Unit Testing Skill

Write comprehensive unit tests with full coverage: happy paths, edge cases, and error conditions.

Core Principles

1. Test behavior, not implementation - Tests verify what code does, not how
2. One assertion concept per test - Each test validates a single logical behavior
3. Arrange-Act-Assert structure - Setup, execute, verify
4. Descriptive test names - Name describes scenario and expected outcome
5. Independent tests - No test depends on another's state or execution order
6. Fast tests - Mock expensive operations (network, disk, databases) unless integration testing

Workflow

0. MANDATORY: Use context7 Before Writing Tests

CRITICAL: Before writing ANY tests, use context7 to look up current testing framework documentation and best practices.