Failed to resolve import "bun:test" since v3.18.0

[AloisSeckar]

Environment

• Operating System: Windows_NT
• Node Version: v22.15.1
• Nuxt Version: 4.0.2
• CLI Version: 3.27.0
• Nitro Version: 2.12.4
• Package Manager: pnpm@10.14.0
• Builder: -
• User Config: modules, compatibilityDate, eslint
• Runtime Modules: @nuxt/eslint@1.7.1, @nuxt/test-utils/module@3.17.2
• Build Modules: -

Reproduction

nuxt-spec project GitHub repo

Describe the bug

In my experimental Nuxt-testing related project I tried to bump all deps including @nuxt/test-utils today.

With v3.19.2 my basic e2e test (https://github.com/AloisSeckar/nuxt-spec/blob/main/test/nuxt-e2e.test.ts) started failing with:

Error: Failed to resolve import "bun:test" from "node_modules/.pnpm/@nuxt+test-utils@3.19.2_@vu_4cf1b4df40656f546fe6453b9bd863ee/node_modules/@nuxt/test-utils/dist/shared/test-utils.CT3RJOY3.mjs". Does the file exist?

I was browsing the release notes and noticed Bun support was added in v3.18.0.

I pinned my @nuxt/test-utils down to v3.17.2 and the test run smoothly.

Bumped up to v3.18.0 and the error was back:

Error: Failed to resolve import "bun:test" from "node_modules/.pnpm/@nuxt+test-utils@3.18.0_@ty_e83edee9a3fff740a26abcfe3b3f2831/node_modules/@nuxt/test-utils/dist/shared/test-utils.CT3RJOY3.mjs". Does the file exist?

I don't have Bun installed and I don't plan to install it anytime soon.

Did I just miss something? Do I need to do something specific in config to opt-out from it? The PR says it is "auto-detected if used". The Nuxt docs testing page doesn't mention any special treatment for Bun runner either.

Additional context

No response

Logs

[danielroe]

does it make a difference if you use a configuration using vitest projects, like this:

import { defineConfig } from 'vitest/config'
import { defineVitestProject } from '@nuxt/test-utils/config'

export default defineConfig({
  test: {
    projects: [
      {
        test: {
          name: 'unit',
          include: ['test/{e2e,unit}/*.{test,spec}.ts'],
          environment: 'node',
        },
      },
      await defineVitestProject({
        test: {
          name: 'nuxt',
          include: ['test/nuxt/*.{test,spec}.ts'],
          environment: 'nuxt',
        },
      }),
    ],
  },
})

This is what we're recommending going forward, to avoid a lot of issues like this one.

nuxt/nuxt#32863

[AloisSeckar]

Hi, Daniel, thanks for quick reply and for the swift addition into the Nuxt docs!

Changing config the way you proposed worked for me, the error is gone and my test are passing again.

I just somehow fail to grasp why this test needs to be run in node? I need a little help to update my mental model. Or maybe just to verify it:

The simple test should be testing the ability of Nuxt app to render itself in browser... So, is it like reflecting what is actually happening - the Node runtime wakes up and starts putting things together so they can appear in the browser as a website? While the environment nuxt is only meant to mimic some isolated parts (like single components) of the app, but not to embrace the whole application?

[danielroe]

Yes, an end-to-end test starts a nuxt server and then starts a playwright process (if you have brower mode enabled) and controls it from node (or bun, I suppose, if you are using that).

So it should not run in the nuxt 'runtime' environment, which mimics the browser. Imagine trying to run a nuxt build from your browser console. It wouldn't work. And you definitely couldn't launch a browser process from the devtools of the browser.

[AloisSeckar]

Thanks for clarifying. Case dismissed :)