Cursor rules · apache/superset

First lines (shown under the repo's Apache-2.0 license)

---
description: Apache Superset development standards and guidelines for Cursor IDE
globs: ["**/*.py", "**/*.ts", "**/*.tsx", "**/*.js", "**/*.jsx", "**/*.sql", "**/*.md"]
alwaysApply: true
---

# Apache Superset Development Standards for Cursor IDE

Apache Superset is a data visualization platform with Flask/Python backend and React/TypeScript frontend.

## ⚠️ CRITICAL: Ongoing Refactors (What NOT to Do)

**These migrations are actively happening - avoid deprecated patterns:**

### Frontend Modernization
- **NO `any` types** - Use proper TypeScript types
- **NO JavaScript files** - Convert to TypeScript (.ts/.tsx)
- **NO Enzyme** - Use React Testing Library/Jest (Enzyme fully removed)
- **Use @superset-ui/core** - Don't import Ant Design directly

### Testing Strategy Migration
- **Prefer unit tests** over integration tests
- **Prefer integration tests** over end-to-end tests
- **Use Playwright for E2E tests** - Cypress has been removed
- **Use Jest + React Testing Library** for component testing

### Backend Type Safety
- **Add type hints** - All new Python code needs proper typing
- **MyPy compliance** - Run `pre-commit run mypy` to validate
- **SQLAlchemy typing** - Use proper model annotations

## Code Standards

### TypeScript Frontend
- **NO `any` types** - Use proper TypeScript
- **Functional components** with hooks
- **@superset-ui/core** for UI components (not direct antd)
- **Jest** for testing (NO Enzyme)
- **Redux** for global state, hooks for local

### Python Backend
- **Type hints required** for all new code
- **MyPy compliant** - run `pre-commit run mypy`
- **SQLAlchemy models** with proper typing
- **pytest** for testing

### Apache License Headers
- **New files require ASF license headers** - When creating new code files, include the standard Apache Software Foundation license header
- **LLM instruction files are excluded** - Files like LLMS.md, CLAUDE.md, etc. are in `.rat-excludes` to avoid header token overhead

## Key Directory Structure

```
superset/
├── superset/                    # Python backend (Flask, SQLAlchemy)
│   ├── views/api/              # REST API endpoints
│   ├── models/                 # Database models
│   └── connectors/             # Database connections
├── superset-frontend/src/       # React TypeScript frontend
│   ├── components/             # Reusable components
│   ├── explore/                # Chart builder
│   ├── dashboard/              # Dashboard interface
│   └── SqlLab/                 # SQL editor
├── superset-frontend/packages/
│   └── superset-ui-core/       # UI component library (USE THIS)
├── tests/                      # Python/integration tests
├── docs/                       # Documentation (UPDATE FOR CHANGES)
└── UPDATING.md                 # Breaking changes log
```

## Architecture Patterns

### Dataset-Centric Approach
Charts built from enriched datasets containing:
- Dimension columns with labels/descriptions
- Predefined metrics as SQL expressions
- Self-service analytics within defined contexts

### Security & Features
- **RBAC**: Role-based access via Flask-AppBuilder
- **Feature flags**: Control feature rollouts
- **Row-level security**: SQL-based data access control

## Test Utilities

### Python Test Helpers
- **`SupersetTestCase`** - Base class in `tests/integration_tests/base_tests.py`
- **`@with_config`** - Config mocking decorator
- **`@with_feature_flags`** - Feature flag testing
- **`login_as()`, `login_as_admin()`** - Authentication helpers
- **`create_dashboard()`, `create_slice()`** - Data setup utilities

### TypeScript Test Helpers
- **`superset-frontend/spec/helpers/testing-library.tsx`** - Custom render() with providers
- **`createWrapper()`** - Redux/Router/Theme wrapper
- **`selectOption()`** - Select component helper
- **React Testing Library** - NO Enzyme (removed)

## Pre-commit Validation

**Use pre-commit hooks for quality validation:**

```bash
# Install hooks
pre-commit install

# Quick validation (faster than --all-files)
pre-commit run                   # Staged files only
pre-commit run mypy              # Python type checking
pre-commit run format            # Code formatting
pre-commit run eslint            # Frontend linting
```

## Development Guidelines

- **Documentation**: Update docs/ for any user-facing changes
- **Breaking Changes**: Add to UPDATING.md
- **Docstrings**: Required for new functions/classes
- **Follow existing patterns**: Mimic code style, use existing libraries and utilities
- **Type Safety**: This codebase is actively modernizing toward full TypeScript and type safety
- **Always run `pre-commit run`** to validate changes before committing

---

**Note**: This codebase is actively modernizing toward full TypeScript and type safety. Always run `pre-commit run` to validate changes. Follow the ongoing refactors section to avoid deprecated patterns.