fix(jest-haste-map): tolerate a locked file while indexing on Windows by SimenB · Pull Request #16358 · jestjs/jest

SimenB · 2026-08-17T06:34:26Z

Summary

One behavioural fix plus some minor documentation tweaks.

A file another process holds open aborts the crawl on Windows. workerError treated exactly two codes as recoverable:

if (!["ENOENT", "EACCES"].includes(error.code)) {
  throw error;
}

Anything else fails the whole build. On Windows that includes EPERM, which is what git maintenance touching .git/index.lock or .git/objects looks like from the outside — a transient condition that says nothing about the file being indexable. The watchers already survive it: #16295 added isIgnorableFileError for precisely this, but only on the watch path, so a crawl hitting the same file still died.

That helper lived in watchers/common.ts. Both the watch path and the crawl path want it now, so it moves to lib/isIgnorableFileError.ts instead of having lib/FileProcessor.ts reach sideways into watchers/ for an errno predicate. ParcelWatcher and WatchmanWatcher import it from there, and its tests move with it.

EACCES stays a separate condition rather than folding into the helper, because the two callers want different answers: an unreadable file should not tear a watcher down, but during indexing it only means this one file cannot be read. Collapsing them would silently drop EACCES tolerance.

Docs. Three corrections to packages/jest-haste-map/CLAUDE.md, and a comment in walk.ts:

ChangeQueue's 30 ms interval was described as a debounce. It is a periodic flush that emits whatever has queued and does not reset on activity.
The same line merged two distinct guards into one claim. They are separate: a Set of type:path:mtime keys drops duplicates within a frame, and a direct mtime comparison drops change events for files that were only accessed.
Added that ModuleMap's toJSON/fromJSON run for every test worker, not just for the on-disk cache — worth knowing before touching them, as fix(jest-haste-map): restore the nested duplicates index in ModuleMap.fromJSON #16353 showed.
Added that overlapping roots are collapsed by watchman via watch-project but walked separately by find(), so the shared subtree is traversed twice. The map stays correct, and statCache spares some of the repeated lstat calls — best-effort only, since the walks run concurrently and can both miss a path before either caches it. The traversal is always duplicated.
walk.ts: includeDirs and the dir entry kind have no caller and read as dead surface. They are there for symlinked-directory support.

Test plan

lib/__tests__/FileProcessor.test.ts asserts the changed line on both platforms: EPERM is tolerated on win32 and still thrown on linux. It loads FileProcessor through jest.isolateModules with node:os mocked, because the predicate reads the platform once at module load.

That test is the guard. The error-path cases around it — EACCES and ENOENT dropping the file without throwing, an unrecognised code (EISDIR) propagating — behave the same before and after this change, so on their own they left a full revert green. Reverting workerError to the original array check now fails:

● FileProcessor › processFile › on win32, an EPERM worker error keeps the file: false

FULL REVERT:   1 failed, 16 passed
as committed: 17 passed

watchers/__tests__/common.test.ts → lib/__tests__/isIgnorableFileError.test.ts as a rename, keeping its platform matrix (ENOENT everywhere, EPERM only on win32, EACCES never).

yarn jest packages/jest-haste-map

Test Suites: 23 passed, 23 total
Tests:       213 passed, 213 total
Snapshots:   5 passed, 5 total

Also green: yarn lint, yarn typecheck:tests, yarn check-changelog, yarn check-copyright-headers.

The agent notes called ChangeQueue's 30 ms interval a debounce; it is a periodic flush that emits whatever has queued, and it does not reset on activity. The same line merged two distinct guards — the event-key `Set` and the mtime comparison — into one claim. Add the two things a reader has to discover the hard way: that `ModuleMap`'s `toJSON`/`fromJSON` run for every test worker rather than only for the cache, and that overlapping roots are collapsed by watchman but traversed twice by the node crawler. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

`includeDirs` and `WalkEntryKind`'s `dir` case have no caller — `find()` asks for files only — which reads as dead surface. Both exist for symlinked- directory support, where following a link means walking the directory behind it. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

netlify · 2026-08-17T06:34:33Z

✅ Deploy Preview for jestjs ready!

