  const encodedSourceFromLocal = localStorage.getItem('playgroundStore');
+  const encodedSourceFromLocal = localStorage.getItem("playgroundStore");
  const encodedSource = encodedSourceFromUrl || encodedSourceFromLocal;

  // No data in the URL and no data in the localStorage to fallback to.
@@ -62,6 +62,6 @@ export function initStoreFromUrlOrLocalStorage(): Store {

  const raw = decodeStore(encodedSource);

-  invariant(isValidStore(raw), 'Invalid Store');
+  invariant(isValidStore(raw), "Invalid Store");
  return raw;
 }
--- a/compiler/apps/playground/lib/types.d.ts
+++ b/compiler/apps/playground/lib/types.d.ts
@@ -1,20 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-// v0.17.1
-declare module "hermes-parser" {
-  type HermesParserOptions = {
-    allowReturnOutsideFunction?: boolean;
-    babel?: boolean;
-    flow?: "all" | "detect";
-    enableExperimentalComponentSyntax?: boolean;
-    sourceFilename?: string;
-    sourceType?: "module" | "script" | "unambiguous";
-    tokens?: boolean;
-  };
-  export function parse(code: string, options: Partial<HermesParserOptions>);
-}
--- a/compiler/apps/playground/next.config.js
+++ b/compiler/apps/playground/next.config.js
@@ -5,8 +5,8 @@
 * LICENSE file in the root directory of this source tree.
 */

-const MonacoWebpackPlugin = require('monaco-editor-webpack-plugin');
-const path = require('path');
+const MonacoWebpackPlugin = require("monaco-editor-webpack-plugin");
+const path = require("path");

 const nextConfig = {
  reactStrictMode: true,
@@ -14,36 +14,31 @@ const nextConfig = {
    // Load *.d.ts files as strings using https://webpack.js.org/guides/asset-modules/#source-assets.
    config.module.rules.push({
      test: /\.d\.ts/,
-      type: 'asset/source',
+      type: "asset/source",
    });

    // Monaco Editor
    if (!options.isServer) {
      config.plugins.push(
        new MonacoWebpackPlugin({
-          languages: ['typescript', 'javascript'],
-          filename: 'static/[name].worker.js',
+          languages: ["typescript", "javascript"],
+          filename: "static/[name].worker.js",
        })
      );
    }

    config.resolve.alias = {
      ...config.resolve.alias,
-      'react-compiler-runtime': path.resolve(
+      "react-compiler-runtime": path.resolve(
        __dirname,
-        '../../packages/react-compiler-runtime'
+        "../../packages/react-compiler-runtime"
      ),
    };
-    config.resolve.fallback = {
-      fs: false,
-      path: false,
-      os: false,
-    };

    return config;
  },

-  transpilePackages: ['monaco-editor'],
+  transpilePackages: ["monaco-editor"],
 };

 module.exports = nextConfig;
--- a/compiler/apps/playground/package.json
+++ b/compiler/apps/playground/package.json
@@ -8,11 +8,11 @@
    "vercel-build": "yarn workspaces run build",
    "start": "next start",
    "lint": "next lint",
+    "postinstall": "yarn playwright install",
    "test": "playwright test"
  },
  "dependencies": {
    "@babel/core": "^7.19.1",
-    "@babel/generator": "^7.19.1",
    "@babel/parser": "^7.19.1",
    "@babel/plugin-syntax-typescript": "^7.18.6",
    "@babel/plugin-transform-block-scoping": "^7.18.9",
@@ -25,36 +25,37 @@
    "@monaco-editor/react": "^4.4.6",
    "@playwright/test": "^1.42.1",
    "@use-gesture/react": "^10.2.22",
-    "fs": "^0.0.1-security",
    "hermes-eslint": "^0.14.0",
-    "hermes-parser": "^0.22.0",
    "invariant": "^2.2.4",
    "lz-string": "^1.5.0",
    "monaco-editor": "^0.34.1",
    "next": "^13.5.6",
    "notistack": "^3.0.0-alpha.7",
-    "prettier": "^3.3.3",
+    "prettier": "3.0.3",
    "pretty-format": "^29.3.1",
    "re-resizable": "^6.9.16",
    "react": "18.2.0",
-    "react-compiler-runtime": "*",
-    "react-dom": "18.2.0"
+    "react-dom": "18.2.0",
+    "react-compiler-runtime": "*"
  },
  "devDependencies": {
    "@types/node": "18.11.9",
+    "@types/prettier": "^2.7.1",
    "@types/react": "18.0.25",
    "@types/react-dom": "18.0.9",
    "autoprefixer": "^10.4.13",
    "clsx": "^1.2.1",
    "eslint": "^8.28.0",
    "eslint-config-next": "^13.5.6",
-    "hermes-parser": "^0.22.0",
    "monaco-editor-webpack-plugin": "^7.1.0",
    "postcss": "^8.4.31",
    "tailwindcss": "^3.2.4"
  },
  "resolutions": {
    "./**/@babel/parser": "7.7.4",
-    "./**/@babel/types": "7.7.4"
+    "./**/@babel/types": "7.7.4",
+    "@babel/core": "7.2.0",
+    "@babel/traverse": "7.1.6",
+    "@babel/generator": "7.2.0"
  }
 }
--- a/compiler/apps/playground/playwright.config.js
+++ b/compiler/apps/playground/playwright.config.js
@@ -5,8 +5,8 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {defineConfig, devices} from '@playwright/test';
-import path from 'path';
+import { defineConfig, devices } from "@playwright/test";
+import path from "path";

 // Use process.env.PORT by default and fallback to port 3000
 const PORT = process.env.PORT || 3000;
@@ -19,19 +19,19 @@ export default defineConfig({
  // Timeout per test
  timeout: 30 * 1000,
  // Test directory
-  testDir: path.join(__dirname, '__tests__/e2e'),
+  testDir: path.join(__dirname, "__tests__/e2e"),
  // If a test fails, retry it additional 2 times
  retries: 2,
  // Artifacts folder where screenshots, videos, and traces are stored.
-  outputDir: 'test-results/',
+  outputDir: "test-results/",
  // Note: we only use text snapshots, so its safe to omit the host environment name
-  snapshotPathTemplate: '{testDir}/__snapshots__/{testFilePath}/{arg}{ext}',
+  snapshotPathTemplate: "{testDir}/__snapshots__/{testFilePath}/{arg}{ext}",

  // Run your local dev server before starting the tests:
  // https://playwright.dev/docs/test-advanced#launching-a-development-web-server-during-the-tests
  webServer: {
    command:
-      'yarn workspace babel-plugin-react-compiler build && yarn workspace react-compiler-runtime build && yarn dev',
+      "yarn workspace babel-plugin-react-compiler build && yarn workspace react-compiler-runtime build && yarn dev",
    url: baseURL,
    timeout: 300 * 1000,
    reuseExistingServer: !process.env.CI,
@@ -44,7 +44,7 @@ export default defineConfig({

    // Retry a test if its failing with enabled tracing. This allows you to analyze the DOM, console logs, network traffic etc.
    // More information: https://playwright.dev/docs/trace-viewer
-    trace: 'retry-with-trace',
+    trace: "retry-with-trace",

    // All available context options: https://playwright.dev/docs/api/class-browser#browser-new-context
    // contextOptions: {
@@ -54,8 +54,8 @@ export default defineConfig({

  projects: [
    {
-      name: 'chromium',
-      use: {...devices['Desktop Chrome']},
+      name: "chromium",
+      use: { ...devices["Desktop Chrome"] },
    },
    // {
    //   name: 'Desktop Firefox',
--- a/compiler/apps/playground/scripts/downloadFonts.js
+++ b/compiler/apps/playground/scripts/downloadFonts.js
@@ -5,16 +5,16 @@
 * LICENSE file in the root directory of this source tree.
 */

-const {execSync} = require('child_process');
+const { execSync } = require("child_process");

 // So that we don't need to check them into the repo.
 // See https://github.com/reactjs/reactjs.org/blob/main/beta/scripts/downloadFonts.js.
 execSync(
-  'curl https://conf.reactjs.org/fonts/Optimistic_Display_W_Lt.woff2 --output public/fonts/Optimistic_Display_W_Lt.woff2'
+  "curl https://conf.reactjs.org/fonts/Optimistic_Display_W_Lt.woff2 --output public/fonts/Optimistic_Display_W_Lt.woff2"
 );
 execSync(
-  'curl https://conf.reactjs.org/fonts/Optimistic_Display_W_Md.woff2 --output public/fonts/Optimistic_Display_W_Md.woff2'
+  "curl https://conf.reactjs.org/fonts/Optimistic_Display_W_Md.woff2 --output public/fonts/Optimistic_Display_W_Md.woff2"
 );
 execSync(
-  'curl https://conf.reactjs.org/fonts/Optimistic_Display_W_Bd.woff2 --output public/fonts/Optimistic_Display_W_Bd.woff2'
+  "curl https://conf.reactjs.org/fonts/Optimistic_Display_W_Bd.woff2 --output public/fonts/Optimistic_Display_W_Bd.woff2"
 );
--- a/compiler/apps/playground/tailwind.config.js
+++ b/compiler/apps/playground/tailwind.config.js
@@ -5,33 +5,33 @@
 * LICENSE file in the root directory of this source tree.
 */

-const defaultTheme = require('tailwindcss/defaultTheme');
-const colors = require('./colors');
+const defaultTheme = require("tailwindcss/defaultTheme");
+const colors = require("./colors");

 module.exports = {
  content: [
-    './app/**/*.{js,ts,jsx,tsx}',
-    './pages/**/*.{js,ts,jsx,tsx}',
-    './components/**/*.{js,ts,jsx,tsx}',
-    './lib/forgetMonacoDiagnostics.ts',
+    "./app/**/*.{js,ts,jsx,tsx}",
+    "./pages/**/*.{js,ts,jsx,tsx}",
+    "./components/**/*.{js,ts,jsx,tsx}",
+    "./lib/forgetMonacoDiagnostics.ts",
  ],
  theme: {
    extend: {
      colors,
      width: {
-        toast: 'min(900px, 100vw - 40px)',
-        'toast-body': 'calc(100% - 60px)',
-        'toast-title': 'calc(100% - 40px)',
+        toast: "min(900px, 100vw - 40px)",
+        "toast-body": "calc(100% - 60px)",
+        "toast-title": "calc(100% - 40px)",
      },
      height: {
-        content: 'calc(100vh - 45px)',
-        monaco: 'calc(100vh - 93px)',
-        monaco_small: 'calc(100vh - 129px)',
+        content: "calc(100vh - 45px)",
+        monaco: "calc(100vh - 93px)",
+        monaco_small: "calc(100vh - 129px)",
      },
      fontFamily: {
        sans: [
-          'Optimistic Display',
-          '-apple-system',
+          "Optimistic Display",
+          "-apple-system",
          ...defaultTheme.fontFamily.sans,
        ],
      },
--- a/compiler/package.json
+++ b/compiler/package.json
@@ -12,9 +12,11 @@
  },
  "repository": {
    "type": "git",
-    "url": "git+https://github.com/facebook/react.git"
+    "url": "git+https://github.com/facebook/react-forget.git"
  },
  "scripts": {
+    "bundle:meta": "scripts/bundle-meta.sh",
+    "bundle:oss": "scripts/bundle-oss.sh",
    "copyright": "node scripts/copyright.js",
    "hash": "scripts/hash.sh",
    "start": "yarn workspace playground run start",
@@ -22,6 +24,8 @@
    "build": "yarn workspaces run build",
    "dev": "concurrently --kill-others -n compiler,runtime,playground \"yarn workspace babel-plugin-react-compiler run build --watch\" \"yarn workspace react-compiler-runtime run build --watch\" \"wait-on packages/babel-plugin-react-compiler/dist/index.js && yarn workspace playground run dev\"",
    "test": "yarn workspaces run test",
+    "prettier:write": "prettier --write . --log-level=warn",
+    "prettier:ci": "prettier --check . --log-level=warn",
    "snap": "yarn workspace babel-plugin-react-compiler run snap",
    "snap:build": "yarn workspace snap run build",
    "postinstall": "perl -p -i -e 's/react\\.element/react.transitional.element/' packages/snap/node_modules/fbt/lib/FbtReactUtil.js && perl -p -i -e 's/didWarnAboutUsingAct = false;/didWarnAboutUsingAct = true;/' packages/babel-plugin-react-compiler/node_modules/react-dom/cjs/react-dom-test-utils.development.js",
@@ -38,8 +42,7 @@
    "concurrently": "^7.4.0",
    "folder-hash": "^4.0.4",
    "ora": "5.4.1",
-    "prettier": "^3.3.3",
-    "prettier-plugin-hermes-parser": "^0.23.0",
+    "prettier": "^3.2.5",
    "prompt-promise": "^1.0.3",
    "rollup": "^4.13.2",
    "rollup-plugin-banner2": "^1.2.3",
--- a/compiler/packages/babel-plugin-react-compiler/jest.config.js
+++ b/compiler/packages/babel-plugin-react-compiler/jest.config.js
@@ -7,7 +7,7 @@

 /** @type {import('jest').Config} */
 const config = {
-  projects: ['<rootDir>/scripts/jest/*.config.js'],
+  projects: ["<rootDir>/scripts/jest/*.config.js"],
 };

 module.exports = config;
--- a/compiler/packages/babel-plugin-react-compiler/package.json
+++ b/compiler/packages/babel-plugin-react-compiler/package.json
@@ -1,6 +1,6 @@
 {
  "name": "babel-plugin-react-compiler",
-  "version": "0.0.0-experimental-334f00b-20240725",
+  "version": "0.0.0-experimental-938cd9a-20240601",
  "description": "Babel plugin for React Compiler.",
  "main": "dist/index.js",
  "license": "MIT",
@@ -63,10 +63,5 @@
    "@babel/core": "7.2.0",
    "@babel/generator": "7.2.0",
    "@babel/traverse": "7.7.4"
-  },
-  "repository": {
-    "type": "git",
-    "url": "git+https://github.com/facebook/react.git",
-    "directory": "compiler/packages/babel-plugin-react-compiler"
  }
 }
--- a/compiler/packages/babel-plugin-react-compiler/rollup.config.js
+++ b/compiler/packages/babel-plugin-react-compiler/rollup.config.js
@@ -5,29 +5,29 @@
 * LICENSE file in the root directory of this source tree.
 */

-import typescript from '@rollup/plugin-typescript';
-import {nodeResolve} from '@rollup/plugin-node-resolve';
-import commonjs from '@rollup/plugin-commonjs';
-import json from '@rollup/plugin-json';
-import path from 'path';
-import process from 'process';
-import terser from '@rollup/plugin-terser';
-import prettier from 'rollup-plugin-prettier';
-import banner2 from 'rollup-plugin-banner2';
+import typescript from "@rollup/plugin-typescript";
+import { nodeResolve } from "@rollup/plugin-node-resolve";
+import commonjs from "@rollup/plugin-commonjs";
+import json from "@rollup/plugin-json";
+import path from "path";
+import process from "process";
+import terser from "@rollup/plugin-terser";
+import prettier from "rollup-plugin-prettier";
+import banner2 from "rollup-plugin-banner2";

-const NO_INLINE = new Set(['@babel/types']);
+const NO_INLINE = new Set(["@babel/types"]);

 const DEV_ROLLUP_CONFIG = {
-  input: 'src/index.ts',
+  input: "src/index.ts",
  output: {
-    file: 'dist/index.js',
-    format: 'cjs',
+    file: "dist/index.js",
+    format: "cjs",
    sourcemap: false,
-    exports: 'named',
+    exports: "named",
  },
  plugins: [
    typescript({
-      tsconfig: './tsconfig.json',
+      tsconfig: "./tsconfig.json",
      compilerOptions: {
        noEmit: true,
      },
@@ -35,8 +35,8 @@ const DEV_ROLLUP_CONFIG = {
    json(),
    nodeResolve({
      preferBuiltins: true,
-      resolveOnly: module => NO_INLINE.has(module) === false,
-      rootDir: path.join(process.cwd(), '..'),
+      resolveOnly: (module) => NO_INLINE.has(module) === false,
+      rootDir: path.join(process.cwd(), ".."),
    }),
    commonjs(),
    terser({
--- a/compiler/packages/babel-plugin-react-compiler/scripts/babel-plugin-annotate-react-code.ts
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/babel-plugin-annotate-react-code.ts
@@ -5,15 +5,15 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type * as BabelCore from '@babel/core';
-import {NodePath} from '@babel/core';
-import * as t from '@babel/types';
+import type * as BabelCore from "@babel/core";
+import { NodePath } from "@babel/core";
+import * as t from "@babel/types";

 export default function AnnotateReactCodeBabelPlugin(
-  _babel: typeof BabelCore,
+  _babel: typeof BabelCore
 ): BabelCore.PluginObj {
  return {
-    name: 'annotate-react-code',
+    name: "annotate-react-code",
    visitor: {
      Program(prog): void {
        annotate(prog);
@@ -56,23 +56,23 @@ function buildTypeOfReactForget(): t.Statement {
  // typeof globalThis[Symbol.for("react_forget")]
  return t.expressionStatement(
    t.unaryExpression(
-      'typeof',
+      "typeof",
      t.memberExpression(
-        t.identifier('globalThis'),
+        t.identifier("globalThis"),
        t.callExpression(
          t.memberExpression(
-            t.identifier('Symbol'),
-            t.identifier('for'),
-            false,
+            t.identifier("Symbol"),
+            t.identifier("for"),
            false,
+            false
          ),
-          [t.stringLiteral('react_forget')],
+          [t.stringLiteral("react_forget")]
        ),
        true,
-        false,
+        false
      ),
-      true,
-    ),
+      true
+    )
  );
 }

@@ -89,9 +89,9 @@ type BabelFn =
  | NodePath<t.ArrowFunctionExpression>;

 export function isComponentDeclaration(
-  node: t.FunctionDeclaration,
+  node: t.FunctionDeclaration
 ): node is ComponentDeclaration {
-  return Object.prototype.hasOwnProperty.call(node, '__componentDeclaration');
+  return Object.prototype.hasOwnProperty.call(node, "__componentDeclaration");
 }

 /*
@@ -101,7 +101,7 @@ export function isComponentDeclaration(
 function isComponentOrHookLike(
  node: NodePath<
    t.FunctionDeclaration | t.ArrowFunctionExpression | t.FunctionExpression
-  >,
+  >
 ): boolean {
  const functionName = getFunctionName(node);
  // Check if the name is component or hook like:
@@ -114,7 +114,7 @@ function isComponentOrHookLike(
       * helpers are _usually_ named with lowercase, but some code may
       * violate this rule
       */
-      node.get('params').length <= 1
+      node.get("params").length <= 1
    );
  } else if (functionName !== null && isHook(functionName)) {
    // Hooks have hook invocations or JSX, but can take any # of arguments
@@ -151,11 +151,11 @@ function isHook(path: NodePath<t.Expression | t.PrivateName>): boolean {
  } else if (
    path.isMemberExpression() &&
    !path.node.computed &&
-    isHook(path.get('property'))
+    isHook(path.get("property"))
  ) {
-    const obj = path.get('object').node;
+    const obj = path.get("object").node;
    const isPascalCaseNameSpace = /^[A-Z].*/;
-    return obj.type === 'Identifier' && isPascalCaseNameSpace.test(obj.name);
+    return obj.type === "Identifier" && isPascalCaseNameSpace.test(obj.name);
  } else {
    return false;
  }
@@ -177,8 +177,8 @@ function isComponentName(path: NodePath<t.Expression>): boolean {
 function isForwardRefCallback(path: NodePath<t.Expression>): boolean {
  return !!(
    path.parentPath.isCallExpression() &&
-    path.parentPath.get('callee').isExpression() &&
-    isReactAPI(path.parentPath.get('callee'), 'forwardRef')
+    path.parentPath.get("callee").isExpression() &&
+    isReactAPI(path.parentPath.get("callee"), "forwardRef")
  );
 }

