# Core Library Testing TODOs

## Overview
Testing gaps in core library files that provide foundational functionality for the entire application.

---

## 🔴 High Priority Items

### lib-db-001: Add comprehensive database connection and error handling tests
**File Location**: `lib/db.test.ts` (enhance existing)
**Current Coverage**: 2/10 - Only tests Pool instance creation
**Impact**: High - Database failures could crash the application
**Estimated Effort**: 20 hours

**Specific Tasks**:
- [ ] Test database connection with valid/invalid credentials
- [ ] Test connection pool configuration and limits
- [ ] Test connection timeout behavior
- [ ] Test connection failure and retry logic
- [ ] Test pool exhaustion scenarios
- [ ] Test graceful shutdown procedures
- [ ] Test database schema validation
- [ ] Test environment variable handling

**Critical Test Cases Needed**:
```typescript
describe('Database Connection Error Handling', () => {
  test('should handle invalid database credentials');
  test('should handle database server unavailable');
  test('should handle connection pool exhaustion');
  test('should handle network timeouts');
  test('should retry failed connections');
  test('should validate environment variables');
});
```

---

### lib-redis-001: Implement Redis client functional testing with real Redis instance
**File Location**: `lib/redis-client.test.ts` (enhance existing)
**Current Coverage**: 1/10 - Minimal functional testing
**Impact**: High - Caching failures could cause performance issues
**Estimated Effort**: 24 hours

**Specific Tasks**:
- [ ] Test Redis connection establishment
- [ ] Test Redis connection failure handling
- [ ] Test singleton pattern behavior
- [ ] Test all Redis operations (get, set, hGetAll, ft.search)
- [ ] Test Redis client reconnection logic
- [ ] Test mock vs real client selection
- [ ] Test error handling for each operation
- [ ] Test Redis memory usage and limits

**Critical Test Cases Needed**:
```typescript
describe('Redis Operations', () => {
  test('should establish connection successfully');
  test('should handle connection failures');
  test('should implement singleton pattern correctly');
  test('should handle get/set operations');
  test('should handle hash operations');
  test('should handle search operations');
  test('should handle timeouts and retries');
});
```

---

### lib-stripe-001: Add complete Stripe payment processing functional tests
**File Location**: `lib/stripe.test.ts` (enhance existing)
**Current Coverage**: 3/10 - Missing all functional testing
**Impact**: High - Payment processing errors affect revenue
**Estimated Effort**: 32 hours

**Specific Tasks**:
- [ ] Test Stripe initialization with different configurations
- [ ] Test checkout session creation
- [ ] Test payment intent creation
- [ ] Test webhook signature verification
- [ ] Test refund processing
- [ ] Test customer management
- [ ] Test price/product retrieval
- [ ] Test error scenarios (invalid cards, insufficient funds)
- [ ] Test API rate limiting handling
- [ ] Test network failure scenarios

**Critical Test Cases Needed**:
```typescript
describe('Stripe Payment Processing', () => {
  test('should create checkout session');
  test('should handle payment success');
  test('should handle payment failures');
  test('should process refunds correctly');
  test('should verify webhook signatures');
  test('should handle API rate limits');
  test('should handle network failures');
});
```

---

## 🟡 High Priority Items

### lib-auth-001: Enhance auth-logic.ts with database failure and bcrypt exception tests
**File Location**: `lib/auth-logic.test.ts` (enhance existing)
**Current Coverage**: 8/10 - Good but missing edge cases
**Impact**: Medium - Authentication failures could lock users out
**Estimated Effort**: 12 hours

**Specific Tasks**:
- [ ] Test database connection failures during auth
- [ ] Test bcrypt comparison exceptions
- [ ] Test concurrent login attempts
- [ ] Test malformed input handling
- [ ] Test password hash edge cases
- [ ] Test session management under load
- [ ] Test authentication timeout scenarios

**Critical Test Cases Needed**:
```typescript
describe('Authentication Edge Cases', () => {
  test('should handle database connection failures');
  test('should handle bcrypt exceptions');
  test('should handle concurrent logins');
  test('should handle malformed inputs');
  test('should handle authentication timeouts');
});
```

---

### lib-actions-001: Add caching behavior and performance tests for lib/actions.ts
**File Location**: `lib/actions.test.ts` (enhance existing)
**Current Coverage**: 9/10 - Excellent but missing cache testing
**Impact**: Medium - Performance issues not detected
**Estimated Effort**: 16 hours

**Specific Tasks**:
- [ ] Test React.cache behavior with products
- [ ] Test cache invalidation scenarios
- [ ] Test Redis caching integration
- [ ] Test performance with large datasets
- [ ] Test concurrent access scenarios
- [ ] Test cache hit/miss ratios
- [ ] Test cache memory usage
- [ ] Test cache expiration behavior

**Critical Test Cases Needed**:
```typescript
describe('Actions Caching Performance', () => {
  test('should cache product queries effectively');
  test('should invalidate cache properly');
  test('should handle concurrent cache access');
  test('should maintain performance with large datasets');
});
```

---

## Dependencies and Order

**Phase 1** (Week 1):
1. lib-db-001 (Database foundation) - Required for all other tests
2. lib-redis-001 (Caching layer) - Required for performance testing

**Phase 2** (Week 2):
3. lib-stripe-001 (Payment processing) - Critical business functionality

**Phase 3** (Week 3):
4. lib-auth-001 (Authentication security) - Enhanced security
5. lib-actions-001 (Performance optimization) - Performance monitoring

---

## Success Metrics

- Database test coverage: 90%+
- Redis test coverage: 95%+
- Stripe test coverage: 95%+
- Authentication test coverage: 95%+
- Actions performance test coverage: 90%+

- Test execution time: <30 seconds per suite
- Mock usage reduction: 50% fewer mocks
- Integration tests: 80%+ using real services

---

## Notes for Implementation

1. **Database Testing**: Use testcontainers or Docker for isolated test databases
2. **Redis Testing**: Use real Redis instance in CI with proper cleanup
3. **Stripe Testing**: Use Stripe test keys and test clock for time-based scenarios
4. **Performance Testing**: Measure actual execution times, not just functionality
5. **Error Simulation**: Use dependency injection to simulate failure scenarios

---

## Testing Strategy

### Database Testing
```typescript
// Use transaction rollback for test isolation
beforeEach(async () => {
  await db.query('BEGIN');
});

afterEach(async () => {
  await db.query('ROLLBACK');
});
```

### Redis Testing
```typescript
// Use Redis database selection for test isolation
beforeEach(async () => {
  await redis.select(15); // Use dedicated test DB
});

afterEach(async () => {
  await redis.flushdb();
});
```

### Stripe Testing
```typescript
// Use Stripe test clock for predictable time-based tests
const testClock = await stripe.testHelpers.createTestClock();
// Use in tests for predictable webhook timing
```