superset-frontend/LINTING.md

Superset Frontend Linting

Apache Superset uses a hybrid linting approach combining OXC (Oxidation Compiler) for standard rules and a custom AST-based checker for Superset-specific rules.

Architecture

The linting system consists of two components:

1. OXC Linter (oxlint) - A Rust-based linter that's 50-100x faster than ESLint

   • Handles all standard JavaScript/TypeScript rules
   • Configured via oxlint.json
   • Runs via npm run lint or npm run lint-fix

2. Custom Rules Checker - A Node.js AST-based checker for Superset-specific patterns

   • Enforces no literal colors (use theme colors)
   • Prevents FontAwesome usage (use @superset-ui/core Icons)
   • Validates i18n template usage (no template variables)
   • Runs via npm run check:custom-rules

Usage

Quick Commands

# Run both OXC and custom rules
npm run lint:full

# Run OXC linter only (faster for most checks)
npm run lint

# Fix auto-fixable issues with OXC
npm run lint-fix

# Run custom rules checker only
npm run check:custom-rules

# Run on specific files
npm run lint-fix src/components/Button/index.tsx
npm run check:custom-rules src/theme/*.tsx

Pre-commit Hooks

The linting system is integrated with pre-commit hooks:

# Install pre-commit hooks
pre-commit install

# Run hooks manually on staged files
pre-commit run

# Run on specific files
pre-commit run --files superset-frontend/src/file.tsx

Configuration

OXC Configuration (oxlint.json)

The OXC configuration includes:

• Standard ESLint rules
• React and React Hooks rules
• TypeScript rules
• Import/export rules
• JSX accessibility rules
• Unicorn rules for additional coverage

Custom Rules

The custom rules are implemented in scripts/check-custom-rules.js and check for:

1. No Literal Colors: Enforces using theme colors instead of hardcoded hex/rgb values
2. No FontAwesome: Requires using @superset-ui/core Icons component
3. Proper i18n Usage: Prevents template variables in translation functions

Performance

The hybrid approach provides:

• 50-100x faster linting compared to ESLint for standard rules via OXC
• Selective checking - custom rules only run on changed files during pre-commit
• Parallel execution - OXC and custom rules can run concurrently

Troubleshooting

"Plugin 'basic-custom-plugin' not found" Error

If you see this error when running npm run lint, ensure you're using the explicit config:

npx oxlint --config oxlint.json

Custom Rules Not Running

Verify the AST parsing dependencies are installed:

npm ls @babel/parser @babel/traverse glob

Pre-commit Hook Failures

Ensure your changes are staged:

git add .
pre-commit run

Development

Adding New Custom Rules

1. Edit scripts/check-custom-rules.js
2. Add a new check function following the pattern:

function checkNewRule(ast, filepath) {
  traverse(ast, {
    // AST visitor pattern
  });
}

1. Call the function in processFile()

Updating OXC Rules

1. Edit oxlint.json
2. Test with npm run lint
3. Update ignore patterns if needed

Migration from ESLint

This hybrid approach replaces the previous ESLint setup while maintaining all custom Superset linting rules. The migration provides:

• Significantly faster linting (50-100x improvement)
• Compatibility with Apache Software Foundation requirements (no custom binaries)
• Maintainable JavaScript-based custom rules

CI/CD Integration

The linting system is integrated into CI via GitHub Actions. See .github/workflows/superset-frontend-lint.yml for the CI configuration.