pitfalls-express-apilisted

# Express API Pitfalls Common pitfalls and correct patterns for Express APIs. ## When to Use - Building REST API routes - Implementing storage interfaces - Setting HTTP status codes - Validating request bodies - Reviewing Express API code ## Workflow ### Step 1: Verify Route Structure Check that routes follow REST conventions. ### Step 2: Check Status Codes Ensure correct status codes for each operation. ### Step 3: Verify Validation Confirm input validation middleware is in place. --- ## Route Structure ```typescript // Public routes GET /api/resource // List GET /api/resource/:id // Get one // Admin routes (with auth middleware) POST /api/admin/resource // Create (201) PATCH /api/admin/resource/:id // Update (200) DELETE /api/admin/resource/:id // Delete (204) // ✅ Always validate before storage router.post('/', validateBody(schema), async (req, res) => { const validated = req.body; // Already validated by middleware }); ``` ## Status Codes | Operation | Success | Not Found | Invalid | |-----------|---------|-----------|---------| | GET | 200 | 404 | 400 | | POST | 201 | - | 400 | | PATCH | 200 | 404 | 400 | | DELETE | 204 | 404 | - | ## Storage Interface Pattern ```typescript // ✅ Define interface for all storage operations interface IStorage { // Strategies getStrategies(): Promise<Strategy[]>; getStrategy(id: string): Promise<Strategy | undefined>; createStrategy(data: NewStrategy): Promise<Strategy>; updateStrateg