Biome Tooling

Biome Tooling

Biome is a modern, performant toolchain for JavaScript, TypeScript, and related web languages. It combines formatting, linting, and import organization into a single tool that's 15-20x faster than ESLint/Prettier.

Keep ESLint alongside when the project needs plugin-only rules (React hooks, a11y), framework-specific rules (Next.js, Nuxt), or carries heavy custom ESLint configuration.

Hybrid approach: Use Biome for formatting, ESLint for specialized linting.

Core Expertise

What is Biome?

• All-in-one toolchain: Linter + formatter + import sorter
• Zero-config: Works out of the box with sensible defaults
• Fast: Written in Rust, processes files in parallel
• Compatible: Matches Prettier formatting 97%+
• Supports: JavaScript, TypeScript, JSX, TSX, JSON, CSS

Installation

# Project-local (recommended)
bun add --dev @biomejs/biome

# Verify installation
bunx biome --version

# Initialize configuration
bunx biome init

Essential Commands

# Format files
bunx biome format --write src/

# Lint with fixes
bunx biome lint --write src/

# Check everything (format + lint + organize imports)
bunx biome check --write src/

# Check without changes (CI mode)
bunx biome check src/

# CI mode (exits with error on issues)
bunx biome ci src/

# Migrate from ESLint/Prettier
bunx biome migrate eslint --write
bunx biome migrate prettier --write

# Explain a rule
bunx biome explain noUnusedVariables

Configuration (biome.json)

Minimal Setup (Zero Config)

Biome works without configuration. For basic customization:

{
  "$schema": "https://biomejs.dev/schemas/1.9.4/schema.json",
  "vcs": {
    "enabled": true,
    "clientKind": "git",
    "useIgnoreFile": true
  },
  "files": {
    "ignoreUnknown": false,
    "ignore": ["dist", "build", "node_modules", ".next", "coverage"]
  },
  "formatter": {
    "enabled": true,
    "indentStyle": "space",
    "indentWidth": 2,
    "lineWidth": 100
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true
    }
  },
  "organizeImports": {
    "enabled": true
  }
}

Rule Categories

Common Patterns

Ignore Files and Directories

Via biome.json:

{
  "files": {
    "ignore": [
      "dist",
      "build",
      "node_modules",
      "**/*.config.js",
      "scripts/legacy/**"
    ]
  }
}

Via .gitignore (automatic):

{
  "vcs": {
    "enabled": true,
    "useIgnoreFile": true
  }
}

Performance Comparison

Agentic Optimizations

Quick Reference

For detailed examples, advanced patterns, and best practices, see REFERENCE.md.

References

• Official docs: https://biomejs.dev
• Configuration: https://biomejs.dev/reference/configuration/
• Rules: https://biomejs.dev/linter/
• Migration guide: https://biomejs.dev/guides/migrate-eslint-prettier/
• Editor integration: https://biomejs.dev/