Cursor rule

1---
2alwaysApply: true
3description: Testing patterns and best practices for PRPM codebase with Vitest
4---
5 
6# PRPM Testing Patterns
7 
8Expert guidance for testing the Prompt Package Manager codebase.
9 
10## Testing Philosophy
11 
12### Test Pyramid
13- **70% Unit Tests**: Format converters, parsers, utilities
14- **20% Integration Tests**: API routes, database operations, CLI commands
15- **10% E2E Tests**: Full workflows (install, publish, search)
16 
17### Coverage Goals
18- **Format Converters**: 100% coverage (critical path)
19- **CLI Commands**: 90% coverage
20- **API Routes**: 85% coverage
21- **Utilities**: 90% coverage
22 
23## Key Testing Patterns
24 
25### Format Converter Tests
26```typescript
27describe('toCursor', () => {
28  it('preserves all data in roundtrip', () => {
29    const result = toCursor(canonical);
30    const back = fromCursor(result.content);
31    expect(back).toEqual(canonical);
32  });
33  
34  it('flags lossy conversions', () => {
35    const result = toCursor(canonicalWithClaudeSpecific);
36    expect(result.lossyConversion).toBe(true);
37    expect(result.qualityScore).toBeLessThan(100);
38  });
39});
40```
41 
42### CLI Command Tests
43```typescript
44describe('install command', () => {
45  it('downloads and installs package', async () => {
46    await handleInstall('test-package', { as: 'cursor' });
47    expect(fs.existsSync('.cursor/rules/test-package.md')).toBe(true);
48  });
49});
50```
51 
52### Integration Tests
53```typescript
54describe('registry API', () => {
55  it('searches packages with filters', async () => {
56    const results = await searchPackages({ 
57      query: 'react', 
58      category: 'frontend' 
59    });
60    expect(results.length).toBeGreaterThan(0);
61  });
62});
63```
64 
65## Best Practices
66 
671. **Test Isolation**: Each test should be independent
682. **Clear Assertions**: Use descriptive expect messages
693. **Mock External Services**: Don't hit real APIs in tests
704. **Test Edge Cases**: Empty inputs, null values, large datasets
715. **Performance**: Keep unit tests under 100ms each
72 
73## Running Tests
74 
75```bash
76# All tests
77npm run test
78 
79# Watch mode
80npm run test:watch
81 
82# Coverage
83npm run test:coverage
84 
85# Specific file
86npm run test -- to-cursor.test.ts
87```
88 
89Remember: High test coverage ensures PRPM stays reliable as critical infrastructure.
90