Codestin Search App

SimenB · 2026-05-16T11:57:02Z

Summary

jest-haste-map has two hand-rolled directory walkers:

crawlers/node.ts — a recursive fs.readdir loop with a manual activeCalls counter, used as the JS fallback when find(1) is unavailable or forceNodeFilesystemAPI is set.
watchers/common.js recReaddir and FSEventsWatcher.ts — both wrap the walker npm dep to enumerate the initial file tree at watcher startup.

Both walk a tree and lstat each entry. This PR replaces them with a single shared helper at lib/walk.ts, backed by fdir.

fdir fans readdir calls out across libuv's threadpool natively. The lstat phase uses a bounded callback pool (no Promise-per-file overhead) — the pool size defaults to Math.max(os.availableParallelism() * 4, 32) so the threadpool stays saturated on large trees without queuing all callbacks at once.

What's unchanged:

findNative (the find(1) shell-out in crawlers/node.ts) — still the fastest path on large POSIX trees; still gated behind hasNativeFindSupport.
forceNodeFilesystemAPI — still functional; now forces the fdir path instead of the old fs.readdir recursion.
WatchmanWatcher and the watchman crawler — untouched.

Test plan

yarn build:js
yarn jest packages/jest-haste-map   # 154 tests, all pass
yarn typecheck:tests
yarn lint
yarn check-changelog
yarn constraints
yarn dedupe --check

Introduces a shared `lib/walk.ts` that replaces the two hand-rolled directory walkers in jest-haste-map: - `crawlers/node.ts` `find()` — recursive readdir with activeCalls counter - `watchers/common.js` `recReaddir` — wraps the `walker` npm dep Both walk a tree and stat per entry. `walk` uses fdir's async crawl (which fans readdir out across libuv's threadpool) plus a bounded callback-based lstat pool (fdir's `.withCallback()` API, keeping all internals callback-driven with a single Promise at the outer boundary) that avoids Promise-per-file overhead on million-file trees. Call sites are converted in follow-up commits.

Replace the hand-rolled fs.readdir recursive walker in crawlers/node.ts with the new lib/walk helper. The find(1) shell-out path (findNative) is unchanged; only the JS fallback path (used when find is unavailable or forceNodeFilesystemAPI is true) is replaced.

Replace `walker` npm dep usage in `watchers/common.js` and the private `recReaddir` in `FSEventsWatcher.ts` with the shared `lib/walk` helper.

- Fix "This options" → "This option" in enableSymlinks JSDoc (jest-types, jest-schemas, docs) - Fix inaccurate test comment in watchers/__tests__/index.test.ts — the ready-timeout is what triggers the rejection, not monkey-patching - Delete unused WatcherBackend union from watchers/types.ts - Add test for shouldUseWatchman(true) when isWatchmanInstalled() returns false - Fix README: forceNodeFilesystemAPI, hasteImplModulePath, hasteMapModulePath, skipPackageJson, throwOnModuleCollision are all optional with sane defaults - Note: HasteMapOptions.watchman is intentionally required (breaking change from the PR 16186 rewrite; callers must be explicit)

netlify · 2026-05-16T11:57:07Z

✅ Deploy Preview for jestjs ready!

Name	Link
🔨 Latest commit	`57c19e7`
🔍 Latest deploy log	https://app.netlify.com/projects/jestjs/deploys/6a08a1a6ae0a0e00082812f8
😎 Deploy Preview	https://deploy-preview-16187--jestjs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

To edit notification comments on pull requests, go to your Netlify project configuration.

Copilot

Pull request overview

Replaces jest-haste-map's hand-rolled directory walkers (the recursive fs.readdir loop in crawlers/node.ts and the walker npm dep used by FSEventsWatcher startup and watchers/common.js recReaddir) with a single shared helper at lib/walk.ts backed by fdir. The walker dependency is dropped from the package.

Changes:

New lib/walk.ts wraps fdir.crawl().withCallback() with a bounded callback-driven lstat pool and exposes a small walk(opts, done) API; covered by a new walk.test.ts.
crawlers/node.ts find and watchers/{FSEventsWatcher,common.js} switch to walk; findNative is simplified.
Misc cleanup: drops unused WatcherBackend type, fixes "This options" typo in three places, expands README defaults, adds CHANGELOG entry and updates CLAUDE.md.

