unit-testing-expert

What This Skill Does

The unit-testing-expert skill provides comprehensive assistance for developers working with Vitest and Jest. It acts as an interactive pair programmer that helps you write robust, maintainable tests for your TypeScript and JavaScript projects. Whether you are adopting a Test-Driven Development (TDD) workflow, debugging complex async logic, or setting up mocking for external dependencies, this skill provides real-time architectural guidance and code generation. It covers the full lifecycle of testing, including unit, integration, and snapshot testing strategies, ensuring your codebase remains reliable and easy to refactor.

Installation

To integrate this skill into your environment, run the following command in your terminal: clawhub install openclaw/skills/skills/anton-abyzov/sw-unit-testing-expert

Use Cases

• TDD Implementation: Use the agent to guide you through the Red-Green-Refactor cycle for new features.
• Mocking Strategy: Quickly generate mock implementations for databases, API clients, or complex object dependencies using vi.fn() or vi.mock().
• Refactoring Support: Run tests against legacy code to ensure regression-free refactoring.
• Async Testing: Solve complex challenges with promises, timers, or event loops within your test suite.
• Code Coverage Improvement: Analyze existing test suites to identify untested branches or missing edge cases.

Example Prompts

1. "I have a UserService that calls an external API. Can you help me write a Vitest suite that mocks the API response using vi.mock?"
2. "I am getting a 'TypeError' in my Jest test when trying to mock a static method. How should I use vi.spyOn to intercept this call properly?"
3. "Follow the TDD approach to help me build a simple URL validator function. Start by writing the failing test for the edge case of an empty string."

Tips & Limitations

• Context is Key: Always provide the snippet of the code you are testing so the agent can understand the dependency injection patterns.
• Environment Compatibility: Ensure your project is configured for Vitest or Jest. If you are switching frameworks, let the agent know immediately so it can adapt its syntax suggestions.
• Avoid Over-Mocking: The agent will assist with mocks, but be careful not to mock your entire application logic, which can lead to 'false green' tests that do not actually verify system behavior.
• Isolation: Remember that each test file should be independent. If your tests share state, the agent can help you set up beforeEach hooks to reset mocks and cleanup variables between runs.