fix: allow async functions in beforeSend and afterSend

[Bobby-McBobface]

This patch allows async functions to be in beforeSend and afterSend to be executed correctly. Sync functions aren't affected because await works for sync functions too.

[ganigeorgiev]

Could you elaborate what is your use case for this?

[Bobby-McBobface]

pb.beforeSend = async (url, option) => { 
    // Do async stuff here. 
    await ...
} 

My use case is to run await a fetch in the beforeSend, but this would allow many more async usecases, without much code change.

[ganigeorgiev]

I understand what it does, but I don't know why you would want to run fetch in a beforeSend function for example.

In any case, I guess we can allow it but we also need to update the beforeSend TS return signature (maybe with union type?) - https://github.com/pocketbase/js-sdk/blob/master/src/Client.ts#L42

[ganigeorgiev]

We also will need unit tests for the async hook behavior in https://github.com/pocketbase/js-sdk/blob/master/tests/Client.spec.ts#L197-L254

[Bobby-McBobface]

I have added passing tests that fail without the change.

but I don't know why you would want to run fetch in a beforeSend function for example.

My use case is a little bit dumb, but basically my hosting provider goes to sleep after a while of inactivity, and I have a beforeSend hook to check if it's alive and to start it if it's not. However, I believe this is a small change with little maintenance needed, and it allows for more usecases than my own.

[Bobby-McBobface]

Wait, don't merge yet, it seems like I ran a linter on unrelated parts of the code
It's now ready for a review.

[ganigeorgiev]

I've squash merged it locally with some minor changes in relation to the tests to ensure that the hooks Promise is actually resolved.

I will push sometime later today v0.13.0-rc release (the stable release will be available most likely together with the PocketBase v0.14.0 release in the next couple weeks).