Biome Guidelines

Biome Guidelines

Biome is used for linting and formatting. The PostToolUse hook automatically runs biome check --fix on file changes.

Fix Warnings Too

When modifying files, fix both errors AND warnings reported by Biome. Don't leave warnings behind.

After editing a file:

1. Check if Biome reported any warnings
2. Fix them before moving on
3. Run bunx biome check <file> to verify

Manual Commands

# Check a specific file
bunx biome check path/to/file.ts

# Check and fix a file
bunx biome check --fix path/to/file.ts

# Check entire project
bunx biome check .

# Format only (no linting)
bunx biome format --write path/to/file.ts

# Lint only (no formatting)
bunx biome lint path/to/file.ts

Common Issues to Fix

• Unused imports and variables
• Missing semicolons or extra semicolons (per project config)
• Inconsistent quotes
• Trailing commas
• Unsafe operations (use --unsafe flag when appropriate)
• Accessibility issues in JSX

Configuration

Biome config is in biome.json or biome.jsonc at project root. Respect project-specific rules.