npm / jest-util
jest-util
What changed in jest-util 30, from its official release notes, upgrade guides and advisories. Also covers @jest/environment, @jest/fake-timers, @jest/globals, @jest/reporters, @jest/test-result, @jest/types, babel-jest, expect, jest-diff, jest-environment-jsdom, jest-environment-node, jest-matcher-utils, jest-message-util, jest-mock, jest-resolve, jest-snapshot, jest-worker, pretty-format. Sources checked 2026-10-23.
1 deprecations1 new APIs and options1 performance7 fixes and other
See which of these apply to your code, ranked, in your agent:
npx @unstale/cli initjest-util 3010 changes
Deprecations 1
The JEST-01 deprecation warning now names this option and links to its documentation, which describes the option's modes.
New APIs and options 1
Adds the isError helper.
Performance 1
Global variables are cleaned up on environment teardown to reduce memory leaks.
Fixes and other changes 7
Only warn about a conflicting globalsCleanup mode when one was explicitly configured, and follow the mode actually in effect.
Matchers no longer reuse cached results compiled with different picomatch options, and the dot: true default is preserved when dot is undefined.
Environment setup no longer resolves lazy globals, preventing Node 26 builtin module globals and their deprecation warnings from loading for every test file.
Reverted node: protocol imports to restore webpack/browser-bundle compatibility.
Ensure process.features.require_module is false.
Fixed
isInteractiveto work in a browser.Always load
mjsfiles withimport.