소개
Provides detailed guidance and implementation patterns for establishing high-quality testing environments in JavaScript and TypeScript projects. It covers configuration for modern runners like Jest and Vitest, unit testing patterns for functions and classes, sophisticated mocking strategies for external dependencies, and full-scale API integration testing. Whether you are implementing Test-Driven Development (TDD) from scratch or seeking to improve code coverage and reliability in existing services, this skill offers the blueprints needed for professional-grade software verification.