[1.x] Adds `Feature::activeForAny()`

[cosmastech]

I want to be able to check if any of a user's related models have a particular feature enabled.

$schools = $user->loadMissing('schools');
$featureIsActive = Feature::for($schools)->someAreActive('enrolled-in-beta');

But this actually is checking that all of the schools have at least one of the features (in this case it's just one feature, 'enrolled-in-beta', which is gets wrapped as an array) being passed in. So if all of the user's schools don't have the feature enabled, $featureIsActive is false.

With the change in this PR, we can accomplish that with:

$featureIsActive = Feature::for($schools)->activeForAny('enrolled-in-beta');

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I would have just changed someAreActive() but it seems like that would be a breaking change (proven by the fact I would have to modify tests) 😢 hence the new method.

[timacdonald]

@cosmastech, thinking out loud here, I feel like the API we really want here is something like this:

Feature::forSome($schools)->active('enrolled-in-beta');

This better indicates that the "some" applies to the schools and not the features.

$school1 = School::find(1);
$school2 = School::find(2);

Feature::forSome([$school1, $school2])->active('enrolled-in-beta'); // false

Feature::for($school2)->activate('enrolled-in-beta');

Feature::forSome([$school1, $school2])->active('enrolled-in-beta'); // true

We then have better composition, for example we could mix forSome with someAreActive:

$model1 = Model::find(1);
$model2 = Model::find(2);

Feature::forSome([$model1, $model2])->someAreActive(['feature-1', 'feature-2']); // false

Feature::for($model1)->activate('feature-2');

Feature::forSome([$model1, $model2])->someAreActive(['feature-1', 'feature-2']); // true

Thoughts?

[cosmastech]

That's a great call @timacdonald. My first thought was "should we make scopes Enumerable?"

Feature::for($models)->some()->active('feature1');
// or even
Feature::for($models)->some->active('feature1');

But looking at Enumerable interface, I imagine most of those wouldn't apply. So maybe just methods for some() and every() would be sufficient.

edit: plus adding that Feature::forSome($models) helper method :+1:

[cosmastech]

I just realized that this doesn't make any sense:

Feature::forSome(['taylor', 'tim'])->activate('foo'); // or deactivate

What do we do in that case? Throw an exception? Just activate them for both scopes? Maybe throw each scope into a lottery?

My thinking is that the composition makes it more confusing here. @timacdonald I have started on an implementation that would allow for querying by some(), but I'm starting to feel like adding explicit methods will cause less headaches.

[timacdonald]

@cosmastech, I don't think all methods would be available. Only a subset of methods would be available after calling forSome.

I'm on something else at the moment, but will circle back to this. I don't want you to put in a heap of work on something we aren't sure on just yet.