Name	Link
🔨 Latest commit	`a618f0f`
🔍 Latest deploy log	https://app.netlify.com/projects/jestjs/deploys/6a82b3fb5bde7a0008592902
😎 Deploy Preview	https://deploy-preview-16358--jestjs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
🤖 Make changes	Run an agent on this branch

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

`workerError` treated only `ENOENT` and `EACCES` as recoverable, so an `EPERM` from a file another process holds open failed the whole crawl. The watchers already survive that case via `isIgnorableFileError` (jestjs#16295); file processing did not. Move that helper from `watchers/common.ts` into `lib/`: both the watch path and the crawl path use it now, and `lib/FileProcessor.ts` should not reach sideways into `watchers/` for an errno predicate. `EACCES` stays a separate condition: an unreadable file should not tear a watcher down, but here it only means this one file cannot be indexed. Also correct the agent notes and add two comments from the same review pass: `ChangeQueue`'s 30 ms interval is a periodic flush rather than a debounce, its two dedup guards are distinct, `ModuleMap`'s `toJSON`/`fromJSON` run for every test worker, overlapping roots are collapsed by watchman but walked twice by `find()`, and `walk()`'s `includeDirs`/`dir` surface exists for symlinked directories. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Copilot

Pull request overview

Improves Windows crawl resilience by treating transient EPERM errors as ignorable during indexing.

Changes:

Shares the ignorable-file-error predicate across crawlers and watchers.
Adds worker error-path tests.
Updates haste-map documentation and changelog.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
`CHANGELOG.md`	Records the Windows indexing fix.
`packages/jest-haste-map/CLAUDE.md`	Updates architecture notes.
`packages/jest-haste-map/src/lib/FileProcessor.ts`	Ignores Windows `EPERM` during indexing.
`packages/jest-haste-map/src/lib/__tests__/FileProcessor.test.ts`	Expands worker-error tests.
`packages/jest-haste-map/src/lib/__tests__/isIgnorableFileError.test.ts`	Relocates helper tests.
`packages/jest-haste-map/src/lib/isIgnorableFileError.ts`	Houses the shared error predicate.
`packages/jest-haste-map/src/lib/walk.ts`	Documents directory-entry support.
`packages/jest-haste-map/src/watchers/ParcelWatcher.ts`	Imports the relocated helper.
`packages/jest-haste-map/src/watchers/WatchmanWatcher.js`	Imports the relocated helper.
`packages/jest-haste-map/src/watchers/common.ts`	Removes the former helper definition.

