ts-testing-vitest

When to Use This Skill

Use when you need to:

• Write a unit test for a function, module, or utility
• Write a component test that renders a React component and asserts on its output
• Test a custom hook in isolation
• Mock a module, a function, or a fetch/API call in a test
• Decide whether a test belongs here or in an e2e suite

Trigger keywords: Vitest, vi.fn, vi.mock, vi.spyOn, React Testing Library, RTL, render, screen, getByRole, userEvent, renderHook, jsdom, happy-dom, test coverage, component test, unit test.

Freshness rule: Vitest's browser-mode API and RTL's async utilities have shifted across majors — recheck current docs before relying on a specific matcher or config shape.