Quality assurance

Quality Assurance - High-Density Standards

Standards for maintaining code hygiene, automated checks, and testing integrity.

Priority: P1 (MAINTENANCE)

Standards for maintaining code quality, automated checks, and testing integrity.

🔍 Code Quality & Linting

• Zero Tolerance: Treat all linter warnings/infos as fatal errors in CI.
• Automated Formatting: Enforce strict formatting on every commit using hooks.
• Type Safety: Never use any or dynamic unless absolutely necessary. Use specific interfaces/types for all data boundaries.
• Dead Code: Proactively remove unused imports, variables, and deprecated methods.

🧪 Testing & TDD

• F-I-R-S-T: Test must be Fast, Independent, Repeatable, Self-Validating, and Timely.
• TDD (Red-Green-Refactor): See our dedicated TDD Skill for strict cycle enforcement.
• Edge Cases: Always test null/empty states, boundary limits, and error conditions.
• Mock Dependencies: Isolate code by mocking external systems (APIs, DBs) to ensure deterministic results.

🔺 The Test Pyramid

• Unit Tests (70%): Fast, isolated, test individual functions/classes. (TDD focus).
• Integration Tests (20%): Test interactions between modules (e.g., Service + DB).
• E2E Tests (10%): Slow, realistic, test user flows from UI to Backend.

🎯 Risk-Based Testing

• Prioritize Critical Paths: Login, Payments, Data Integrity must have the highest coverage.
• Impact Analysis: Ask "What happens if this fails?" If the answer is "Data Loss", test it thoroughly.

🛠 Refactoring & Code Reviews

• Code Smells: Proactively refactor duplicated code, long methods (>20 lines), and "god classes".
• Incremental Changes: Perform small, behavior-preserving transformations (Extract Method, Rename Variable).
• Quality Gate: Use peer reviews to share knowledge and catch logic errors before merging.
• Constructive Feedback: Critique the code, not the author. Explain the "why" behind suggestions.

🛠 Automation & Hooks

• Pre-commit Hooks: Validate linting, formatting, and unit tests before every push.
• Documentation: Keep public APIs documented. Use triple-slash/JSDoc.
• Strict Dependencies: Lock versions in pubspec.lock / package-lock.json / pnpm-lock.yaml.

🚫 Anti-Patterns

• Broken Window: **No Ignoring Warnings**: Leaving "small" lint errors leads to codebase rot.
• Testing Implementation: **No Testing Internals**: Changes to private methods shouldn't break tests.
• Manual QA Dependency: **No "Test-Last"**: Verification must be automated and continuous, not a final manual gate.
• Magic Strings: **No Hardcoded IDs**: Use constants or generated keys for accessibility/test IDs.

📚 References

• TDD Cycle & Feedback Examples