Reviewed changes

Copilot reviewed 15 out of 16 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
packages/jest-haste-map/src/lib/walk.ts	New fdir-backed walker with bounded lstat pool.
packages/jest-haste-map/src/lib/tests/walk.test.ts	Tests for the new helper.
packages/jest-haste-map/src/crawlers/node.ts	Rewrites `find` on top of `walk`; drops `enableSymlinks` plumbing and simplifies `findNative`.
packages/jest-haste-map/src/crawlers/tests/node.test.js	Adjusts the `graceful-fs` mock for fdir (adds `isFile`, `readdirSync`, `realpath`, trailing-slash normalization).
packages/jest-haste-map/src/watchers/FSEventsWatcher.ts	Replaces `walker`-based startup walk with `walk`; drops local `recReaddir`/`normalizeProxy`.
packages/jest-haste-map/src/watchers/common.js	`recReaddir` now uses `walk`.
packages/jest-haste-map/src/watchers/types.ts	Removes unused `WatcherBackend` export.
packages/jest-haste-map/src/watchers/tests/index.test.ts	Tightens `shouldUseWatchman` tests; clarifies a comment.
packages/jest-haste-map/package.json	Adds `fdir`, removes `walker`.
packages/jest-haste-map/README.md	Marks several options as not required and documents defaults.
packages/jest-haste-map/CLAUDE.md	Documents `lib/walk.ts` and updates crawler/watcher notes.
packages/jest-types/src/Config.ts, packages/jest-schemas/src/raw-types.ts, docs/Configuration.md	Fixes "This options" → "This option" typo.
yarn.lock	Reflects added `fdir` and dropped `walker` resolutions.
CHANGELOG.md	Adds entry under Chore & Maintenance.

