Implement distanceN.

[crhallberg]

Closes #784

• [x] Running yarn lint does not trigger any linter errors
• [x] The test of the method you have fixed is passing
• [x] You have written a new skeleton method for someone else to work on!
• [x] You have written tests to accompany your skeleton method

[crhallberg]

I haven't added a new skeleton method, but I do think that mapArray isn't working the way most developers would expect a map function to work. You can see this in the test where the callback is iterating through an entire array, not just an element: https://github.com/BlakeGuilloud/ganon/blob/master/test/mapArray.test.js#L6

[mtso]

@crhallberg it would be helpful to show how you think it should work by updating the test to fail the existing implementation.

Just to clarify, though: are you expecting mapArray to work like Array.map?

[crhallberg]

That is correct. Right now mapArray is passing the whole array to the callback, which is not what I expected when I was looking to use map for distanceN.

[crhallberg]

mapObject is iterating over the items: https://github.com/BlakeGuilloud/ganon/blob/master/lib/mapCollection.js#L23

I think it may be a case of the implementer misinterpreting the doc comment at the top of the file: "Implement your own map function, obviously without using JavaScript's map function"

[crhallberg]

I mean... I'm probably taking this too seriously...

[ktilcu]

@crhallberg thanks for pointing that out! i made a PR to fix it.

[crhallberg]

Added a skeleton to pass this on. I think we're ready to go!

[ktilcu]

Looks goo to me! Please add an issue for your new skeleton. Happy Hacktobering!