@@ -190,22 +190,22 @@ function isForwardRefCallback(path: NodePath<t.Expression>): boolean {
 function isMemoCallback(path: NodePath<t.Expression>): boolean {
  return (
    path.parentPath.isCallExpression() &&
-    path.parentPath.get('callee').isExpression() &&
-    isReactAPI(path.parentPath.get('callee'), 'memo')
+    path.parentPath.get("callee").isExpression() &&
+    isReactAPI(path.parentPath.get("callee"), "memo")
  );
 }

 function isReactAPI(
  path: NodePath<t.Expression | t.PrivateName | t.V8IntrinsicIdentifier>,
-  functionName: string,
+  functionName: string
 ): boolean {
  const node = path.node;
  return (
-    (node.type === 'Identifier' && node.name === functionName) ||
-    (node.type === 'MemberExpression' &&
-      node.object.type === 'Identifier' &&
-      node.object.name === 'React' &&
-      node.property.type === 'Identifier' &&
+    (node.type === "Identifier" && node.name === functionName) ||
+    (node.type === "MemberExpression" &&
+      node.object.type === "Identifier" &&
+      node.object.name === "React" &&
+      node.property.type === "Identifier" &&
      node.property.name === functionName)
  );
 }
@@ -218,7 +218,7 @@ function callsHooksOrCreatesJsx(node: NodePath<t.Node>): boolean {
      createsJsx = true;
    },
    CallExpression(call) {
-      const callee = call.get('callee');
+      const callee = call.get("callee");
      if (callee.isExpression() && isHook(callee)) {
        invokesHooks = true;
      }
@@ -239,10 +239,10 @@ function callsHooksOrCreatesJsx(node: NodePath<t.Node>): boolean {
 function getFunctionName(
  path: NodePath<
    t.FunctionDeclaration | t.ArrowFunctionExpression | t.FunctionExpression
-  >,
+  >
 ): NodePath<t.Expression> | null {
  if (path.isFunctionDeclaration()) {
-    const id = path.get('id');
+    const id = path.get("id");
    if (id.isIdentifier()) {
      return id;
    }
@@ -250,31 +250,31 @@ function getFunctionName(
  }
  let id: NodePath<t.LVal | t.Expression | t.PrivateName> | null = null;
  const parent = path.parentPath;
-  if (parent.isVariableDeclarator() && parent.get('init').node === path.node) {
+  if (parent.isVariableDeclarator() && parent.get("init").node === path.node) {
    // const useHook = () => {};
-    id = parent.get('id');
+    id = parent.get("id");
  } else if (
    parent.isAssignmentExpression() &&
-    parent.get('right').node === path.node &&
-    parent.get('operator') === '='
+    parent.get("right").node === path.node &&
+    parent.get("operator") === "="
  ) {
    // useHook = () => {};
-    id = parent.get('left');
+    id = parent.get("left");
  } else if (
    parent.isProperty() &&
-    parent.get('value').node === path.node &&
-    !parent.get('computed') &&
-    parent.get('key').isLVal()
+    parent.get("value").node === path.node &&
+    !parent.get("computed") &&
+    parent.get("key").isLVal()
  ) {
    /*
     * {useHook: () => {}}
     * {useHook() {}}
     */
-    id = parent.get('key');
+    id = parent.get("key");
  } else if (
    parent.isAssignmentPattern() &&
-    parent.get('right').node === path.node &&
-    !parent.get('computed')
+    parent.get("right").node === path.node &&
+    !parent.get("computed")
  ) {
    /*
     * const {useHook = () => {}} = {};
@@ -283,7 +283,7 @@ function getFunctionName(
     * Kinda clowny, but we'd said we'd follow spec convention for
     * `IsAnonymousFunctionDefinition()` usage.
     */
-    id = parent.get('left');
+    id = parent.get("left");
  }
  if (id !== null && (id.isIdentifier() || id.isMemberExpression())) {
    return id;
--- a/compiler/packages/babel-plugin-react-compiler/scripts/build-react-hooks-fixures.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/build-react-hooks-fixures.js
@@ -5,27 +5,27 @@
 * LICENSE file in the root directory of this source tree.
 */

-'use strict';
+"use strict";

-const {tests} = require('./eslint-plugin-react-hooks-test-cases');
+const { tests } = require("./eslint-plugin-react-hooks-test-cases");
 const {
  runBabelPluginReactCompiler,
-} = require('../dist/Babel/RunReactCompilerBabelPlugin');
-const fs = require('fs');
-const path = require('path');
-const prettier = require('prettier');
-const prettierConfigPath = require.resolve('../.prettierrc');
-const process = require('process');
-const {createHash} = require('crypto');
-const {create} = require('domain');
+} = require("../dist/Babel/RunReactCompilerBabelPlugin");
+const fs = require("fs");
+const path = require("path");
+const prettier = require("prettier");
+const prettierConfigPath = require.resolve("../.prettierrc");
+const process = require("process");
+const { createHash } = require("crypto");
+const { create } = require("domain");

 const FIXTURES_DIR = path.join(
  process.cwd(),
-  'src',
-  '__tests__',
-  'fixtures',
-  'compiler',
-  'rules-of-hooks'
+  "src",
+  "__tests__",
+  "fixtures",
+  "compiler",
+  "rules-of-hooks"
 );

 const PRETTIER_OPTIONS = prettier.resolveConfig.sync(FIXTURES_DIR, {
@@ -34,10 +34,10 @@ const PRETTIER_OPTIONS = prettier.resolveConfig.sync(FIXTURES_DIR, {

 const fixtures = [];
 for (const test of tests.valid) {
-  fixtures.push({code: test.code, valid: true});
+  fixtures.push({ code: test.code, valid: true });
 }
 for (const test of tests.invalid) {
-  fixtures.push({code: test.code, valid: false});
+  fixtures.push({ code: test.code, valid: false });
 }

 for (const fixture of fixtures) {
@@ -47,8 +47,8 @@ for (const fixture of fixtures) {
    // Does the fixture pass with hooks validation disabled? if not skip it
    runBabelPluginReactCompiler(
      fixture.code,
-      'rules-of-hooks.js',
-      'typescript',
+      "rules-of-hooks.js",
+      "typescript",
      {
        environment: {
          validateHooksUsage: false,
@@ -59,8 +59,8 @@ for (const fixture of fixtures) {
    try {
      runBabelPluginReactCompiler(
        fixture.code,
-        'rules-of-hooks.js',
-        'typescript',
+        "rules-of-hooks.js",
+        "typescript",
        {
          environment: {
            validateHooksUsage: true,
@@ -74,7 +74,7 @@ for (const fixture of fixtures) {
    error = e;
  }
  let code = fixture.code;
-  let prefix = '';
+  let prefix = "";
  if (error !== null) {
    prefix = `todo.bail.`;
    code = `// @skip\n// Unsupported input\n${code}`;
@@ -92,11 +92,11 @@ for (const fixture of fixtures) {
    code = `// @skip\n// Failed but should have passed\n${code}`;
  }
  const formatted = prettier.format(code, PRETTIER_OPTIONS);
-  const hmac = createHash('sha256');
-  hmac.update(formatted, 'utf8');
+  const hmac = createHash("sha256");
+  hmac.update(formatted, "utf8");
  let name = `${prefix}rules-of-hooks-${hmac
-    .digest('hex')
+    .digest("hex")
    .substring(0, 12)}.js`;
  const fixturePath = path.join(FIXTURES_DIR, name);
-  fs.writeFileSync(fixturePath, formatted, 'utf8');
+  fs.writeFileSync(fixturePath, formatted, "utf8");
 }
--- a/compiler/packages/babel-plugin-react-compiler/scripts/eslint-plugin-react-hooks-test-cases.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/eslint-plugin-react-hooks-test-cases.js
@@ -5,7 +5,7 @@
 * LICENSE file in the root directory of this source tree.
 */

-'use strict';
+"use strict";

 // NOTE: Extracted from https://github.com/facebook/react/blob/main/packages/eslint-plugin-react-hooks/__tests__/ESLintRulesOfHooks-test.js

@@ -13,9 +13,9 @@
 * A string template tag that removes padding from the left side of multi-line strings
 */
 function normalizeIndent(strings) {
-  const codeLines = strings[0].split('\n');
+  const codeLines = strings[0].split("\n");
  const leftPadding = codeLines[1].match(/\s+/)[0];
-  return codeLines.map(line => line.slice(leftPadding.length)).join('\n');
+  return codeLines.map((line) => line.slice(leftPadding.length)).join("\n");
 }

 module.exports.tests = {
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/e2e-classic.config.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/e2e-classic.config.js
@@ -5,6 +5,6 @@
 * LICENSE file in the root directory of this source tree.
 */

-const makeE2EConfig = require('../jest/makeE2EConfig');
+const makeE2EConfig = require("../jest/makeE2EConfig");

-module.exports = makeE2EConfig('e2e no forget', false);
+module.exports = makeE2EConfig("e2e no forget", false);
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/e2e-forget.config.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/e2e-forget.config.js
@@ -5,9 +5,9 @@
 * LICENSE file in the root directory of this source tree.
 */

-const makeE2EConfig = require('../jest/makeE2EConfig');
+const makeE2EConfig = require("../jest/makeE2EConfig");

-const config = makeE2EConfig('e2e with forget', true);
-config.setupFilesAfterEnv = ['<rootDir>/../scripts/jest/setupEnvE2E.js'];
+const config = makeE2EConfig("e2e with forget", true);
+config.setupFilesAfterEnv = ["<rootDir>/../scripts/jest/setupEnvE2E.js"];

 module.exports = config;
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/main.config.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/main.config.js
@@ -6,10 +6,10 @@
 */

 module.exports = {
-  displayName: 'main',
-  preset: 'ts-jest',
-  rootDir: '../../src',
-  testPathIgnorePatterns: ['e2e', 'TestDriver', 'test-utils', 'fixtures'],
+  displayName: "main",
+  preset: "ts-jest",
+  rootDir: "../../src",
+  testPathIgnorePatterns: ["e2e", "TestDriver", "test-utils", "fixtures"],
  globals: {
    __DEV__: true,
  },
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/makeE2EConfig.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/makeE2EConfig.js
@@ -8,27 +8,27 @@
 module.exports = function makeE2EConfig(displayName, useForget) {
  return {
    displayName,
-    testEnvironment: 'jsdom',
-    rootDir: '../../src',
-    testMatch: ['**/*.e2e.(js|tsx)'],
+    testEnvironment: "jsdom",
+    rootDir: "../../src",
+    testMatch: ["**/*.e2e.(js|tsx)"],
    modulePathIgnorePatterns: [
      // ignore snapshots from the opposite forget configuration
-      useForget ? '.*\\.no-forget\\.snap$' : '.*\\.with-forget\\.snap$',
+      useForget ? ".*\\.no-forget\\.snap$" : ".*\\.with-forget\\.snap$",
      // ignore snapshots from the main project
-      '.*\\.ts\\.snap$',
+      ".*\\.ts\\.snap$",
    ],
    globals: {
      __FORGET__: useForget,
    },
    snapshotResolver: useForget
-      ? '<rootDir>/../scripts/jest/snapshot-resolver-with-forget.js'
-      : '<rootDir>/../scripts/jest/snapshot-resolver-no-forget.js',
+      ? "<rootDir>/../scripts/jest/snapshot-resolver-with-forget.js"
+      : "<rootDir>/../scripts/jest/snapshot-resolver-no-forget.js",

    transform: {
-      '\\.[tj]sx?$': useForget
-        ? '<rootDir>/../scripts/jest/transform-with-forget'
-        : '<rootDir>/../scripts/jest/transform-no-forget',
+      "\\.[tj]sx?$": useForget
+        ? "<rootDir>/../scripts/jest/transform-with-forget"
+        : "<rootDir>/../scripts/jest/transform-no-forget",
    },
-    transformIgnorePatterns: ['/node_modules/'],
+    transformIgnorePatterns: ["/node_modules/"],
  };
 };
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/makeSnapshotResolver.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/makeSnapshotResolver.js
@@ -6,7 +6,7 @@
 */

 module.exports = function makeSnapshotResolver(useForget) {
-  const modeExtension = useForget ? '.with-forget' : '.no-forget';
+  const modeExtension = useForget ? ".with-forget" : ".no-forget";
  return {
    resolveSnapshotPath: (testPath, snapshotExtension) =>
      testPath + modeExtension + snapshotExtension,
@@ -17,6 +17,6 @@ module.exports = function makeSnapshotResolver(useForget) {
        -modeExtension.length - snapshotExtension.length
      ),

-    testPathForConsistencyCheck: 'some/__tests__/example.test.js',
+    testPathForConsistencyCheck: "some/__tests__/example.test.js",
  };
 };
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/makeTransform.ts
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/makeTransform.ts
@@ -5,19 +5,19 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {jsx} from '@babel/plugin-syntax-jsx';
-import babelJest from 'babel-jest';
-import {compile} from 'babel-plugin-react-compiler';
-import {execSync} from 'child_process';
+import { jsx } from "@babel/plugin-syntax-jsx";
+import babelJest from "babel-jest";
+import { compile } from "babel-plugin-react-compiler";
+import { execSync } from "child_process";

-import type {NodePath, Visitor} from '@babel/traverse';
-import type {CallExpression, FunctionDeclaration} from '@babel/types';
-import * as t from '@babel/types';
+import type { NodePath, Visitor } from "@babel/traverse";
+import type { CallExpression, FunctionDeclaration } from "@babel/types";
+import * as t from "@babel/types";
 import {
  EnvironmentConfig,
  validateEnvironmentConfig,
-} from 'babel-plugin-react-compiler';
-import {basename} from 'path';
+} from "babel-plugin-react-compiler";
+import { basename } from "path";

 /**
 * -- IMPORTANT --
@@ -28,16 +28,15 @@ import {basename} from 'path';
 const e2eTransformerCacheKey = 1;
 const forgetOptions: EnvironmentConfig = validateEnvironmentConfig({
  enableAssumeHooksFollowRulesOfReact: true,
-  enableFunctionOutlining: false,
 });
-const debugMode = process.env['DEBUG_FORGET_COMPILER'] != null;
+const debugMode = process.env["DEBUG_FORGET_COMPILER"] != null;

 module.exports = (useForget: boolean) => {
  function createTransformer() {
    return babelJest.createTransformer({
      passPerPreset: true,
      presets: [
-        '@babel/preset-typescript',
+        "@babel/preset-typescript",
        {
          plugins: [
            useForget
@@ -49,36 +48,36 @@ module.exports = (useForget: boolean) => {
                     * (see https://github.com/jestjs/jest/blob/v29.6.2/packages/babel-jest/src/index.ts#L84)
                     */
                    compilerCacheKey: execSync(
-                      'yarn --silent --cwd ../.. hash packages/babel-plugin-react-compiler/dist',
+                      "yarn --silent --cwd ../.. hash packages/babel-plugin-react-compiler/dist"
                    ).toString(),
                    transformOptionsCacheKey: forgetOptions,
                    e2eTransformerCacheKey,
                  },
                ]
-              : '@babel/plugin-syntax-jsx',
+              : "@babel/plugin-syntax-jsx",
          ],
        },
-        '@babel/preset-react',
+        "@babel/preset-react",
        {
          plugins: [
            [
-              function BabelPluginRewriteRequirePath(): {visitor: Visitor} {
+              function BabelPluginRewriteRequirePath(): { visitor: Visitor } {
                return {
                  visitor: {
                    CallExpression(path: NodePath<CallExpression>): void {
-                      const {callee} = path.node;
+                      const { callee } = path.node;
                      if (
-                        callee.type === 'Identifier' &&
-                        callee.name === 'require'
+                        callee.type === "Identifier" &&
+                        callee.name === "require"
                      ) {
                        const arg = path.node.arguments[0];
-                        if (arg.type === 'StringLiteral') {
+                        if (arg.type === "StringLiteral") {
                          /*
                           * The compiler adds requires of "React", which is expected to be a wrapper
                           * around the "react" package. For tests, we just rewrite the require.
                           */
-                          if (arg.value === 'React') {
-                            arg.value = 'react';
+                          if (arg.value === "React") {
+                            arg.value = "react";
                          }
                        }
                      }
@@ -87,7 +86,7 @@ module.exports = (useForget: boolean) => {
                };
              },
            ],
-            '@babel/plugin-transform-modules-commonjs',
+            "@babel/plugin-transform-modules-commonjs",
          ],
        },
      ],
@@ -125,7 +124,7 @@ function isReactComponentLike(fn: NodePath<FunctionDeclaration>): boolean {

  fn.traverse({
    DirectiveLiteral(path) {
-      if (path.node.value === 'use no forget') {
+      if (path.node.value === "use no forget") {
        hasNoUseForgetDirective = true;
      }
    },
@@ -140,7 +139,7 @@ function isReactComponentLike(fn: NodePath<FunctionDeclaration>): boolean {
    CallExpression(path) {
      // Is there hook usage?
      if (
-        path.node.callee.type === 'Identifier' &&
+        path.node.callee.type === "Identifier" &&
        !/^use[A-Z0-9]/.test(path.node.callee.name)
      ) {
        isReactComponent = true;
@@ -170,7 +169,7 @@ function ReactForgetFunctionTransform() {
        const filename = basename(state.file.opts.filename);
        if (fn.node.loc && fn.node.id) {
          console.log(
-            ` Compiling ${filename}:${fn.node.loc.start.line}:${fn.node.loc.start.column}  ${fn.node.id.name}`,
+            ` Compiling ${filename}:${fn.node.loc.start.line}:${fn.node.loc.start.column}  ${fn.node.id.name}`
          );
        } else {
          console.log(` Compiling ${filename} ${fn.node.id?.name}`);
@@ -180,11 +179,11 @@ function ReactForgetFunctionTransform() {
      const compiled = compile(
        fn,
        forgetOptions,
-        'Other',
-        '_c',
-        null,
+        "Other",
+        "_c",
        null,
        null,
+        null
      );
      compiledFns.add(compiled);

@@ -193,14 +192,14 @@ function ReactForgetFunctionTransform() {
        compiled.params,
        compiled.body,
        compiled.generator,
-        compiled.async,
+        compiled.async
      );
      fn.replaceWith(fun);
      fn.skip();
    },
  };
  return {
-    name: 'react-forget-e2e',
+    name: "react-forget-e2e",
    inherits: jsx,
    visitor,
  };
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/setupEnvE2E.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/setupEnvE2E.js
@@ -5,7 +5,7 @@
 * LICENSE file in the root directory of this source tree.
 */

-const ReactCompilerRuntime = require('react/compiler-runtime');
+const ReactCompilerRuntime = require("react/compiler-runtime");

 /*
 * Our e2e babel transform currently only compiles functions, not programs.
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/snapshot-resolver-no-forget.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/snapshot-resolver-no-forget.js
@@ -5,6 +5,6 @@
 * LICENSE file in the root directory of this source tree.
 */

-const makeSnapshotResolver = require('./makeSnapshotResolver');
+const makeSnapshotResolver = require("./makeSnapshotResolver");

 module.exports = makeSnapshotResolver(false);
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/snapshot-resolver-with-forget.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/snapshot-resolver-with-forget.js
@@ -5,6 +5,6 @@
 * LICENSE file in the root directory of this source tree.
 */

-const makeSnapshotResolver = require('./makeSnapshotResolver');
+const makeSnapshotResolver = require("./makeSnapshotResolver");

 module.exports = makeSnapshotResolver(true);
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/transform-no-forget.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/transform-no-forget.js
@@ -5,4 +5,4 @@
 * LICENSE file in the root directory of this source tree.
 */

-module.exports = require('./makeTransform')(false);
+module.exports = require("./makeTransform")(false);
--- a/compiler/packages/babel-plugin-react-compiler/scripts/jest/transform-with-forget.js
+++ b/compiler/packages/babel-plugin-react-compiler/scripts/jest/transform-with-forget.js
@@ -5,4 +5,4 @@
 * LICENSE file in the root directory of this source tree.
 */

-module.exports = require('./makeTransform')(true);
+module.exports = require("./makeTransform")(true);
--- a/compiler/packages/babel-plugin-react-compiler/src/Babel/BabelPlugin.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Babel/BabelPlugin.ts
@@ -5,12 +5,12 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type * as BabelCore from '@babel/core';
-import {compileProgram, parsePluginOptions} from '../Entrypoint';
+import type * as BabelCore from "@babel/core";
+import { compileProgram, parsePluginOptions } from "../Entrypoint";
 import {
  injectReanimatedFlag,
  pipelineUsesReanimatedPlugin,
-} from '../Entrypoint/Reanimated';
+} from "../Entrypoint/Reanimated";

