Add failing spec for sorted block with missing sorted property

[Stuk]

The number of items in the array increase(!) when the property that is sorted on does not exist in the objects, and is then added.

[Stuk]

Added another failing spec :(

[kriskowal]

Joy. Nothing can be simple :P

[kriskowal]

I’m now convinced that this should be solved by omitting values from the output if the relation produces null. This probably involves tracking whether each value is currently included in the output.

SortedArray in Collections should be modified to complain loudly if someone adds an incomparable value, as SortedSet already does.

[Stuk]

relation produces null

I'm not sure what you mean by this. Would it mean that line 43 of the diff would read

expect(object.sorted.length).toEqual(0);

but the remainder of that test would remain the same?

[kriskowal]

@Stuk Yes, I believe that might work.

[hthetiot]

Need montagejs/collections#171

[hthetiot]

montagejs/collections#171 landed in collections master need release.