Iterate over an array to return name of array

UPDATE

There was a problem with the Chai test that the class provided. Thanks for all of your help anyway!

I'm working on a problem for a class. It asks us to write a function called "each." It should call iterator(value, key, collection) for each element of collection. It should iterate over arrays, providing access to the element, index, and array itself. It also should only iterate over the array elements, not properties of the array (another problem I'm having). It also accepts both arrays and objects.

On the test I'm running (at the bottom), it should return:

['ant', 'a', animals],
['bat', 'b', animals],
['cat', 'c', animals]

However, it is returning:

['ant', '0', Array[3] [0:"ant", 1:"bat", 2:"cat"]] 

...and so on in the array.

How do iterate over the array so that it returns the list name, rather than the full array itself?

var testeach = function(collection, iterator) {
        if (Array.isArray(collection)) {
            var len = collection.length;
            for (var i in collection)
                iterator(collection[i], collection.indexOf(collection[i]), collection);
        } else {
            for (var key in collection)
                if (collection.hasOwnProperty(key)) {
                     iterator(collection[key], key, collection);
                }
        }
    };

var animals = ['ant', 'bat', 'cat'];
var iterationInputs = [];
testeach(animals, function(animal, index, list) {
  iterationInputs.push([animal, index, list]);
});

console.log(iterationInputs);

Here is the code for the test, which uses Chai.

describe('each', function() {
      it('should iterate over arrays, providing access to the element, index, and array itself', function() {
        var animals = ['ant', 'bat', 'cat'];
        var iterationInputs = [];

        _.each(animals, function(animal, index, list) {
          iterationInputs.push([animal, index, list]);
        });

        expect(iterationInputs).to.eql([
          ['ant', 0, animals],
          ['bat', 1, animals],
          ['cat', 2, animals]
        ]);
      });