 /*
 * The React Forget Babel Plugin
@@ -18,10 +18,10 @@ import {
 * @returns
 */
 export default function BabelPluginReactCompiler(
-  _babel: typeof BabelCore,
+  _babel: typeof BabelCore
 ): BabelCore.PluginObj {
  return {
-    name: 'react-forget',
+    name: "react-forget",
    visitor: {
      /*
       * Note: Babel does some "smart" merging of visitors across plugins, so even if A is inserted
@@ -30,16 +30,13 @@ export default function BabelPluginReactCompiler(
       */
      Program(prog, pass): void {
        let opts = parsePluginOptions(pass.opts);
-        const isDev =
-          (typeof __DEV__ !== 'undefined' && __DEV__ === true) ||
-          process.env['NODE_ENV'] === 'development';
        if (
          opts.enableReanimatedCheck === true &&
          pipelineUsesReanimatedPlugin(pass.file.opts.plugins)
        ) {
          opts = injectReanimatedFlag(opts);
        }
-        if (isDev) {
+        if (process.env["NODE_ENV"] === "development") {
          opts = {
            ...opts,
            environment: {
--- a/compiler/packages/babel-plugin-react-compiler/src/Babel/RunReactCompilerBabelPlugin.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Babel/RunReactCompilerBabelPlugin.ts
@@ -5,25 +5,25 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type * as BabelCore from '@babel/core';
-import {transformFromAstSync} from '@babel/core';
-import * as BabelParser from '@babel/parser';
-import invariant from 'invariant';
-import type {PluginOptions} from '../Entrypoint';
-import BabelPluginReactCompiler from './BabelPlugin';
+import type * as BabelCore from "@babel/core";
+import { transformFromAstSync } from "@babel/core";
+import * as BabelParser from "@babel/parser";
+import invariant from "invariant";
+import type { PluginOptions } from "../Entrypoint";
+import BabelPluginReactCompiler from "./BabelPlugin";

-export const DEFAULT_PLUGINS = ['babel-plugin-fbt', 'babel-plugin-fbt-runtime'];
+export const DEFAULT_PLUGINS = ["babel-plugin-fbt", "babel-plugin-fbt-runtime"];
 export function runBabelPluginReactCompiler(
  text: string,
  file: string,
-  language: 'flow' | 'typescript',
+  language: "flow" | "typescript",
  options: Partial<PluginOptions> | null,
-  includeAst: boolean = false,
+  includeAst: boolean = false
 ): BabelCore.BabelFileResult {
  const ast = BabelParser.parse(text, {
    sourceFilename: file,
-    plugins: [language, 'jsx'],
-    sourceType: 'module',
+    plugins: [language, "jsx"],
+    sourceType: "module",
  });
  const result = transformFromAstSync(ast, text, {
    ast: includeAst,
@@ -32,16 +32,16 @@ export function runBabelPluginReactCompiler(
    retainLines: true,
    plugins: [
      [BabelPluginReactCompiler, options],
-      'babel-plugin-fbt',
-      'babel-plugin-fbt-runtime',
+      "babel-plugin-fbt",
+      "babel-plugin-fbt-runtime",
    ],
-    sourceType: 'module',
+    sourceType: "module",
    configFile: false,
    babelrc: false,
  });
  invariant(
    result?.code != null,
-    `Expected BabelPluginReactForget to codegen successfully, got: ${result}`,
+    `Expected BabelPluginReactForget to codegen successfully, got: ${result}`
  );
  return result;
 }
--- a/compiler/packages/babel-plugin-react-compiler/src/CompilerError.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/CompilerError.ts
@@ -5,37 +5,37 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type {SourceLocation} from './HIR';
-import {assertExhaustive} from './Utils/utils';
+import type { SourceLocation } from "./HIR";
+import { assertExhaustive } from "./Utils/utils";

 export enum ErrorSeverity {
  /**
   * Invalid JS syntax, or valid syntax that is semantically invalid which may indicate some
   * misunderstanding on the user’s part.
   */
-  InvalidJS = 'InvalidJS',
+  InvalidJS = "InvalidJS",
  /**
   * Code that breaks the rules of React.
   */
-  InvalidReact = 'InvalidReact',
+  InvalidReact = "InvalidReact",
  /**
   * Incorrect configuration of the compiler.
   */
-  InvalidConfig = 'InvalidConfig',
+  InvalidConfig = "InvalidConfig",
  /**
   * Code that can reasonably occur and that doesn't break any rules, but is unsafe to preserve
   * memoization.
   */
-  CannotPreserveMemoization = 'CannotPreserveMemoization',
+  CannotPreserveMemoization = "CannotPreserveMemoization",
  /**
   * Unhandled syntax that we don't support yet.
   */
-  Todo = 'Todo',
+  Todo = "Todo",
  /**
   * An unexpected internal error in the compiler that indicates critical issues that can panic
   * the compiler.
   */
-  Invariant = 'Invariant',
+  Invariant = "Invariant",
 }

 export enum CompilerSuggestionOperation {
@@ -79,19 +79,19 @@ export class CompilerErrorDetail {
    this.options = options;
  }

-  get reason(): CompilerErrorDetailOptions['reason'] {
+  get reason(): CompilerErrorDetailOptions["reason"] {
    return this.options.reason;
  }
-  get description(): CompilerErrorDetailOptions['description'] {
+  get description(): CompilerErrorDetailOptions["description"] {
    return this.options.description;
  }
-  get severity(): CompilerErrorDetailOptions['severity'] {
+  get severity(): CompilerErrorDetailOptions["severity"] {
    return this.options.severity;
  }
-  get loc(): CompilerErrorDetailOptions['loc'] {
+  get loc(): CompilerErrorDetailOptions["loc"] {
    return this.options.loc;
  }
-  get suggestions(): CompilerErrorDetailOptions['suggestions'] {
+  get suggestions(): CompilerErrorDetailOptions["suggestions"] {
    return this.options.suggestions;
  }

@@ -100,10 +100,10 @@ export class CompilerErrorDetail {
    if (this.description != null) {
      buffer.push(`. ${this.description}`);
    }
-    if (this.loc != null && typeof this.loc !== 'symbol') {
+    if (this.loc != null && typeof this.loc !== "symbol") {
      buffer.push(` (${this.loc.start.line}:${this.loc.end.line})`);
    }
-    return buffer.join('');
+    return buffer.join("");
  }

  toString(): string {
@@ -116,7 +116,7 @@ export class CompilerError extends Error {

  static invariant(
    condition: unknown,
-    options: Omit<CompilerErrorDetailOptions, 'severity'>,
+    options: Omit<CompilerErrorDetailOptions, "severity">
  ): asserts condition {
    if (!condition) {
      const errors = new CompilerError();
@@ -124,57 +124,57 @@ export class CompilerError extends Error {
        new CompilerErrorDetail({
          ...options,
          severity: ErrorSeverity.Invariant,
-        }),
+        })
      );
      throw errors;
    }
  }

  static throwTodo(
-    options: Omit<CompilerErrorDetailOptions, 'severity'>,
+    options: Omit<CompilerErrorDetailOptions, "severity">
  ): never {
    const errors = new CompilerError();
    errors.pushErrorDetail(
-      new CompilerErrorDetail({...options, severity: ErrorSeverity.Todo}),
+      new CompilerErrorDetail({ ...options, severity: ErrorSeverity.Todo })
    );
    throw errors;
  }

  static throwInvalidJS(
-    options: Omit<CompilerErrorDetailOptions, 'severity'>,
+    options: Omit<CompilerErrorDetailOptions, "severity">
  ): never {
    const errors = new CompilerError();
    errors.pushErrorDetail(
      new CompilerErrorDetail({
        ...options,
        severity: ErrorSeverity.InvalidJS,
-      }),
+      })
    );
    throw errors;
  }

  static throwInvalidReact(
-    options: Omit<CompilerErrorDetailOptions, 'severity'>,
+    options: Omit<CompilerErrorDetailOptions, "severity">
  ): never {
    const errors = new CompilerError();
    errors.pushErrorDetail(
      new CompilerErrorDetail({
        ...options,
        severity: ErrorSeverity.InvalidReact,
-      }),
+      })
    );
    throw errors;
  }

  static throwInvalidConfig(
-    options: Omit<CompilerErrorDetailOptions, 'severity'>,
+    options: Omit<CompilerErrorDetailOptions, "severity">
  ): never {
    const errors = new CompilerError();
    errors.pushErrorDetail(
      new CompilerErrorDetail({
        ...options,
        severity: ErrorSeverity.InvalidConfig,
-      }),
+      })
    );
    throw errors;
  }
@@ -187,7 +187,7 @@ export class CompilerError extends Error {

  constructor(...args: Array<any>) {
    super(...args);
-    this.name = 'ReactCompilerError';
+    this.name = "ReactCompilerError";
  }

  override get message(): string {
@@ -197,7 +197,7 @@ export class CompilerError extends Error {
  override set message(_message: string) {}

  override toString(): string {
-    return this.details.map(detail => detail.toString()).join('\n\n');
+    return this.details.map((detail) => detail.toString()).join("\n\n");
  }

  push(options: CompilerErrorDetailOptions): CompilerErrorDetail {
@@ -206,7 +206,7 @@ export class CompilerError extends Error {
      description: options.description ?? null,
      severity: options.severity,
      suggestions: options.suggestions,
-      loc: typeof options.loc === 'symbol' ? null : options.loc,
+      loc: typeof options.loc === "symbol" ? null : options.loc,
    });
    return this.pushErrorDetail(detail);
  }
@@ -226,7 +226,7 @@ export class CompilerError extends Error {
   * but otherwise continue compiling the rest of the app.
   */
  isCritical(): boolean {
-    return this.details.some(detail => {
+    return this.details.some((detail) => {
      switch (detail.severity) {
        case ErrorSeverity.Invariant:
        case ErrorSeverity.InvalidJS:
@@ -237,7 +237,7 @@ export class CompilerError extends Error {
        case ErrorSeverity.Todo:
          return false;
        default:
-          assertExhaustive(detail.severity, 'Unhandled error severity');
+          assertExhaustive(detail.severity, "Unhandled error severity");
      }
    });
  }
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Gating.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Gating.ts
@@ -5,9 +5,9 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {NodePath} from '@babel/core';
-import * as t from '@babel/types';
-import {PluginOptions} from './Options';
+import { NodePath } from "@babel/core";
+import * as t from "@babel/types";
+import { PluginOptions } from "./Options";

 export function insertGatedFunctionDeclaration(
  fnPath: NodePath<
@@ -17,14 +17,15 @@ export function insertGatedFunctionDeclaration(
    | t.FunctionDeclaration
    | t.ArrowFunctionExpression
    | t.FunctionExpression,
-  gating: NonNullable<PluginOptions['gating']>,
-): void {
+  gating: NonNullable<PluginOptions["gating"]>
+): NodePath<t.ConditionalExpression | t.VariableDeclaration> {
  const gatingExpression = t.conditionalExpression(
    t.callExpression(t.identifier(gating.importSpecifierName), []),
    buildFunctionExpression(compiled),
-    buildFunctionExpression(fnPath.node),
+    buildFunctionExpression(fnPath.node)
  );

+  let compiledFn;
  /*
   * Convert function declarations to named variables *unless* this is an
   * `export default function ...` since `export default const ...` is
@@ -32,50 +33,33 @@ export function insertGatedFunctionDeclaration(
   * conditional expression
   */
  if (
-    fnPath.parentPath.node.type !== 'ExportDefaultDeclaration' &&
-    fnPath.node.type === 'FunctionDeclaration' &&
+    fnPath.parentPath.node.type !== "ExportDefaultDeclaration" &&
+    fnPath.node.type === "FunctionDeclaration" &&
    fnPath.node.id != null
  ) {
-    fnPath.replaceWith(
-      t.variableDeclaration('const', [
+    compiledFn = 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,
-        ),
-      ]),
-    );
+      ])
+    )[0];
  } else {
-    fnPath.replaceWith(gatingExpression);
+    compiledFn = fnPath.replaceWith(gatingExpression)[0];
  }
+
+  return compiledFn;
 }

 function buildFunctionExpression(
-  node:
-    | t.FunctionDeclaration
-    | t.ArrowFunctionExpression
-    | t.FunctionExpression,
+  node: t.FunctionDeclaration | t.ArrowFunctionExpression | t.FunctionExpression
 ): t.ArrowFunctionExpression | t.FunctionExpression {
  if (
-    node.type === 'ArrowFunctionExpression' ||
-    node.type === 'FunctionExpression'
+    node.type === "ArrowFunctionExpression" ||
+    node.type === "FunctionExpression"
  ) {
    return node;
  } else {
    const fn: t.FunctionExpression = {
-      type: 'FunctionExpression',
+      type: "FunctionExpression",
      async: node.async,
      generator: node.generator,
      loc: node.loc ?? null,
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Imports.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Imports.ts
@@ -5,19 +5,19 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {NodePath} from '@babel/core';
-import * as t from '@babel/types';
-import {CompilerError} from '../CompilerError';
-import {ExternalFunction, GeneratedSource} from '../HIR';
-import {getOrInsertDefault} from '../Utils/utils';
+import { NodePath } from "@babel/core";
+import * as t from "@babel/types";
+import { CompilerError } from "../CompilerError";
+import { ExternalFunction, GeneratedSource } from "../HIR";
+import { getOrInsertDefault } from "../Utils/utils";

 export function addImportsToProgram(
  path: NodePath<t.Program>,
-  importList: Array<ExternalFunction>,
+  importList: Array<ExternalFunction>
 ): void {
  const identifiers: Set<string> = new Set();
  const sortedImports: Map<string, Array<string>> = new Map();
-  for (const {importSpecifierName, source} of importList) {
+  for (const { importSpecifierName, source } of importList) {
    /*
     * Codegen currently does not rename import specifiers, so we do additional
     * validation here
@@ -35,28 +35,28 @@ export function addImportsToProgram(
        description: null,
        loc: GeneratedSource,
        suggestions: null,
-      },
+      }
    );
    identifiers.add(importSpecifierName);

    const importSpecifierNameList = getOrInsertDefault(
      sortedImports,
      source,
-      [],
+      []
    );
    importSpecifierNameList.push(importSpecifierName);
  }

  const stmts: Array<t.ImportDeclaration> = [];
  for (const [source, importSpecifierNameList] of sortedImports) {
-    const importSpecifiers = importSpecifierNameList.map(name => {
+    const importSpecifiers = importSpecifierNameList.map((name) => {
      const id = t.identifier(name);
      return t.importSpecifier(id, id);
    });

    stmts.push(t.importDeclaration(importSpecifiers, t.stringLiteral(source)));
  }
-  path.unshiftContainer('body', stmts);
+  path.unshiftContainer("body", stmts);
 }

 /*
@@ -65,21 +65,21 @@ export function addImportsToProgram(
 */
 function isNonNamespacedImport(
  importDeclPath: NodePath<t.ImportDeclaration>,
-  moduleName: string,
+  moduleName: string
 ): boolean {
  return (
-    importDeclPath.get('source').node.value === moduleName &&
+    importDeclPath.get("source").node.value === moduleName &&
    importDeclPath
-      .get('specifiers')
-      .every(specifier => specifier.isImportSpecifier()) &&
-    importDeclPath.node.importKind !== 'type' &&
-    importDeclPath.node.importKind !== 'typeof'
+      .get("specifiers")
+      .every((specifier) => specifier.isImportSpecifier()) &&
+    importDeclPath.node.importKind !== "type" &&
+    importDeclPath.node.importKind !== "typeof"
  );
 }

 function hasExistingNonNamespacedImportOfModule(
  program: NodePath<t.Program>,
-  moduleName: string,
+  moduleName: string
 ): boolean {
  let hasExistingImport = false;
  program.traverse({
@@ -100,7 +100,7 @@ function hasExistingNonNamespacedImportOfModule(
 function addMemoCacheFunctionSpecifierToExistingImport(
  program: NodePath<t.Program>,
  moduleName: string,
-  identifierName: string,
+  identifierName: string
 ): boolean {
  let didInsertUseMemoCache = false;
  program.traverse({
@@ -110,8 +110,8 @@ function addMemoCacheFunctionSpecifierToExistingImport(
        isNonNamespacedImport(importDeclPath, moduleName)
      ) {
        importDeclPath.pushContainer(
-          'specifiers',
-          t.importSpecifier(t.identifier(identifierName), t.identifier('c')),
+          "specifiers",
+          t.importSpecifier(t.identifier(identifierName), t.identifier("c"))
        );
        didInsertUseMemoCache = true;
      }
@@ -123,7 +123,7 @@ function addMemoCacheFunctionSpecifierToExistingImport(
 export function updateMemoCacheFunctionImport(
  program: NodePath<t.Program>,
  moduleName: string,
-  useMemoCacheIdentifier: string,
+  useMemoCacheIdentifier: string
 ): void {
  /*
   * If there isn't already an import of * as React, insert it so useMemoCache doesn't
@@ -131,25 +131,25 @@ export function updateMemoCacheFunctionImport(
   */
  const hasExistingImport = hasExistingNonNamespacedImportOfModule(
    program,
-    moduleName,
+    moduleName
  );

  if (hasExistingImport) {
    const didUpdateImport = addMemoCacheFunctionSpecifierToExistingImport(
      program,
      moduleName,
-      useMemoCacheIdentifier,
+      useMemoCacheIdentifier
    );
    if (!didUpdateImport) {
      throw new Error(
-        `Expected an ImportDeclaration of \`${moduleName}\` in order to update ImportSpecifiers with useMemoCache`,
+        `Expected an ImportDeclaration of \`${moduleName}\` in order to update ImportSpecifiers with useMemoCache`
      );
    }
  } else {
    addMemoCacheFunctionImportDeclaration(
      program,
      moduleName,
-      useMemoCacheIdentifier,
+      useMemoCacheIdentifier
    );
  }
 }
@@ -157,13 +157,13 @@ export function updateMemoCacheFunctionImport(
 function addMemoCacheFunctionImportDeclaration(
  program: NodePath<t.Program>,
  moduleName: string,
-  localName: string,
+  localName: string
 ): void {
  program.unshiftContainer(
-    'body',
+    "body",
    t.importDeclaration(
-      [t.importSpecifier(t.identifier(localName), t.identifier('c'))],
-      t.stringLiteral(moduleName),
-    ),
+      [t.importSpecifier(t.identifier(localName), t.identifier("c"))],
+      t.stringLiteral(moduleName)
+    )
  );
 }
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Options.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Options.ts
@@ -5,11 +5,11 @@
 * LICENSE file in the root directory of this source tree.
 */

