spyOn mocks break with @vitest/web-worker on consecutive calls

[adroste]

Describe the bug

When running a test suite that uses spyOn to mock something in a module, it only works for the first test and first call of spyOn.

  it('first test', async () => {
    vi.spyOn(textModule, 'getText').mockReturnValue("I'm a mocked text"); // works
  });

  it('second test', async () => {
    vi.spyOn(textModule, 'getText').mockReturnValue("I'm a mocked text");  // does not mock anything
  });

Does not matter if mockReturnValue or mockImplementation is used. Mocking the whole module above the test suite with vi.mock works fine.

Reproduction

https://stackblitz.com/edit/vitest-webworker-spyon-bug?file=src%2Fmain.test.js

System Info

@vitest/web-worker

  System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.20.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    @vitest/ui: latest => 3.0.5 
    @vitest/web-worker: latest => 3.0.5 
    vite: latest => 6.1.0 
    vitest: latest => 3.0.5 

Used Package Manager

npm

Validations

• [x] Follow our Code of Conduct
• [x] Read the Contributing Guidelines.
• [x] Read the docs.
• [x] Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• [x] Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• [x] The provided reproduction is a minimal reproducible example of the bug.

[falldowngoboone]

Just updated Vitest today (3.0.8 -> 3.2.4) and ran into this.