---

name: biome-linting description: Biome 2.0+ linting and formatting for fast, unified code quality. Includes type inference, ESLint migration, CI integration, and 421 lint rules. Use when migrating from ESLint/Prettier or setting up new projects. context: fork agent: frontend-ui-developer version: 1.0.0 tags: [biome, linting, formatting, eslint-migration, ci, code-quality, typescript] user-invocable: false

Biome Linting

Fast, unified linting and formatting (10-25x faster than ESLint + Prettier).

Why Biome in 2026

Quick Start

Copy# Install
npm install --save-dev --save-exact @biomejs/biome

# Initialize
npx @biomejs/biome init

# Check (lint + format)
npx @biomejs/biome check .

# Fix
npx @biomejs/biome check --write .

# CI mode (fails on errors)
npx @biomejs/biome ci .

Biome 2.0 Features

Type Inference: Reads .d.ts from node_modules for type-aware rules:

Copy{
  "linter": {
    "rules": {
      "nursery": {
        "noFloatingPromises": "error"  // Catches unhandled promises
      }
    }
  }
}

Multi-file Analysis: Cross-module analysis for better diagnostics.

Basic Configuration

Copy{
  "$schema": "https://biomejs.dev/schemas/2.0.0/schema.json",
  "formatter": {
    "enabled": true,
    "indentStyle": "space",
    "indentWidth": 2,
    "lineWidth": 100
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true,
      "correctness": {
        "noUnusedVariables": "error",
        "noUnusedImports": "error"
      },
      "suspicious": {
        "noExplicitAny": "warn"
      }
    }
  },
  "javascript": {
    "formatter": {
      "quoteStyle": "single",
      "trailingCommas": "all"
    }
  }
}

ESLint Migration

Copy# Auto-migrate configuration
npx @biomejs/biome migrate eslint --write

Common Rule Mappings:

CI Integration

Copy# .github/workflows/lint.yml
- uses: biomejs/setup-biome@v2
- run: biome ci .

Overrides for Gradual Adoption

Copy{
  "overrides": [
    {
      "include": ["*.test.ts", "*.spec.ts"],
      "linter": {
        "rules": {
          "suspicious": { "noExplicitAny": "off" }
        }
      }
    },
    {
      "include": ["legacy/**"],
      "linter": { "enabled": false }
    }
  ]
}

Key Decisions

Related Skills

• vite-advanced - Build tooling integration
• react-server-components-framework - React linting rules
• ci-cd-engineer - CI pipeline setup

References

• ESLint Migration - Step-by-step migration
• Biome Config - Full configuration options
• Type-Aware Rules - Biome 2.0 type inference
• CI Integration - GitHub Actions setup