-import * as t from '@babel/types';
-import {z} from 'zod';
-import {CompilerErrorDetailOptions} from '../CompilerError';
-import {ExternalFunction, PartialEnvironmentConfig} from '../HIR/Environment';
-import {hasOwnProperty} from '../Utils/utils';
+import * as t from "@babel/types";
+import { z } from "zod";
+import { CompilerErrorDetailOptions } from "../CompilerError";
+import { ExternalFunction, PartialEnvironmentConfig } from "../HIR/Environment";
+import { hasOwnProperty } from "../Utils/utils";

 const PanicThresholdOptionsSchema = z.enum([
  /*
@@ -18,15 +18,15 @@ const PanicThresholdOptionsSchema = z.enum([
   * If Forget is invoked through `BabelPluginReactCompiler`, this will at the least
   * skip Forget compilation for the rest of current file.
   */
-  'all_errors',
+  "all_errors",
  /*
   * Panic by throwing an exception only on critical or unrecognized errors.
   * For all other errors, skip the erroring function without inserting
   * a Forget-compiled version (i.e. same behavior as noEmit).
   */
-  'critical_errors',
+  "critical_errors",
  // Never panic by throwing an exception.
-  'none',
+  "none",
 ]);

 export type PanicThresholdOptions = z.infer<typeof PanicThresholdOptionsSchema>;
@@ -130,13 +130,11 @@ const CompilationModeSchema = z.enum([
   *     false positives, since compilation has a greater impact than linting.
   * This is the default mode
   */
-  'infer',
-  // Compile only components using Flow component syntax and hooks using hook syntax.
-  'syntax',
+  "infer",
  // Compile only functions which are explicitly annotated with "use forget"
-  'annotation',
+  "annotation",
  // Compile all top-level functions
-  'all',
+  "all",
 ]);

 export type CompilationMode = z.infer<typeof CompilationModeSchema>;
@@ -156,27 +154,24 @@ export type CompilationMode = z.infer<typeof CompilationModeSchema>;
 */
 export type LoggerEvent =
  | {
-      kind: 'CompileError';
+      kind: "CompileError";
      fnLoc: t.SourceLocation | null;
      detail: CompilerErrorDetailOptions;
    }
  | {
-      kind: 'CompileDiagnostic';
+      kind: "CompileDiagnostic";
      fnLoc: t.SourceLocation | null;
-      detail: Omit<Omit<CompilerErrorDetailOptions, 'severity'>, 'suggestions'>;
+      detail: Omit<Omit<CompilerErrorDetailOptions, "severity">, "suggestions">;
    }
  | {
-      kind: 'CompileSuccess';
+      kind: "CompileSuccess";
      fnLoc: t.SourceLocation | null;
      fnName: string | null;
      memoSlots: number;
      memoBlocks: number;
-      memoValues: number;
-      prunedMemoBlocks: number;
-      prunedMemoValues: number;
    }
  | {
-      kind: 'PipelineError';
+      kind: "PipelineError";
      fnLoc: t.SourceLocation | null;
      data: string;
    };
@@ -186,8 +181,8 @@ export type Logger = {
 };

 export const defaultOptions: PluginOptions = {
-  compilationMode: 'infer',
-  panicThreshold: 'none',
+  compilationMode: "infer",
+  panicThreshold: "none",
  environment: {},
  logger: null,
  gating: null,
@@ -196,19 +191,19 @@ export const defaultOptions: PluginOptions = {
  eslintSuppressionRules: null,
  flowSuppressions: false,
  ignoreUseNoForget: false,
-  sources: filename => {
-    return filename.indexOf('node_modules') === -1;
+  sources: (filename) => {
+    return filename.indexOf("node_modules") === -1;
  },
  enableReanimatedCheck: true,
 } as const;

 export function parsePluginOptions(obj: unknown): PluginOptions {
-  if (obj == null || typeof obj !== 'object') {
+  if (obj == null || typeof obj !== "object") {
    return defaultOptions;
  }
  const parsedOptions = Object.create(null);
  for (let [key, value] of Object.entries(obj)) {
-    if (typeof value === 'string') {
+    if (typeof value === "string") {
      // normalize string configs to be case insensitive
      value = value.toLowerCase();
    }
@@ -216,7 +211,7 @@ export function parsePluginOptions(obj: unknown): PluginOptions {
      parsedOptions[key] = value;
    }
  }
-  return {...defaultOptions, ...parsedOptions};
+  return { ...defaultOptions, ...parsedOptions };
 }

 function isCompilerFlag(s: string): s is keyof PluginOptions {
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
@@ -5,15 +5,14 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {NodePath} from '@babel/traverse';
-import * as t from '@babel/types';
-import prettyFormat from 'pretty-format';
-import {Logger} from '.';
+import { NodePath } from "@babel/traverse";
+import * as t from "@babel/types";
+import prettyFormat from "pretty-format";
+import { Logger } from ".";
 import {
  HIRFunction,
  ReactiveFunction,
  assertConsistentIdentifiers,
-  assertTerminalPredsExist,
  assertTerminalSuccessorsExist,
  assertValidBlockNesting,
  assertValidMutableRanges,
@@ -22,13 +21,13 @@ import {
  mergeConsecutiveBlocks,
  mergeOverlappingReactiveScopesHIR,
  pruneUnusedLabelsHIR,
-} from '../HIR';
+} from "../HIR";
 import {
  Environment,
  EnvironmentConfig,
  ReactFunctionType,
-} from '../HIR/Environment';
-import {findContextIdentifiers} from '../HIR/FindContextIdentifiers';
+} from "../HIR/Environment";
+import { findContextIdentifiers } from "../HIR/FindContextIdentifiers";
 import {
  analyseFunctions,
  dropManualMemoization,
@@ -36,13 +35,12 @@ import {
  inferReactivePlaces,
  inferReferenceEffects,
  inlineImmediatelyInvokedFunctionExpressions,
-} from '../Inference';
+} from "../Inference";
 import {
  constantPropagation,
  deadCodeElimination,
  pruneMaybeThrows,
-} from '../Optimization';
-import {instructionReordering} from '../Optimization/InstructionReordering';
+} from "../Optimization";
 import {
  CodegenFunction,
  alignObjectMethodScopes,
@@ -69,23 +67,20 @@ import {
  pruneUnusedLabels,
  pruneUnusedScopes,
  renameVariables,
-} from '../ReactiveScopes';
-import {alignMethodCallScopes} from '../ReactiveScopes/AlignMethodCallScopes';
-import {alignReactiveScopesToBlockScopesHIR} from '../ReactiveScopes/AlignReactiveScopesToBlockScopesHIR';
-import {flattenReactiveLoopsHIR} from '../ReactiveScopes/FlattenReactiveLoopsHIR';
-import {flattenScopesWithHooksOrUseHIR} from '../ReactiveScopes/FlattenScopesWithHooksOrUseHIR';
-import {pruneAlwaysInvalidatingScopes} from '../ReactiveScopes/PruneAlwaysInvalidatingScopes';
-import pruneInitializationDependencies from '../ReactiveScopes/PruneInitializationDependencies';
-import {stabilizeBlockIds} from '../ReactiveScopes/StabilizeBlockIds';
-import {eliminateRedundantPhi, enterSSA, leaveSSA} from '../SSA';
-import {inferTypes} from '../TypeInference';
+} from "../ReactiveScopes";
+import { alignMethodCallScopes } from "../ReactiveScopes/AlignMethodCallScopes";
+import { alignReactiveScopesToBlockScopesHIR } from "../ReactiveScopes/AlignReactiveScopesToBlockScopesHIR";
+import { pruneAlwaysInvalidatingScopes } from "../ReactiveScopes/PruneAlwaysInvalidatingScopes";
+import { stabilizeBlockIds } from "../ReactiveScopes/StabilizeBlockIds";
+import { eliminateRedundantPhi, enterSSA, leaveSSA } from "../SSA";
+import { inferTypes } from "../TypeInference";
 import {
  logCodegenFunction,
  logDebug,
  logHIRFunction,
  logReactiveFunction,
-} from '../Utils/logger';
-import {assertExhaustive} from '../Utils/utils';
+} from "../Utils/logger";
+import { assertExhaustive } from "../Utils/utils";
 import {
  validateContextVariableLValues,
  validateHooksUsage,
@@ -95,15 +90,14 @@ import {
  validateNoSetStateInRender,
  validatePreservedManualMemoization,
  validateUseMemo,
-} from '../Validation';
-import {validateLocalsNotReassignedAfterRender} from '../Validation/ValidateLocalsNotReassignedAfterRender';
-import {outlineFunctions} from '../Optimization/OutlineFunctions';
+} from "../Validation";
+import pruneInitializationDependencies from "../ReactiveScopes/PruneInitializationDependencies";

 export type CompilerPipelineValue =
-  | {kind: 'ast'; name: string; value: CodegenFunction}
-  | {kind: 'hir'; name: string; value: HIRFunction}
-  | {kind: 'reactive'; name: string; value: ReactiveFunction}
-  | {kind: 'debug'; name: string; value: string};
+  | { kind: "ast"; name: string; value: CodegenFunction }
+  | { kind: "hir"; name: string; value: HIRFunction }
+  | { kind: "reactive"; name: string; value: ReactiveFunction }
+  | { kind: "debug"; name: string; value: string };

 export function* run(
  func: NodePath<
@@ -114,22 +108,21 @@ export function* run(
  useMemoCacheIdentifier: string,
  logger: Logger | null,
  filename: string | null,
-  code: string | null,
+  code: string | null
 ): Generator<CompilerPipelineValue, CodegenFunction> {
  const contextIdentifiers = findContextIdentifiers(func);
  const env = new Environment(
-    func.scope,
    fnType,
    config,
    contextIdentifiers,
    logger,
    filename,
    code,
-    useMemoCacheIdentifier,
+    useMemoCacheIdentifier
  );
  yield {
-    kind: 'debug',
-    name: 'EnvironmentConfig',
+    kind: "debug",
+    name: "EnvironmentConfig",
    value: prettyFormat(env.config),
  };
  const ast = yield* runWithEnvironment(func, env);
@@ -144,13 +137,13 @@ function* runWithEnvironment(
  func: NodePath<
    t.FunctionDeclaration | t.ArrowFunctionExpression | t.FunctionExpression
  >,
-  env: Environment,
+  env: Environment
 ): Generator<CompilerPipelineValue, CodegenFunction> {
  const hir = lower(func, env).unwrap();
-  yield log({kind: 'hir', name: 'HIR', value: hir});
+  yield log({ kind: "hir", name: "HIR", value: hir });

  pruneMaybeThrows(hir);
-  yield log({kind: 'hir', name: 'PruneMaybeThrows', value: hir});
+  yield log({ kind: "hir", name: "PruneMaybeThrows", value: hir });

  validateContextVariableLValues(hir);
  validateUseMemo(hir);
@@ -161,35 +154,35 @@ function* runWithEnvironment(
    !env.config.enableChangeDetectionForDebugging
  ) {
    dropManualMemoization(hir);
-    yield log({kind: 'hir', name: 'DropManualMemoization', value: hir});
+    yield log({ kind: "hir", name: "DropManualMemoization", value: hir });
  }

  inlineImmediatelyInvokedFunctionExpressions(hir);
  yield log({
-    kind: 'hir',
-    name: 'InlineImmediatelyInvokedFunctionExpressions',
+    kind: "hir",
+    name: "InlineImmediatelyInvokedFunctionExpressions",
    value: hir,
  });

  mergeConsecutiveBlocks(hir);
-  yield log({kind: 'hir', name: 'MergeConsecutiveBlocks', value: hir});
+  yield log({ kind: "hir", name: "MergeConsecutiveBlocks", value: hir });

  assertConsistentIdentifiers(hir);
  assertTerminalSuccessorsExist(hir);

  enterSSA(hir);
-  yield log({kind: 'hir', name: 'SSA', value: hir});
+  yield log({ kind: "hir", name: "SSA", value: hir });

  eliminateRedundantPhi(hir);
-  yield log({kind: 'hir', name: 'EliminateRedundantPhi', value: hir});
+  yield log({ kind: "hir", name: "EliminateRedundantPhi", value: hir });

  assertConsistentIdentifiers(hir);

  constantPropagation(hir);
-  yield log({kind: 'hir', name: 'ConstantPropagation', value: hir});
+  yield log({ kind: "hir", name: "ConstantPropagation", value: hir });

  inferTypes(hir);
-  yield log({kind: 'hir', name: 'InferTypes', value: hir});
+  yield log({ kind: "hir", name: "InferTypes", value: hir });

  if (env.config.validateHooksUsage) {
    validateHooksUsage(hir);
@@ -200,27 +193,20 @@ function* runWithEnvironment(
  }

  analyseFunctions(hir);
-  yield log({kind: 'hir', name: 'AnalyseFunctions', value: hir});
+  yield log({ kind: "hir", name: "AnalyseFunctions", value: hir });

  inferReferenceEffects(hir);
-  yield log({kind: 'hir', name: 'InferReferenceEffects', value: hir});
-
-  validateLocalsNotReassignedAfterRender(hir);
+  yield log({ kind: "hir", name: "InferReferenceEffects", value: hir });

  // Note: Has to come after infer reference effects because "dead" code may still affect inference
  deadCodeElimination(hir);
-  yield log({kind: 'hir', name: 'DeadCodeElimination', value: hir});
-
-  if (env.config.enableInstructionReordering) {
-    instructionReordering(hir);
-    yield log({kind: 'hir', name: 'InstructionReordering', value: hir});
-  }
+  yield log({ kind: "hir", name: "DeadCodeElimination", value: hir });

  pruneMaybeThrows(hir);
-  yield log({kind: 'hir', name: 'PruneMaybeThrows', value: hir});
+  yield log({ kind: "hir", name: "PruneMaybeThrows", value: hir });

  inferMutableRanges(hir);
-  yield log({kind: 'hir', name: 'InferMutableRanges', value: hir});
+  yield log({ kind: "hir", name: "InferMutableRanges", value: hir });

  if (env.config.assertValidMutableRanges) {
    assertValidMutableRanges(hir);
@@ -235,93 +221,72 @@ function* runWithEnvironment(
  }

  inferReactivePlaces(hir);
-  yield log({kind: 'hir', name: 'InferReactivePlaces', value: hir});
+  yield log({ kind: "hir", name: "InferReactivePlaces", value: hir });

  leaveSSA(hir);
-  yield log({kind: 'hir', name: 'LeaveSSA', value: hir});
+  yield log({ kind: "hir", name: "LeaveSSA", value: hir });

  inferReactiveScopeVariables(hir);
-  yield log({kind: 'hir', name: 'InferReactiveScopeVariables', value: hir});
-
-  if (env.config.enableFunctionOutlining) {
-    outlineFunctions(hir);
-    yield log({kind: 'hir', name: 'OutlineFunctions', value: hir});
-  }
+  yield log({ kind: "hir", name: "InferReactiveScopeVariables", value: hir });

  alignMethodCallScopes(hir);
  yield log({
-    kind: 'hir',
-    name: 'AlignMethodCallScopes',
+    kind: "hir",
+    name: "AlignMethodCallScopes",
    value: hir,
  });

  alignObjectMethodScopes(hir);
  yield log({
-    kind: 'hir',
-    name: 'AlignObjectMethodScopes',
+    kind: "hir",
+    name: "AlignObjectMethodScopes",
    value: hir,
  });

-  const fbtOperands = memoizeFbtOperandsInSameScope(hir);
+  memoizeFbtOperandsInSameScope(hir);
  yield log({
-    kind: 'hir',
-    name: 'MemoizeFbtAndMacroOperandsInSameScope',
+    kind: "hir",
+    name: "MemoizeFbtOperandsInSameScope",
    value: hir,
  });

  if (env.config.enableReactiveScopesInHIR) {
    pruneUnusedLabelsHIR(hir);
    yield log({
-      kind: 'hir',
-      name: 'PruneUnusedLabelsHIR',
+      kind: "hir",
+      name: "PruneUnusedLabelsHIR",
      value: hir,
    });

    alignReactiveScopesToBlockScopesHIR(hir);
    yield log({
-      kind: 'hir',
-      name: 'AlignReactiveScopesToBlockScopesHIR',
+      kind: "hir",
+      name: "AlignReactiveScopesToBlockScopesHIR",
      value: hir,
    });

    mergeOverlappingReactiveScopesHIR(hir);
    yield log({
-      kind: 'hir',
-      name: 'MergeOverlappingReactiveScopesHIR',
+      kind: "hir",
+      name: "MergeOverlappingReactiveScopesHIR",
      value: hir,
    });
    assertValidBlockNesting(hir);

    buildReactiveScopeTerminalsHIR(hir);
    yield log({
-      kind: 'hir',
-      name: 'BuildReactiveScopeTerminalsHIR',
+      kind: "hir",
+      name: "BuildReactiveScopeTerminalsHIR",
      value: hir,
    });

    assertValidBlockNesting(hir);
-
-    flattenReactiveLoopsHIR(hir);
-    yield log({
-      kind: 'hir',
-      name: 'FlattenReactiveLoopsHIR',
-      value: hir,
-    });
-
-    flattenScopesWithHooksOrUseHIR(hir);
-    yield log({
-      kind: 'hir',
-      name: 'FlattenScopesWithHooksOrUseHIR',
-      value: hir,
-    });
-    assertTerminalSuccessorsExist(hir);
-    assertTerminalPredsExist(hir);
  }

  const reactiveFunction = buildReactiveFunction(hir);
  yield log({
-    kind: 'reactive',
-    name: 'BuildReactiveFunction',
+    kind: "reactive",
+    name: "BuildReactiveFunction",
    value: reactiveFunction,
  });

@@ -329,147 +294,147 @@ function* runWithEnvironment(

  pruneUnusedLabels(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PruneUnusedLabels',
+    kind: "reactive",
+    name: "PruneUnusedLabels",
    value: reactiveFunction,
  });

  if (!env.config.enableReactiveScopesInHIR) {
    alignReactiveScopesToBlockScopes(reactiveFunction);
    yield log({
-      kind: 'reactive',
-      name: 'AlignReactiveScopesToBlockScopes',
+      kind: "reactive",
+      name: "AlignReactiveScopesToBlockScopes",
      value: reactiveFunction,
    });

    mergeOverlappingReactiveScopes(reactiveFunction);
    yield log({
-      kind: 'reactive',
-      name: 'MergeOverlappingReactiveScopes',
+      kind: "reactive",
+      name: "MergeOverlappingReactiveScopes",
      value: reactiveFunction,
    });

    buildReactiveBlocks(reactiveFunction);
    yield log({
-      kind: 'reactive',
-      name: 'BuildReactiveBlocks',
-      value: reactiveFunction,
-    });
-
-    flattenReactiveLoops(reactiveFunction);
-    yield log({
-      kind: 'reactive',
-      name: 'FlattenReactiveLoops',
-      value: reactiveFunction,
-    });
-
-    flattenScopesWithHooksOrUse(reactiveFunction);
-    yield log({
-      kind: 'reactive',
-      name: 'FlattenScopesWithHooks',
+      kind: "reactive",
+      name: "BuildReactiveBlocks",
      value: reactiveFunction,
    });
  }

+  flattenReactiveLoops(reactiveFunction);
+  yield log({
+    kind: "reactive",
+    name: "FlattenReactiveLoops",
+    value: reactiveFunction,
+  });
+
  assertScopeInstructionsWithinScopes(reactiveFunction);

+  flattenScopesWithHooksOrUse(reactiveFunction);
+  yield log({
+    kind: "reactive",
+    name: "FlattenScopesWithHooks",
+    value: reactiveFunction,
+  });
+
  propagateScopeDependencies(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PropagateScopeDependencies',
+    kind: "reactive",
+    name: "PropagateScopeDependencies",
    value: reactiveFunction,
  });

  pruneNonEscapingScopes(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PruneNonEscapingScopes',
+    kind: "reactive",
+    name: "PruneNonEscapingScopes",
    value: reactiveFunction,
  });

  pruneNonReactiveDependencies(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PruneNonReactiveDependencies',
+    kind: "reactive",
+    name: "PruneNonReactiveDependencies",
    value: reactiveFunction,
  });

  pruneUnusedScopes(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PruneUnusedScopes',
+    kind: "reactive",
+    name: "PruneUnusedScopes",
    value: reactiveFunction,
  });

  mergeReactiveScopesThatInvalidateTogether(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'MergeReactiveScopesThatInvalidateTogether',
+    kind: "reactive",
+    name: "MergeReactiveScopesThatInvalidateTogether",
    value: reactiveFunction,
  });

  pruneAlwaysInvalidatingScopes(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PruneAlwaysInvalidatingScopes',
+    kind: "reactive",
+    name: "PruneAlwaysInvalidatingScopes",
    value: reactiveFunction,
  });

  if (env.config.enableChangeDetectionForDebugging != null) {
    pruneInitializationDependencies(reactiveFunction);
    yield log({
-      kind: 'reactive',
-      name: 'PruneInitializationDependencies',
+      kind: "reactive",
+      name: "PruneInitializationDependencies",
      value: reactiveFunction,
    });
  }

  propagateEarlyReturns(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PropagateEarlyReturns',
+    kind: "reactive",
+    name: "PropagateEarlyReturns",
    value: reactiveFunction,
  });

  promoteUsedTemporaries(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PromoteUsedTemporaries',
+    kind: "reactive",
+    name: "PromoteUsedTemporaries",
    value: reactiveFunction,
  });

  pruneUnusedLValues(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PruneUnusedLValues',
+    kind: "reactive",
+    name: "PruneUnusedLValues",
    value: reactiveFunction,
  });

  extractScopeDeclarationsFromDestructuring(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'ExtractScopeDeclarationsFromDestructuring',
+    kind: "reactive",
+    name: "ExtractScopeDeclarationsFromDestructuring",
    value: reactiveFunction,
  });

  stabilizeBlockIds(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'StabilizeBlockIds',
+    kind: "reactive",
+    name: "StabilizeBlockIds",
    value: reactiveFunction,
  });

  const uniqueIdentifiers = renameVariables(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'RenameVariables',
+    kind: "reactive",
+    name: "RenameVariables",
    value: reactiveFunction,
  });

  pruneHoistedContexts(reactiveFunction);
  yield log({
-    kind: 'reactive',
-    name: 'PruneHoistedContexts',
+    kind: "reactive",
+    name: "PruneHoistedContexts",
    value: reactiveFunction,
  });

@@ -484,14 +449,8 @@ function* runWithEnvironment(
    validatePreservedManualMemoization(reactiveFunction);
  }

-  const ast = codegenFunction(reactiveFunction, {
-    uniqueIdentifiers,
-    fbtOperands,
-  }).unwrap();
-  yield log({kind: 'ast', name: 'Codegen', value: ast});
-  for (const outlined of ast.outlined) {
-    yield log({kind: 'ast', name: 'Codegen (outlined)', value: outlined.fn});
-  }
+  const ast = codegenFunction(reactiveFunction, uniqueIdentifiers).unwrap();
+  yield log({ kind: "ast", name: "Codegen", value: ast });

