Vitest - @ src folder alias not resolved in test files

Question

I have a vue3 project using Vite/Vitest, as recommanded in Vue.js documentation.

Here is the structure of the project:

src
  components
    // my Vue components here, potentially in sub-folders. For example:
    HelloWorld.vue 
  router
    index.ts
  App.vue
  main.ts
vitest
  components
    // My test specs. For example:
    HelloWorld.spec.ts
// ...
tsconfig.app.json
tsconfig.json
tsconfig.vite-config.json
tsconfig.vitest.json
vite.config.ts

The @/ alias for src folder is resolved properly in components files. However, in my test files, I get an error: cannot find module.

For example, in HelloWorld.spec.ts:

import HelloWorld from '@/components/HelloWorld.vue'; // <-- error !
import { describe, it } from 'vitest';

describe('HelloWorld', () => {
  it('should day hello', () => {
    // ...
  });
});

tsconfig.app.json

{
  "extends": "@vue/tsconfig/tsconfig.web.json",
  "include": [
    "env.d.ts",
    "src/**/*",
    "src/**/*.vue"
  ],
  "exclude": [
    "vitest/**/*"
  ],
  "compilerOptions": {
    "composite": true,
    "baseUrl": ".",
    "paths": {
      "@/*": [
        "./src/*"
      ]
    },
    "strict": true,
    "experimentalDecorators": true
  }
}

vite.config.js

import vue from '@vitejs/plugin-vue';
import { fileURLToPath, URL } from 'url';
import { defineConfig } from 'vite';

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [vue()],
  resolve: {
    alias: {
      '@': fileURLToPath(new URL('./src', import.meta.url)),
    },
  },
  test: {
    include: ['./vitest/**/*.{test,spec}.{js,mjs,cjs,ts,mts,cts,jsx,tsx}'],
  },
});

You could first try with a more standarized way to build aliases in **vite.config.js**: `alias: { "@": "./src" }` . If it's not working, or if you want to keep the same config, I suggest you to publish a **reproducible project**. — flydev, Jun 02 '22 at 13:10
The alias config came as-is with the initialization of the project, using `npm init vue@latest`. But I tried other configs and none is working. — Eria, Jun 03 '22 at 08:12
Yes - then you should give us a [reproducible project](https://stackoverflow.com/help/minimal-reproducible-example), i suspect a typescript config issue or it could be also possible that you hit a recent issue which require the project to be built at least one time before setting the `test.include`. — flydev, Jun 03 '22 at 09:05
Any idea why we should exclude test files in `tsconfig.app.json`? Because including this files instead of excluding them solves the problem. — Eria, Jun 13 '22 at 20:02
The reason is to avoid these files being compiled. You can be more "precise" about what you want to do with these files by using the typescript `configurations` option. — flydev, Jun 14 '22 at 12:04
same prob for me also. I tried to configure the `resolve.alias` vite config property but it still not working — Adri HM, Jul 04 '22 at 08:23

score 39 · Answer 1 · edited Jun 28 '23 at 05:11

39

You just have to specify the aliases in your vitest.config.js file:

import path from 'path'
import vue from '@vitejs/plugin-vue'

export default {
  plugins: [vue()],
  test: {
    globals: true,
    environment: 'jsdom',
  },
  resolve: {
    alias: {
      '@': path.resolve(__dirname, './src')
    },
  },
}

edited Jun 28 '23 at 05:11

Penny Liu

15,447
5
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98

answered Jul 17 '22 at 17:43

Adri HM

2,314
2
17
30

1

I guess it should be `'@': path.resolve(__dirname, './src'),` – eXception Aug 26 '22 at 11:07
oh yes you're right – Adri HM Nov 06 '22 at 12:59
This resolve option is not listed in their official documentation https://vitest.dev/config Where do you find it ? ^^ – Poyoman Jan 17 '23 at 14:21
I went to module sources lol, but I think it's here https://vitest.dev/config/#alias – Adri HM Jan 17 '23 at 15:59
It doesn't work. And it breaks half my existing unit tests. – Eria Jan 25 '23 at 15:59

score 3 · Answer 2 · edited Jun 28 '23 at 05:19

For SvelteKit users I ran into similar issue and had to add $lib to vitest.config.js

import { defineConfig } from 'vitest/config';
import { svelte } from '@sveltejs/vite-plugin-svelte';
import path from 'path';

export default defineConfig({
  plugins: [svelte({ hot: !process.env.VITEST })],
  test: {
    globals: true,
    environment: 'jsdom',
  },
  resolve: {
    alias: {
      $lib: path.resolve(__dirname, './src/lib'),
    },
  },
});

score 1 · Accepted Answer · answered Jan 25 '23 at 16:10

The final solution that worked for me was to include the test files in tsconfig.vitest.json:

tsconfig.app.json (unchanged from question post)

{
  "extends": "@vue/tsconfig/tsconfig.web.json",
  "include": [
    "env.d.ts",
    "src/**/*",
    "src/**/*.vue"
  ],
  "exclude": [
    "vitest/**/*"
  ],
  "compilerOptions": {
    "composite": true,
    "baseUrl": ".",
    "paths": {
      "@/*": [
        "./src/*"
      ]
    },
    "strict": true,
    "experimentalDecorators": true
  }
}

tsconfig.vitest.json

{
  "extends": "./tsconfig.app.json",
  "include": [
    "vitest/**/*",
  ],
  "exclude": [],
  "compilerOptions": {
    "composite": true,
    "lib": [],
    "types": [
      "node",
      "jsdom"
    ],
  }
}

Yep, worked for me as well, like include=[...., "test"] in the regular tsconfing.app.json — alekshandru, Jun 03 '23 at 07:55

Vitest - @ src folder alias not resolved in test files

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