eslint-skilld

name	eslint-skilld
description	ALWAYS use when writing code importing "eslint". Consult for debugging, best practices, or modifying eslint.
metadata	{"version":"10.6.0","generated_by":"Anthropic · Haiku 4.5","generated_at":"2026-06-28T00:00:00.000Z"}

eslint/eslint eslint@10.6.0

Tags: es6jsx: 0.11.0-alpha.0, next: 10.0.0-rc.2, maintenance: 9.39.4

References: package.json • README • Docs • Issues • Discussions • Releases

Search

Use skilld search "query" -p eslint instead of grepping .skilld/ directories. Run skilld search --guide -p eslint for full syntax, filters, and operators.

API Changes

This section documents version-specific API changes — prioritize recent major/minor releases.

Breaking Changes from v9 → v10

• BREAKING: chalk removed from stylish formatter, replaced with Node.js styleText API in v10.0.0 — output behavior changes with environment variables (NO_COLOR, NODE_DISABLE_COLORS, FORCE_COLOR) and --color/--no-color flags now take precedence source · migration

• BREAKING: JSX references are now tracked — <Card> is treated as a variable reference, affecting no-unused-vars and no-undef rules; custom rules relying on scope analysis may encounter JSXIdentifier references source · migration

• BREAKING: eslint:recommended configuration updated — three new rules enabled: no-unassigned-vars, no-useless-assignment, preserve-caught-error source · migration

• BREAKING: Config file lookup algorithm changed — eslint.config.js is now located starting from each linted file's directory, not the cwd; v10_config_lookup_from_file flag removed source · migration

• BREAKING: ESLintrc format (.eslintrc, .eslintrc.json) no longer supported — only flat config (eslint.config.js) is supported; FlatESLint and LegacyESLint exports removed, use ESLint only source · migration

• BREAKING: eslint-env comments reported as errors — /* eslint-env node */ style comments no longer supported source · migration

• BREAKING: SourceCode deprecated methods removed (#20137) — use alternatives from current API source

• BREAKING: Rule context deprecated methods removed (#20086) — update custom rules to use non-deprecated equivalents source

• BREAKING: LintMessage#nodeType property removed (#20096) — do not access this field source

• BREAKING: TestCaseError#type property removed (#20096) — replaced with RuleTester location estimation source

• BREAKING: Program AST node range now spans entire source text (#20133) — affects node boundary calculations source

• BREAKING: RuleFixer methods require string text arguments (#20082) — all fixer methods must receive string values, not other types source

• BREAKING: ScopeManager implementations must support addGlobals() method (#20132) — custom parser implementations need to implement this source

• BREAKING: Minimatch v10 with POSIX character classes in glob patterns — bracket expressions now support [[:upper:]], [[:lower:]] etc., existing glob patterns may match differently source · migration

• BREAKING: no-shadow-restricted-names now reports globalThis by default (#20027) — may produce new linting errors in existing codebases source

• BREAKING: func-names schema stricter (#20119) — validation rules tightened source

• BREAKING: no-invalid-regexp allowConstructorFlags option requires uniqueItems: true (#20155) — duplicates in this array are now rejected source

New APIs in v10.x

• NEW: meta.languages support in rules (#20571, v10.2.0) — rules can now declare supported languages via meta.languages array source

• NEW: includeIgnoreFile() function in eslint/config (#20735, v10.4.0) — enables programmatic inclusion of .eslintignore-style files in flat config source

• NEW: name property on configuration objects (v10.0.0) — configs can now be named for debugging and reporting source

• NEW: Bulk-suppressions API (v10.1.0) — ESLint API now supports bulk suppression operations for multiple files source

• NEW: RuleTester requireData assertion option (#20409, v10.0.0) — allows tests to require specific data from rule context source

• NEW: RuleTester error assertion options (#20247, v10.0.0) — enhanced error validation in test cases source

Deprecated APIs

• DEPRECATED: radix rule options "always" and "as-needed" (v10.0.0) — rule now always enforces providing radix; remove explicit option or leave as default source · migration

Also changed: Temporal added to ES2026 globals (v10.2.0) · Temporal added to no-obj-calls rule (v10.2.0) · Array.fromAsync handling in array-callback-return (v10.0.0) · self parameter in no-implied-eval (v10.0.0) · Rule tester failure location estimation improved (v10.0.0) · Error location reporting for require-yield and no-useless-constructor (v10.0.0) · no-var autofix improvements (v10.1.0) · Node.js v20.19.0+, v22.13.0+, v24+ required (v10.0.0)

Best Practices

• Use defineConfig() helper when creating configuration arrays — enables type inference, plugin namespace resolution, and makes composition more explicit source

• Apply rules to specific file patterns with files and ignores keys in configuration objects — files without these keys apply globally, which may be unintended source

• Set name property on configuration objects for clarity in debugging output and config inspector — helps identify which config object is applying rules to a file source

• Use configuration objects without files or ignores to define global rule configuration — they automatically apply to any file matched by other config objects source

• Combine configurations with extends to merge predefined and shareable configs — preferred over manual property merging source

• Enable reportUnusedDisableDirectives to catch stale eslint disable comments that no longer affect rules source

• Declare languages property in custom rules to restrict execution to specific language types — prevents errors when rules are applied to unsupported languages source

• Use messageIds in context.report() instead of hardcoded message strings — enables maintainability, i18n, and consistency across rule variants source

• Specify meta.fixable property when rule can modify code and meta.hasSuggestions when rule provides alternatives — ESLint throws if these are missing when attempting fixes or suggestions source

• Use AST selectors in rule visitors for targeted node matching instead of broad visitor patterns — enables more concise rules and filters nodes before callback execution source

• Provide meta.namespace in plugins to enable ESLint to resolve the plugin even if users register it under a different name — recommended for better plugin discovery source

• Run config inspector with --inspect-config flag during setup to verify which configuration objects match target files — crucial for diagnosing unexpected rule application source

• Separate JavaScript-specific configuration into its own config object with files: ["**/*.js", "**/*.cjs", "**/*.mjs"] rather than relying on defaults — ensures rules don't unexpectedly apply to non-JS files source

• Use baseConfig and overrideConfig in the Node.js API when linting text in tests — allows full control over configuration without relying on config file discovery source