diff --git a/packages/ember-glimmer/tests/unit/utils/iterable-test.js b/packages/ember-glimmer/tests/unit/utils/iterable-test.js
new file mode 100644
index 00000000000..e29fb774183
--- /dev/null
+++ b/packages/ember-glimmer/tests/unit/utils/iterable-test.js
@@ -0,0 +1,204 @@
+import Ember from 'ember';
+import { moduleFor, TestCase } from 'ember-glimmer/tests/utils/test-case';
+import iterableFor from 'ember-glimmer/utils/iterable';
+import { UpdatableReference } from 'ember-glimmer/utils/references';
+import eachIn from 'ember-glimmer/helpers/each-in';
+import { EvaluatedPositionalArgs } from 'glimmer-runtime';
+
+const ITERATOR_KEY_GUID = 'be277757-bbbe-4620-9fcb-213ef433cca2';
+
+moduleFor('Iterable', class extends TestCase {
+  ['@test returns an `ArrayIterable` for array refs']() {
+    let ref = new UpdatableReference([]);
+    let iterable = iterableFor(ref);
+
+    this.assert.equal(iterable.constructor.name, 'ArrayIterable');
+  }
+
+  ['@test returns an `EachInIterable` for each-in refs']() {
+    let vm = null;
+    let positionalArgs = EvaluatedPositionalArgs.create([new UpdatableReference({})]);
+    let ref = eachIn(vm, { positional: positionalArgs });
+    let iterable = iterableFor(ref);
+
+    this.assert.equal(iterable.constructor.name, 'EachInIterable');
+  }
+
+  ['@test iterates over an array']() {
+    let iterator = iteratorForArray(['foo', 'bar']);
+
+    this.assert.deepEqual(iterator.next(), { key: 'foo', memo: 0, value: 'foo' });
+    this.assert.deepEqual(iterator.next(), { key: 'bar', memo: 1, value: 'bar' });
+  }
+
+  ['@test iterates over an `Ember.A`']() {
+    let iterator = iteratorForArray(Ember.A(['foo', 'bar']));
+
+    this.assert.deepEqual(iterator.next(), { key: 'foo', memo: 0, value: 'foo' });
+    this.assert.deepEqual(iterator.next(), { key: 'bar', memo: 1, value: 'bar' });
+  }
+
+  ['@test returns `null` when out of items']() {
+    let iterator = iteratorForArray(['foo']);
+
+    this.assert.deepEqual(iterator.next(), { key: 'foo', memo: 0, value: 'foo' });
+    this.assert.deepEqual(iterator.next(), null);
+  }
+
+  ['@test iterates over an array with indices as keys']() {
+    let iterator = iteratorForArray(['foo', 'bar'], '@index');
+
+    this.assert.deepEqual(iterator.next(), { key: '0', memo: 0, value: 'foo' });
+    this.assert.deepEqual(iterator.next(), { key: '1', memo: 1, value: 'bar' });
+  }
+
+  ['@test iterates over an array with identities as keys']() {
+    let iterator = iteratorForArray(['foo', 'bar'], '@identity');
+
+    this.assert.deepEqual(iterator.next(), { key: 'foo', memo: 0, value: 'foo' });
+    this.assert.deepEqual(iterator.next(), { key: 'bar', memo: 1, value: 'bar' });
+  }
+
+  ['@test iterates over an array with arbitrary properties as keys']() {
+    let iterator = iteratorForArray([{ k: 'first', v: 'foo' }, { k: 'second', v: 'bar' }], 'k');
+
+    this.assert.deepEqual(iterator.next(), { key: 'first', memo: 0, value: { k: 'first', v: 'foo' } });
+    this.assert.deepEqual(iterator.next(), { key: 'second', memo: 1, value: { k: 'second', v: 'bar' } });
+  }
+
+  ['@test errors on `#next` with an undefined ref']() {
+    let iterator = iteratorForArray(undefined);
+
+    this.assert.expect(1);
+
+    try {
+      iterator.next();
+    } catch({ message }) {
+      this.assert.equal(message, 'Cannot call next() on an empty iterator');
+    }
+  }
+
+  ['@test errors on `#next` with a null ref']() {
+    let iterator = iteratorForArray(null);
+
+    this.assert.expect(1);
+
+    try {
+      iterator.next();
+    } catch({ message }) {
+      this.assert.equal(message, 'Cannot call next() on an empty iterator');
+    }
+  }
+
+  ['@test errors on `#next` with an invalid ref type']() {
+    let iterator = iteratorForArray('string');
+
