fix(hitsPerPageSelector): Issue when state did not have a hitsPerPage

[ElPicador]

No description provided.

[vvo]

WFM, widgets should not be dependent from other widget instantiation

[Jerska]

@vvo 2fast2merge

We just talked with @ElPicador and here is the breakdown:

The hits widget has a default value on hitsPerPage, so it should almost never be undefined, and if it is, I'm fine with forcing the user to set it in options.searchParameters at initialization time to be one of these values.

To solve it in the docs, it's easy, just add searchParameters: {hitsPerPage: 6} to the init call

I'm seeing one issue with it though, if there was a specific hitsPerPage at some point that was shared in a link and the dev overrides the available options. To solve this, I think it might make sense to do a warning instead of an error, but not silently accepting undefined.

[vvo]

The hits widget has a default value on hitsPerPage, so it should almost never be undefined, and if it is, I'm fine with forcing the user to set it in options.searchParameters at initialization time to be one of these values.

It is undefined if you have not instantiated a hits widget OR if you have your own way to display the hits (custom widget). Then state.hitsPerPage is not mandatory, you may just want to use the one from the index parameters/key etc..?

That's why I added "widgets should not be dependent from other widget instantiation" which was the case here before this fix.

You should be able to instantiate the hitsPerPage widget whether or not you have a hits widget or a custom hits widget or maybe no hits widget at all at this point (because you are building the interface asynchronously etc..)

[Jerska]

For me we shouldn't silently let it go, you never want to have no selected value on a hits per page selector.

And this PR works for undefined, but not for any number that isn't in the options.

[vvo]

And this PR works for undefined, but not for any number that isn't in the options.

I do not understand the issue for this one, can you give an example?

[vvo]

I fail at seeing every cases/issues here so if you have another proposition @jerskouille go for it.

[vvo]

Thanks to @jerskouille we found more issues linked to this one, will do some more changes