  /**
   * This flag should be only set for unit / fixture tests to check
@@ -499,7 +458,7 @@ function* runWithEnvironment(
   * thrown by babel functions or other unexpected exceptions).
   */
  if (env.config.throwUnknownException__testonly) {
-    throw new Error('unexpected error');
+    throw new Error("unexpected error");
  }

  return ast;
@@ -514,7 +473,7 @@ export function compileFn(
  useMemoCacheIdentifier: string,
  logger: Logger | null,
  filename: string | null,
-  code: string | null,
+  code: string | null
 ): CodegenFunction {
  let generator = run(
    func,
@@ -523,7 +482,7 @@ export function compileFn(
    useMemoCacheIdentifier,
    logger,
    filename,
-    code,
+    code
  );
  while (true) {
    const next = generator.next();
@@ -535,24 +494,24 @@ export function compileFn(

 export function log(value: CompilerPipelineValue): CompilerPipelineValue {
  switch (value.kind) {
-    case 'ast': {
+    case "ast": {
      logCodegenFunction(value.name, value.value);
      break;
    }
-    case 'hir': {
+    case "hir": {
      logHIRFunction(value.name, value.value);
      break;
    }
-    case 'reactive': {
+    case "reactive": {
      logReactiveFunction(value.name, value.value);
      break;
    }
-    case 'debug': {
+    case "debug": {
      logDebug(value.name, value.value);
      break;
    }
    default: {
-      assertExhaustive(value, 'Unexpected compilation kind');
+      assertExhaustive(value, "Unexpected compilation kind");
    }
  }
  return value;
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Program.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Program.ts
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Reanimated.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Reanimated.ts
@@ -1,13 +1,13 @@
-import type * as BabelCore from '@babel/core';
-import {hasOwnProperty} from '../Utils/utils';
-import {PluginOptions} from './Options';
+import type * as BabelCore from "@babel/core";
+import { hasOwnProperty } from "../Utils/utils";
+import { PluginOptions } from "./Options";

 function hasModule(name: string): boolean {
  try {
    return !!require.resolve(name);
  } catch (error: any) {
    if (
-      error.code === 'MODULE_NOT_FOUND' &&
+      error.code === "MODULE_NOT_FOUND" &&
      error.message.indexOf(name) !== -1
    ) {
      return false;
@@ -24,22 +24,22 @@ function hasModule(name: string): boolean {
 * See https://github.com/expo/expo/blob/e4b8d86442482c7316365a6b7ec1141eec73409d/packages/babel-preset-expo/src/index.ts#L300-L301
 */
 export function pipelineUsesReanimatedPlugin(
-  plugins: Array<BabelCore.PluginItem> | null | undefined,
+  plugins: Array<BabelCore.PluginItem> | null | undefined
 ): boolean {
  if (Array.isArray(plugins)) {
    for (const plugin of plugins) {
-      if (hasOwnProperty(plugin, 'key')) {
+      if (hasOwnProperty(plugin, "key")) {
        const key = (plugin as any).key; // already checked
        if (
-          typeof key === 'string' &&
-          key.indexOf('react-native-reanimated') !== -1
+          typeof key === "string" &&
+          key.indexOf("react-native-reanimated") !== -1
        ) {
          return true;
        }
      }
    }
  }
-  return hasModule('react-native-reanimated');
+  return hasModule("react-native-reanimated");
 }

 export function injectReanimatedFlag(options: PluginOptions): PluginOptions {
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Suppression.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Suppression.ts
@@ -5,15 +5,15 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {NodePath} from '@babel/core';
-import * as t from '@babel/types';
+import { NodePath } from "@babel/core";
+import * as t from "@babel/types";
 import {
  CompilerError,
  CompilerErrorDetail,
  CompilerSuggestionOperation,
  ErrorSeverity,
-} from '../CompilerError';
-import {assertExhaustive} from '../Utils/utils';
+} from "../CompilerError";
+import { assertExhaustive } from "../Utils/utils";

 /**
 * Captures the start and end range of a pair of eslint-disable ... eslint-enable comments. In the
@@ -29,7 +29,7 @@ export type SuppressionRange = {
  source: SuppressionSource;
 };

-type SuppressionSource = 'Eslint' | 'Flow';
+type SuppressionSource = "Eslint" | "Flow";

 /**
 * An suppression affects a function if:
@@ -38,7 +38,7 @@ type SuppressionSource = 'Eslint' | 'Flow';
 */
 export function filterSuppressionsThatAffectFunction(
  suppressionRanges: Array<SuppressionRange>,
-  fn: NodePath<t.Function>,
+  fn: NodePath<t.Function>
 ): Array<SuppressionRange> {
  const suppressionsInScope: Array<SuppressionRange> = [];
  const fnNode = fn.node;
@@ -78,21 +78,21 @@ export function filterSuppressionsThatAffectFunction(
 export function findProgramSuppressions(
  programComments: Array<t.Comment>,
  ruleNames: Array<string>,
-  flowSuppressions: boolean,
+  flowSuppressions: boolean
 ): Array<SuppressionRange> {
  const suppressionRanges: Array<SuppressionRange> = [];
  let disableComment: t.Comment | null = null;
  let enableComment: t.Comment | null = null;
  let source: SuppressionSource | null = null;

-  const rulePattern = `(${ruleNames.join('|')})`;
+  const rulePattern = `(${ruleNames.join("|")})`;
  const disableNextLinePattern = new RegExp(
-    `eslint-disable-next-line ${rulePattern}`,
+    `eslint-disable-next-line ${rulePattern}`
  );
  const disablePattern = new RegExp(`eslint-disable ${rulePattern}`);
  const enablePattern = new RegExp(`eslint-enable ${rulePattern}`);
  const flowSuppressionPattern = new RegExp(
-    '\\$(FlowFixMe\\w*|FlowExpectedError|FlowIssue)\\[react\\-rule',
+    "\\$(FlowFixMe\\w*|FlowExpectedError|FlowIssue)\\[react\\-rule"
  );

  for (const comment of programComments) {
@@ -110,7 +110,7 @@ export function findProgramSuppressions(
    ) {
      disableComment = comment;
      enableComment = comment;
-      source = 'Eslint';
+      source = "Eslint";
    }

    if (
@@ -120,15 +120,15 @@ export function findProgramSuppressions(
    ) {
      disableComment = comment;
      enableComment = comment;
-      source = 'Flow';
+      source = "Flow";
    }

    if (disablePattern.test(comment.value)) {
      disableComment = comment;
-      source = 'Eslint';
+      source = "Eslint";
    }

-    if (enablePattern.test(comment.value) && source === 'Eslint') {
+    if (enablePattern.test(comment.value) && source === "Eslint") {
      enableComment = comment;
    }

@@ -147,7 +147,7 @@ export function findProgramSuppressions(
 }

 export function suppressionsToCompilerError(
-  suppressionRanges: Array<SuppressionRange>,
+  suppressionRanges: Array<SuppressionRange>
 ): CompilerError | null {
  if (suppressionRanges.length === 0) {
    return null;
@@ -162,21 +162,21 @@ export function suppressionsToCompilerError(
    }
    let reason, suggestion;
    switch (suppressionRange.source) {
-      case 'Eslint':
+      case "Eslint":
        reason =
-          'React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled';
+          "React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled";
        suggestion =
-          'Remove the ESLint suppression and address the React error';
+          "Remove the ESLint suppression and address the React error";
        break;
-      case 'Flow':
+      case "Flow":
        reason =
-          'React Compiler has skipped optimizing this component because one or more React rule violations were reported by Flow';
-        suggestion = 'Remove the Flow suppression and address the React error';
+          "React Compiler has skipped optimizing this component because one or more React rule violations were reported by Flow";
+        suggestion = "Remove the Flow suppression and address the React error";
        break;
      default:
        assertExhaustive(
          suppressionRange.source,
-          'Unhandled suppression source',
+          "Unhandled suppression source"
        );
    }
    error.pushErrorDetail(
@@ -195,7 +195,7 @@ export function suppressionsToCompilerError(
            op: CompilerSuggestionOperation.Remove,
          },
        ],
-      }),
+      })
    );
  }
  return error;
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/index.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/index.ts
@@ -5,9 +5,9 @@
 * LICENSE file in the root directory of this source tree.
 */

-export * from './Gating';
-export * from './Imports';
-export * from './Options';
-export * from './Pipeline';
-export * from './Program';
-export * from './Suppression';
+export * from "./Gating";
+export * from "./Imports";
+export * from "./Options";
+export * from "./Pipeline";
+export * from "./Program";
+export * from "./Suppression";
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertConsistentIdentifiers.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertConsistentIdentifiers.ts
@@ -5,20 +5,20 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {CompilerError} from '../CompilerError';
+import { CompilerError } from "../CompilerError";
 import {
  GeneratedSource,
  HIRFunction,
  Identifier,
  IdentifierId,
  SourceLocation,
-} from './HIR';
-import {printPlace} from './PrintHIR';
+} from "./HIR";
+import { printPlace } from "./PrintHIR";
 import {
  eachInstructionLValue,
  eachInstructionValueOperand,
  eachTerminalOperand,
-} from './visitors';
+} from "./visitors";

 /*
 * Validation pass to check that there is a 1:1 mapping between Identifier objects and IdentifierIds,
@@ -44,7 +44,7 @@ export function assertConsistentIdentifiers(fn: HIRFunction): void {
      CompilerError.invariant(!assignments.has(instr.lvalue.identifier.id), {
        reason: `Expected lvalues to be assigned exactly once`,
        description: `Found duplicate assignment of '${printPlace(
-          instr.lvalue,
+          instr.lvalue
        )}'`,
        loc: instr.lvalue.loc,
        suggestions: null,
@@ -68,7 +68,7 @@ type Identifiers = Map<IdentifierId, Identifier>;
 function validate(
  identifiers: Identifiers,
  identifier: Identifier,
-  loc: SourceLocation | null = null,
+  loc: SourceLocation | null = null
 ): void {
  const previous = identifiers.get(identifier.id);
  if (previous === undefined) {
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertTerminalBlocksExist.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertTerminalBlocksExist.ts
@@ -1,48 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {CompilerError} from '../CompilerError';
-import {GeneratedSource, HIRFunction} from './HIR';
-import {printTerminal} from './PrintHIR';
-import {eachTerminalSuccessor, mapTerminalSuccessors} from './visitors';
-
-export function assertTerminalSuccessorsExist(fn: HIRFunction): void {
-  for (const [, block] of fn.body.blocks) {
-    mapTerminalSuccessors(block.terminal, successor => {
-      CompilerError.invariant(fn.body.blocks.has(successor), {
-        reason: `Terminal successor references unknown block`,
-        description: `Block bb${successor} does not exist for terminal '${printTerminal(
-          block.terminal,
-        )}'`,
-        loc: (block.terminal as any).loc ?? GeneratedSource,
-        suggestions: null,
-      });
-      return successor;
-    });
-  }
-}
-
-export function assertTerminalPredsExist(fn: HIRFunction): void {
-  for (const [, block] of fn.body.blocks) {
-    for (const pred of block.preds) {
-      const predBlock = fn.body.blocks.get(pred);
-      CompilerError.invariant(predBlock != null, {
-        reason: 'Expected predecessor block to exist',
-        description: `Block ${block.id} references non-existent ${pred}`,
-        loc: GeneratedSource,
-      });
-      CompilerError.invariant(
-        [...eachTerminalSuccessor(predBlock.terminal)].includes(block.id),
-        {
-          reason: 'Terminal successor does not reference correct predecessor',
-          description: `Block bb${block.id} has bb${predBlock.id} as a predecessor, but bb${predBlock.id}'s successors do not include bb${block.id}`,
-          loc: GeneratedSource,
-        },
-      );
-    }
-  }
-}
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertTerminalSuccessorsExist.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertTerminalSuccessorsExist.ts
@@ -0,0 +1,27 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import { CompilerError } from "../CompilerError";
+import { GeneratedSource, HIRFunction } from "./HIR";
+import { printTerminal } from "./PrintHIR";
+import { mapTerminalSuccessors } from "./visitors";
+
+export function assertTerminalSuccessorsExist(fn: HIRFunction): void {
+  for (const [, block] of fn.body.blocks) {
+    mapTerminalSuccessors(block.terminal, (successor) => {
+      CompilerError.invariant(fn.body.blocks.has(successor), {
+        reason: `Terminal successor references unknown block`,
+        description: `Block bb${successor} does not exist for terminal '${printTerminal(
+          block.terminal
+        )}'`,
+        loc: (block.terminal as any).loc ?? GeneratedSource,
+        suggestions: null,
+      });
+      return successor;
+    });
+  }
+}
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertValidBlockNesting.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertValidBlockNesting.ts
@@ -1,4 +1,4 @@
-import {CompilerError} from '..';
+import { CompilerError } from "..";
 import {
  BlockId,
  GeneratedSource,
@@ -7,13 +7,13 @@ import {
  Place,
  ReactiveScope,
  ScopeId,
-} from './HIR';
+} from "./HIR";
 import {
  eachInstructionLValue,
  eachInstructionOperand,
  eachTerminalOperand,
  terminalFallthrough,
-} from './visitors';
+} from "./visitors";

 /**
 * This pass asserts that program blocks and scopes properly form a tree hierarchy
@@ -41,11 +41,11 @@ import {
 */
 type Block =
  | ({
-      kind: 'ProgramBlockSubtree';
+      kind: "ProgramBlockSubtree";
      id: BlockId;
    } & MutableRange)
  | ({
-      kind: 'Scope';
+      kind: "Scope";
      id: ScopeId;
    } & MutableRange);

@@ -96,7 +96,7 @@ export function getScopes(fn: HIRFunction): Set<ReactiveScope> {
 */
 export function rangePreOrderComparator(
  a: MutableRange,
-  b: MutableRange,
+  b: MutableRange
 ): number {
  const startDiff = a.start - b.start;
  if (startDiff !== 0) return startDiff;
@@ -108,7 +108,7 @@ export function recursivelyTraverseItems<T, TContext>(
  getRange: (val: T) => MutableRange,
  context: TContext,
  enter: (val: T, context: TContext) => void,
-  exit: (val: T, context: TContext) => void,
+  exit: (val: T, context: TContext) => void
 ): void {
  items.sort((a, b) => rangePreOrderComparator(getRange(a), getRange(b)));
  let activeItems: Array<T> = [];
@@ -122,7 +122,7 @@ export function recursivelyTraverseItems<T, TContext>(
      const disjoint = currRange.start >= maybeParentRange.end;
      const nested = currRange.end <= maybeParentRange.end;
      CompilerError.invariant(disjoint || nested, {
-        reason: 'Invalid nesting in program blocks or scopes',
+        reason: "Invalid nesting in program blocks or scopes",
        description: `Items overlap but are not nested: ${maybeParentRange.start}:${maybeParentRange.end}(${currRange.start}:${currRange.end})`,
        loc: GeneratedSource,
      });
@@ -148,8 +148,8 @@ const no_op: () => void = () => {};
 export function assertValidBlockNesting(fn: HIRFunction): void {
  const scopes = getScopes(fn);

-  const blocks: Array<Block> = [...scopes].map(scope => ({
-    kind: 'Scope',
+  const blocks: Array<Block> = [...scopes].map((scope) => ({
+    kind: "Scope",
    id: scope.id,
    ...scope.range,
  })) as Array<Block>;
@@ -159,7 +159,7 @@ export function assertValidBlockNesting(fn: HIRFunction): void {
      const fallthrough = fn.body.blocks.get(fallthroughId)!;
      const end = fallthrough.instructions[0]?.id ?? fallthrough.terminal.id;
      blocks.push({
-        kind: 'ProgramBlockSubtree',
+        kind: "ProgramBlockSubtree",
        id: block.id,
        start: block.terminal.id,
        end,
@@ -167,5 +167,5 @@ export function assertValidBlockNesting(fn: HIRFunction): void {
    }
  }

-  recursivelyTraverseItems(blocks, block => block, null, no_op, no_op);
+  recursivelyTraverseItems(blocks, (block) => block, null, no_op, no_op);
 }
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertValidMutableRanges.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/AssertValidMutableRanges.ts
@@ -5,13 +5,13 @@
 * LICENSE file in the root directory of this source tree.
 */

-import invariant from 'invariant';
-import {HIRFunction, Identifier, MutableRange} from './HIR';
+import invariant from "invariant";
+import { HIRFunction, Identifier, MutableRange } from "./HIR";
 import {
  eachInstructionLValue,
  eachInstructionOperand,
  eachTerminalOperand,
-} from './visitors';
+} from "./visitors";

 /*
 * Checks that all mutable ranges in the function are well-formed, with
@@ -49,8 +49,8 @@ function validateMutableRange(mutableRange: MutableRange): void {
  invariant(
    (mutableRange.start === 0 && mutableRange.end === 0) ||
      mutableRange.end > mutableRange.start,
-    'Identifier scope mutableRange was invalid: [%s:%s]',
+    "Identifier scope mutableRange was invalid: [%s:%s]",
    mutableRange.start,
-    mutableRange.end,
+    mutableRange.end
  );
 }
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildReactiveScopeTerminalsHIR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildReactiveScopeTerminalsHIR.ts
@@ -1,6 +1,6 @@
-import {CompilerError} from '../CompilerError';
-import {getScopes, recursivelyTraverseItems} from './AssertValidBlockNesting';
-import {Environment} from './Environment';
+import { CompilerError } from "../CompilerError";
+import { getScopes, recursivelyTraverseItems } from "./AssertValidBlockNesting";
+import { Environment } from "./Environment";
 import {
  BasicBlock,
  BlockId,
@@ -12,12 +12,7 @@ import {
  ReactiveScope,
  ReactiveScopeTerminal,
  ScopeId,
-} from './HIR';
-import {
-  markInstructionIds,
-  markPredecessors,
-  reversePostorderBlocks,
-} from './HIRBuilder';
+} from "./HIR";

 /**
 * This pass assumes that all program blocks are properly nested with respect to fallthroughs
@@ -77,14 +72,14 @@ export function buildReactiveScopeTerminalsHIR(fn: HIRFunction): void {
  const queuedRewrites: Array<TerminalRewriteInfo> = [];
  recursivelyTraverseItems(
    [...getScopes(fn)],
-    scope => scope.range,
+    (scope) => scope.range,
    {
      fallthroughs: new Map(),
      rewrites: queuedRewrites,
      env: fn.env,
    },
    pushStartScopeTerminal,
-    pushEndScopeTerminal,
+    pushEndScopeTerminal
  );

  /**
@@ -147,9 +142,16 @@ export function buildReactiveScopeTerminalsHIR(fn: HIRFunction): void {

