Biome Validator Validates Biome 2.3+ configuration and prevents outdated patterns. Ensures type-aware linting, domains, and modern Biome features are properly configured. When This Activates Setting up linting for a new project Before any code quality work Auditing existing Biome configurations After AI generates biome.json CI/CD pipeline validation Quick Start python3 ~/.claude/skills/biome-validator/scripts/validate.py --root . python3 ~/.claude/skills/biome-validator/scripts/validate.py --root . --strict What Gets Checked 1. Biome Version & Schema GOOD - Biome 2.3+: { "$schema" : "https://biomejs.dev/schemas/2.3.11/schema.json" } BAD - Old schema: { "$schema" : "https://biomejs.dev/schemas/1.9.0/schema.json" } 2. Package Version // GOOD: v2.3+ "@biomejs/biome" : "^2.3.0" // BAD: v1.x or v2.0-2.2 "@biomejs/biome" : "^1.9.0" 3. Linter Configuration GOOD - Biome 2.x: { "linter" : { "enabled" : true , "rules" : { "recommended" : true , "suspicious" : { "noExplicitAny" : "warn" } } } } 4. Biome Assist (2.0+) GOOD - Using assist: { "assist" : { "actions" : { "source" : { "organizeImports" : "on" } } } } BAD - Old organizeImports location: { "organizeImports" : { "enabled" : true } } 5. Domains (2.0+) GOOD - Using domains for framework-specific rules: { "linter" : { "domains" : { "react" : "on" , "next" : "on" } } } 6. Suppression Comments GOOD - Biome 2.0+ comments: // biome-ignore lint/suspicious/noExplicitAny: legacy code // biome-ignore-all lint/style/useConst // biome-ignore-start lint/complexity // biome-ignore-end BAD - Wrong format: // @ts-ignore // Not Biome // eslint-disable // Wrong tool Biome 2.3+ Features Type-Aware Linting Biome 2.0+ includes type inference without requiring TypeScript compiler: { "linter" : { "rules" : { "correctness" : { "noUndeclaredVariables" : "error" , "useAwaitThenable" : "error" } } } } Assist Actions { "assist" : { "actions" : { "source" : { "organizeImports" : "on" , "useSortedKeys" : "on" } } } } Multi-file Analysis Lint rules can query information from other files for more powerful analysis. Framework Domains { "linter" : { "domains" : { "react" : "on" , // React-specific rules "next" : "on" , // Next.js rules "test" : "on" // Testing framework rules } } } Recommended Configuration { "$schema" : "https://biomejs.dev/schemas/2.3.11/schema.json" , "assist" : { "actions" : { "source" : { "organizeImports" : "on" } } } , "linter" : { "enabled" : true , "rules" : { "recommended" : true , "complexity" : { "noForEach" : "off" } , "style" : { "noNonNullAssertion" : "off" } , "suspicious" : { "noArrayIndexKey" : "off" , "noExplicitAny" : "warn" } , "correctness" : { "useAwaitThenable" : "error" , "noLeakedRender" : "error" } } , "domains" : { "react" : "on" , "next" : "on" } } , "formatter" : { "enabled" : true , "indentStyle" : "space" , "indentWidth" : 2 , "lineWidth" : 100 } , "javascript" : { "formatter" : { "quoteStyle" : "single" , "trailingCommas" : "es5" , "semicolons" : "always" } } , "files" : { "ignore" : [ "node_modules" , "dist" , "build" , ".next" , "out" , ".cache" , ".turbo" , "coverage" ] } } Deprecated Patterns Deprecated Replacement (2.3+) organizeImports.enabled assist.actions.source.organizeImports Schema < 2.0 Schema 2.3.11+ @biomejs/biome < 2.3 @biomejs/biome@latest No domains config Use linter.domains for frameworks Validation Output === Biome 2.3+ Validation Report === Package Version: @biomejs/biome@2.3.11 ✓ Configuration: ✓ Schema version: 2.3.11 ✓ Linter enabled with recommended rules ✓ Using assist.actions for imports ✗ No domains configured (consider enabling react, next) ✓ Formatter configured Rules: ✓ noExplicitAny: warn ✓ useAwaitThenable: error ✗ noLeakedRender not enabled (recommended) Summary: 2 issues found Migration from ESLint Step 1: Install Biome bun remove eslint prettier eslint-config- eslint-plugin- bun add -D @biomejs/biome@latest Step 2: Create biome.json bunx biome init Step 3: Migrate rules bunx biome migrate eslint --write Step 4: Update scripts { "scripts" : { "lint" : "biome lint ." , "lint:fix" : "biome lint --write ." , "format" : "biome format --write ." , "check" : "biome check ." , "check:fix" : "biome check --write ." } } Step 5: Remove old configs rm .eslintrc .prettierrc .eslintignore .prettierignore VS Code Integration // .vscode/settings.json { "editor.formatOnSave" : true , "editor.defaultFormatter" : "biomejs.biome" , "editor.codeActionsOnSave" : { "source.organizeImports.biome" : "explicit" , "quickfix.biome" : "explicit" } } CI/CD Integration

.github/workflows/lint.yml

- name : Validate Biome Config run : | python3 ~/.claude/skills/biome-validator/scripts/validate.py \ --root . \ --strict \ --ci - name : Lint run : bunx biome check - - error - on - warnings . Integration linter-formatter-init - Sets up Biome from scratch nextjs-validator - Validates Next.js (enable next domain) bun-validator - Validates Bun workspace