Summary:

Write integration tests that verify the complete donation flow from HTTP request through service layer to database persistence. Test all endpoints and error scenarios.

Files to create:

• apps/backend/test/donations.e2e-spec.ts

Test scenarios:

1. POST /api/donations - successful one-time donation creation
2. POST /api/donations - successful recurring donation with interval
3. POST /api/donations - validation errors:
   • Negative amount returns 400
   • Invalid email format returns 400
   • Recurring without interval returns 400
   • One-time with interval returns 400
4. GET /api/donations/public - returns only non-anonymous donations
5. GET /api/donations/stats - returns correct total and count

Acceptance criteria:

• Tests use real database (test database or in-memory SQLite)
• All endpoints return correct status codes
• Response bodies match expected DTO shapes
• Database state verified after POST operations
• Tests clean up after themselves (transactions or teardown)

Notes:

Use supertest for HTTP testing and NestJS Test.createTestingModule(). Reference existing test patterns in the repo. Each test should be independent.