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

pkg-pr-new · 2026-08-17T06:51:24Z

Open in StackBlitz

babel-jest

npm i https://pkg.pr.new/babel-jest@16358

babel-plugin-jest-hoist

npm i https://pkg.pr.new/babel-plugin-jest-hoist@16358

babel-preset-jest

npm i https://pkg.pr.new/babel-preset-jest@16358

create-jest

npm i https://pkg.pr.new/create-jest@16358

@jest/diff-sequences

npm i https://pkg.pr.new/@jest/diff-sequences@16358

expect

npm i https://pkg.pr.new/expect@16358

@jest/expect-utils

npm i https://pkg.pr.new/@jest/expect-utils@16358

jest

npm i https://pkg.pr.new/jest@16358

jest-changed-files

npm i https://pkg.pr.new/jest-changed-files@16358

jest-circus

npm i https://pkg.pr.new/jest-circus@16358

jest-cli

npm i https://pkg.pr.new/jest-cli@16358

jest-config

npm i https://pkg.pr.new/jest-config@16358

@jest/console

npm i https://pkg.pr.new/@jest/console@16358

@jest/core

npm i https://pkg.pr.new/@jest/core@16358

@jest/create-cache-key-function

npm i https://pkg.pr.new/@jest/create-cache-key-function@16358

jest-diff

npm i https://pkg.pr.new/jest-diff@16358

jest-docblock

npm i https://pkg.pr.new/jest-docblock@16358

jest-each

npm i https://pkg.pr.new/jest-each@16358

@jest/environment

npm i https://pkg.pr.new/@jest/environment@16358

jest-environment-jsdom

npm i https://pkg.pr.new/jest-environment-jsdom@16358

@jest/environment-jsdom-abstract

npm i https://pkg.pr.new/@jest/environment-jsdom-abstract@16358

jest-environment-node

npm i https://pkg.pr.new/jest-environment-node@16358

@jest/expect

npm i https://pkg.pr.new/@jest/expect@16358

@jest/fake-timers

npm i https://pkg.pr.new/@jest/fake-timers@16358

@jest/get-type

npm i https://pkg.pr.new/@jest/get-type@16358

@jest/globals

npm i https://pkg.pr.new/@jest/globals@16358

jest-haste-map

npm i https://pkg.pr.new/jest-haste-map@16358

jest-jasmine2

npm i https://pkg.pr.new/jest-jasmine2@16358

jest-leak-detector

npm i https://pkg.pr.new/jest-leak-detector@16358

jest-matcher-utils

npm i https://pkg.pr.new/jest-matcher-utils@16358

jest-message-util

npm i https://pkg.pr.new/jest-message-util@16358

jest-mock

npm i https://pkg.pr.new/jest-mock@16358

@jest/pattern

npm i https://pkg.pr.new/@jest/pattern@16358

jest-phabricator

npm i https://pkg.pr.new/jest-phabricator@16358

jest-regex-util

npm i https://pkg.pr.new/jest-regex-util@16358

@jest/reporters

npm i https://pkg.pr.new/@jest/reporters@16358

jest-resolve

npm i https://pkg.pr.new/jest-resolve@16358

jest-resolve-dependencies

npm i https://pkg.pr.new/jest-resolve-dependencies@16358

jest-runner

npm i https://pkg.pr.new/jest-runner@16358

jest-runtime

npm i https://pkg.pr.new/jest-runtime@16358

@jest/schemas

npm i https://pkg.pr.new/@jest/schemas@16358

jest-snapshot

npm i https://pkg.pr.new/jest-snapshot@16358

@jest/snapshot-utils

npm i https://pkg.pr.new/@jest/snapshot-utils@16358

@jest/source-map

npm i https://pkg.pr.new/@jest/source-map@16358

@jest/test-result

npm i https://pkg.pr.new/@jest/test-result@16358

@jest/test-sequencer

npm i https://pkg.pr.new/@jest/test-sequencer@16358

@jest/transform

npm i https://pkg.pr.new/@jest/transform@16358

@jest/types

npm i https://pkg.pr.new/@jest/types@16358

jest-util

npm i https://pkg.pr.new/jest-util@16358

jest-validate

npm i https://pkg.pr.new/jest-validate@16358

jest-watcher

npm i https://pkg.pr.new/jest-watcher@16358

jest-worker

npm i https://pkg.pr.new/jest-worker@16358

pretty-format

npm i https://pkg.pr.new/pretty-format@16358

commit: a618f0f

The added tests covered `EACCES`, `ENOENT` and `EISDIR`, all of which behave identically before and after the change, so reverting the fix outright left them green — the `EPERM`-on-Windows path they exist for was never asserted. Cover both platforms, loading `FileProcessor` through `jest.isolateModules` because the predicate reads the platform once at module load. Also fix two claims found in review. The comment cited `nodejs/node#4337`, which is an HTTP Upgrade change rather than anything about file locking; drop the reference and describe the behaviour on its own. And `statCache` spares repeated `lstat` calls only best-effort — the per-root walks run concurrently and can both miss a path before either caches it, as `walk.ts` already notes. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

