When using vi.doMock from vitest, I found that imports cannot be called ahead of time in JavaScript files,

[lrsoy]

Describe the bug

When using vi.doMock in vitest, I found that the import cannot be called ahead of time in the JavaScript file, causing vi.doMock to fail. Normally, I can use vi.doMock to mock a function or module, but calling it before the import statement doesn't seem to have an effect. I'd like to know how to fix this so that I can use vi.doMock correctly in JavaScript files.，

But I don't have any problems in ts, it can run completely and get the correct result

In the screenshot below, I took the sample code of vi.doMock from the vitest document, and he couldn’t run it in the end. Although ts is the most commonly used, this problem will occur when I use js when I’m learning.

Forgive me for not being able to post the code and only show it by screenshots, so I hope that you can try it yourself when you see this problem, this problem does exist

my development environment

pnpm 8.4.0
vitest 0.33.0
node 16.x

Reproduction

System Info

FAIL  increment.spec.js > 官方文档案例vi.doMock > importing the next module imports mocked one
AssertionError: expected 100 to be 101 // Object.is equality

- Expected
+ Received

- 101
+ 100

 ❯ increment.spec.js:24:32


⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/1]⎯

 Test Files  1 failed (1)
      Tests  1 failed (1)
   Start at  18:38:39
   Duration  398ms (transform 49ms, setup 0ms, collect 36ms, tests 12ms, environment 0ms, prepare 147ms)


 FAIL  Tests failed. Watching for file changes...
       press h to show help, press q to quit

Used Package Manager

pnpm

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[sheremet-va]

This is not a reproduction, it is a screenshot

[github-actions]

Hello @lrsoy. Please provide a minimal reproduction using a GitHub repository or StackBlitz. Issues marked with need reproduction will be closed if they have no activity within 3 days.

[sheremet-va]

But even in the screenshot, you can see that vi.doMock works correctly. If it didn't, you would get 2 and not 100. The only bug here is the mocked implementation - it should use ++ at the start and not after mockedIncrement.

[lrsoy]

Sorry for my mistake, I put the specific code on stackblitz, you can see how the specific implementation is, I wrote two versions, one ts and one js, you can distinguish them by distinguishing the folder name , but it is true that ts can run through, but js can't run through, I really don't understand why this is

link address： https://stackblitz.com/edit/vitest-dev-vitest-7kveii?file=test%2Fincrement-js%2Fincrement.spec.js&initialPath=__vitest__/

[sheremet-va]

Vitest automatically removes unused imports in TypeScript files, so your example works correctly in ts files.

Modules are cached, so next import returns already evaluated result. vi.doMock clears the cache for specified modules, but doesn't clear the cache for modules that import it, you need to do it yourself by calling vi.resetModules:

beforeEach(() => {
  vi.resetModules()
})

[lrsoy]

thanks, this is very helpful for me