概要
This skill provides comprehensive guidance for setting up and implementing testing workflows in JavaScript and TypeScript applications. It covers essential patterns for unit, integration, and end-to-end testing using industry-standard tools like Jest, Vitest, and Testing Library. Whether you are building new test infrastructure, mocking complex dependencies, or adopting Test-Driven Development (TDD), this skill helps ensure code reliability and quality through best practices in modular testing, dependency injection, and asynchronous function verification.