Deep equality check for collection membership

[duncanbeevers]

Support deep equality comparison for collection membership.

expect([{ id: 1 }, { id: 2 }]).to.have.deep.members([{ id: 1 }, { id: 2 }])

[coveralls]

Coverage remained the same when pulling 476c636 on duncanbeevers:deep_members into 564af34 on chaijs:master.

[logicalparadox]

This PR fails on Travis. It seems to be due to a karma problem which we have fixed in master. Can you please rebase upstream?

Furthermore, please include a failing and a negation test case for your new assertion.
Finally, please review #230 and explain how your PR is different.

Thanks.

[duncanbeevers]

Rebased and added new test cases.

#230 applies to the include assertion, while this PR applies to the members assertion.

members is more strict than include, although the two can be used in conjunction to produce a weaker members (superset comparison vs equivalence comparison)

Additionally, this PR only adds the deep object comparison behavior when the deep flag is applied allowing for the stricter object-identity comparison behavior to continue being used.

For example, with this PR, the following test passes.

expect([{ id: 1 }]).deep.include.members([{ id: 1 }]); // passes

While this test does not.

expect([{ id: 1 }]).include.members([{ id: 1 }]); // fails

[logicalparadox]

Ah fantastic! Thank you. One final thing... can you update the inline comment for members specifying that it can support deep and include your code samples.

I just release 1.9.0 not but an hour ago. Sorry this didn't make it in. I will be releasing 1.9.1 on Friday with a few non-critical things I couldn't get to this evening. Given your promptness it shouldn't be an issue getting this included as well.

[duncanbeevers]

I updated the inline documentation to include a deep.include example as well as added an additional test case to the non-deep members spec to highlight when the flag might be needed.

[duncanbeevers]

Additionally, I actually think #230 is a little over-reaching. I like having strict-equality comparison available and exposing the more computationally-expensive and conceptually-fuzzier deep-equality through assertion flags.

[logicalparadox]

Looks great, merged. Also, fair point about #230. Will investigate and discuss.