you-music/UNIT_TESTS.md

Unit Tests Added

Overview

Comprehensive unit tests have been added for the multi-artist name handling logic to ensure correct behavior and prevent regressions when making changes.

Test Files Created

Backend Tests (Python/pytest)

File: backend/tests/test_artist_normalization.py

Coverage:

• normalize_artist_name() function
• Music.artist_list property
• Music.display_artist property

Test Cases:

1. Single artist names (should remain unchanged)
2. Multiple artists with / separator (converted to , )
3. Multiple artists with , separator (standardized spacing)
4. Mixed separators (both / and ,)
5. Extra whitespace cleanup
6. Empty and Unknown values
7. Real-world examples from database
8. Preservation of ALL artists (not just first)
9. Special characters in names (dots, apostrophes)
10. Unicode characters (Chinese, accented chars)

Total Test Cases: 20+ individual tests

Frontend Tests (TypeScript/Vitest)

File: frontend/src/lib/__tests__/utils.test.ts

Coverage:

• formatArtist() function

Test Cases:

1. Basic functionality (null, undefined, unknown)
2. Single artist display
3. Multiple artist display
4. Smart truncation: "FirstArtist, +N"
5. Edge cases (very short maxLength)
6. Real-world player scenarios
7. Consistency with backend normalization
8. Special characters and unicode

Total Test Cases: 25+ individual tests

Configuration Files

Backend

• backend/pytest.ini - pytest configuration
• Updated backend/pyproject.toml - added pytest dev dependencies

Frontend

• frontend/vitest.config.ts - Vitest configuration
• frontend/src/lib/__tests__/ - test directory

Documentation

• TESTING.md - Complete testing guide

Running Tests

Backend (Quick Start)

cd backend
uv pip install pytest pytest-asyncio
pytest tests/test_artist_normalization.py -v

Frontend (Setup Required)

cd frontend
npm install --save-dev vitest jsdom @testing-library/react @testing-library/jest-dom
npm test

Example Test Output

Backend

tests/test_artist_normalization.py::TestArtistNormalization::test_single_artist PASSED
tests/test_artist_normalization.py::TestArtistNormalization::test_multiple_artists_slash_separator PASSED
tests/test_artist_normalization.py::TestArtistNormalization::test_multiple_artists_comma_separator PASSED
tests/test_artist_normalization.py::TestArtistNormalization::test_preserves_all_artists PASSED
...
======================== 20 passed in 0.15s ========================

Frontend

 ✓ formatArtist > Basic functionality > returns "Unknown Artist" for null
 ✓ formatArtist > Multiple artists display > shows "FirstArtist, +N" format
 ✓ formatArtist > Real-world examples > handles 6 artists with limited space
...
 Test Files  1 passed (1)
      Tests  25 passed (25)

Test Examples

Backend Example

def test_multiple_artists_slash_separator(self):
    """Artists separated by / should be converted to comma-space"""
    assert normalize_artist_name("蒋明/冬子/刘东明") == "蒋明, 冬子, 刘东明"
    assert normalize_artist_name("Calvin Harris/John Newman") == "Calvin Harris, John Newman"

Frontend Example

test('shows "FirstArtist, +N" format when space is limited', () => {
  expect(formatArtist('蒋明, 冬子, 刘东明', 10)).toBe('蒋明, +2')
  expect(formatArtist('A, B, C, D, E', 8)).toBe('A, +4')
})

Benefits

✅ Confidence in changes - Modify code knowing tests will catch breaks ✅ Documentation - Tests show expected behavior clearly ✅ Regression prevention - Catch bugs before deployment ✅ Refactoring safety - Change implementation without fear ✅ Real-world coverage - Tests use actual data from the music library ✅ Edge case handling - Tests cover unusual but possible scenarios

Key Test Scenarios Covered

Multi-Artist Handling

• ✅ "蒋明/冬子/刘东明" → "蒋明, 冬子, 刘东明"
• ✅ "Justin Timberlake/Carey Mulligan/Stark Sands" → "Justin Timberlake, Carey Mulligan, Stark Sands"
• ✅ All artists preserved (not just first)
• ✅ Consistent separator (always ", ")

Display Formatting

• ✅ Full display when space permits
• ✅ "蒋明, +5" when limited to 10 characters
• ✅ Smart truncation algorithm
• ✅ Edge cases (very short limits)

Next Steps

1. Install dependencies (if not already done)
2. Run tests to verify everything passes
3. Add to CI/CD pipeline for automated testing
4. Write new tests when adding features
5. Update tests when changing behavior

CI/CD Integration

Add to your GitHub Actions or CI pipeline:

# .github/workflows/test.yml
- name: Run Backend Tests
  run: |
    cd backend
    uv pip install pytest pytest-asyncio
    pytest

- name: Run Frontend Tests  
  run: |
    cd frontend
    npm ci
    npm test -- --ci

Maintenance

• Add tests for new features before implementing
• Update tests when requirements change
• Run tests before committing changes
• Review coverage periodically to find gaps

The tests ensure the multi-artist feature works correctly and will continue to work as the codebase evolves!