| datasource | package | from | to | | ---------- | ------- | ------ | ------ | | npm | jest | 30.4.2 | 30.5.0 | ## [v30.5.0](https://github.com/jestjs/jest/blob/HEAD/CHANGELOG.md#3050) ##### Features - `[@jest/expect-utils, jest-mock]` Add `mockFn.whenCalledWith(...args)` for configuring return values per argument list, with first-class asymmetric-matcher support ([#16053](jestjs/jest#16053)) - `[@jest/expect-utils]` Export `AsymmetricMatcher` and `FunctionParameters` types (previously private to `expect`) ([#16053](jestjs/jest#16053)) - `[jest-circus, jest-core, jest-jasmine2, jest-test-result, jest-types]` `--collectTests` now expands `test.each`/`describe.each` cases and reports per-status counts (skipped/todo via the new `wouldRun` flag for selected tests) plus a summary line that match a real run, including under `--testNamePattern` and `.only`/`fdescribe` focus on both the circus and jasmine2 runners ([#16259](jestjs/jest#16259)) - `[jest-circus, jest-environment, jest-runtime, jest-types]` Add describe-level retries via `jest.retryTimes(..., {entireDescribe: true})` ([#16322](jestjs/jest#16322)) - `[jest-circus, jest-message-util, jest-reporters, jest-types]` Add `retryMessages` to `AssertionResult` and export `formatErrorStack`, so the retry log renders nested `cause` and `AggregateError` sections with code frames instead of serialized `[cause]:`/`[errors]:` markers ([#16316](jestjs/jest#16316)) - `[jest-circus, jest-types]` Add `unhandledErrorsDetailed` to `Circus.RunResult`, so an unhandled rejection reports its `cause` chain and `AggregateError` entries with code frames instead of a pre-serialized stack ([#16316](jestjs/jest#16316)) - `[jest-haste-map]` Replace `NodeWatcher` and `FSEventsWatcher` with `@parcel/watcher` for the non-watchman watch path ([#16188](jestjs/jest#16188)) - `[jest-resolve]` Bump `unrs-resolver` to 1.12.1, remove `jest-pnp-resolver` and unnecessary checks ([#15721](jestjs/jest#15721)) - `[jest-resolve]` Honor Node's `--preserve-symlinks` / `NODE_PRESERVE_SYMLINKS` in the default resolver by passing `symlinks: false` to `unrs-resolver` ([#16260](jestjs/jest#16260)) - `[jest-runtime]` Apply automocking and manual `__mocks__` files to synchronously evaluable ESM graphs on Node 24.9+ - static imports, dynamic `import()` and `require()` of an ESM file now generate an automock from the real module's namespace instead of failing with "Attempting to import a mock without a factory". Graphs that need async evaluation (top-level await) or an async-only resolver or transformer still throw ([#16391](jestjs/jest#16391)) - `[jest-runtime]` Route `process.getBuiltinModule` through the sandbox, so it returns the sandbox `process` and the hooked `node:module` instead of the host's ([#16391](jestjs/jest#16391)) - `[jest-runtime]` Throw an actionable error from `module.register()` and `module.registerHooks()` inside a test - the hooks attached to the loader running Jest itself, never saw the sandboxed requires they were meant for, and stayed registered for every later test file in the worker ([#16391](jestjs/jest#16391)) - `[jest-runtime]` Surface resolution and import-attribute errors in an ESM graph before executing any of its CJS dependencies on Node 24.9+, matching Node's run-nothing-on-a-broken-graph behavior; the legacy loader on older versions keeps its linking-time execution order ([#16391](jestjs/jest#16391)) - `[jest-runtime]` Throw `ERR_SOURCE_PHASE_NOT_DEFINED` with an actionable message for `import source` and `import.source()`, instead of failing at instantiation with V8's bare "Source phase import object is not defined" ([#16391](jestjs/jest#16391)) - `[jest-runtime]` Emit the JSON-without-import-attribute deprecation warning once per test file instead of once per worker, so it is no longer silently swallowed for every file after the first ([#16391](jestjs/jest#16391)) - `[jest-runtime]` Set `import.meta.main` to `true` in the test file and `false` in every module it loads, matching Node 24+ ([#16367](jestjs/jest#16367)) - `[jest-runtime]` Resolve the `module-sync` export condition, so a package that exposes its ESM entry point for `require()` loads the same file Node would ([#16336](jestjs/jest#16336)) - `[jest-snapshot]` Add external snapshot paths to custom reporter failure details ([#16374](jestjs/jest#16374)) ##### Fixes - `[jest-console, jest-reporters]` `CustomConsole` now buffers console output so `TestResult.console` is populated for reporters when `verbose` is enabled, while `GitHubActionsReporter` avoids replaying buffered output in verbose mode ([#16155](jestjs/jest#16155)) - `[expect, jest-message-util, jest-pattern, jest-regex-util, jest-util]` Revert `node:` protocol imports to restore webpack/browser-bundle compatibility ([#16167](jestjs/jest#16167)) - `[expect]` Widen `toMatchObject` and `objectContaining` parameter type from `Record<string, unknown>` to `object` so class instances are accepted ([#16196](jestjs/jest#16196)) - `[jest-circus]` Call a generator test body with the shared test context, so `this` matches what a regular test function receives ([#16347](jestjs/jest#16347)) - `[jest-circus]` Capture the error listeners of the parent process instead of the in-sandbox `process`, so listeners registered before the test file survive teardown and sandbox listeners no longer leak onto the parent ([#16347](jestjs/jest#16347)) - `[jest-circus]` Clear `currentlyRunningTest` after skipped and todo tests ([#16342](jestjs/jest#16342)) - `[jest-circus]` Prevent late `done()` callbacks from affecting later test or hook invocations ([#16343](jestjs/jest#16343)) - `[jest-circus, jest-jasmine2]` Honor `--expand` when formatting `node:assert` failures, instead of always collapsing the diff ([#16347](jestjs/jest#16347)) - `[jest-circus, jest-jasmine2, jest-message-util]` Serialize the inner errors of an `AggregateError` into `failureMessages`, `retryReasons` and `unhandledErrors`, so `--json` output and reporter annotations include them ([#16316](jestjs/jest#16316)) - `[jest-circus, jest-snapshot]` Keep snapshot state and counts correct when a test retries ([#16344](jestjs/jest#16344)) - `[@jest/create-cache-key-function]` Include the caller support flags in the generated key, so a transformer that emits ESM or CJS based on them no longer shares one cache entry between the two ([#16331](jestjs/jest#16331)) - `[@jest/create-cache-key-function]` Include the stringified project config in the generated key, so editing a transformer's own settings invalidates what it cached ([#16331](jestjs/jest#16331)) - `[@jest/transform]` Include the caller support flags in a transform's cache key, so a file transformed both as ESM and as CJS no longer serves one shape's output for the other ([#16331](jestjs/jest#16331)) - `[jest-config]` Add missing `findRelatedTests`, `outputFile`, and `replname` entries to `ValidConfig` so they no longer trigger spurious "Unknown option" warnings ([#16224](jestjs/jest#16224)) - `[jest-config]` Use `--config` for the global config when multiple `--projects` are specified ([#16273](jestjs/jest#16273)) - `[jest-core]` Serialize `bigint` values in `--json` and `--outputFile` output as their literal form (`4n`), instead of failing the run with `TypeError: Do not know how to serialize a BigInt` ([#16338](jestjs/jest#16338)) - `[jest-core]` Do not report a `CustomGC` async resource (used by N-API addons such as napi-rs for per-isolate GC bookkeeping) as an open handle, since it is `napi_unref`'d by the addon and can never keep the event loop alive ([#16379](jestjs/jest#16379)) - `[jest-each]` Keep a `$&`, `` $` ``, `$'` or `$$` inside a `%p` param value out of the replacement, so the title shows the value instead of the text around it ([#16338](jestjs/jest#16338)) - `[jest-each]` Interpolate a `bigint` into a `%j` title as its literal form (`"4n"`) at any depth, instead of throwing `TypeError: Do not know how to serialize a BigInt` while collecting the tests ([#16338](jestjs/jest#16338)) - `[jest-environment, jest-runtime]` Bind `sandboxInjectedGlobals` to the right values when `injectGlobals` is `false`, instead of shifting every one of them by a position ([#16377](jestjs/jest#16377)) - `[jest-environment-node, jest-util]` Only warn about a conflicting `globalsCleanup` mode when one was explicitly configured, and follow the mode that is actually in effect ([#16323](jestjs/jest#16323)) - `[jest-environment-node, jest-util]` Stop resolving lazy globals when setting up an environment, so Node 26's builtin module globals are no longer loaded (and no longer emit their deprecation warnings) for every test file ([#16324](jestjs/jest#16324)) - `[jest-haste-map]` Keep watch mode alive when an outside process briefly makes a file unreadable on Windows, instead of tearing the watcher down on `EPERM` ([#16295](jestjs/jest#16295)) - `[jest-haste-map]` Keep indexing when an outside process holds a file open on Windows, instead of failing the whole crawl on `EPERM` ([#16358](jestjs/jest#16358)) - `[jest-haste-map]` Keep a duplicated manual mock resolving when the file it pointed at is deleted in watch mode ([#16360](jestjs/jest#16360)) - `[jest-haste-map]` Shut the worker farm down when a duplicate manual mock aborts the build under `throwOnModuleCollision` ([#16354](jestjs/jest#16354)) - `[jest-haste-map]` Attach the watchman client's `error` listener before the first command, so a watchman failure falls back to the node crawler instead of crashing on an unhandled `error` event, and always end the client ([#16355](jestjs/jest#16355)) - `[jest-haste-map]` Stop delivering watch events after `WatchmanWatcher` is closed, and route its warnings through the configured console ([#16355](jestjs/jest#16355)) - `[jest-haste-map]` Restore the nested `duplicates` index correctly in `ModuleMap.fromJSON`, so a haste collision reported inside a test worker raises `DuplicateHasteCandidatesError` instead of a `TypeError` ([#16353](jestjs/jest#16353)) - `[jest-haste-map]` Match watched files on a full extension, so `moduleFileExtensions: ['js']` no longer accepts `foo.mjs` ([#16352](jestjs/jest#16352)) - `[jest-haste-map]` Delimit the fields that make up the haste map cache key, so two different option sets cannot hash to the same cache file ([#16352](jestjs/jest#16352)) - `[jest-message-util]` Print the inner errors of an `AggregateError` thrown inside a test ([#16316](jestjs/jest#16316)) - `[jest-message-util]` Indent nested `cause` and `AggregateError` sections of a test failure by one level per depth, so the nesting is legible instead of rendering flat ([#16316](jestjs/jest#16316)) - `[jest-message-util]` Color stack traces line by line so blank lines stay blank ([#16316](jestjs/jest#16316)) - `[jest-message-util]` Detect Jest's own frames without assuming the checkout directory's name, and cover `@jest/*` packages, so stack traces and code frames point at user code ([#16326](jestjs/jest#16326)) - `[jest-mock]` `mockResolvedValue` / `mockRejectedValue` now see all overload return types, so a Promise-returning overload survives even when a later overload returns a non-Promise (e.g. `pg.Client['end']`) ([#16237](jestjs/jest#16237)) - `[@jest-environment/jsdom-abstract]` Make `@types/jsdom` a peer dependency ([#16166](jestjs/jest#16166)) - `[jest-mock]` Remove the leftover own accessor descriptor when restoring a `spyOn` of an inherited getter or setter, so the instance keeps reflecting the prototype ([#16226](jestjs/jest#16226)) - `[jest-resolve]` Include `extensionsToTreatAsEsm` in the `shouldLoadAsEsm` cache key, so projects with different extension lists don't read each other's answers ([#16369](jestjs/jest#16369)) - `[jest-resolve]` Make `getModuleIDAsync` build