Testing with vp test

What it is#

vp test runs Vitest, reusing the same resolve and transform config as your app. You get Jest-style expectations, snapshots, coverage, and native ESM/TS/JSX — configured in the same vite.config.ts as everything else.

Why you'd care#

Tests share your app's Vite pipeline, so what runs in dev is what runs in tests. And because vite-plus bundles Vitest, a plain vp install is enough for node-mode tests — no separate vitest dependency to manage.

Before#

A separate vitest.config.ts, a vitest dependency to keep in sync with Vite, and vitest sitting in watch mode by default (surprising in CI).

After#

vp test              # run once and exit
vp test watch        # watch mode when you want it
vp test run --coverage

Do it yourself#

1. Configure tests in vite.config.ts#

import { defineConfig } from 'vite-plus'

export default defineConfig({
  test: {
    include: ['src/**/*.test.ts'],
  },
})

Vite+ recommends putting test config here rather than a separate vitest.config.ts.

2. Write a test — import from vite-plus/test#

In a Vite+ project, pull test utilities from vite-plus/test, not vitest:

import { describe, expect, it } from 'vite-plus/test'
import { sum } from './sum'

describe('sum', () => {
  it('adds', () => {
    expect(sum(2, 3)).toBe(5)
  })
})

3. Run it#

vp test

4. Coverage#

vp test run --coverage

Gotchas#

• vp test runs once by default — the opposite of raw Vitest. Use vp test watch for the interactive loop.
• vp test ≠ vp run test. vp test is the built-in Vitest command; vp run test runs a test script from package.json. (Next lesson makes this distinction concrete.)
• Browser mode is partly opt-in. The base browser runtime and preview provider ship with vite-plus, but the Playwright and WebdriverIO providers do not — install @vitest/browser-playwright (+ playwright) or @vitest/browser-webdriverio (+ webdriverio) yourself, pinned to the bundled Vitest version.
• Leave any declare module 'vitest' type augmentations pointing at 'vitest' — vite-plus/test is a thin re-export, so augmentations must target the upstream module identity.

Recap#

vp test is Vitest wired into your Vite config, run-once by default. Configure it in the test block, import from vite-plus/test, add watch or --coverage as needed, and install browser providers explicitly. Next: how vp run fits your existing scripts.