eslint 9.27.0

on Node.js NPM

Features

• d71e37f feat: Allow flags to be set in ESLINT_FLAGS env variable (#19717) (Nicholas C. Zakas)
• ba456e0 feat: Externalize MCP server (#19699) (Nicholas C. Zakas)
• 07c1a7e feat: add allowRegexCharacters to no-useless-escape (#19705) (sethamus)
• 7bc6c71 feat: add no-unassigned-vars rule (#19618) (Jacob Bandes-Storch)
• ee40364 feat: convert no-array-constructor suggestions to autofixes (#19621) (sethamus)
• 32957cd feat: support TS syntax in max-params (#19557) (Nitin Kumar)

Bug Fixes

• 5687ce7 fix: correct mismatched removed rules (#19734) (루밀LuMir)
• dc5ed33 fix: correct types and tighten type definitions in SourceCode class (#19731) (루밀LuMir)
• de1b5de fix: correct service property name in Linter.ESLintParseResult type (#19713) (Francesco Trotta)
• 60c3e2c fix: sort keys in eslint-suppressions.json to avoid git churn (#19711) (Ron Waldon-Howe)
• 9da90ca fix: add allowReserved to Linter.ParserOptions type (#19710) (Francesco Trotta)
• fbb8be9 fix: add info to ESLint.DeprecatedRuleUse type (#19701) (Francesco Trotta)

Documentation

• 25de550 docs: Update description of frozen rules to mention TypeScript (#19736) (Nicholas C. Zakas)
• bd5def6 docs: Clean up configuration files docs (#19735) (Nicholas C. Zakas)
• 4d0c60d docs: Add Neovim to editor integrations (#19729) (Maria José Solano)
• 71317eb docs: Update README (GitHub Actions Bot)
• 4c289e6 docs: Update README (GitHub Actions Bot)
• f0f0d46 docs: clarify that unused suppressions cause non-zero exit code (#19698) (Milos Djermanovic)
• 8ed3273 docs: fix internal usages of ConfigData type (#19688) (Francesco Trotta)
• eb316a8 docs: add fmt and check sections to Package.json Conventions (#19686) (루밀LuMir)
• a3a2559 docs: fix wording in Combine Configs (#19685) (Milos Djermanovic)
• c8d17e1 docs: Update README (GitHub Actions Bot)

Chores

• f8f1560 chore: upgrade @eslint/js@9.27.0 (#19739) (Milos Djermanovic)
• ecaef73 chore: package.json update for @eslint/js release (Jenkins)
• 596fdc6 chore: update dependency @arethetypeswrong/cli to ^0.18.0 (#19732) (renovate[bot])
• f791da0 chore: remove unbalanced curly brace from .editorconfig (#19730) (Maria José Solano)
• e86edee refactor: Consolidate Config helpers (#19675) (Nicholas C. Zakas)
• cf36352 chore: remove shared types (#19718) (Francesco Trotta)
• f60f276 refactor: Easier RuleContext creation (#19709) (Nicholas C. Zakas)
• 58a171e chore: update dependency @eslint/plugin-kit to ^0.3.1 (#19712) (renovate[bot])
• 3a075a2 chore: update dependency @eslint/core to ^0.14.0 (#19715) (renovate[bot])
• 44bac9d ci: run tests in Node.js 24 (#19702) (Francesco Trotta)
• 35304dd chore: add missing funding field to packages (#19684) (루밀LuMir)
• f305beb test: mock process.emitWarning to prevent output disruption (#19687) (Francesco Trotta)