ESLint v9.34.0 released

Highlights

ESLint v9.34.0 introduces multithread linting — the ability to process multiple files simultaneously using multiple threads. This feature can significantly reduce lint times for large projects. To enable it, run ESLint with the --concurrency flag:

npx eslint --concurrency=auto

Read everything in the announcement.

Features

• 0bb777a feat: multithread linting (#19794) (Francesco Trotta)
• 43a5f9e feat: add eslint-plugin-regexp to eslint-config-eslint base config (#19951) (Pixel998)

Bug Fixes

• 9b89903 fix: default value of accessor-pairs option in rule.d.ts file (#20024) (Tanuj Kanti)
• 6c07420 fix: fix spurious failure in neostandard integration test (#20023) (Kirk Waiblinger)
• 676f4ac fix: allow scientific notation with trailing zeros matching exponent (#20002) (Sweta Tanwar)

Documentation

• 0b4a590 docs: make rulesdir deprecation clearer (#20018) (Domenico Gemoli)
• 327c672 docs: Update README (GitHub Actions Bot)
• bf26229 docs: Fix typo in core-concepts/index.md (#20009) (Tobias Hernstig)
• 2309327 docs: fix typo in the “Configuring Rules” section (#20001) (ghazi-git)
• 2b87e21 docs: [no-else-return] clarify sample code. (#19991) (Yuki Takada (Yukinosuke Takada))
• c36570c docs: Update README (GitHub Actions Bot)

Chores

• f19ad94 chore: upgrade to @eslint/js@9.34.0 (#20030) (Francesco Trotta)
• b48fa20 chore: package.json update for @eslint/js release (Jenkins)
• 4bce8a2 chore: package.json update for eslint-config-eslint release (Jenkins)
• 0c9999c refactor: prefer default options in grouped-accessor-pairs (#20028) (루밀LuMir)
• d503f19 ci: fix stale.yml (#20010) (루밀LuMir)
• e2dc67d ci: centralize stale.yml (#19994) (루밀LuMir)
• 7093cb8 ci: bump actions/checkout from 4 to 5 (#20005) (dependabot[bot])