Biome Guidelines

Biome is a high-performance toolchain for web projects, intended to replace Prettier and ESLint in modern codebases.

1. Configuration (biome.json)

• Single Config: Define all rules in a unified biome.json at the root of the project.
• Formatting Match: Configure Biome's formatter to match standard Prettier settings (e.g., lineWidth: 80, indentStyle: "space").
• Import Sorting: Enable organizeImports to automatically sort and group imports on save.

{
  "$schema": "https://biomejs.dev/schemas/1.8.3/schema.json",
  "formatter": {
    "enabled": true,
    "formatWithErrors": false,
    "indentStyle": "space",
    "indentWidth": 2,
    "lineWidth": 100
  },
  "organizeImports": {
    "enabled": true
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true,
      "style": {
        "useImportType": "error"
      }
    }
  }
}

2. CI/CD Integration

• Check Command: Run npx @biomejs/biome ci . in CI pipelines. This command checks formatting, runs the linter, and verifies import sorting all in one pass. It fails if any violations are found.
• Pre-commit Hooks: Integrate biome check --write --no-errors-on-unmatched --files-ignore-unknown=true {staged_files} into Husky/lint-staged to format code before committing.

3. Editor Integration

• VS Code: Ensure the .vscode/settings.json sets Biome as the default formatter and enables "format on save" and "organize imports on save".

{
  "editor.defaultFormatter": "biomejs.biome",
  "editor.formatOnSave": true,
  "editor.codeActionsOnSave": {
    "source.organizeImports.biome": "explicit"
  }
}