  /**
   * Step 3:
-   * Repoint phis when they refer to a rewritten block.
+   * Repoint preds and phis when they refer to a rewritten block.
   */
  for (const [, block] of originalBlocks) {
+    for (const pred of block.preds) {
+      const newId = rewrittenFinalBlocks.get(pred);
+      if (newId != null) {
+        block.preds.delete(pred);
+        block.preds.add(newId);
+      }
+    }
    for (const phi of block.phis) {
      for (const [originalId, value] of phi.operands) {
        const newId = rewrittenFinalBlocks.get(originalId);
@@ -160,48 +162,18 @@ export function buildReactiveScopeTerminalsHIR(fn: HIRFunction): void {
      }
    }
  }
-
-  /**
-   * Step 4:
-   * Fixup the HIR to restore RPO, ensure correct predecessors, and
-   * renumber instructions. Note that the renumbering instructions
-   * invalidates scope and identifier ranges, so we fix them in the
-   * next step.
-   */
-  reversePostorderBlocks(fn.body);
-  markPredecessors(fn.body);
-  markInstructionIds(fn.body);
-
-  /**
-   * Step 5:
-   * Fix scope and identifier ranges to account for renumbered instructions
-   */
-  for (const [, block] of fn.body.blocks) {
-    const terminal = block.terminal;
-    if (terminal.kind === 'scope' || terminal.kind === 'pruned-scope') {
-      /*
-       * Scope ranges should always align to start at the 'scope' terminal
-       * and end at the first instruction of the fallthrough block
-       */
-      const fallthroughBlock = fn.body.blocks.get(terminal.fallthrough)!;
-      const firstId =
-        fallthroughBlock.instructions[0]?.id ?? fallthroughBlock.terminal.id;
-      terminal.scope.range.start = terminal.id;
-      terminal.scope.range.end = firstId;
-    }
-  }
 }

 type TerminalRewriteInfo =
  | {
-      kind: 'StartScope';
+      kind: "StartScope";
      blockId: BlockId;
      fallthroughId: BlockId;
      instrId: InstructionId;
      scope: ReactiveScope;
    }
  | {
-      kind: 'EndScope';
+      kind: "EndScope";
      instrId: InstructionId;
      fallthroughId: BlockId;
    };
@@ -218,12 +190,12 @@ type ScopeTraversalContext = {

 function pushStartScopeTerminal(
  scope: ReactiveScope,
-  context: ScopeTraversalContext,
+  context: ScopeTraversalContext
 ): void {
  const blockId = context.env.nextBlockId;
  const fallthroughId = context.env.nextBlockId;
  context.rewrites.push({
-    kind: 'StartScope',
+    kind: "StartScope",
    blockId,
    fallthroughId,
    instrId: scope.range.start,
@@ -234,15 +206,15 @@ function pushStartScopeTerminal(

 function pushEndScopeTerminal(
  scope: ReactiveScope,
-  context: ScopeTraversalContext,
+  context: ScopeTraversalContext
 ): void {
  const fallthroughId = context.fallthroughs.get(scope.id);
  CompilerError.invariant(fallthroughId != null, {
-    reason: 'Expected scope to exist',
+    reason: "Expected scope to exist",
    loc: GeneratedSource,
  });
  context.rewrites.push({
-    kind: 'EndScope',
+    kind: "EndScope",
    fallthroughId,
    instrId: scope.range.end,
  });
@@ -276,13 +248,13 @@ type RewriteContext = {
 function handleRewrite(
  terminalInfo: TerminalRewriteInfo,
  idx: number,
-  context: RewriteContext,
+  context: RewriteContext
 ): void {
  // TODO make consistent instruction IDs instead of reusing
  const terminal: ReactiveScopeTerminal | GotoTerminal =
-    terminalInfo.kind === 'StartScope'
+    terminalInfo.kind === "StartScope"
      ? {
-          kind: 'scope',
+          kind: "scope",
          fallthrough: terminalInfo.fallthroughId,
          block: terminalInfo.blockId,
          scope: terminalInfo.scope,
@@ -290,7 +262,7 @@ function handleRewrite(
          loc: GeneratedSource,
        }
      : {
-          kind: 'goto',
+          kind: "goto",
          variant: GotoVariant.Break,
          block: terminalInfo.fallthroughId,
          id: terminalInfo.instrId,
@@ -309,7 +281,7 @@ function handleRewrite(
  });
  context.nextPreds = new Set([currBlockId]);
  context.nextBlockId =
-    terminalInfo.kind === 'StartScope'
+    terminalInfo.kind === "StartScope"
      ? terminalInfo.blockId
      : terminalInfo.fallthroughId;
  context.instrSliceIdx = idx;
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/ComputeUnconditionalBlocks.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/ComputeUnconditionalBlocks.ts
@@ -5,8 +5,8 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {BlockId, HIRFunction, computePostDominatorTree} from '.';
-import {CompilerError} from '..';
+import { BlockId, HIRFunction, computePostDominatorTree } from ".";
+import { CompilerError } from "..";

 export function computeUnconditionalBlocks(fn: HIRFunction): Set<BlockId> {
  // Construct the set of blocks that is always reachable from the entry block.
@@ -23,7 +23,7 @@ export function computeUnconditionalBlocks(fn: HIRFunction): Set<BlockId> {
  while (current !== null && current !== exit) {
    CompilerError.invariant(!unconditionalBlocks.has(current), {
      reason:
-        'Internal error: non-terminating loop in ComputeUnconditionalBlocks',
+        "Internal error: non-terminating loop in ComputeUnconditionalBlocks",
      loc: null,
      suggestions: null,
    });
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/Dominator.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/Dominator.ts
@@ -5,10 +5,10 @@
 * LICENSE file in the root directory of this source tree.
 */

-import prettyFormat from 'pretty-format';
-import {CompilerError} from '../CompilerError';
-import {BlockId, HIRFunction} from './HIR';
-import {eachTerminalSuccessor} from './visitors';
+import prettyFormat from "pretty-format";
+import { CompilerError } from "../CompilerError";
+import { BlockId, HIRFunction } from "./HIR";
+import { eachTerminalSuccessor } from "./visitors";

 /*
 * Computes the dominator tree of the given function. The returned `Dominator` stores the immediate
@@ -34,7 +34,7 @@ export function computeDominatorTree(fn: HIRFunction): Dominator<BlockId> {
 */
 export function computePostDominatorTree(
  fn: HIRFunction,
-  options: {includeThrowsAsExitNode: boolean},
+  options: { includeThrowsAsExitNode: boolean }
 ): PostDominator<BlockId> {
  const graph = buildReverseGraph(fn, options.includeThrowsAsExitNode);
  const nodes = computeImmediateDominators(graph);
@@ -87,7 +87,7 @@ export class Dominator<T> {
  get(id: T): T | null {
    const dominator = this.#nodes.get(id);
    CompilerError.invariant(dominator !== undefined, {
-      reason: 'Unknown node',
+      reason: "Unknown node",
      description: null,
      loc: null,
      suggestions: null,
@@ -128,7 +128,7 @@ export class PostDominator<T> {
  get(id: T): T | null {
    const dominator = this.#nodes.get(id);
    CompilerError.invariant(dominator !== undefined, {
-      reason: 'Unknown node',
+      reason: "Unknown node",
      description: null,
      loc: null,
      suggestions: null,
@@ -217,7 +217,7 @@ function intersect<T>(a: T, b: T, graph: Graph<T>, nodes: Map<T, T>): T {

 // Turns the HIRFunction into a simplified internal form that is shared for dominator/post-dominator computation
 function buildGraph(fn: HIRFunction): Graph<BlockId> {
-  const graph: Graph<BlockId> = {entry: fn.body.entry, nodes: new Map()};
+  const graph: Graph<BlockId> = { entry: fn.body.entry, nodes: new Map() };
  let index = 0;
  for (const [id, block] of fn.body.blocks) {
    graph.nodes.set(id, {
@@ -237,7 +237,7 @@ function buildGraph(fn: HIRFunction): Graph<BlockId> {
 */
 function buildReverseGraph(
  fn: HIRFunction,
-  includeThrowsAsExitNode: boolean,
+  includeThrowsAsExitNode: boolean
 ): Graph<BlockId> {
  const nodes: Map<BlockId, Node<BlockId>> = new Map();
  const exitId = fn.env.nextBlockId;
@@ -256,10 +256,10 @@ function buildReverseGraph(
      preds: new Set(eachTerminalSuccessor(block.terminal)),
      succs: new Set(block.preds),
    };
-    if (block.terminal.kind === 'return') {
+    if (block.terminal.kind === "return") {
      node.preds.add(exitId);
      exit.succs.add(id);
-    } else if (block.terminal.kind === 'throw' && includeThrowsAsExitNode) {
+    } else if (block.terminal.kind === "throw" && includeThrowsAsExitNode) {
      node.preds.add(exitId);
      exit.succs.add(id);
    }
@@ -282,7 +282,7 @@ function buildReverseGraph(
  }
  visit(exitId);

-  const rpo: Graph<BlockId> = {entry: exitId, nodes: new Map()};
+  const rpo: Graph<BlockId> = { entry: exitId, nodes: new Map() };
  let index = 0;
  for (const id of postorder.reverse()) {
    const node = nodes.get(id)!;
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts
@@ -5,37 +5,34 @@
 * LICENSE file in the root directory of this source tree.
 */

-import * as t from '@babel/types';
-import {ZodError, z} from 'zod';
-import {fromZodError} from 'zod-validation-error';
-import {CompilerError} from '../CompilerError';
-import {Logger} from '../Entrypoint';
-import {Err, Ok, Result} from '../Utils/Result';
+import * as t from "@babel/types";
+import { ZodError, z } from "zod";
+import { fromZodError } from "zod-validation-error";
+import { CompilerError } from "../CompilerError";
+import { Logger } from "../Entrypoint";
+import { Err, Ok, Result } from "../Utils/Result";
 import {
  DEFAULT_GLOBALS,
  DEFAULT_SHAPES,
  Global,
  GlobalRegistry,
  installReAnimatedTypes,
-} from './Globals';
+} from "./Globals";
 import {
  BlockId,
  BuiltInType,
  Effect,
  FunctionType,
-  HIRFunction,
  IdentifierId,
  NonLocalBinding,
  PolyType,
  ScopeId,
  Type,
-  ValidatedIdentifier,
  ValueKind,
  makeBlockId,
  makeIdentifierId,
-  makeIdentifierName,
  makeScopeId,
-} from './HIR';
+} from "./HIR";
 import {
  BuiltInMixedReadonlyId,
  DefaultMutatingHook,
@@ -43,8 +40,7 @@ import {
  FunctionSignature,
  ShapeRegistry,
  addHook,
-} from './ObjectShape';
-import {Scope as BabelScope} from '@babel/traverse';
+} from "./ObjectShape";

 export const ExternalFunctionSchema = z.object({
  // Source for the imported module that exports the `importSpecifierName` functions
@@ -61,8 +57,8 @@ export const InstrumentationSchema = z
    globalGating: z.string().nullish(),
  })
  .refine(
-    opts => opts.gating != null || opts.globalGating != null,
-    'Expected at least one of gating or globalGating',
+    (opts) => opts.gating != null || opts.globalGating != null,
+    "Expected at least one of gating or globalGating"
  );

 export type ExternalFunction = z.infer<typeof ExternalFunctionSchema>;
@@ -123,18 +119,6 @@ export type Hook = z.infer<typeof HookSchema>;
 const EnvironmentConfigSchema = z.object({
  customHooks: z.map(z.string(), HookSchema).optional().default(new Map()),

-  /**
-   * A list of functions which the application compiles as macros, where
-   * the compiler must ensure they are not compiled to rename the macro or separate the
-   * "function" from its argument.
-   *
-   * For example, Meta has some APIs such as `featureflag("name-of-feature-flag")` which
-   * are rewritten by a plugin. Assigning `featureflag` to a temporary would break the
-   * plugin since it looks specifically for the name of the function being invoked, not
-   * following aliases.
-   */
-  customMacros: z.nullable(z.array(z.string())).default(null),
-
  /**
   * Enable a check that resets the memoization cache when the source code of the file changes.
   * This is intended to support hot module reloading (HMR), where the same runtime component
@@ -281,18 +265,6 @@ const EnvironmentConfigSchema = z.object({

  enableEmitHookGuards: ExternalFunctionSchema.nullish(),

-  /**
-   * Enable instruction reordering. See InstructionReordering.ts for the details
-   * of the approach.
-   */
-  enableInstructionReordering: z.boolean().default(false),
-
-  /**
-   * Enables function outlinining, where anonymous functions that do not close over
-   * local variables can be extracted into top-level helper functions.
-   */
-  enableFunctionOutlining: z.boolean().default(true),
-
  /*
   * Enables instrumentation codegen. This emits a dev-mode only call to an
   * instrumentation function, for components and hooks that Forget compiles.
@@ -417,23 +389,6 @@ const EnvironmentConfigSchema = z.object({
   * and identifiers have been changed.
   */
  hookPattern: z.string().nullable().default(null),
-
-  /**
-   * If enabled, this will treat objects named as `ref` or if their names end with the substring `Ref`,
-   * and contain a property named `current`, as React refs.
-   *
-   * ```
-   * const ref = useMyRef();
-   * const myRef = useMyRef2();
-   * useEffect(() => {
-   *   ref.current = ...;
-   *   myRef.current = ...;
-   * })
-   * ```
-   *
-   * Here the variables `ref` and `myRef` will be typed as Refs.
-   */
-  enableTreatRefLikeIdentifiersAsRefs: z.boolean().nullable().default(false),
 });

 export type EnvironmentConfig = z.infer<typeof EnvironmentConfigSchema>;
@@ -443,34 +398,23 @@ export function parseConfigPragma(pragma: string): EnvironmentConfig {
  // Get the defaults to programmatically check for boolean properties
  const defaultConfig = EnvironmentConfigSchema.parse({});

-  for (const token of pragma.split(' ')) {
-    if (!token.startsWith('@')) {
+  for (const token of pragma.split(" ")) {
+    if (!token.startsWith("@")) {
      continue;
    }
    const keyVal = token.slice(1);
-    let [key, val]: any = keyVal.split(':');
+    let [key, val]: any = keyVal.split(":");

-    if (key === 'validateNoCapitalizedCalls') {
+    if (key === "validateNoCapitalizedCalls") {
      maybeConfig[key] = [];
      continue;
    }

-    if (
-      key === 'enableChangeDetectionForDebugging' &&
-      (val === undefined || val === 'true')
-    ) {
-      maybeConfig[key] = {
-        source: 'react-compiler-runtime',
-        importSpecifierName: '$structuralCheck',
-      };
-      continue;
-    }
-
-    if (typeof defaultConfig[key as keyof EnvironmentConfig] !== 'boolean') {
+    if (typeof defaultConfig[key as keyof EnvironmentConfig] !== "boolean") {
      // skip parsing non-boolean properties
      continue;
    }
-    if (val === undefined || val === 'true') {
+    if (val === undefined || val === "true") {
      val = true;
    } else {
      val = false;
@@ -483,7 +427,7 @@ export function parseConfigPragma(pragma: string): EnvironmentConfig {
    return config.data;
  }
  CompilerError.invariant(false, {
-    reason: 'Internal error, could not parse config from pragma string',
+    reason: "Internal error, could not parse config from pragma string",
    description: `${fromZodError(config.error)}`,
    loc: null,
    suggestions: null,
@@ -492,18 +436,18 @@ export function parseConfigPragma(pragma: string): EnvironmentConfig {

 export type PartialEnvironmentConfig = Partial<EnvironmentConfig>;

-export type ReactFunctionType = 'Component' | 'Hook' | 'Other';
+export type ReactFunctionType = "Component" | "Hook" | "Other";

 export function printFunctionType(type: ReactFunctionType): string {
  switch (type) {
-    case 'Component': {
-      return 'component';
+    case "Component": {
+      return "component";
    }
-    case 'Hook': {
-      return 'hook';
+    case "Hook": {
+      return "hook";
    }
    default: {
-      return 'function';
+      return "function";
    }
  }
 }
@@ -514,11 +458,6 @@ export class Environment {
  #nextIdentifer: number = 0;
  #nextBlock: number = 0;
  #nextScope: number = 0;
-  #scope: BabelScope;
-  #outlinedFunctions: Array<{
-    fn: HIRFunction;
-    type: ReactFunctionType | null;
-  }> = [];
  logger: Logger | null;
  filename: string | null;
  code: string | null;
@@ -530,16 +469,14 @@ export class Environment {
  #hoistedIdentifiers: Set<t.Identifier>;

  constructor(
-    scope: BabelScope,
    fnType: ReactFunctionType,
    config: EnvironmentConfig,
    contextIdentifiers: Set<t.Identifier>,
    logger: Logger | null,
    filename: string | null,
    code: string | null,
-    useMemoCacheIdentifier: string,
+    useMemoCacheIdentifier: string
  ) {
-    this.#scope = scope;
    this.fnType = fnType;
    this.config = config;
    this.filename = filename;
@@ -574,13 +511,13 @@ export class Environment {
          positionalParams: [],
          restParam: hook.effectKind,
          returnType: hook.transitiveMixedData
-            ? {kind: 'Object', shapeId: BuiltInMixedReadonlyId}
-            : {kind: 'Poly'},
+            ? { kind: "Object", shapeId: BuiltInMixedReadonlyId }
+            : { kind: "Poly" },
          returnValueKind: hook.valueKind,
          calleeEffect: Effect.Read,
-          hookKind: 'Custom',
+          hookKind: "Custom",
          noAlias: hook.noAlias,
-        }),
+        })
      );
    }

@@ -612,30 +549,12 @@ export class Environment {
    return this.#hoistedIdentifiers.has(node);
  }

-  generateGloballyUniqueIdentifierName(
-    name: string | null,
-  ): ValidatedIdentifier {
-    const identifierNode = this.#scope.generateUidIdentifier(name ?? undefined);
-    return makeIdentifierName(identifierNode.name);
-  }
-
-  outlineFunction(fn: HIRFunction, type: ReactFunctionType | null): void {
-    this.#outlinedFunctions.push({fn, type});
-  }
-
-  getOutlinedFunctions(): Array<{
-    fn: HIRFunction;
-    type: ReactFunctionType | null;
-  }> {
-    return this.#outlinedFunctions;
-  }
-
  getGlobalDeclaration(binding: NonLocalBinding): Global | null {
    if (this.config.hookPattern != null) {
      const match = new RegExp(this.config.hookPattern).exec(binding.name);
      if (
        match != null &&
-        typeof match[1] === 'string' &&
+        typeof match[1] === "string" &&
        isHookName(match[1])
      ) {
        const resolvedName = match[1];
@@ -644,17 +563,17 @@ export class Environment {
    }

    switch (binding.kind) {
-      case 'ModuleLocal': {
+      case "ModuleLocal": {
        // don't resolve module locals
        return isHookName(binding.name) ? this.#getCustomHookType() : null;
      }
-      case 'Global': {
+      case "Global": {
        return (
          this.#globals.get(binding.name) ??
          (isHookName(binding.name) ? this.#getCustomHookType() : null)
        );
      }
-      case 'ImportSpecifier': {
+      case "ImportSpecifier": {
        if (this.#isKnownReactModule(binding.module)) {
          /**
           * For `import {imported as name} from "..."` form, we use the `imported`
@@ -681,8 +600,8 @@ export class Environment {
            : null;
        }
      }
-      case 'ImportDefault':
-      case 'ImportNamespace': {
+      case "ImportDefault":
+      case "ImportNamespace": {
        if (this.#isKnownReactModule(binding.module)) {
          // only resolve imports to modules we know about
          return (
@@ -698,19 +617,19 @@ export class Environment {

  #isKnownReactModule(moduleName: string): boolean {
    return (
-      moduleName.toLowerCase() === 'react' ||
-      moduleName.toLowerCase() === 'react-dom' ||
+      moduleName.toLowerCase() === "react" ||
+      moduleName.toLowerCase() === "react-dom" ||
      (this.config.enableSharedRuntime__testonly &&
-        moduleName === 'shared-runtime')
+        moduleName === "shared-runtime")
    );
  }

  getPropertyType(
    receiver: Type,
-    property: string,
+    property: string
  ): BuiltInType | PolyType | null {
    let shapeId = null;
-    if (receiver.kind === 'Object' || receiver.kind === 'Function') {
+    if (receiver.kind === "Object" || receiver.kind === "Function") {
      shapeId = receiver.shapeId;
    }
    if (shapeId !== null) {
@@ -726,7 +645,7 @@ export class Environment {
        suggestions: null,
      });
      let value =
-        shape.properties.get(property) ?? shape.properties.get('*') ?? null;
+        shape.properties.get(property) ?? shape.properties.get("*") ?? null;
      if (value === null && isHookName(property)) {
        value = this.#getCustomHookType();
      }
@@ -739,7 +658,7 @@ export class Environment {
  }

  getFunctionSignature(type: FunctionType): FunctionSignature | null {
-    const {shapeId} = type;
+    const { shapeId } = type;
    if (shapeId !== null) {
      const shape = this.#shapes.get(shapeId);
      CompilerError.invariant(shape !== undefined, {
@@ -773,7 +692,7 @@ export function isHookName(name: string): boolean {
 }

 export function parseEnvironmentConfig(
-  partialConfig: PartialEnvironmentConfig,
+  partialConfig: PartialEnvironmentConfig
 ): Result<EnvironmentConfig, ZodError<PartialEnvironmentConfig>> {
  const config = EnvironmentConfigSchema.safeParse(partialConfig);
  if (config.success) {
@@ -784,7 +703,7 @@ export function parseEnvironmentConfig(
 }

 export function validateEnvironmentConfig(
-  partialConfig: PartialEnvironmentConfig,
+  partialConfig: PartialEnvironmentConfig
 ): EnvironmentConfig {
  const config = EnvironmentConfigSchema.safeParse(partialConfig);
  if (config.success) {
@@ -793,7 +712,7 @@ export function validateEnvironmentConfig(

  CompilerError.throwInvalidConfig({
    reason:
-      'Could not validate environment config. Update React Compiler config to fix the error',
+      "Could not validate environment config. Update React Compiler config to fix the error",
    description: `${fromZodError(config.error)}`,
    loc: null,
    suggestions: null,
@@ -801,10 +720,10 @@ export function validateEnvironmentConfig(
 }

 export function tryParseExternalFunction(
-  maybeExternalFunction: any,
+  maybeExternalFunction: any
 ): ExternalFunction {
  const externalFunction = ExternalFunctionSchema.safeParse(
-    maybeExternalFunction,
+    maybeExternalFunction
  );
  if (externalFunction.success) {
    return externalFunction.data;
@@ -812,7 +731,7 @@ export function tryParseExternalFunction(