and cache `data:` URI module IDs the same way as `getModuleID` ([#16370](jestjs/jest#16370)) - `[jest-resolve]` Keep the `node:` prefix when resolving a core module asynchronously, so a builtin that only exists prefixed (`node:sea`, `node:sqlite`, `node:test`, `node:test/reporters`) resolves instead of failing as a missing bare package ([#16388](jestjs/jest#16388)) - `[jest-resolve]` Look up manual mocks for `node:` protocol specifiers under the unprefixed name they are stored as ([#16388](jestjs/jest#16388)) - `[jest-resolve]` Apply `moduleNameMapper` consistently to both spellings of core module specifiers (`fs` vs `node:fs`) ([#16390](jestjs/jest#16390)) - `[jest-resolve]` Keep virtual and ordinary mock module IDs isolated across test files ([#16296](jestjs/jest#16296)) - `[jest-resolve]` Guard missing `require.resolve.paths` ([#16052](jestjs/jest#16052)) - `[jest-resolve, jest-config, jest-runner]` Support a user resolver written as an ES module ([#16332](jestjs/jest#16332)) - `[jest-resolve, jest-runtime]` Throw the CJS parse error for ESM syntax in a `"type": "commonjs"` package or a `.cjs` file instead of loading it as ESM, matching Node ([#16368](jestjs/jest#16368)) - `[@jest/source-map]` Keep source map sources that name a scheme, such as `webpack:///`, instead of resolving them into a path that does not exist ([#16327](jestjs/jest#16327)) - `[@jest/source-map]` Look up `--testLocationInResults` positions at the right column, and keep a mapping to the first column instead of discarding it ([#16327](jestjs/jest#16327)) - `[@jest/source-map]` Warn when a source map cannot be parsed, instead of silently leaving its frames untranslated ([#16327](jestjs/jest#16327)) - `[jest-runner, @jest/source-map]` Keep a source-mapped stack for an error thrown after the test environment was torn down ([#16327](jestjs/jest#16327)) - `[jest-runtime, @jest/source-map]` Keep source maps past teardown and past the next test file's `install`, so a stack from a file no earlier stack mentioned still points at the original source ([#16330](jestjs/jest#16330)) - `[jest-runtime]` Report that no coverage was collected when `getAllV8CoverageInfoCopy` is called after `teardown`, instead of returning an empty result ([#16385](jestjs/jest#16385)) - `[jest-runtime]` Cache a CJS module's parsed exports before walking its re-exports, so two modules that re-export each other no longer overflow the stack when imported from ESM ([#16363](jestjs/jest#16363)) - `[jest-runtime]` Keep a re-exported ES module's parse failure from marking the re-exporting CommonJS file as ESM, so `module.exports = require('./dep.mjs')` loads instead of failing with `module is not defined` ([#16363](jestjs/jest#16363)) - `[jest-runtime]` Scope module mocks instantiated inside `jest.isolateModules`/`isolateModulesAsync` to that block, so a mock first imported there no longer outlives it - matching how CommonJS mocks already behave ([#16365](jestjs/jest#16365)) - `[jest-runtime]` Suspend module isolation while generating an automock, so loading the real module to read its shape no longer populates the isolated registry ([#16365](jestjs/jest#16365)) - `[jest-runtime]` Check a cached ES module's status before `require()` returns it, so a module whose evaluation threw rethrows that error and one left linked by a failed sibling is evaluated instead of returning uninitialized bindings ([#16364](jestjs/jest#16364)) - `[jest-runtime]` Report the original `ERR_REQUIRE_ASYNC_MODULE` when a `require()` of a top-level-await graph is retried, instead of a spurious "concurrent `import()`" error ([#16364](jestjs/jest#16364)) - `[jest-runtime]` Throw the evaluation error when another caller's `import()` of the same module failed while we awaited it, instead of resolving with the errored module ([#16364](jestjs/jest#16364)) - `[jest-runtime]` Mark the result of `require()`ing an ES module that has a default export with `__esModule: true` through a live-binding facade, and serve the same object from `require.cache`, matching Node ([#16367](jestjs/jest#16367)) - `[jest-runtime]` Provide a CommonJS module's exports under the `'module.exports'` named export when imported from ESM, matching Node 23+ ([#16367](jestjs/jest#16367)) - `[jest-runtime]` Give the test file itself a non-null `require.main` ([#16367](jestjs/jest#16367)) - `[jest-runtime]` Populate `module.children` with the modules a file loads, matching Node ([#16368](jestjs/jest#16368)) - `[jest-runtime]` Provide `import.meta.resolve` and `import.meta.jest` in `data:` URI modules, accept any-case mediatype parameters, and use Node's error codes for invalid `data:` URIs ([#16368](jestjs/jest#16368)) - `[jest-runtime]` Key ES modules by full URL, so query and fragment suffixes create the same module instances as Node and show up in `import.meta.url` ([#16375](jestjs/jest#16375)) - `[jest-runtime]` Share modules between overlapping graphs when a CommonJS module `require()`s an ES module mid-load, instead of evaluating shared dependencies twice ([#16375](jestjs/jest#16375)) - `[jest-runtime]` Throw `ERR_REQUIRE_CYCLE_MODULE` like Node when a CommonJS module `require()`s an ES module that is still being loaded, instead of evaluating the module a second time ([#16366](jestjs/jest#16366)) - `[jest-runtime]` Key builtin modules in the ESM registry by one canonical specifier ([#16341](jestjs/jest#16341)) - `[jest-runtime]` `import.meta.resolve()` for a builtin uses its `node:` specifier ([#16341](jestjs/jest#16341)) - `[jest-runtime]` Fall back to native ESM when a `.js` file contains ESM syntax but has no `"type":"module"` marker ([#16152](jestjs/jest#16152)) - `[jest-runtime]` Allow `require()` of ESM-marked files on Node < 24.9 via transform fallback ([#16244](jestjs/jest#16244)) - `[jest-runtime, @jest/transform]` Surface actionable `ERR_REQUIRE_ESM` error