add test for filterBy Array

[mulderp]

Add test for filter by Array, addresses: https://github.com/jmorrell/backbone.obscura/issues/3

[jmorrell]

Not sure I understand the need for this added test. The group of tests below it:

https://github.com/mulderp/backbone.obscura/blob/dd19e8191751f83202ae234a067fb5587d2921b8/test/filtered.js#L143

test the case where you have a filter function on a specific key's value.

Nothing against merging this in (more tests are almost never a bad thing) but can you help me understand the motivation?

[mulderp]

I was looking for documentation in the tests actually. The use case I was looking for that sometimes we need to filter "inclusive" not exclusive, e.g. Imagine buying a T-Shirt, we might like to filter for a size range "medium" to "large". So, we just check whether elements are part in a range. What might be interesting for documentation would be, filtering for a range is possible with:

 _.contains(['medium','large'], val)

[mulderp]

But I agree the location of the tests is not right, and maybe it would go best under documentation directly.

[jmorrell]

Is there something unclear about the existing documentation?

https://github.com/jmorrell/backbone.obscura#proxyfilterbyfiltername-filter

ex:

filtered.filterBy('a > 2', { a: function(val) { 
  return val > 2;
}});

shows that you can use arbitrary function predicates.

Would more examples make it clearer? Your case of filtering if it's included in a set is certainly a common case.

[mulderp]

My confusion was that I didn't realize that

    _.contains(range, val)

is a predicate. I jumped into fiddling with a function(range, val) { ... } first. And realized that this is a use case of {a: predicate(x) }.

[jmorrell]

Understandable. I'll add the _.contains example to the docs.