fix(stubs): Pass stubbed function to function props

[markrian]

The original implementation, added in
22c7698, passed a string value to a function prop. This instead passes an actual function, which stringifies to the same string.

The problem with the previous approach is that Vue started warning about strings passed to function props in
vuejs/core@7ccd453. As a result, this produced excessive noise in the logs that the user can do nothing about.

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[markrian]

@xanf Would you take a look at this please, given you wrote 22c7698?

For context, see https://gitlab.com/gitlab-org/gitlab-foss/-/jobs/8790444271/viewer, showing the log exceeding the size limit due to these messages.

[cexbrayat]

Hi @markrian

Thank you for your contribution.
IIRC we already fixed this in #2413 and released it in v2.4.6

If you are still experimenting this issue with v2.4.6, can you add a unit test to your PR that reproduces the issue and demonstrates your fix please?

[markrian]

@cexbrayat Aha, I didn't realise. As it happens we're on v2.3.1, but we're also monkey patching createStubs (long story), which recreates the issue that #2413 fixed. So our own monkey patching is to blame.

In any case:

We can "trick" the warning introduced in Vue v3.4.22 (See vuejs/core@7ccd453) by using an array of strings instead of a string (as the new check allows functions and arrays, but not strings).

It seems to me the solution here of passing an actual function with a custom toString method is a bit more robust, since if Vue changes how it checks the value to something like isFunction(value) || (isArray(value) && value.every(isFunction)) then the current approach would cause the warnings to appear again.

WDYT? I'm happy to close this PR anyway if you'd rather keep it as-is.

[cexbrayat]

👍 I think we're fine for now then, lets' close this.
Thank you anyway!