Fix require('ReactFeatureFlags') in eslint-plugin-react-hooks www build#36243
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EugeneChoi4 merged 1 commit intofacebook:mainfrom Apr 9, 2026
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PR facebook#35951 added FB_WWW_DEV builds for eslint-plugin-react-hooks to get www-specific feature flag values. However, the FB_WWW build uses the full ReactFeatureFlags.www.js fork, which contains: const dynamicFeatureFlags = require('ReactFeatureFlags'); This is a www Haste module that only exists in the www runtime. Rollup can't tree-shake CJS require() calls (they're assumed side-effectful), so the bare require('ReactFeatureFlags') survives in the build output even though the eslint plugin only uses the static eprh_* exports. When the built artifact is synced to www at scripts/lint/eslint/rules/eslint-plugin-react-hooks/index.js, Node.js fails with "Cannot find module 'ReactFeatureFlags'" because Haste modules aren't available in the Node.js lint environment. Create a dedicated fork (ReactFeatureFlags.eslint-plugin.www.js) that exports only the static eprh_* flags with www values, without the require('ReactFeatureFlags') dependency. Wire it up in forks.js for the eslint-plugin-react-hooks entry point.
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…ld (#36243) PR #35951 added FB_WWW_DEV builds for eslint-plugin-react-hooks to get www-specific feature flag values. However, the FB_WWW build uses the full ReactFeatureFlags.www.js fork, which contains: const dynamicFeatureFlags = require('ReactFeatureFlags'); This is a www Haste module that only exists in the www runtime. Rollup can't tree-shake CJS require() calls (they're assumed side-effectful), so the bare require('ReactFeatureFlags') survives in the build output even though the eslint plugin only uses the static eprh_* exports. When the built artifact is synced to www at scripts/lint/eslint/rules/eslint-plugin-react-hooks/index.js, Node.js fails with "Cannot find module 'ReactFeatureFlags'" because Haste modules aren't available in the Node.js lint environment. Create a dedicated fork (ReactFeatureFlags.eslint-plugin.www.js) that exports only the static eprh_* flags with www values, without the require('ReactFeatureFlags') dependency. Wire it up in forks.js for the eslint-plugin-react-hooks entry point. <!-- Thanks for submitting a pull request! We appreciate you spending the time to work on these changes. Please provide enough information so that others can review your pull request. The three fields below are mandatory. Before submitting a pull request, please make sure the following is done: 1. Fork [the repository](https://github.com/facebook/react) and create your branch from `main`. 2. Run `yarn` in the repository root. 3. If you've fixed a bug or added code that should be tested, add tests! 4. Ensure the test suite passes (`yarn test`). Tip: `yarn test --watch TestName` is helpful in development. 5. Run `yarn test --prod` to test in the production environment. It supports the same options as `yarn test`. 6. If you need a debugger, run `yarn test --debug --watch TestName`, open `chrome://inspect`, and press "Inspect". 7. Format your code with [prettier](https://github.com/prettier/prettier) (`yarn prettier`). 8. Make sure your code lints (`yarn lint`). Tip: `yarn linc` to only check changed files. 9. Run the [Flow](https://flowtype.org/) type checks (`yarn flow`). 10. If you haven't already, complete the CLA. Learn more about contributing: https://reactjs.org/docs/how-to-contribute.html --> Co-authored-by: Eugene Choi <eugenechoi@meta.com> DiffTrain build for [705268d](705268d)
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…uilders-bounty#4) Claude Code sub-agent that reviews GitHub PRs with structured output: - CLI: claude-review --pr <url> [--post] [--output file] - GitHub Action: auto-reviews on PR open/sync - Output: summary, risks, suggestions, confidence score - Zero npm deps: pure bash + gh + claude CLI - Tested on 2 real PRs: facebook/react#36243, microsoft/vscode#308831 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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…ld (facebook#36243) PR facebook#35951 added FB_WWW_DEV builds for eslint-plugin-react-hooks to get www-specific feature flag values. However, the FB_WWW build uses the full ReactFeatureFlags.www.js fork, which contains: const dynamicFeatureFlags = require('ReactFeatureFlags'); This is a www Haste module that only exists in the www runtime. Rollup can't tree-shake CJS require() calls (they're assumed side-effectful), so the bare require('ReactFeatureFlags') survives in the build output even though the eslint plugin only uses the static eprh_* exports. When the built artifact is synced to www at scripts/lint/eslint/rules/eslint-plugin-react-hooks/index.js, Node.js fails with "Cannot find module 'ReactFeatureFlags'" because Haste modules aren't available in the Node.js lint environment. Create a dedicated fork (ReactFeatureFlags.eslint-plugin.www.js) that exports only the static eprh_* flags with www values, without the require('ReactFeatureFlags') dependency. Wire it up in forks.js for the eslint-plugin-react-hooks entry point. <!-- Thanks for submitting a pull request! We appreciate you spending the time to work on these changes. Please provide enough information so that others can review your pull request. The three fields below are mandatory. Before submitting a pull request, please make sure the following is done: 1. Fork [the repository](https://github.com/facebook/react) and create your branch from `main`. 2. Run `yarn` in the repository root. 3. If you've fixed a bug or added code that should be tested, add tests! 4. Ensure the test suite passes (`yarn test`). Tip: `yarn test --watch TestName` is helpful in development. 5. Run `yarn test --prod` to test in the production environment. It supports the same options as `yarn test`. 6. If you need a debugger, run `yarn test --debug --watch TestName`, open `chrome://inspect`, and press "Inspect". 7. Format your code with [prettier](https://github.com/prettier/prettier) (`yarn prettier`). 8. Make sure your code lints (`yarn lint`). Tip: `yarn linc` to only check changed files. 9. Run the [Flow](https://flowtype.org/) type checks (`yarn flow`). 10. If you haven't already, complete the CLA. Learn more about contributing: https://reactjs.org/docs/how-to-contribute.html --> Co-authored-by: Eugene Choi <eugenechoi@meta.com> DiffTrain build for [705268d](facebook@705268d)
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PR #35951 added FB_WWW_DEV builds for eslint-plugin-react-hooks to get www-specific feature flag values. However, the FB_WWW build uses the full ReactFeatureFlags.www.js fork, which contains:
const dynamicFeatureFlags = require('ReactFeatureFlags');
This is a www Haste module that only exists in the www runtime. Rollup can't tree-shake CJS require() calls (they're assumed side-effectful), so the bare require('ReactFeatureFlags') survives in the build output even though the eslint plugin only uses the static eprh_* exports.
When the built artifact is synced to www at
scripts/lint/eslint/rules/eslint-plugin-react-hooks/index.js, Node.js fails with "Cannot find module 'ReactFeatureFlags'" because Haste modules aren't available in the Node.js lint environment.
Create a dedicated fork (ReactFeatureFlags.eslint-plugin.www.js) that exports only the static eprh_* flags with www values, without the require('ReactFeatureFlags') dependency. Wire it up in forks.js for the eslint-plugin-react-hooks entry point.