Add a failing test case

Unloading a new record that is related to another record does not remove it from the relationship.

tests/main/tests/integration/records/new-record-unload-test.js

@@ -60,6 +60,41 @@ module('Integration | Records | New Record Unload', function (hooks) {
     assert.strictEqual(people.length, 1, 'precond - one person left in the store');
   });
 
+  test('Rolling Back Attributes on multiple New (related) Records unloads them safely', async function (assert) {
+    const store = this.owner.lookup('service:store');
+    let Pat = store.createRecord('person', { name: 'Patrick Wachter' });
+    let Matt = store.createRecord('person', { name: 'Matthew Seidel' });
+    const friends = Matt.hasMany('friends').value();
+    friends.push(Pat);
+    let people = store.peekAll('person');
+
+    assert.strictEqual(friends.length, 1, 'Matt has friends');
+    assert.strictEqual(people.length, 2, 'precond - two people records in the store');
+    assert.true(Matt.hasDirtyAttributes, 'precond - record has dirty attributes');
+    assert.true(Matt.isNew, 'precond - record is new');
+    assert.true(Pat.hasDirtyAttributes, 'precond - record has dirty attributes');
+    assert.true(Pat.isNew, 'precond - record is new');
+
+    Pat.rollbackAttributes();
+
+    assert.false(Pat.isDestroyed, 'record is not yet destroyed');
+    assert.true(Pat.isDestroying, 'record is destroying');
+    assert.strictEqual(friends.length, 0, 'Matt has no friends');
+    assert.strictEqual(people.length, 1, 'precond - one person left in the store');
+
+    await settled();
+
+    assert.true(Pat.isDestroyed, 'record is destroyed');
+    assert.true(Pat.isDestroying, 'record is destroying');
+    assert.strictEqual(friends.length, 0, 'Matt has no friends');
+    assert.strictEqual(people.length, 1, 'precond - one person left in the store');
+
+    Matt.rollbackAttributes();
+    assert.false(Matt.isDestroyed, 'record is not yet destroyed');
+    assert.true(Matt.isDestroying, 'record is destroying');
+    assert.strictEqual(people.length, 0, 'precond - no person left in the store');
+  });
+
   test('Unload on a New Record unloads that record safely', async function (assert) {
     const store = this.owner.lookup('service:store');
     const Matt = store.push({