[🐞] vitest mocks (vi.fn()) cause lexical scope errors and might cause Qwik errors

[ianlet]

Describe the bug

As seen in this example, eslint is not happy because the callbacks (vi.fn() mocks) are not serializable and cross a serialization boundary. In most cases, it doesn't prevent tests to be run, but issues can arise if Qwik actually needs to serialize the values.

Explore if there could be elegant workarounds or if we need to provide mocking functionalities written for Qwik.

Reproduction

https://github.com/ianlet/qwik-testing-library/blob/main/apps/qwik-basic-demo/src/components/qwik-component.spec.tsx#L223

Steps to reproduce

No response

System Info

System:
    OS: Linux 6.10 Arch Linux
    CPU: (8) x64 Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
    Memory: 4.71 GB / 15.37 GB
    Container: Yes
    Shell: 3.7.1 - /usr/bin/fish
  Binaries:
    Node: 22.9.0 - ~/.asdf/installs/nodejs/22.9.0/bin/node
    Yarn: 1.22.19 - ~/.asdf/shims/yarn
    npm: 10.8.3 - ~/.asdf/plugins/nodejs/shims/npm
    pnpm: 9.11.0 - ~/.asdf/installs/pnpm/9.11.0/bin/pnpm
  Browsers:
    Chromium: 129.0.6668.58

Additional Information

No response

[ianlet]

7a9c01c introduces an experimental mock$ function to offer mocking utilities for QRL when used as component callbacks. Any feedback is welcome!