Vitest not mocking dependency when module uses it?

[RPDeshaies]

Hi,

I was wondering if it was normal that Vitest doesn't use the provided module mock when a package listed as a dependency is using it ?

What I mean is, we have an internal package (bundled in CommonJS) that uses dependency-to-mock.

When I call

vi.mock("dependency-to-mock", ()=> { 
// return my mock
})

I expect Vitest to mock all imports of that module, but I have the impression it only works if my code imports dependency-to-mock, but it doesn't work if another package does it.

Any thoughts? Thanks in advance! :)

[sheremet-va]

Yes, It works only for code, that goes through vite-node pipeline. Usually it's user code, but you can try inlining it with deps.inline

[RPDeshaies]

So I'd do something like

test : {
  deps : {
    inline:["dependency-to-mock"] // or would I pass the name of the lib (in my example "internal") here ?
  }
}

[sheremet-va]

You need to inline deps that imports the mocked module

[RPDeshaies]

In this case, I get something like

 > node_modules/my-internal-library/file.js:7:23: error: Could not resolve "dependency-tomock" (mark it as external to exclude it from the bundle, or surround it with try/catch to handle the failure at run-time)

Any other suggestions? Right now, I'm thinking about :

• Exporting the content of my module inside a single file (export * from 'internal module')
• Updating all my files to load from this file instead of the module directly
• Telling Vitest to mock that file (that way the original import just never happens)

Expect if you have a better idea? (thanks for helping me BTW, it's super appreciated)