ESLint v9.38.0 released

Highlights

Plugin config resolution improvements

This release introduces improvements in determining which configuration to use from plugins that support both old (eslintrc) and new configuration formats. When extending a plugin configuration, for example extends: ["my-plugin/recommended"], the defineConfig() config helper was already looking for configs["flat/recommended"] configuration if configs["recommended"] configuration exists in the plugin but is detected as the eslintrc configuration format.

As of this release:

• The defineConfig() config helper will look for configs["flat/recommended"] configuration even if configs["recommended"] configuration does not exist in the plugin.
• Configurations that have array values as the plugins property will be detected as the eslintrc configuration format.

Other notable changes

• The complexity rule now highlights only the function header instead of the entire function.

Features

• ce40f74 feat: update complexity rule to only highlight function header (#20048) (Atul Nair)
• e37e590 feat: correct no-loss-of-precision false positives with e notation (#20187) (Francesco Trotta)

Bug Fixes

• 50c3dfd fix: improve type support for isolated dependencies in pnpm (#20201) (Francesco Trotta)
• a1f06a3 fix: correct SourceCode typings (#20114) (Pixel998)

Documentation

• 462675a docs: improve web accessibility by hiding non-semantic character (#20205) (루밀LuMir)
• c070e65 docs: correct formatting in no-irregular-whitespace rule documentation (#20203) (루밀LuMir)
• b39e71a docs: Update README (GitHub Actions Bot)
• cd39983 docs: move custom-formatters type descriptions to nodejs-api (#20190) (Percy Ma)

Chores

• d17c795 chore: upgrade @eslint/js@9.38.0 (#20221) (Milos Djermanovic)
• 25d0e33 chore: package.json update for @eslint/js release (Jenkins)
• c82b5ef refactor: Use types from @eslint/core (#20168) (Nicholas C. Zakas)
• ff31609 ci: add Node.js 25 to ci.yml (#20220) (루밀LuMir)
• 004577e ci: bump github/codeql-action from 3 to 4 (#20211) (dependabot[bot])
• eac71fb test: remove use of nodejsScope option of eslint-scope from tests (#20206) (Milos Djermanovic)
• 4168a18 chore: fix typo in legacy-eslint.js (#20202) (Sweta Tanwar)
• 205dbd2 chore: fix typos (#20200) (ntnyq)
• dbb200e chore: use team member’s username when name is not available in data (#20194) (Milos Djermanovic)
• 8962089 chore: mark deprecated rules as available until v11.0.0 (#20184) (Pixel998)