Skip to content

[No QA] Rewrite React Compiler CI compliance check#87182

Open
roryabraham wants to merge 17 commits intomainfrom
rory/react-compiler-ci-check
Open

[No QA] Rewrite React Compiler CI compliance check#87182
roryabraham wants to merge 17 commits intomainfrom
rory/react-compiler-ci-check

Conversation

@roryabraham
Copy link
Copy Markdown
Contributor

@roryabraham roryabraham commented Apr 6, 2026

Explanation of Change

Rewrites the React Compiler compliance check CI workflow from scratch. The new implementation is much simpler and has much simpler requirements - it just enforces:

  • New components and hooks must compile with React Compiler
  • Any existing components that already compile with React Compiler on main must not regress

The previous implementation (~860 lines) shelled out to npx react-compiler-healthcheck, parsed its stdout with regexes, and applied complex line-level diff analysis with manual memoization checking. The new implementation is ~200 lines and uses @babel/core's transformSync with babel-plugin-react-compiler directly, which is simpler, faster, and more reliable. The healthcheck is deprecated anyways.

One key difference is that we _don't suppress BuildHIR exceptions. In my experience it's pretty trivial to work around these, and I haven't really found any cases that are insurmountable. So I'm letting those surface so they can be fixed.

Key changes:

  • Use the babel transform directly to check if a file compiles with React Compiler (same approach proven in the ESLint plugin)
  • Three-state result per file: compiled / failed / no-components (leverages the compiler's own component/hook detection)
  • Two simple CI rules: new components/hooks must compile, existing ones must not regress vs main
  • Simple local CLI: npm run react-compiler-compliance-check check <files...>
  • Extract shared ReactCompilerConfig to eliminate duplication across babel.config.js, ESLint plugin, and this script
  • Fix pagination bug in Git.getChangedFileNames() (was only fetching first page of GitHub API results)
  • Add variadic positional arg support to scripts/utils/CLI.ts
  • Remove react-compiler-healthcheck dependency and its 3 patch files
  • Expand workflow path trigger to include .ts and .jsx files (hooks live in .ts files)

Fixed Issues

$ #68765

Tests

  1. Run npm run react-compiler-compliance-check check src/components/Button/index.tsx and verify it reports COMPILED
  2. Run npm run react-compiler-compliance-check check src/CONST.ts and verify it skips (no components)
  3. Run npx jest tests/unit/CLIVariadicTest.ts tests/unit/ReactCompilerComplianceCheckTest.ts and verify all 9 tests pass

Offline tests

N/A - CI tooling only, no runtime behavior.

QA Steps

N/A - CI tooling only.

  • Verify that no errors appear in the JS console

PR Author Checklist

  • I linked the correct issue in the ### Fixed Issues section above
  • I wrote clear testing steps that cover the changes made in this PR
    • I added steps for local testing in the Tests section
    • I added steps for the expected offline behavior in the Offline steps section
    • I added steps for Staging and/or Production testing in the QA steps section
    • I added steps to cover failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
    • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline)
    • I tested this PR with a High Traffic account against the staging or production API to ensure there are no regressions (e.g. long loading states that impact usability).
  • I included screenshots or videos for tests on all platforms
  • I ran the tests on all platforms & verified they passed on:
    • Android: Native
    • Android: mWeb Chrome
    • iOS: Native
    • iOS: mWeb Safari
    • MacOS: Chrome / Safari
  • I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
  • I verified there are no new alerts related to the canBeMissing param for useOnyx
  • I followed proper code patterns (see Reviewing the code)
    • I verified that any callback methods that were added or modified are named for what the method does and never what callback they handle (i.e. toggleReport and not onIconClick)
    • I verified that comments were added to code that is not self explanatory
    • I verified that any new or modified comments were clear, correct English, and explained "why" the code was doing something instead of only explaining "what" the code was doing.
    • I verified any copy / text shown in the product is localized by adding it to src/languages/* files and using the translation method
      • If any non-english text was added/modified, I used JaimeGPT to get English > Spanish translation. I then posted it in #expensify-open-source and it was approved by an internal Expensify engineer. Link to Slack message:
    • I verified all numbers, amounts, dates and phone numbers shown in the product are using the localization methods
    • I verified any copy / text that was added to the app is grammatically correct in English. It adheres to proper capitalization guidelines (note: only the first word of header/labels should be capitalized), and is either coming verbatim from figma or has been approved by marketing (in order to get marketing approval, ask the Bug Zero team member to add the Waiting for copy label to the issue)
    • I verified proper file naming conventions were followed for any new files or renamed files. All non-platform specific files are named after what they export and are not named "index.js". All platform-specific files are named for the platform the code supports as outlined in the README.
    • I verified the JSDocs style guidelines (in STYLE.md) were followed
  • If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
  • I followed the guidelines as stated in the Review Guidelines
  • I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
  • I verified all code is DRY (the PR doesn't include any logic written more than once, with the exception of tests)
  • I verified any variables that can be defined as constants (ie. in CONST.ts or at the top of the file that uses the constant) are defined as such
  • I verified that if a function's arguments changed that all usages have also been updated correctly
  • If any new file was added I verified that:
    • The file has a description of what it does and/or why is needed at the top of the file if the code is not self explanatory
  • If a new CSS style is added I verified that:
    • A similar style doesn't already exist
    • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(theme.componentBG))
  • If new assets were added or existing ones were modified, I verified that:
    • The assets are optimized and compressed (for SVG files, run npm run compress-svg)
    • The assets load correctly across all supported platforms.
  • If the PR modifies code that runs when editing or sending messages, I tested and verified there is no unexpected behavior for all supported markdown - URLs, single line code, code blocks, quotes, headings, bold, strikethrough, and italic.
  • If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
  • If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
  • If the PR modifies a component or page that can be accessed by a direct deeplink, I verified that the code functions as expected when the deeplink is used - from a logged in and logged out account.
  • If the PR modifies the UI (e.g. new buttons, new UI components, changing the padding/spacing/sizing, moving components, etc) or modifies the form input styles:
    • I verified that all the inputs inside a form are aligned with each other.
    • I added Design label and/or tagged @Expensify/design so the design team can review the changes.
  • If a new page is added, I verified it's using the ScrollView component to make it scrollable when more elements are added to the page.
  • I added unit tests for any new feature or bug fix in this PR to help automatically prevent regressions in this user flow.
  • If the main branch was merged into this PR after a review, I tested again and verified the outcome was still expected according to the Test steps.

