you-music/TESTING.md

# Testing Guide

## Backend Tests (Python)

### Setup
```bash
cd backend
uv pip install pytest pytest-asyncio
```

### Run All Tests
```bash
pytest
```

### Run Specific Test File
```bash
pytest tests/test_artist_normalization.py
```

### Run With Verbose Output
```bash
pytest -v
```

### Run Specific Test
```bash
pytest tests/test_artist_normalization.py::TestArtistNormalization::test_multiple_artists_slash_separator
```

## Frontend Tests (TypeScript/Jest)

### Setup
```bash
cd frontend
npm install
```

### Run All Tests
```bash
npm test
```

### Run Specific Test File
```bash
npm test utils.test.ts
```

### Run Tests in Watch Mode
```bash
npm test -- --watch
```

## What's Tested

### Artist Normalization (`test_artist_normalization.py`)
- Single artist names
- Multiple artists with / separator
- Multiple artists with , separator  
- Mixed separators
- Whitespace cleanup
- Unicode characters (Chinese, special chars)
- Real-world examples from database
- All artists are preserved (not just first one)

### Artist Display Formatting (`utils.test.ts`)
- Display all artists when space permits
- Smart truncation: "FirstArtist, +N"
- Single vs multiple artist handling
- Edge cases (very short maxLength)
- Real-world player scenarios

## Continuous Integration

Add to your CI/CD pipeline:

```yaml
# Backend
- cd backend && pytest

# Frontend  
- cd frontend && npm test -- --ci
```

## Writing New Tests

### Backend
```python
def test_your_feature():
    """Test description"""
    result = function_to_test(input)
    assert result == expected_output
```

### Frontend
```typescript
test('description', () => {
  const result = functionToTest(input)
  expect(result).toBe(expectedOutput)
})
```