prpm-testing-patterns

PRPM Testing Patterns

Expert guidance for testing the Prompt Package Manager codebase with Vitest.

Testing Philosophy

Test Pyramid for PRPM

• 70% Unit Tests: Format converters, parsers, utilities
• 20% Integration Tests: API routes, database operations, CLI commands
• 10% E2E Tests: Full workflows (install, publish, search)

Coverage Goals

• Format Converters: 100% coverage (critical path)
• CLI Commands: 90% coverage
• API Routes: 85% coverage
• Utilities: 90% coverage

Test Structure

Organize Test Files

src/
  converters/
    to-cursor.ts
    __tests__/
      setup.ts          # Shared fixtures
      to-cursor.test.ts # Converter tests
      roundtrip.test.ts # Round-trip validation

Key Testing Patterns

Format Converter Tests

describe('toCursor', () => {
  it('preserves all data in roundtrip', () => {
    const result = toCursor(canonical);
    const back = fromCursor(result.content);
    expect(back).toEqual(canonical);
  });
  
  it('flags lossy conversions', () => {
    const result = toCursor(canonicalWithClaudeSpecific);
    expect(result.lossyConversion).toBe(true);
    expect(result.qualityScore).toBeLessThan(100);
  });
});

CLI Command Tests

describe('install command', () => {
  it('downloads and installs package', async () => {
    await handleInstall('test-package', { as: 'cursor' });
    expect(fs.existsSync('.cursor/rules/test-package.md')).toBe(true);
  });
});

Integration Tests

describe('registry API', () => {
  it('searches packages with filters', async () => {
    const results = await searchPackages({ 
      query: 'react', 
      category: 'frontend' 
    });
    expect(results.length).toBeGreaterThan(0);
  });
});

Best Practices

1. Test Isolation: Each test should be independent
2. Clear Assertions: Use descriptive expect messages
3. Mock External Services: Don't hit real APIs in tests
4. Test Edge Cases: Empty inputs, null values, large datasets
5. Performance: Keep unit tests under 100ms each