toBeEmpty Map and Set

[mattphillips]

Add support to toBeEmpty for Map and Set data structures

[moredip]

How would you feel about implementing this by modifying the toBeEmpty predicate to match on either {} or an empty Iterable? That would, I believe, provide the existing verification on empty object, Array, or String, plus all the other built-in iterables like Map and Set, plus user-defined iterables.

[mattphillips]

Hey @moredip that sounds like a sensible approach! I like that it will also apply to custom iterables 😄

I think we might be able to leverage the spread operator to condense the logic to something like:

[...iterable].length === 0

Fancy sending a PR for this?

[mattphillips]

Merged 🎉