+    this.assert.expect(1);
+
+    try {
+      iterator.next();
+    } catch({ message }) {
+      this.assert.equal(message, 'Cannot call next() on an empty iterator');
+    }
+  }
+
+  ['@test errors on `#next` with an empty array']() {
+    let iterator = iteratorForArray([]);
+
+    this.assert.expect(1);
+
+    try {
+      iterator.next();
+    } catch({ message }) {
+      this.assert.equal(message, 'Cannot call next() on an empty iterator');
+    }
+  }
+
+  ['@test iterates over an object\'s own properties']() {
+    let iterator = iteratorForObject({ first: 'foo', second: 'bar' });
+
+    this.assert.deepEqual(iterator.next(), { key: 'first', memo: 'first', value: 'foo' });
+    this.assert.deepEqual(iterator.next(), { key: 'second', memo: 'second', value: 'bar' });
+  }
+
+  ['@test iterates over an object\'s own properties with indices as keys']() {
+    let iterator = iteratorForObject({ first: 'foo', second: 'bar' }, '@index');
+
+    this.assert.deepEqual(iterator.next(), { key: 'first', memo: 'first', value: 'foo' });
+    this.assert.deepEqual(iterator.next(), { key: 'second', memo: 'second', value: 'bar' });
+  }
+
+  ['@test iterates over an object\'s own properties with identities as keys']() {
+    let iterator = iteratorForObject({ first: 'foo', second: 'bar' }, '@identity');
+
+    this.assert.deepEqual(iterator.next(), { key: 'foo', memo: 'first', value: 'foo' });
+    this.assert.deepEqual(iterator.next(), { key: 'bar', memo: 'second', value: 'bar' });
+  }
+
+  ['@test iterates over an object\'s own properties with arbitrary properties as keys']() {
+    let iterator = iteratorForObject({ first: { k: 'uno', v: 'foo' }, second: { k: 'dos', v: 'bar' } }, 'k');
+
+    this.assert.deepEqual(iterator.next(), { key: 'uno', memo: 'first', value: { k: 'uno', v: 'foo' } });
+    this.assert.deepEqual(iterator.next(), { key: 'dos', memo: 'second', value: { k: 'dos', v: 'bar' } });
+  }
+
+  ['@test each-in errors on `#next` with an undefined ref']() {
+    let iterator = iteratorForObject(undefined);
+
+    this.assert.expect(1);
+
+    try {
+      iterator.next();
+    } catch({ message }) {
+      this.assert.equal(message, 'Cannot call next() on an empty iterator');
+    }
+  }
+
+  ['@test each-in errors on `#next` with a null ref']() {
+    let iterator = iteratorForObject(null);
+
+    this.assert.expect(1);
+
+    try {
+      iterator.next();
+    } catch({ message }) {
+      this.assert.equal(message, 'Cannot call next() on an empty iterator');
+    }
+  }
+
+  ['@test each-in errors on `#next` with an invalid ref type']() {
+    let iterator = iteratorForObject('string');
+
+    this.assert.expect(1);
+
+    try {
+      iterator.next();
+    } catch({ message }) {
+      this.assert.equal(message, 'Cannot call next() on an empty iterator');
+    }
+  }
+
+  ['@test ensures keys are unique']() {
+    let iterator = iteratorForArray([{ k: 'qux', v: 'foo' }, { k: 'qux', v: 'bar' }, { k: 'qux', v: 'baz' }], 'k');
+
+    this.assert.deepEqual(iterator.next(), { key: 'qux', memo: 0, value: { k: 'qux', v: 'foo' } });
+    this.assert.deepEqual(iterator.next(), { key: `qux${ITERATOR_KEY_GUID}1`, memo: 1, value: { k: 'qux', v: 'bar' } });
+    this.assert.deepEqual(iterator.next(), { key: `qux${ITERATOR_KEY_GUID}2`, memo: 2, value: { k: 'qux', v: 'baz' } });
+  }
+});
+
+function iteratorForArray(arr, keyPath) {
+  let ref = new UpdatableReference(arr);
+  let iterable = iterableFor(ref, keyPath);
+
+  return iterable.iterate();
+}
+
+function iteratorForObject(obj, keyPath) {
+  let vm = null;
+  let positionalArgs = EvaluatedPositionalArgs.create([new UpdatableReference(obj)]);
+  let ref = eachIn(vm, { positional: positionalArgs });
+  let iterable = iterableFor(ref, keyPath);
+
+  return iterable.iterate();
+}