tests: Add tests for StaticArray

[saulecabrera]

Adds the following missing tests for StaticArray:

• constructor

• fromArray

• concat (static)

• slice (static)

• concat (instance)

• includes

• indexOf

• join + toString

• I've read the contributing guidelines

[saulecabrera]

@dcodeIO @MaxGraey one thing that I noticed while working on this is that we have isArray for which the documentation states the following:

Tests if the specified type or expression can be used as an array. Compiles to a constant.

But isArray returns false with StaticArray, which can be used as an array (I know that it technically doesn't extend it) but this seems inconsistent/counterintuitive. Should this be fixed in the docs?

There's also isArrayLike, and in this case, isArrayLike returns true for a StaticArray, but there is no documentation for this one (maybe I missed it 🤷‍♂️), is there a reason for this? Or should we document it?

[saulecabrera]

@dcodeIO 👋 any thoughts on this?

[dcodeIO]

It's a bit unfortunate that StaticArray is somewhat incompatible with normal Arrays, even though that's about the point to introduce it. My immediate thought was that we should have named it differently, something without an Array in it perhaps, but now we are kinda stuck with it. So, to be honest, I don't know what to do, but documenting the difference certainly makes sense :)

[saulecabrera]

So, to be honest, I don't know what to do, but documenting the difference certainly makes sense :)

That's a valid outcome of this discussion, I think that as long as the differences are pointed out correctly then the name becomes less relevant. That said, I didn't intend to make my comment above a blocker to merge this, it was mostly observation. I'll follow up with a documentation issue/PR.

[dcodeIO]

Thanks! :)