debug

name	debug
description	Investigate bugs using a systematic approach: reproduce, identify the layer, write a failing test, fix root cause.

Steps

1. Reproduce: Identify the exact steps to reproduce the issue
2. Read errors: Check terminal, browser console, and test output
3. Identify the layer: Is the bug in Domain, Database, API, or Frontend?
4. Write a failing test that demonstrates the bug
5. Fix the root cause (not just the symptom)
6. Verify: Run the test, ensure it passes
7. Run full suite: pnpm test && pnpm lint

Common Debug Commands

# Check API responses
curl -s http://localhost:3000/health | jq

# Check database content
pnpm --filter @acme/database db:studio

# Run specific test file
pnpm --filter @acme/domain test -- --run src/use-cases/__tests__/MyUseCase.test.ts

# Run E2E with visible browser
pnpm test:e2e --headed --project=chromium

# Check TypeScript errors
pnpm lint

Layer-Specific Tips

Layer	Common Issues
Domain	Missing validation, wrong error type
Database	Schema mismatch, missing seed data, FK constraints
API	Missing @Public() decorator, wrong DI token, DTO validation
Frontend	Wrong query key, missing invalidation, stale cache