Vitest

Vitest

Blazing-fast unit test framework powered by Vite.

Quick Start

// sum.test.js
import { describe, it, expect } from 'vitest'

function sum(a, b) { return a + b }

describe('sum', () => {
  it('adds numbers', () => {
    expect(sum(1, 2)).toBe(3)
  })
})

When to Use

• Vite-based projects
• Vue/React/Svelte component testing
• TypeScript-native testing
• Fast feedback development

Step-by-Step

1. Install: npm install --save-dev vitest
2. Add "test": "vitest" to package.json
3. Write tests with Jest-compatible API
4. Run: npm test

Dependencies

npm install --save-dev vitest @vue/test-utils jsdom

Examples

import { mount } from '@vue/test-utils'
import Counter from './Counter.vue'

it('increments on click', async () => {
  const wrapper = mount(Counter)
  await wrapper.find('button').trigger('click')
  expect(wrapper.text()).toContain('1')
})

Resources

• Vitest Guide

Validation

1. Tests pass with vitest run
2. Watch mode works: vitest
3. Coverage generates: vitest --coverage