for files with untransformed ESM syntax instead of the generic "unexpected token" message ([#16244](jestjs/jest#16244)) - `[jest-runtime]` Support older test environments whose `moduleMocker` does not implement `clearMocksOnScope` ([#16169](jestjs/jest#16169)) - `[jest-runtime]` Apply `jest.unstable_mockModule` when the mocked file itself is `require()`d, not only when it is imported as a dependency ([#16389](jestjs/jest#16389)) - `[jest-runtime]` Apply `jest.unstable_mockModule` to statically imported `data:` URIs on Node 24.9+, matching dynamic `import()` ([#16389](jestjs/jest#16389)) - `[jest-runtime]` Run an async `jest.unstable_mockModule` factory once per module instead of twice, and fail the import instead of crashing the worker when the factory rejects ([#16389](jestjs/jest#16389)) - `[jest-runtime]` Hide a `require(esm)` module that failed to evaluate from `require.cache`, as Node does, instead of exposing a namespace with uninitialized bindings ([#16389](jestjs/jest#16389)) - `[jest-runtime]` Strip the byte-order mark when importing a JSON module, matching `require()` and Node ([#16389](jestjs/jest#16389)) - `[jest-runtime]` Throw `ERR_REQUIRE_ASYNC_MODULE` when `require(esm)` runs under an async-only custom resolver, instead of silently resolving with the default resolver ([#16389](jestjs/jest#16389)) - `[jest-runtime]` Parse imported JSON modules with the test realm's `JSON`, so their objects pass `instanceof Object` inside the test like `require()`d JSON does ([#16389](jestjs/jest#16389)) - `[jest-runtime]` Accept every `file:` URL string in the sandboxed `module.createRequire`, including one with a `localhost` authority, as Node does ([#16389](jestjs/jest#16389)) - `[jest-runtime]` Point at `{virtual: true}` when `jest.mock` or `jest.unstable_mockModule` is given a module that cannot be resolved ([#16389](jestjs/jest#16389)) - `[jest-reporters]` Fix coverage report table formatting in CI/GitHub Actions environments where `process.stdout.columns` is undefined by falling back to the `COLUMNS` env var or `80` columns in CI, preserving existing behaviour in other non-TTY environments ([#16227](jestjs/jest#16227)) - `[jest-runtime]` Support CJS-in-ESM exports via `"module.exports"` named exports ([#16277](jestjs/jest#16277)) - `[jest-snapshot]` Keep a skipped or failed test's hinted snapshots, instead of reporting them obsolete ([#16348](jestjs/jest#16348)) - `[jest-util]` Stop `globsToMatcher` reusing a cached matcher compiled with different picomatch options, and keep its `dot: true` default when `dot` is passed as `undefined` ([#16381](jestjs/jest#16381)) - `[pretty-format]` Move the `react-is` aliases into the `@jest` scope, so they cannot be shadowed by unrelated packages published under the alias names ([#16333](jestjs/jest#16333)) ##### Chore & Maintenance - `[docs]` Document the intentional divergences from Node's module system in the ECMAScript Modules page ([#16368](jestjs/jest#16368)) - `[docs]` Note deprecation of `react-test-renderer` in React Native tutorial and `pretty-format` README ([#16294](jestjs/jest#16294)) - `[docs]` Use `@testing-library/react-native` in the React Native tutorial instead of the deprecated `react-test-renderer` ([#16318](jestjs/jest#16318)) - `[babel-jest, @jest/transform]` Update `babel-plugin-istanbul` to v8 ([#16049](jestjs/jest#16049)) - `[jest-config, @jest/reporters, jest-runtime]` Update `glob` to v13 ([#16397](jestjs/jest#16397)) - `[jest-haste-map]` Refactor massive class into multiple files ([#16180](jestjs/jest#16180)) - `[jest-haste-map]` Drop `walker` dependency; replace hand-rolled directory recursion in the JS crawler and watcher startup with `fdir` ([#16187](jestjs/jest#16187)) - `[jest-haste-map]` Reuse cached metadata for files whose haste name is a known duplicate, instead of re-reading and re-parsing them on every startup ([#16351](jestjs/jest#16351)) - `[jest-haste-map]` Cache the watchman socket path and replace the `watchman --version` probe with `get-sockname`, so warm runs spawn no watchman processes ([#16386](jestjs/jest#16386)) - `[jest-resolve]` Store the per-directory package-type lookup in the cache it reads, so it actually memoizes ([#16369](jestjs/jest#16369)) - `[jest-resolve, jest-runtime]` Cut repeated work on the resolution hot path: hoist the platform-extension list to construction, memoize `isCoreModule` and the options cache-key serialization, skip mapper preparation when no `moduleNameMapper` is configured, run each mapper regex once, and stop re-parsing `NODE_OPTIONS` on every default-resolver call ([#16371](jestjs/jest#16371)) - `[jest-resolve]` Cut warm resolution cost to about a third: reuse one `unrs-resolver` factory per options shape instead of cloning per resolution, compose the factory cache key from per-array cached strings instead of serializing options, and stop constructing an `Error` for misses that `findNodeModule` swallows; add a `__benchmarks__` suite for the default resolver ([#16373](jestjs/jest#16373)) - `[jest-runner, @jest/source-map]` Replace `source-map-support` with an implementation in `@jest/source-map` ([#16327](jestjs/jest#16327)) - `[jest-snapshot]` Load babel, semver and synckit lazily, so requiring the package (which every test process does through `@jest/expect`) no longer loads \~200 modules that only writing inline snapshots needs ([#16387](jestjs/jest#16387)) - `[jest-runtime]` Reduce per-require overhead: skip module ID resolution when no mock can apply, answer core modules before probing for a manual mock, share one `require.cache` proxy across modules, and cache empty files ([#16376](jestjs/jest#16376)) - `[@jest/source-map]` Deprecate `getCallsite` in favour of `SourceMapSupport#getCallsite` ([#16327](jestjs/jest#16327)) - `[jest-runtime]` Avoid magical `null` value in ESM loader ([#16160](jestjs/jest#16160))