pkg-pr-new · 2026-05-16T12:02:46Z

Open in StackBlitz

babel-jest

npm i https://pkg.pr.new/babel-jest@16187

babel-plugin-jest-hoist

npm i https://pkg.pr.new/babel-plugin-jest-hoist@16187

babel-preset-jest

npm i https://pkg.pr.new/babel-preset-jest@16187

create-jest

npm i https://pkg.pr.new/create-jest@16187

@jest/diff-sequences

npm i https://pkg.pr.new/@jest/diff-sequences@16187

expect

npm i https://pkg.pr.new/expect@16187

@jest/expect-utils

npm i https://pkg.pr.new/@jest/expect-utils@16187

jest

npm i https://pkg.pr.new/jest@16187

jest-changed-files

npm i https://pkg.pr.new/jest-changed-files@16187

jest-circus

npm i https://pkg.pr.new/jest-circus@16187

jest-cli

npm i https://pkg.pr.new/jest-cli@16187

jest-config

npm i https://pkg.pr.new/jest-config@16187

@jest/console

npm i https://pkg.pr.new/@jest/console@16187

@jest/core

npm i https://pkg.pr.new/@jest/core@16187

@jest/create-cache-key-function

npm i https://pkg.pr.new/@jest/create-cache-key-function@16187

jest-diff

npm i https://pkg.pr.new/jest-diff@16187

jest-docblock

npm i https://pkg.pr.new/jest-docblock@16187

jest-each

npm i https://pkg.pr.new/jest-each@16187

@jest/environment

npm i https://pkg.pr.new/@jest/environment@16187

jest-environment-jsdom

npm i https://pkg.pr.new/jest-environment-jsdom@16187

@jest/environment-jsdom-abstract

npm i https://pkg.pr.new/@jest/environment-jsdom-abstract@16187

jest-environment-node

npm i https://pkg.pr.new/jest-environment-node@16187

@jest/expect

npm i https://pkg.pr.new/@jest/expect@16187

@jest/fake-timers

npm i https://pkg.pr.new/@jest/fake-timers@16187

@jest/get-type

npm i https://pkg.pr.new/@jest/get-type@16187

@jest/globals

npm i https://pkg.pr.new/@jest/globals@16187

jest-haste-map

npm i https://pkg.pr.new/jest-haste-map@16187

jest-jasmine2

npm i https://pkg.pr.new/jest-jasmine2@16187

jest-leak-detector

npm i https://pkg.pr.new/jest-leak-detector@16187

jest-matcher-utils

npm i https://pkg.pr.new/jest-matcher-utils@16187

jest-message-util

npm i https://pkg.pr.new/jest-message-util@16187

jest-mock

npm i https://pkg.pr.new/jest-mock@16187

@jest/pattern

npm i https://pkg.pr.new/@jest/pattern@16187

jest-phabricator

npm i https://pkg.pr.new/jest-phabricator@16187

jest-regex-util

npm i https://pkg.pr.new/jest-regex-util@16187

@jest/reporters

npm i https://pkg.pr.new/@jest/reporters@16187

jest-resolve

npm i https://pkg.pr.new/jest-resolve@16187

jest-resolve-dependencies

npm i https://pkg.pr.new/jest-resolve-dependencies@16187

jest-runner

npm i https://pkg.pr.new/jest-runner@16187

jest-runtime

npm i https://pkg.pr.new/jest-runtime@16187

@jest/schemas

npm i https://pkg.pr.new/@jest/schemas@16187

jest-snapshot

npm i https://pkg.pr.new/jest-snapshot@16187

@jest/snapshot-utils

npm i https://pkg.pr.new/@jest/snapshot-utils@16187

@jest/source-map

npm i https://pkg.pr.new/@jest/source-map@16187

@jest/test-result

npm i https://pkg.pr.new/@jest/test-result@16187

@jest/test-sequencer

npm i https://pkg.pr.new/@jest/test-sequencer@16187

@jest/transform

npm i https://pkg.pr.new/@jest/transform@16187

@jest/types

npm i https://pkg.pr.new/@jest/types@16187

jest-util

npm i https://pkg.pr.new/jest-util@16187

jest-validate

npm i https://pkg.pr.new/jest-validate@16187

jest-watcher

npm i https://pkg.pr.new/jest-watcher@16187

jest-worker

npm i https://pkg.pr.new/jest-worker@16187

pretty-format

npm i https://pkg.pr.new/pretty-format@16187

commit: 57c19e7

Copilot

Pull request overview

Copilot reviewed 15 out of 16 changed files in this pull request and generated 2 comments.

Copilot

Pull request overview

Copilot reviewed 15 out of 16 changed files in this pull request and generated 3 comments.

Copilot

Pull request overview

Copilot reviewed 15 out of 16 changed files in this pull request and generated no new comments.

Copilot

Pull request overview

Copilot reviewed 17 out of 18 changed files in this pull request and generated 1 comment.

Copilot

Pull request overview

Copilot reviewed 17 out of 18 changed files in this pull request and generated no new comments.

SimenB added 5 commits May 16, 2026 13:56

refactor(jest-haste-map): use walk in recReaddir

ec8e05f

Replace `walker` npm dep usage in `watchers/common.js` and the private `recReaddir` in `FSEventsWatcher.ts` with the shared `lib/walk` helper.

update claude.md

7430931

Copilot AI review requested due to automatic review settings May 16, 2026 11:57

Copilot started reviewing on behalf of SimenB May 16, 2026 11:57 View session

Copilot AI reviewed May 16, 2026

View reviewed changes

Comment thread packages/jest-haste-map/src/crawlers/node.ts Outdated

Comment thread packages/jest-haste-map/src/crawlers/node.ts

Comment thread packages/jest-haste-map/CLAUDE.md Outdated

oops

26e6e0a

SimenB requested a review from Copilot May 16, 2026 12:22

Copilot started reviewing on behalf of SimenB May 16, 2026 12:25 View session

we want to resolve link ourself

5ab0c00

Copilot AI reviewed May 16, 2026

View reviewed changes

Comment thread packages/jest-haste-map/src/watchers/FSEventsWatcher.ts

Comment thread packages/jest-haste-map/src/crawlers/node.ts Outdated

Oops again

cf0219d

SimenB commented May 16, 2026

View reviewed changes

Comment thread packages/jest-haste-map/src/crawlers/node.ts Outdated

Apply suggestion from @SimenB

2c881c4

SimenB requested a review from Copilot May 16, 2026 12:44

SimenB closed this May 16, 2026

Copilot started reviewing on behalf of SimenB May 16, 2026 12:45 View session

SimenB commented May 16, 2026

View reviewed changes

Comment thread packages/jest-haste-map/src/crawlers/node.ts Outdated

Copilot AI reviewed May 16, 2026

View reviewed changes

Comment thread packages/jest-haste-map/src/crawlers/node.ts Outdated

Comment thread packages/jest-haste-map/CLAUDE.md Outdated

Comment thread packages/jest-haste-map/src/lib/walk.ts Outdated

SimenB added 2 commits May 16, 2026 17:19

review comments

30a13d4

readability++

244cf4e

SimenB reopened this May 16, 2026

SimenB requested a review from Copilot May 16, 2026 15:20

Copilot started reviewing on behalf of SimenB May 16, 2026 15:21 View session

Copilot AI reviewed May 16, 2026

View reviewed changes

self review

5883cba

add stat cache

3e0b596

SimenB requested a review from Copilot May 16, 2026 16:07

Copilot started reviewing on behalf of SimenB May 16, 2026 16:09 View session

Copilot AI reviewed May 16, 2026

View reviewed changes

Comment thread packages/jest-haste-map/src/lib/__tests__/walk.test.ts

more test coverage

5e72812

SimenB requested a review from Copilot May 16, 2026 16:23

Copilot started reviewing on behalf of SimenB May 16, 2026 16:24 View session

Copilot AI reviewed May 16, 2026

View reviewed changes

SimenB added 2 commits May 16, 2026 18:48

reduce string allocations

597bcfb

performance consideration

57c19e7

SimenB merged commit d6cdf48 into jestjs:main May 16, 2026
90 checks passed

SimenB deleted the fdir-replacement branch May 16, 2026 17:25

Uh oh!

Conversation

SimenB commented May 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Test plan

Uh oh!

netlify Bot commented May 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

✅ Deploy Preview for jestjs ready!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

pkg-pr-new Bot commented May 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

SimenB commented May 16, 2026 •

edited

Loading

netlify Bot commented May 16, 2026 •

edited

Loading

pkg-pr-new Bot commented May 16, 2026 •

edited

Loading