Add filter feature on Selector functions and WrapperArray

[Toilal]

This is an alternative to #328 to allow user to filter elements from WrapperArray.

[eddyerburgh]

Thanks for the PR.

I'm not sure we should add this feature. We talked about adding array methods a few months ago and decided against it as it would make the API to large. Perhaps we could make an exception for filter, but my concern would be that users would expect other array methods to be implemented.

[eddyerburgh]

I'm also not sure about adding a predicate to methods that take a selector. We should start a feature request issue and get some feedback.

[Toilal]

I need either this feature or #337, or I just can't use vue-test-utils for my component.

[eddyerburgh]

You can use the suggestion 38elements gave:

wrapperArr = findAll('div')
wrapperArr.wrappers = wrapperArr.wrappers.filter(w => w.element.style.visibility === 'hidden')

[Toilal]

On TypeScript, wrappers is marked as readonly so it won't compile. And I think length property will not be updated too.

[eddyerburgh]

Ah, well we could potentially update the length property. I understand your use case, and we'll find a solution, but we need to discuss it first.

[eddyerburgh]

We'll add the filter method, but we're not going to add a predicate to selector methods for now. Can you remove the predicate from this PR, or create a new PR that adds the filter method?

[eddyerburgh]

Thanks for the PR.

I've added the filter method in another PR, so we can close the issue.