Testing Standards

Unit and integration testing as one discipline. Unit tests verify behaviour in isolation; integration tests verify real wiring across boundaries. Together they are the only automated evidence that generated code actually works.

Maverick's Rules

Unit tests

• Test behaviour, not implementation. Assert on outputs and effects, never on reimplemented logic (tautological tests) or internal calls.
• Mock at the boundary only (APIs, DB, filesystem). Never mock what you own; prefer stubs over mocks; >3 mocks in one test means the unit's design is wrong.
• No logic in tests — no conditionals, loops, or try/catch in test bodies. No test interdependence. Delete flaky tests rather than keep them.
• A unit test taking >100ms is hitting real I/O — fix it.

Integration tests

• Complement, don't duplicate — cover cross-boundary behaviour (endpoints, persistence, external clients); never re-test unit-covered logic.
• Each test owns its data and cleans up; parallel runs never collide.
• Real dependencies in order of preference: containers → sandboxes → fakes. Never production services.
• Health-check polling with timeouts, never sleeps. Every test has an explicit timeout.

Coverage (enforced, not aspirational)

• Unit: 60% minimum, gated in CI — the build fails below it. The number is a floor, not a goal: coverage with weak assertions is worse than less coverage with strong ones.
• Integration: every critical cross-boundary path (auth, payment, persistence, external APIs) has at least one test, and coverage must not decrease — a ratchet, not a percentage floor.

Project Implementation Lookup

Check docs/maverick/skills/unit-testing/SKILL.md and docs/maverick/skills/integration-testing/SKILL.md for the project's framework, conventions, and extra requirements. If present, they win on specifics. If missing, proceed with these standards and note the gap in your summary — do not trigger skill generation mid-task.

Detecting Testing Issues in Code Review

Pattern	Issue	Fix
Test with no assertions	False confidence	Add meaningful assertions
Mocking internal modules	Brittle tests	Mock at boundaries only
Test name describes implementation	Couples to internals	Describe behaviour instead
Shared mutable state between tests	Test pollution	Use beforeEach/factory functions
Test catches and swallows errors	Hidden failures	Let errors propagate or assert on them
>3 mocks in one test	Unit has too many dependencies	Refactor the unit's design
Test duplicates implementation logic	Tautological test	Assert on outputs, not reimplemented logic
Commented-out tests	Dead tests hiding failures	Delete or fix
Test hits production service	Side effects and flakiness	Use container, sandbox, or stub
No cleanup after test	Data leaks between tests	Add teardown or transaction rollback
Sleep-based waits for dependencies	Flaky timing	Health-check polling with timeout
Integration test duplicates unit coverage	Wasted execution time	Delete and rely on the unit test
No timeout set	Hanging test blocks CI	Set explicit per-test timeout
Hard-coded connection strings	Breaks across environments	Use environment variables or config
Test requires manual environment setup	Not reproducible	Automate with containers or scripts

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