Biome npm-scripts Configuration

This is the pattern for npm-scripts that you almost always set up when introducing Biome into a project. It handles both lint and format uniformly using the biome check command.

Basic Configuration

{
  "scripts": {
    "lint": "biome check .",
    "format": "biome check . --write"
  }
}

Grouping with Prefixes

In projects with many npm-scripts, grouping with prefixes makes organization easier.

{
  "scripts": {
    "code:lint": "biome check .",
    "code:format": "biome check . --write"
  }
}

Command Differences

Command	Behavior
biome check .	Detects issues and reports them, exit code is non-zero on error
biome check . —write	Fixes auto-fixable issues
biome format .	Runs formatting only
biome lint .	Runs linting only

check runs both lint and format. It’s common to use check . in CI and --write during development.

CI Usage Example

Example configuration in GitHub Actions:

- name: Check code
  run: npm run lint

- name: Check formatting
  run: npx biome format . --check

Or use check --changed to validate only changed files:

{
  "scripts": {
    "lint:changed": "biome check --changed ."
  }
}

This allows you to target only the diff and reduce processing time.

Relationship with Configuration Files

Configure details in biome.json:

{
  "formatter": {
    "indentStyle": "space",
    "indentWidth": 2
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true
    }
  }
}

It’s best to keep npm-scripts simple as entry points and delegate detailed configuration to the configuration file.