  CompilerError.throwInvalidConfig({
    reason:
-      'Could not parse external function. Update React Compiler config to fix the error',
+      "Could not parse external function. Update React Compiler config to fix the error",
    description: `${fromZodError(externalFunction.error)}`,
    loc: null,
    suggestions: null,
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/FindContextIdentifiers.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/FindContextIdentifiers.ts
@@ -5,11 +5,11 @@
 * LICENSE file in the root directory of this source tree.
 */

-import type {NodePath} from '@babel/traverse';
-import type * as t from '@babel/types';
-import {CompilerError} from '../CompilerError';
-import {getOrInsertDefault} from '../Utils/utils';
-import {GeneratedSource} from './HIR';
+import type { NodePath } from "@babel/traverse";
+import type * as t from "@babel/types";
+import { CompilerError } from "../CompilerError";
+import { getOrInsertDefault } from "../Utils/utils";
+import { GeneratedSource } from "./HIR";

 type IdentifierInfo = {
  reassigned: boolean;
@@ -35,7 +35,7 @@ type FindContextIdentifierState = {
 const withFunctionScope = {
  enter: function (
    path: BabelFunction,
-    state: FindContextIdentifierState,
+    state: FindContextIdentifierState
  ): void {
    state.currentFn.push(path);
  },
@@ -45,7 +45,7 @@ const withFunctionScope = {
 };

 export function findContextIdentifiers(
-  func: NodePath<t.Function>,
+  func: NodePath<t.Function>
 ): Set<t.Identifier> {
  const state: FindContextIdentifierState = {
    currentFn: [],
@@ -60,17 +60,17 @@ export function findContextIdentifiers(
      ObjectMethod: withFunctionScope,
      AssignmentExpression(
        path: NodePath<t.AssignmentExpression>,
-        state: FindContextIdentifierState,
+        state: FindContextIdentifierState
      ): void {
-        const left = path.get('left');
+        const left = path.get("left");
        const currentFn = state.currentFn.at(-1) ?? null;
        handleAssignment(currentFn, state.identifiers, left);
      },
      UpdateExpression(
        path: NodePath<t.UpdateExpression>,
-        state: FindContextIdentifierState,
+        state: FindContextIdentifierState
      ): void {
-        const argument = path.get('argument');
+        const argument = path.get("argument");
        const currentFn = state.currentFn.at(-1) ?? null;
        if (argument.isLVal()) {
          handleAssignment(currentFn, state.identifiers, argument);
@@ -78,7 +78,7 @@ export function findContextIdentifiers(
      },
      Identifier(
        path: NodePath<t.Identifier>,
-        state: FindContextIdentifierState,
+        state: FindContextIdentifierState
      ): void {
        const currentFn = state.currentFn.at(-1) ?? null;
        if (path.isReferencedIdentifier()) {
@@ -86,7 +86,7 @@ export function findContextIdentifiers(
        }
      },
    },
-    state,
+    state
  );

  const result = new Set<t.Identifier>();
@@ -103,7 +103,7 @@ export function findContextIdentifiers(
 function handleIdentifier(
  currentFn: BabelFunction | null,
  identifiers: Map<t.Identifier, IdentifierInfo>,
-  path: NodePath<t.Identifier>,
+  path: NodePath<t.Identifier>
 ): void {
  const name = path.node.name;
  const binding = path.scope.getBinding(name);
@@ -126,7 +126,7 @@ function handleIdentifier(
 function handleAssignment(
  currentFn: BabelFunction | null,
  identifiers: Map<t.Identifier, IdentifierInfo>,
-  lvalPath: NodePath<t.LVal>,
+  lvalPath: NodePath<t.LVal>
 ): void {
  /*
   * Find all reassignments to identifiers declared outside of currentFn
@@ -134,7 +134,7 @@ function handleAssignment(
   */
  const lvalNode = lvalPath.node;
  switch (lvalNode.type) {
-    case 'Identifier': {
+    case "Identifier": {
      const path = lvalPath as NodePath<t.Identifier>;
      const name = path.node.name;
      const binding = path.scope.getBinding(name);
@@ -155,20 +155,20 @@ function handleAssignment(
      }
      break;
    }
-    case 'ArrayPattern': {
+    case "ArrayPattern": {
      const path = lvalPath as NodePath<t.ArrayPattern>;
-      for (const element of path.get('elements')) {
+      for (const element of path.get("elements")) {
        if (nonNull(element)) {
          handleAssignment(currentFn, identifiers, element);
        }
      }
      break;
    }
-    case 'ObjectPattern': {
+    case "ObjectPattern": {
      const path = lvalPath as NodePath<t.ObjectPattern>;
-      for (const property of path.get('properties')) {
+      for (const property of path.get("properties")) {
        if (property.isObjectProperty()) {
-          const valuePath = property.get('value');
+          const valuePath = property.get("value");
          CompilerError.invariant(valuePath.isLVal(), {
            reason: `[FindContextIdentifiers] Expected object property value to be an LVal, got: ${valuePath.type}`,
            description: null,
@@ -188,18 +188,18 @@ function handleAssignment(
      }
      break;
    }
-    case 'AssignmentPattern': {
+    case "AssignmentPattern": {
      const path = lvalPath as NodePath<t.AssignmentPattern>;
-      const left = path.get('left');
+      const left = path.get("left");
      handleAssignment(currentFn, identifiers, left);
      break;
    }
-    case 'RestElement': {
+    case "RestElement": {
      const path = lvalPath as NodePath<t.RestElement>;
-      handleAssignment(currentFn, identifiers, path.get('argument'));
+      handleAssignment(currentFn, identifiers, path.get("argument"));
      break;
    }
-    case 'MemberExpression': {
+    case "MemberExpression": {
      // Interior mutability (not a reassign)
      break;
    }
@@ -215,7 +215,7 @@ function handleAssignment(
 }

 function nonNull<T extends NonNullable<t.Node>>(
-  t: NodePath<T | null>,
+  t: NodePath<T | null>
 ): t is NodePath<T> {
  return t.node != null;
 }
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/Globals.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/Globals.ts
@@ -5,24 +5,22 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {Effect, ValueKind, ValueReason} from './HIR';
+import { Effect, ValueKind, ValueReason } from "./HIR";
 import {
  BUILTIN_SHAPES,
  BuiltInArrayId,
-  BuiltInUseActionStateId,
  BuiltInUseEffectHookId,
  BuiltInUseInsertionEffectHookId,
  BuiltInUseLayoutEffectHookId,
  BuiltInUseOperatorId,
-  BuiltInUseReducerId,
  BuiltInUseRefId,
  BuiltInUseStateId,
  ShapeRegistry,
  addFunction,
  addHook,
  addObject,
-} from './ObjectShape';
-import {BuiltInType, PolyType} from './Types';
+} from "./ObjectShape";
+import { BuiltInType, PolyType } from "./Types";

 /*
 * This file exports types and defaults for JavaScript global objects.
@@ -37,59 +35,59 @@ export const DEFAULT_SHAPES: ShapeRegistry = new Map(BUILTIN_SHAPES);

 // Hack until we add ObjectShapes for all globals
 const UNTYPED_GLOBALS: Set<string> = new Set([
-  'String',
-  'Object',
-  'Function',
-  'Number',
-  'RegExp',
-  'Date',
-  'Error',
-  'Function',
-  'TypeError',
-  'RangeError',
-  'ReferenceError',
-  'SyntaxError',
-  'URIError',
-  'EvalError',
-  'Boolean',
-  'DataView',
-  'Float32Array',
-  'Float64Array',
-  'Int8Array',
-  'Int16Array',
-  'Int32Array',
-  'Map',
-  'Set',
-  'WeakMap',
-  'Uint8Array',
-  'Uint8ClampedArray',
-  'Uint16Array',
-  'Uint32Array',
-  'ArrayBuffer',
-  'JSON',
-  'parseFloat',
-  'parseInt',
-  'console',
-  'isNaN',
-  'eval',
-  'isFinite',
-  'encodeURI',
-  'decodeURI',
-  'encodeURIComponent',
-  'decodeURIComponent',
+  "String",
+  "Object",
+  "Function",
+  "Number",
+  "RegExp",
+  "Date",
+  "Error",
+  "Function",
+  "TypeError",
+  "RangeError",
+  "ReferenceError",
+  "SyntaxError",
+  "URIError",
+  "EvalError",
+  "Boolean",
+  "DataView",
+  "Float32Array",
+  "Float64Array",
+  "Int8Array",
+  "Int16Array",
+  "Int32Array",
+  "Map",
+  "Set",
+  "WeakMap",
+  "Uint8Array",
+  "Uint8ClampedArray",
+  "Uint16Array",
+  "Uint32Array",
+  "ArrayBuffer",
+  "JSON",
+  "parseFloat",
+  "parseInt",
+  "console",
+  "isNaN",
+  "eval",
+  "isFinite",
+  "encodeURI",
+  "decodeURI",
+  "encodeURIComponent",
+  "decodeURIComponent",
 ]);

 const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
  [
-    'Array',
-    addObject(DEFAULT_SHAPES, 'Array', [
+    "Array",
+    addObject(DEFAULT_SHAPES, "Array", [
      [
-        'isArray',
+        "isArray",
        // Array.isArray(value)
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [Effect.Read],
          restParam: null,
-          returnType: {kind: 'Primitive'},
+          returnType: { kind: "Primitive" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Primitive,
        }),
@@ -106,12 +104,12 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
       *    function)
       */
      [
-        'of',
+        "of",
        // Array.of(element0, ..., elementN)
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Read,
-          returnType: {kind: 'Object', shapeId: BuiltInArrayId},
+          returnType: { kind: "Object", shapeId: BuiltInArrayId },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Mutable,
        }),
@@ -119,85 +117,85 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
    ]),
  ],
  [
-    'Math',
-    addObject(DEFAULT_SHAPES, 'Math', [
+    "Math",
+    addObject(DEFAULT_SHAPES, "Math", [
      // Static properties (TODO)
-      ['PI', {kind: 'Primitive'}],
+      ["PI", { kind: "Primitive" }],
      // Static methods (TODO)
      [
-        'max',
+        "max",
        // Math.max(value0, ..., valueN)
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Read,
-          returnType: {kind: 'Primitive'},
+          returnType: { kind: "Primitive" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Primitive,
        }),
      ],
    ]),
  ],
-  ['Infinity', {kind: 'Primitive'}],
-  ['NaN', {kind: 'Primitive'}],
+  ["Infinity", { kind: "Primitive" }],
+  ["NaN", { kind: "Primitive" }],
  [
-    'console',
-    addObject(DEFAULT_SHAPES, 'console', [
+    "console",
+    addObject(DEFAULT_SHAPES, "console", [
      [
-        'error',
+        "error",
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Read,
-          returnType: {kind: 'Primitive'},
+          returnType: { kind: "Primitive" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Primitive,
        }),
      ],
      [
-        'info',
+        "info",
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Read,
-          returnType: {kind: 'Primitive'},
+          returnType: { kind: "Primitive" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Primitive,
        }),
      ],
      [
-        'log',
+        "log",
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Read,
-          returnType: {kind: 'Primitive'},
+          returnType: { kind: "Primitive" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Primitive,
        }),
      ],
      [
-        'table',
+        "table",
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Read,
-          returnType: {kind: 'Primitive'},
+          returnType: { kind: "Primitive" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Primitive,
        }),
      ],
      [
-        'trace',
+        "trace",
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Read,
-          returnType: {kind: 'Primitive'},
+          returnType: { kind: "Primitive" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Primitive,
        }),
      ],
      [
-        'warn',
+        "warn",
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Read,
-          returnType: {kind: 'Primitive'},
+          returnType: { kind: "Primitive" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Primitive,
        }),
@@ -205,31 +203,31 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
    ]),
  ],
  [
-    'Boolean',
+    "Boolean",
    addFunction(DEFAULT_SHAPES, [], {
      positionalParams: [],
      restParam: Effect.Read,
-      returnType: {kind: 'Primitive'},
+      returnType: { kind: "Primitive" },
      calleeEffect: Effect.Read,
      returnValueKind: ValueKind.Primitive,
    }),
  ],
  [
-    'Number',
+    "Number",
    addFunction(DEFAULT_SHAPES, [], {
      positionalParams: [],
      restParam: Effect.Read,
-      returnType: {kind: 'Primitive'},
+      returnType: { kind: "Primitive" },
      calleeEffect: Effect.Read,
      returnValueKind: ValueKind.Primitive,
    }),
  ],
  [
-    'String',
+    "String",
    addFunction(DEFAULT_SHAPES, [], {
      positionalParams: [],
      restParam: Effect.Read,
-      returnType: {kind: 'Primitive'},
+      returnType: { kind: "Primitive" },
      calleeEffect: Effect.Read,
      returnValueKind: ValueKind.Primitive,
    }),
@@ -244,179 +242,155 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
 */
 const REACT_APIS: Array<[string, BuiltInType]> = [
  [
-    'useContext',
+    "useContext",
    addHook(DEFAULT_SHAPES, {
      positionalParams: [],
      restParam: Effect.Read,
-      returnType: {kind: 'Poly'},
+      returnType: { kind: "Poly" },
      calleeEffect: Effect.Read,
-      hookKind: 'useContext',
+      hookKind: "useContext",
      returnValueKind: ValueKind.Frozen,
      returnValueReason: ValueReason.Context,
    }),
  ],
  [
-    'useState',
+    "useState",
    addHook(DEFAULT_SHAPES, {
      positionalParams: [],
      restParam: Effect.Freeze,
-      returnType: {kind: 'Object', shapeId: BuiltInUseStateId},
+      returnType: { kind: "Object", shapeId: BuiltInUseStateId },
      calleeEffect: Effect.Read,
-      hookKind: 'useState',
+      hookKind: "useState",
      returnValueKind: ValueKind.Frozen,
      returnValueReason: ValueReason.State,
    }),
  ],
  [
-    'useActionState',
-    addHook(DEFAULT_SHAPES, {
-      positionalParams: [],
-      restParam: Effect.Freeze,
-      returnType: {kind: 'Object', shapeId: BuiltInUseActionStateId},
-      calleeEffect: Effect.Read,
-      hookKind: 'useActionState',
-      returnValueKind: ValueKind.Frozen,
-      returnValueReason: ValueReason.State,
-    }),
-  ],
-  [
-    'useReducer',
-    addHook(DEFAULT_SHAPES, {
-      positionalParams: [],
-      restParam: Effect.Freeze,
-      returnType: {kind: 'Object', shapeId: BuiltInUseReducerId},
-      calleeEffect: Effect.Read,
-      hookKind: 'useReducer',
-      returnValueKind: ValueKind.Frozen,
-      returnValueReason: ValueReason.ReducerState,
-    }),
-  ],
-  [
-    'useRef',
+    "useRef",
    addHook(DEFAULT_SHAPES, {
      positionalParams: [],
      restParam: Effect.Capture,
-      returnType: {kind: 'Object', shapeId: BuiltInUseRefId},
+      returnType: { kind: "Object", shapeId: BuiltInUseRefId },
      calleeEffect: Effect.Read,
-      hookKind: 'useRef',
+      hookKind: "useRef",
      returnValueKind: ValueKind.Mutable,
    }),
  ],
  [
-    'useMemo',
+    "useMemo",
    addHook(DEFAULT_SHAPES, {
      positionalParams: [],
      restParam: Effect.Freeze,
-      returnType: {kind: 'Poly'},
+      returnType: { kind: "Poly" },
      calleeEffect: Effect.Read,
-      hookKind: 'useMemo',
+      hookKind: "useMemo",
      returnValueKind: ValueKind.Frozen,
    }),
  ],
  [
-    'useCallback',
+    "useCallback",
    addHook(DEFAULT_SHAPES, {
      positionalParams: [],
      restParam: Effect.Freeze,
-      returnType: {kind: 'Poly'},
+      returnType: { kind: "Poly" },
      calleeEffect: Effect.Read,
-      hookKind: 'useCallback',
+      hookKind: "useCallback",
      returnValueKind: ValueKind.Frozen,
    }),
  ],
  [
-    'useEffect',
+    "useEffect",
    addHook(
      DEFAULT_SHAPES,
      {
        positionalParams: [],
        restParam: Effect.Freeze,
-        returnType: {kind: 'Primitive'},
+        returnType: { kind: "Primitive" },
        calleeEffect: Effect.Read,
-        hookKind: 'useEffect',
+        hookKind: "useEffect",
        returnValueKind: ValueKind.Frozen,
      },
-      BuiltInUseEffectHookId,
+      BuiltInUseEffectHookId
    ),
  ],
  [
-    'useLayoutEffect',
+    "useLayoutEffect",
    addHook(
      DEFAULT_SHAPES,
      {
        positionalParams: [],
        restParam: Effect.Freeze,
-        returnType: {kind: 'Poly'},
+        returnType: { kind: "Poly" },
        calleeEffect: Effect.Read,
-        hookKind: 'useLayoutEffect',
+        hookKind: "useLayoutEffect",
        returnValueKind: ValueKind.Frozen,
      },
-      BuiltInUseLayoutEffectHookId,
+      BuiltInUseLayoutEffectHookId
    ),
  ],
  [
-    'useInsertionEffect',
+    "useInsertionEffect",
    addHook(
      DEFAULT_SHAPES,
      {
        positionalParams: [],
        restParam: Effect.Freeze,
-        returnType: {kind: 'Poly'},
+        returnType: { kind: "Poly" },
        calleeEffect: Effect.Read,
-        hookKind: 'useInsertionEffect',
+        hookKind: "useLayoutEffect",
        returnValueKind: ValueKind.Frozen,
      },
-      BuiltInUseInsertionEffectHookId,
+      BuiltInUseInsertionEffectHookId
    ),
  ],
  [
-    'use',
+    "use",
    addFunction(
      DEFAULT_SHAPES,
      [],
      {
        positionalParams: [],
        restParam: Effect.Freeze,
-        returnType: {kind: 'Poly'},
+        returnType: { kind: "Poly" },
        calleeEffect: Effect.Read,
        returnValueKind: ValueKind.Frozen,
      },
-      BuiltInUseOperatorId,
+      BuiltInUseOperatorId
    ),
  ],
 ];

 TYPED_GLOBALS.push(
  [
-    'React',
+    "React",
    addObject(DEFAULT_SHAPES, null, [
      ...REACT_APIS,
      [
-        'createElement',
+        "createElement",
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Freeze,
-          returnType: {kind: 'Poly'},
+          returnType: { kind: "Poly" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Frozen,
        }),
      ],
      [
-        'cloneElement',
+        "cloneElement",
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Freeze,
-          returnType: {kind: 'Poly'},
+          returnType: { kind: "Poly" },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Frozen,
        }),
      ],
      [
-        'createRef',
+        "createRef",
        addFunction(DEFAULT_SHAPES, [], {
          positionalParams: [],
          restParam: Effect.Capture, // createRef takes no paramters
-          returnType: {kind: 'Object', shapeId: BuiltInUseRefId},
+          returnType: { kind: "Object", shapeId: BuiltInUseRefId },
          calleeEffect: Effect.Read,
          returnValueKind: ValueKind.Mutable,
        }),
@@ -424,15 +398,15 @@ TYPED_GLOBALS.push(
    ]),
  ],
  [
-    '_jsx',
+    "_jsx",
    addFunction(DEFAULT_SHAPES, [], {
      positionalParams: [],
      restParam: Effect.Freeze,
-      returnType: {kind: 'Poly'},
+      returnType: { kind: "Poly" },
      calleeEffect: Effect.Read,
      returnValueKind: ValueKind.Frozen,
    }),
-  ],
+  ]
 );

 export type Global = BuiltInType | PolyType;
@@ -442,7 +416,7 @@ export const DEFAULT_GLOBALS: GlobalRegistry = new Map(REACT_APIS);
 // Hack until we add ObjectShapes for all globals
 for (const name of UNTYPED_GLOBALS) {
  DEFAULT_GLOBALS.set(name, {
-    kind: 'Poly',
+    kind: "Poly",
  });
 }