SimenB and others added 2 commits August 17, 2026 08:17

SimenB requested a balanced review from Copilot August 17, 2026 06:37

github-actions Bot added the require-changelog If a PR does requires a changelog entry label Aug 17, 2026

Copilot started reviewing on behalf of SimenB August 17, 2026 06:46 View session

Copilot AI reviewed Aug 17, 2026

View reviewed changes

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

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

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

SimenB force-pushed the haste-map-docs branch from 8f74dcc to a618f0f Compare August 17, 2026 07:10

SimenB merged commit 1cb03b5 into jestjs:main Aug 17, 2026
105 checks passed

SimenB deleted the haste-map-docs branch August 17, 2026 07:57

Navigation Menu

Uh oh!

Uh oh!

fix(jest-haste-map): tolerate a locked file while indexing on Windows - #16358

fix(jest-haste-map): tolerate a locked file while indexing on Windows#16358
SimenB merged 4 commits into
jestjs:mainfrom
SimenB:haste-map-docs

SimenB commented Aug 17, 2026 •

edited

Loading

Uh oh!

netlify Bot commented Aug 17, 2026 •

edited

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

pkg-pr-new Bot commented Aug 17, 2026 •

edited

Loading

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Uh oh!

Uh oh!

Conversation

SimenB commented Aug 17, 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 Aug 17, 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 Aug 17, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

SimenB commented Aug 17, 2026 •

edited

Loading

netlify Bot commented Aug 17, 2026 •

edited

Loading

pkg-pr-new Bot commented Aug 17, 2026 •

edited

Loading