using createTestingPinia to test components that include storeToRefs results in error

[Ben-Pfirsich]

Reproduction

https://github.com/Ben-Pfirsich/testing-pinia-error-example

Steps to reproduce the bug

1. Check out Example Project
2. NPM install
3. call vitest run

Expected behavior

The App.test.ts should pass.
CreateTestingPinia can setup the pinia context for the test.

Test does pass when using Pinia version 2.2.7.

Actual behavior

After upgrading to version 2.2.8 it breaks with the following error:

TypeError: Cannot read properties of undefined (reading 'effect')
    at Module.storeToRefs (file:///C:/DEV/Workspace/test-pinia-error/node_modules/pinia/dist/pinia.mjs:1968:23)
    at setup (C:\DEV\Workspace\test-pinia-error\src\App.vue:7:27)
    at callWithErrorHandling (C:\DEV\Workspace\test-pinia-error\node_modules\@vue\runtime-core\dist\runtime-core.cjs.js:200:19)
    at setupStatefulComponent (C:\DEV\Workspace\test-pinia-error\node_modules\@vue\runtime-core\dist\runtime-core.cjs.js:7848:25)
    at setupComponent (C:\DEV\Workspace\test-pinia-error\node_modules\@vue\runtime-core\dist\runtime-core.cjs.js:7809:36)
    at mountComponent (C:\DEV\Workspace\test-pinia-error\node_modules\@vue\runtime-core\dist\runtime-core.cjs.js:5159:7)
    at processComponent (C:\DEV\Workspace\test-pinia-error\node_modules\@vue\runtime-core\dist\runtime-core.cjs.js:5125:9)
    at patch (C:\DEV\Workspace\test-pinia-error\node_modules\@vue\runtime-core\dist\runtime-core.cjs.js:4654:11)
    at ReactiveEffect.componentUpdateFn [as fn] (C:\DEV\Workspace\test-pinia-error\node_modules\@vue\runtime-core\dist\runtime-core.cjs.js:5269:11)
    at ReactiveEffect.run (C:\DEV\Workspace\test-pinia-error\node_modules\@vue\reactivity\dist\reactivity.cjs.js:229:19)

Additional information

Possibly caused by the following change: 67d3109

[posva]

The createSpy should be just vi.fn, not vi.fn()

[posva]

I improved the existing warning in 394f655