@@ -452,22 +426,22 @@ for (const [name, type_] of TYPED_GLOBALS) {

 // Recursive global type
 DEFAULT_GLOBALS.set(
-  'globalThis',
-  addObject(DEFAULT_SHAPES, 'globalThis', TYPED_GLOBALS),
+  "globalThis",
+  addObject(DEFAULT_SHAPES, "globalThis", TYPED_GLOBALS)
 );

 export function installReAnimatedTypes(
  globals: GlobalRegistry,
-  registry: ShapeRegistry,
+  registry: ShapeRegistry
 ): void {
  // hooks that freeze args and return frozen value
  const frozenHooks = [
-    'useFrameCallback',
-    'useAnimatedStyle',
-    'useAnimatedProps',
-    'useAnimatedScrollHandler',
-    'useAnimatedReaction',
-    'useWorkletCallback',
+    "useFrameCallback",
+    "useAnimatedStyle",
+    "useAnimatedProps",
+    "useAnimatedScrollHandler",
+    "useAnimatedReaction",
+    "useWorkletCallback",
  ];
  for (const hook of frozenHooks) {
    globals.set(
@@ -475,12 +449,12 @@ export function installReAnimatedTypes(
      addHook(registry, {
        positionalParams: [],
        restParam: Effect.Freeze,
-        returnType: {kind: 'Poly'},
+        returnType: { kind: "Poly" },
        returnValueKind: ValueKind.Frozen,
        noAlias: true,
        calleeEffect: Effect.Read,
-        hookKind: 'Custom',
-      }),
+        hookKind: "Custom",
+      })
    );
  }

@@ -488,31 +462,31 @@ export function installReAnimatedTypes(
   * hooks that return a mutable value. ideally these should be modelled as a
   * ref, but this works for now.
   */
-  const mutableHooks = ['useSharedValue', 'useDerivedValue'];
+  const mutableHooks = ["useSharedValue", "useDerivedValue"];
  for (const hook of mutableHooks) {
    globals.set(
      hook,
      addHook(registry, {
        positionalParams: [],
        restParam: Effect.Freeze,
-        returnType: {kind: 'Poly'},
+        returnType: { kind: "Poly" },
        returnValueKind: ValueKind.Mutable,
        noAlias: true,
        calleeEffect: Effect.Read,
-        hookKind: 'Custom',
-      }),
+        hookKind: "Custom",
+      })
    );
  }

  // functions that return mutable value
  const funcs = [
-    'withTiming',
-    'withSpring',
-    'createAnimatedPropAdapter',
-    'withDecay',
-    'withRepeat',
-    'runOnUI',
-    'executeOnUIRuntimeSync',
+    "withTiming",
+    "withSpring",
+    "createAnimatedPropAdapter",
+    "withDecay",
+    "withRepeat",
+    "runOnUI",
+    "executeOnUIRuntimeSync",
  ];
  for (const fn of funcs) {
    globals.set(
@@ -520,11 +494,11 @@ export function installReAnimatedTypes(
      addFunction(registry, [], {
        positionalParams: [],
        restParam: Effect.Read,
-        returnType: {kind: 'Poly'},
+        returnType: { kind: "Poly" },
        calleeEffect: Effect.Read,
        returnValueKind: ValueKind.Mutable,
        noAlias: true,
-      }),
+      })
    );
  }
 }
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/HIRBuilder.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/HIRBuilder.ts
@@ -5,10 +5,10 @@
 * LICENSE file in the root directory of this source tree.
 */

-import {Binding, NodePath} from '@babel/traverse';
-import * as t from '@babel/types';
-import {CompilerError} from '../CompilerError';
-import {Environment} from './Environment';
+import { Binding, NodePath } from "@babel/traverse";
+import * as t from "@babel/types";
+import { CompilerError } from "../CompilerError";
+import { Environment } from "./Environment";
 import {
  BasicBlock,
  BlockId,
@@ -28,13 +28,13 @@ import {
  makeIdentifierName,
  makeInstructionId,
  makeType,
-} from './HIR';
-import {printInstruction} from './PrintHIR';
+} from "./HIR";
+import { printInstruction } from "./PrintHIR";
 import {
  eachTerminalSuccessor,
  mapTerminalSuccessors,
  terminalFallthrough,
-} from './visitors';
+} from "./visitors";

 /*
 * *******************************************************************************************
@@ -54,31 +54,31 @@ export type WipBlock = {
 type Scope = LoopScope | LabelScope | SwitchScope;

 type LoopScope = {
-  kind: 'loop';
+  kind: "loop";
  label: string | null;
  continueBlock: BlockId;
  breakBlock: BlockId;
 };

 type SwitchScope = {
-  kind: 'switch';
+  kind: "switch";
  breakBlock: BlockId;
  label: string | null;
 };

 type LabelScope = {
-  kind: 'label';
+  kind: "label";
  label: string;
  breakBlock: BlockId;
 };

 function newBlock(id: BlockId, kind: BlockKind): WipBlock {
-  return {id, kind, instructions: []};
+  return { id, kind, instructions: [] };
 }

 export type Bindings = Map<
  string,
-  {node: t.Identifier; identifier: Identifier}
+  { node: t.Identifier; identifier: Identifier }
 >;

 /*
@@ -90,13 +90,13 @@ export type ExceptionsMode =
   * Mode used for code not covered by explicit exception handling, any
   * errors are assumed to be thrown out of the function
   */
-  | {kind: 'ThrowExceptions'}
+  | { kind: "ThrowExceptions" }
  /*
   * Mode used for code that *is* covered by explicit exception handling
   * (ie try/catch), which requires modeling the possibility of control
   * flow to the exception handler.
   */
-  | {kind: 'CatchExceptions'; handler: BlockId};
+  | { kind: "CatchExceptions"; handler: BlockId };

 // Helper class for constructing a CFG
 export default class HIRBuilder {
@@ -110,11 +110,6 @@ export default class HIRBuilder {
  #exceptionHandlerStack: Array<BlockId> = [];
  parentFunction: NodePath<t.Function>;
  errors: CompilerError = new CompilerError();
-  /**
-   * Traversal context: counts the number of `fbt` tag parents
-   * of the current babel node.
-   */
-  fbtDepth: number = 0;

  get nextIdentifierId(): IdentifierId {
    return this.#env.nextIdentifierId;
@@ -136,14 +131,14 @@ export default class HIRBuilder {
    env: Environment,
    parentFunction: NodePath<t.Function>, // the outermost function being compiled
    bindings: Bindings | null = null,
-    context: Array<t.Identifier> | null = null,
+    context: Array<t.Identifier> | null = null
  ) {
    this.#env = env;
    this.#bindings = bindings ?? new Map();
    this.parentFunction = parentFunction;
    this.#context = context ?? [];
    this.#entry = makeBlockId(env.nextBlockId);
-    this.#current = newBlock(this.#entry, 'block');
+    this.#current = newBlock(this.#entry, "block");
  }

  currentBlockKind(): BlockKind {
@@ -158,13 +153,13 @@ export default class HIRBuilder {
      const continuationBlock = this.reserve(this.currentBlockKind());
      this.terminateWithContinuation(
        {
-          kind: 'maybe-throw',
+          kind: "maybe-throw",
          continuation: continuationBlock.id,
          handler: exceptionHandler,
          id: makeInstructionId(0),
          loc: instruction.loc,
        },
-        continuationBlock,
+        continuationBlock
      );
    }
  }
@@ -185,7 +180,7 @@ export default class HIRBuilder {
    return {
      id,
      name: null,
-      mutableRange: {start: makeInstructionId(0), end: makeInstructionId(0)},
+      mutableRange: { start: makeInstructionId(0), end: makeInstructionId(0) },
      scope: null,
      type: makeType(),
      loc,
@@ -193,7 +188,7 @@ export default class HIRBuilder {
  }

  #resolveBabelBinding(
-    path: NodePath<t.Identifier | t.JSXIdentifier>,
+    path: NodePath<t.Identifier | t.JSXIdentifier>
  ): Binding | null {
    const originalName = path.node.name;
    const binding = path.scope.getBinding(originalName);
@@ -234,12 +229,12 @@ export default class HIRBuilder {
   * ```
   */
  resolveIdentifier(
-    path: NodePath<t.Identifier | t.JSXIdentifier>,
+    path: NodePath<t.Identifier | t.JSXIdentifier>
  ): VariableBinding {
    const originalName = path.node.name;
    const babelBinding = this.#resolveBabelBinding(path);
    if (babelBinding == null) {
-      return {kind: 'Global', name: originalName};
+      return { kind: "Global", name: originalName };
    }

    // Check if the binding is from module scope
@@ -251,7 +246,7 @@ export default class HIRBuilder {
        const importDeclaration =
          path.parentPath as NodePath<t.ImportDeclaration>;
        return {
-          kind: 'ImportDefault',
+          kind: "ImportDefault",
          name: originalName,
          module: importDeclaration.node.source.value,
        };
@@ -259,11 +254,11 @@ export default class HIRBuilder {
        const importDeclaration =
          path.parentPath as NodePath<t.ImportDeclaration>;
        return {
-          kind: 'ImportSpecifier',
+          kind: "ImportSpecifier",
          name: originalName,
          module: importDeclaration.node.source.value,
          imported:
-            path.node.imported.type === 'Identifier'
+            path.node.imported.type === "Identifier"
              ? path.node.imported.name
              : path.node.imported.value,
        };
@@ -271,13 +266,13 @@ export default class HIRBuilder {
        const importDeclaration =
          path.parentPath as NodePath<t.ImportDeclaration>;
        return {
-          kind: 'ImportNamespace',
+          kind: "ImportNamespace",
          name: originalName,
          module: importDeclaration.node.source.value,
        };
      } else {
        return {
-          kind: 'ModuleLocal',
+          kind: "ModuleLocal",
          name: originalName,
        };
      }
@@ -288,7 +283,7 @@ export default class HIRBuilder {
      babelBinding.scope.rename(originalName, resolvedBinding.name.value);
    }
    return {
-      kind: 'Identifier',
+      kind: "Identifier",
      identifier: resolvedBinding,
      bindingKind: babelBinding.kind,
    };
@@ -299,7 +294,7 @@ export default class HIRBuilder {
    if (binding) {
      // Check if the binding is from module scope, if so return null
      const outerBinding = this.parentFunction.scope.parent.getBinding(
-        path.node.name,
+        path.node.name
      );
      if (binding === outerBinding) {
        return false;
@@ -311,12 +306,6 @@ export default class HIRBuilder {
  }

  resolveBinding(node: t.Identifier): Identifier {
-    if (node.name === 'fbt') {
-      CompilerError.throwTodo({
-        reason: 'Support local variables named "fbt"',
-        loc: node.loc ?? null,
-      });
-    }
    const originalName = node.name;
    let name = originalName;
    let index = 0;
@@ -335,7 +324,7 @@ export default class HIRBuilder {
          type: makeType(),
          loc: node.loc ?? GeneratedSource,
        };
-        this.#bindings.set(name, {node, identifier});
+        this.#bindings.set(name, { node, identifier });
        return identifier;
      } else if (mapping.node === node) {
        return mapping.identifier;
@@ -356,7 +345,7 @@ export default class HIRBuilder {
      if (
        !rpoBlocks.has(id) &&
        block.instructions.some(
-          instr => instr.value.kind === 'FunctionExpression',
+          (instr) => instr.value.kind === "FunctionExpression"
        )
      ) {
        CompilerError.throwTodo({
@@ -380,7 +369,7 @@ export default class HIRBuilder {

  // Terminate the current block w the given terminal, and start a new block
  terminate(terminal: Terminal, nextBlockKind: BlockKind | null): void {
-    const {id: blockId, kind, instructions} = this.#current;
+    const { id: blockId, kind, instructions } = this.#current;
    this.#completed.set(blockId, {
      kind,
      id: blockId,
@@ -400,7 +389,7 @@ export default class HIRBuilder {
   * reserved block as the new current block
   */
  terminateWithContinuation(terminal: Terminal, continuation: WipBlock): void {
-    const {id: blockId, kind, instructions} = this.#current;
+    const { id: blockId, kind, instructions } = this.#current;
    this.#completed.set(blockId, {
      kind: kind,
      id: blockId,
@@ -423,7 +412,7 @@ export default class HIRBuilder {

  // Save a previously reserved block as completed
  complete(block: WipBlock, terminal: Terminal): void {
-    const {id: blockId, kind, instructions} = block;
+    const { id: blockId, kind, instructions } = block;
    this.#completed.set(blockId, {
      kind,
      id: blockId,
@@ -442,7 +431,7 @@ export default class HIRBuilder {
    const current = this.#current;
    this.#current = wip;
    const terminal = fn();
-    const {id: blockId, kind, instructions} = this.#current;
+    const { id: blockId, kind, instructions } = this.#current;
    this.#completed.set(blockId, {
      kind,
      id: blockId,
@@ -470,7 +459,7 @@ export default class HIRBuilder {

  label<T>(label: string, breakBlock: BlockId, fn: () => T): T {
    this.#scopes.push({
-      kind: 'label',
+      kind: "label",
      breakBlock,
      label,
    });
@@ -478,22 +467,22 @@ export default class HIRBuilder {
    const last = this.#scopes.pop();
    CompilerError.invariant(
      last != null &&
-        last.kind === 'label' &&
+        last.kind === "label" &&
        last.label === label &&
        last.breakBlock === breakBlock,
      {
-        reason: 'Mismatched label',
+        reason: "Mismatched label",
        description: null,
        loc: null,
        suggestions: null,
-      },
+      }
    );
    return value;
  }

  switch<T>(label: string | null, breakBlock: BlockId, fn: () => T): T {
    this.#scopes.push({
-      kind: 'switch',
+      kind: "switch",
      breakBlock,
      label,
    });
@@ -501,15 +490,15 @@ export default class HIRBuilder {
    const last = this.#scopes.pop();
    CompilerError.invariant(
      last != null &&
-        last.kind === 'switch' &&
+        last.kind === "switch" &&
        last.label === label &&
        last.breakBlock === breakBlock,
      {
-        reason: 'Mismatched label',
+        reason: "Mismatched label",
        description: null,
        loc: null,
        suggestions: null,
-      },
+      }
    );
    return value;
  }
@@ -524,10 +513,10 @@ export default class HIRBuilder {
    continueBlock: BlockId,
    // block following the loop. "break" jumps here.
    breakBlock: BlockId,
-    fn: () => T,
+    fn: () => T
  ): T {
    this.#scopes.push({
-      kind: 'loop',
+      kind: "loop",
      label,
      continueBlock,
      breakBlock,
@@ -536,16 +525,16 @@ export default class HIRBuilder {
    const last = this.#scopes.pop();
    CompilerError.invariant(
      last != null &&
-        last.kind === 'loop' &&
+        last.kind === "loop" &&
        last.label === label &&
        last.continueBlock === continueBlock &&
        last.breakBlock === breakBlock,
      {
-        reason: 'Mismatched loops',
+        reason: "Mismatched loops",
        description: null,
        loc: null,
        suggestions: null,
-      },
+      }
    );
    return value;
  }
@@ -559,14 +548,14 @@ export default class HIRBuilder {
      const scope = this.#scopes[ii];
      if (
        (label === null &&
-          (scope.kind === 'loop' || scope.kind === 'switch')) ||
+          (scope.kind === "loop" || scope.kind === "switch")) ||
        label === scope.label
      ) {
        return scope.breakBlock;
      }
    }
    CompilerError.invariant(false, {
-      reason: 'Expected a loop or switch to be in scope',
+      reason: "Expected a loop or switch to be in scope",
      description: null,
      loc: null,
      suggestions: null,
@@ -581,13 +570,13 @@ export default class HIRBuilder {
  lookupContinue(label: string | null): BlockId {
    for (let ii = this.#scopes.length - 1; ii >= 0; ii--) {
      const scope = this.#scopes[ii];
-      if (scope.kind === 'loop') {
+      if (scope.kind === "loop") {
        if (label === null || label === scope.label) {
          return scope.continueBlock;
        }
      } else if (label !== null && scope.label === label) {
        CompilerError.invariant(false, {
-          reason: 'Continue may only refer to a labeled loop',
+          reason: "Continue may only refer to a labeled loop",
          description: null,
          loc: null,
          suggestions: null,
@@ -595,7 +584,7 @@ export default class HIRBuilder {
      }
    }
    CompilerError.invariant(false, {
-      reason: 'Expected a loop to be in scope',
+      reason: "Expected a loop to be in scope",
      description: null,
      loc: null,
      suggestions: null,
@@ -644,7 +633,7 @@ function _shrink(func: HIR): void {
    }
    reachable.add(blockId);
    const block = func.blocks.get(blockId)!;
-    block.terminal = mapTerminalSuccessors(block.terminal, prevTarget => {
+    block.terminal = mapTerminalSuccessors(block.terminal, (prevTarget) => {
      const target = resolveBlockTarget(prevTarget);
      queue.push(target);
      return target;
@@ -660,7 +649,7 @@ function _shrink(func: HIR): void {
 export function removeUnreachableForUpdates(fn: HIR): void {
  for (const [, block] of fn.blocks) {
    if (
-      block.terminal.kind === 'for' &&
+      block.terminal.kind === "for" &&
      block.terminal.update !== null &&
      !fn.blocks.has(block.terminal.update)
    ) {
@@ -681,10 +670,10 @@ export function removeDeadDoWhileStatements(func: HIR): void {
   * MergeConsecutiveBlocks figures out how to merge as appropriate.
   */
  for (const [_, block] of func.blocks) {
-    if (block.terminal.kind === 'do-while') {
+    if (block.terminal.kind === "do-while") {
      if (!visited.has(block.terminal.test)) {
        block.terminal = {
-          kind: 'goto',
+          kind: "goto",
          block: block.terminal.loop,
          variant: GotoVariant.Break,
          id: block.terminal.id,
@@ -711,7 +700,7 @@ export function reversePostorderBlocks(func: HIR): void {
 * may be in the output: blocks will be removed in the case of unreachable code in
 * the input.
 */
-function getReversePostorderedBlocks(func: HIR): HIR['blocks'] {
+function getReversePostorderedBlocks(func: HIR): HIR["blocks"] {
  const visited: Set<BlockId> = new Set();
  const used: Set<BlockId> = new Set();
  const usedFallthroughs: Set<BlockId> = new Set();
@@ -783,7 +772,7 @@ function getReversePostorderedBlocks(func: HIR): HIR['blocks'] {
        ...block,
        instructions: [],
        terminal: {
-          kind: 'unreachable',
+          kind: "unreachable",
          id: block.terminal.id,
          loc: block.terminal.loc,
        },
@@ -824,7 +813,7 @@ export function markPredecessors(func: HIR): void {
      return;
    }
    CompilerError.invariant(block != null, {
-      reason: 'unexpected missing block',
+      reason: "unexpected missing block",
      description: `block ${blockId}`,
      loc: GeneratedSource,
    });
@@ -837,7 +826,7 @@ export function markPredecessors(func: HIR): void {
    }
    visited.add(blockId);

-    const {terminal} = block;
+    const { terminal } = block;

    for (const successor of eachTerminalSuccessor(terminal)) {
      visit(successor, block);
@@ -852,7 +841,7 @@ export function markPredecessors(func: HIR): void {
 */
 function getTargetIfIndirection(block: BasicBlock): number | null {
  return block.instructions.length === 0 &&
-    block.terminal.kind === 'goto' &&
+    block.terminal.kind === "goto" &&
    block.terminal.variant === GotoVariant.Break
    ? block.terminal.block
    : null;
@@ -865,14 +854,14 @@ function getTargetIfIndirection(block: BasicBlock): number | null {
 export function removeUnnecessaryTryCatch(fn: HIR): void {
  for (const [, block] of fn.blocks) {
    if (
-      block.terminal.kind === 'try' &&
+      block.terminal.kind === "try" &&
      !fn.blocks.has(block.terminal.handler)
    ) {
      const handlerId = block.terminal.handler;
      const fallthroughId = block.terminal.fallthrough;
      const fallthrough = fn.blocks.get(fallthroughId);
      block.terminal = {
-        kind: 'goto',
+        kind: "goto",
        block: block.terminal.block,
        id: makeInstructionId(0),
        loc: block.terminal.loc,
@@ -893,13 +882,13 @@ export function removeUnnecessaryTryCatch(fn: HIR): void {

 export function createTemporaryPlace(
  env: Environment,
-  loc: SourceLocation,
+  loc: SourceLocation
 ): Place {
  return {
-    kind: 'Identifier',
+    kind: "Identifier",
    identifier: {
      id: env.nextIdentifierId,
-      mutableRange: {start: makeInstructionId(0), end: makeInstructionId(0)},
+      mutableRange: { start: makeInstructionId(0), end: makeInstructionId(0) },
      name: null,
      scope: null,
      type: makeType(),
--- a/Show More
+++ b/Show More