vitest

Vitest provides a fast, Jest-compatible testing framework for Vite projects. It uses your existing vite.config.ts or vitest.config.ts for setup and allows you to write tests using familiar describe and it blocks.

Vitest supports unit and integration testing across Vue, React, and Svelte components. It leverages the Vite pipeline to process and test these frontend components efficiently.

You can create mocks and control timers in Vitest using the built-in vi.fn and vi.mock utilities. These tools allow you to mock dependencies and manipulate timers for isolated unit testing.

Vitest supports parallel test execution and code coverage thresholds. It executes tests concurrently to maximize speed and provides built-in coverage reporting for your Vite project.

Migrating from Jest to Vitest is straightforward because Vitest provides a Jest-compatible API. You can transition your tests to Vite's pipeline for faster execution without major rewrites.

Vitest requires a vitest.config.ts or vite.config.ts file to run. The framework uses frontmatter for test discovery and relies on this configuration to define environments like node or jsdom.