Testing Skill

Create comprehensive, maintainable test suites to ensure code reliability and quality.

When to Use

Use this skill when the user wants to:

• Write unit tests for functions and modules
• Create integration tests for API endpoints
• Implement end-to-end tests with E2E frameworks
• Improve test coverage
• Mock external dependencies
• Set up test environments
• Test database operations

Testing Strategies

Unit Testing

• Test individual functions and methods in isolation
• Use mocks and stubs for dependencies
• Test edge cases and error conditions
• Aim for high coverage (>80%)

Integration Testing

• Test component interactions
• Test API endpoint combinations
• Test database operations and migrations
• Verify data flow across modules

E2E Testing

• Test complete user workflows
• Use frameworks like Playwright, Cypress, or Puppeteer
• Test from user perspective
• Verify visual regression

Best Practices

• AAA pattern: Arrange, Act, Assert
• Tests should be: Independent, repeatable, fast, and self-contained
• Naming: Describe what is being tested
• One assertion per test (when possible)
• Arrange-Act-Assert structure

Frameworks

• JavaScript: Jest, Mocha, Vitest
• Python: pytest, unittest, nose2
• Java: JUnit, TestNG
• Ruby: RSpec, Minitest

Deliverables

• Test suite implementation
• Test configuration
• Coverage report
• Test data setup scripts
• Test utilities

Quality Checklist

• Tests are meaningful and descriptive
• Edge cases are covered
• Tests are fast and don’t block builds
• Setup/teardown is handled
• Mocks are properly isolated
• Tests fail on bugs