ExUnit Code Review Quick Reference | Issue Type | Reference | |------------|-----------| | Async tests, setup, describe, tags | references/exunit-patterns.md | | Behavior-based mocking, expectations | references/mox-boundaries.md | | Bypass, Swoosh, Oban testing | references/test-adapters.md | | What to mock vs real, Ecto sandbox | references/integration-tests.md | Mock Boundary Philosophy Mock at external boundaries: - HTTP clients, external APIs, third-party services - Slow resources: file system, email, job queues - Non-deterministic: DateTime.utc now(), :rand DO NOT mock internal code: -…