unit-testing-principles-aaa-pattern

---
name: unit-testing-principles-aaa-pattern
description: Use this skill when structuring clean, deterministic unit tests following Arrange-Act-Assert principles and strict assertion hygiene.
---
# Unit Testing Principles & AAA Pattern

## When to use
Use this skill when you need to structuring clean, deterministic unit tests following Arrange-Act-Assert principles and strict assertion hygiene.

## Prerequisites
- Deep familiarity with relevant domain standards, developer tooling, or testing frameworks.
- Access to testing repository, mobile simulator, or operational workspace.

## Step-by-step workflow
1. **Analyze requirements and constraints**: Review code quality gates, mobile runtime targets, or architecture patterns.
2. **Design implementation strategy**: Draft explicit interfaces, test cases, or declarative configurations.
3. **Execute implementation**: Build and integrate components according to domain best practices.
4. **Validate correctness**: Run automated test suites, verify build outputs, and inspect diagnostic logs.
5. **Establish maintenance guardrails**: Configure CI/CD quality checks, alerts, and documentation.

## Commands / code examples
```bash
# Operational command and verification workflow for unit-testing-principles-aaa-pattern
echo "Executing verification check for unit-testing-principles-aaa-pattern"
```

## Common mistakes & pitfalls
- Bypassing automated testing or linting checks under delivery pressure.
- Neglecting to isolate side effects, leading to flaky tests or fragile architectures.
- Introducing tight coupling between distinct architectural domains or deployment units.

## Verification checklist
- [ ] Implementations adhere strictly to domain conventions and standards.
- [ ] Automated verification passes cleanly with zero warnings or errors.
- [ ] Edge cases, error paths, and resource lifecycles are explicitly handled.
- [ ] Documentation and architectural decision records are updated.

## Related skills
- unit-testing-principles-aaa-pattern
- domain-driven-design-bounded-contexts
- ci-cd-github-actions-workflows
- git-interactive-rebase-squash-clean-history