.members should work with ES6 Sets/WeakSets

[rijnhard]

Similar to #632

An ES6 Set should work with the members function just like an array.

Pass conditions

expect(new Set([1, 2, 3])).to.have.members([2, 1, 3]);
expect(new Set([{a: 1}])).to.have.deep.members([{a: 1}]);
expect(new Set([1, 2, 3])).to.have.ordered.members([1, 2, 3]);

// it may also be a good idea to flip it and allow sets to be used just as arrays would
expect([1, 2, 3]).to.have.members(new Set([2, 1, 3]));
expect([{a: 1}]).to.have.deep.members(new Set([{a: 1}]));
expect([1, 2, 3]).to.have.ordered.members(new Set([1, 2, 3]));

Fail conditions should eb the exact same as that of arrays.

[rijnhard]

For WeakSets it's the same.

const x = { t: 1 },
    y = { t: 2 },
    z = { t: 3 };

expect(new WeakSet([x, y, z])).to.have.members([x, y, z]);

[rijnhard]

And just for anybody else that gets here the workaround is using Array.from

expect(Array.from(new Set([1, 2, 3]))).to.have.members([2, 1, 3]);

[meeber]

@rijnhard It makes sense to me that .members should support both Maps and Sets. In the meantime, it's worth noting though that .keys already provides some of the functionality you're looking for:

expect(new Set([1, 2, 3])).to.have.keys([2, 1, 3]);
expect(new Set([{a: 1}])).to.have.deep.keys([{a: 1}]);

[keithamus]

Hey @rijnhard thanks for the issue.

This would be awesome! We've added this to our Roadmap https://github.com/chaijs/chai/projects/2! We'll be releasing chai 5 soon, but for now I'll close this issue because it is tracked on our roadmap.