vite-jest

0.1.4 verified Mon Apr 27 auth: no javascript

A Jest transformer for seamless Vite integration in testing, version 0.1.4. Provides Vite's transform pipeline for Jest, allowing use of Vite plugins and TypeScript without separate config. Lightweight alternative to ts-jest when using Vite. Active development but experimental.

Common errors

error Cannot find module 'vite-jest' from 'jest.config.js' ↓

cause vite-jest not installed or not in node_modules.

fix

Run npm install -D vite-jest

error TypeError: Invalid value: Vite config must be a sync function or an object. ↓

cause Passing an async Vite config to vite-jest; vite-jest expects sync config.

fix

Make vite.config.ts export a sync object or a sync function.

error vite-jest: rootDir option must be specified in Jest config transform block. ↓

cause vite-jest cannot determine the project root automatically in some setups.

fix

Add rootDir: __dirname to the transform options in jest.config.js.

Warnings

breaking vite-jest 0.1.x requires Jest 27+ and Vite 2.4.2+. Using older versions causes undefined transform errors. ↓

fix Upgrade to vite-jest@0.1.4, Jest 27, Vite 2.4.2+.

deprecated vite-jest is experimental and may break with Vite or Jest minor updates. ↓

fix Consider using vitest for production testing.

gotcha Using CommonJS require() to import vite-jest throws 'require is not defined' or similar ESM errors. ↓

fix Use ESM import syntax. If Jest config is in CommonJS, use dynamic import: `module.exports = { transform: { '^.+\.ts$': ['vite-jest', { rootDir: __dirname }] } }`

gotcha When using Vite plugins that rely on server context (e.g., @vitejs/plugin-legacy), tests may fail because there is no dev server. ↓

fix Avoid plugins that require server context in tests, or mock them.

Install

npm install vite-jest

yarn add vite-jest

pnpm add vite-jest

Imports

viteJest
wrong
```
const viteJest = require('vite-jest')
```
correct
```
import viteJest from 'vite-jest'
```
Default export. ESM only; CommonJS require not supported.
createTransformer
```
import { createTransformer } from 'vite-jest'
```
Named export. Use to customize transformer options.

ProjectConfig

wrong

import { ProjectConfig } from 'vite-jest'

correct

import type { ProjectConfig } from 'vite-jest'

TypeScript type import only, not a runtime value.

Quickstart

Shows base Jest config with vite-jest transformer, a simple TypeScript module, and a corresponding test using Vite's transform.

// jest.config.js
module.exports = {
  testEnvironment: 'node',
  transform: {
    '^.+\.[jt]sx?$': ['vite-jest', { rootDir: __dirname }]
  }
};

// sum.ts
export const sum = (a: number, b: number) => a + b;

// sum.test.ts
import { sum } from './sum';
test('adds 1 + 2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3);
});