Screenshots/Videos

Android: Native

N/A - CI tooling only

Android: mWeb Chrome

N/A - CI tooling only

iOS: Native

N/A - CI tooling only

iOS: mWeb Safari

N/A - CI tooling only

MacOS: Chrome / Safari

N/A - CI tooling only

Made with Cursor

Allow the last positional arg in a CLI config to be marked
`variadic: true`, which collects all remaining positional args
into a string[]. The type system correctly infers string[] for
variadic args.

Made-with: Cursor
New method returns {filename, status}[] using paginated GitHub API
in CI and git diff locally. Refactors getChangedFileNames() to be
a lightweight wrapper around it, fixing a pagination bug where
large PRs could have files silently dropped.

Made-with: Cursor
The compiler config was duplicated in babel.config.js and the
eslint-plugin-react-compiler-compat. Now both import from a
single source of truth at scripts/utils/reactCompilerConfig.js.

Made-with: Cursor
Replace the 860-line script that shelled out to react-compiler-healthcheck
and parsed stdout with regexes. The new implementation uses @babel/core's
transformSync with babel-plugin-react-compiler directly (~200 lines).

Two modes:
- `check <files...>` -- local CLI for checking specific files
- `check-changed` -- CI mode with two rules:
  1. New files with components/hooks must compile
  2. Modified files must not regress vs main

Uses a three-state return (compiled/failed/no-components) to correctly
skip non-React files without false positives.

Made-with: Cursor
Hooks typically live in .ts files, not just .tsx. The path trigger
now includes .ts, .tsx, and .jsx so the compliance check covers
all files that could contain React components or hooks.

Made-with: Cursor
The compliance check now uses babel-plugin-react-compiler directly,
making the react-compiler-healthcheck package unnecessary.

Made-with: Cursor
Simplify docs to reflect the rewritten tool: direct babel transform,
two CI rules (new files must compile, no regressions on modified files),
and simpler CLI usage.

Made-with: Cursor
The repo has zero .jsx files — everything is TypeScript.

Made-with: Cursor
Use `variadic?: true` literal type and explicit cast at the call
site to work around TypeScript's inability to narrow conditional
mapped types through tuple inference.

Made-with: Cursor
The `check` command now accepts directories (recursively finds
.ts/.tsx files) and glob patterns in addition to individual file
paths. Inputs are deduplicated and non-.ts/.tsx files are filtered.

Made-with: Cursor
Copy link
Copy Markdown
Contributor

@chrispader chrispader left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks good to me aside from minor requests! 🙌🏼

- Move resolveFilePaths to FileUtils.ts with configurable extensions
- Cache fs.existsSync/statSync to avoid redundant calls
- Use FILE_EXTENSIONS variable in log message

Made-with: Cursor
…JS check

The typecheck workflow blocks new .js files; add an exclusion for
config/babel/*.js since this config must be plain JS (consumed by
babel.config.js before TS compilation). Also rebuild GitHub Action
bundles to reflect getChangedFilesWithStatus() changes in Git.ts.

Made-with: Cursor
@roryabraham roryabraham requested a review from mountiny April 8, 2026 00:03
@roryabraham roryabraham marked this pull request as ready for review April 8, 2026 00:03
@roryabraham roryabraham requested a review from a team as a code owner April 8, 2026 00:03
@melvin-bot melvin-bot bot requested review from parasharrajat and removed request for a team April 8, 2026 00:03
@melvin-bot
Copy link
Copy Markdown

melvin-bot bot commented Apr 8, 2026

@parasharrajat Please copy/paste the Reviewer Checklist from here into a new comment on this PR and complete it. If you have the K2 extension, you can simply click: [this button]

@roryabraham
Copy link
Copy Markdown
Contributor Author

@mountiny do you think we should add this check as just a warning first, or just enable it? There might be some cases where it would be a bit confusing for people to fix. If we decide to merge through a failure, it will not continue to fail on subsequent PRs, because it only complains when:

  • a new file is added that doesn't compile
  • a file that was compiling before starts failing

Copy link
Copy Markdown

@chatgpt-codex-connector chatgpt-codex-connector bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 270c39d10d

ℹ️ About Codex in GitHub

Codex has been enabled to automatically review pull requests in this repo. Reviews are triggered when you

  • Open a pull request for review
  • Mark a draft as ready
  • Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

When you sign up for Codex through ChatGPT, Codex can also answer questions or update the PR, like "@codex address that feedback".

For renamed files, the GitHub API provides previous_filename which
we now surface through getChangedFilesWithStatus(). The regression
check uses this to look up the file on main at its old path,
correctly detecting regressions even when a file is renamed.

Made-with: Cursor
Use -M flag in git diff to detect file renames locally. Without
this, renames appeared as delete + add, incorrectly subjecting
renamed files to the "new files must compile" rule. Now renames
are properly detected with their previous path, matching the
behavior of the GitHub API in CI.

Made-with: Cursor
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants