Allow any iterable in toInclude*Members

[bogdanb]

What

Modifies the three toInclude{All,Any,Some}Members matchers to also match on iterables.

Why

This is meant mostly for testing things that return Set and Map instances, but it’s generally useful for any Iterable.

Notes

I’m not sure exactly what’s wrong with the typing file, I get TS2304: Cannot find name 'Iterable'. errors.

Housekeeping

• Unit tests
• Documentation is up to date
• No additional lint warnings
• Typescript definitions are added/updated where relevant

[bogdanb]

I’m not actually sure where to update the documentation. I updated the comments in the TypeScript definition file (to say Iterable instead of Array), but I’m not sure if there’s anything else to update.

The type definitions show errors, though, on the type of the argument (which can also be an Iterable, now), so maybe this also needs some config update to see the Iterable definition?

[SimenB]

I’m not actually sure where to update the documentation. I updated the comments in the TypeScript definition file (to say Iterable instead of Array), but I’m not sure if there’s anything else to update.

Could you update the docs? It currently says "Array", and maybe add an example using a Set?

[keeganwitt]

This won't work for maps. contains() uses findIndex(), which won't work for maps.

One way to test whether something is iterable is with

function isIterable(obj) {
  // checks for null and undefined
  if (obj == null) {
    return false;
  }
  return typeof obj[Symbol.iterator] === 'function';
}

But this also returns true for a string -- do we think that's expected behavior for these functions?

[WORMSS]

But this also returns true for a string -- do we think that's expected behavior for these functions?

Since string IS an iterable, it would be weird if it said false..
Is there advantage of a if null check instead of doing

return typeof obj?.[Symbol.iterator] === 'function';

[keeganwitt]

Since string IS an iterable, it would be weird if it said false..

I agree, I just wasn't sure that was something considered when this was opened.

Is there advantage of a if null check instead of doing

return typeof obj?.[Symbol.iterator] === 'function';

Nope, just didn't think of it when I grabbed that example.