fourteen-testing-api - During model transform preserve the argument p…

__testfixtures__/fourteen-testing-api/setup-model-test2.input.js

@@ -0,0 +1,14 @@
+import { expect } from 'chai';
+import { describe, it } from 'mocha';
+import { setupModelTest } from 'ember-mocha';
+
+describe('Unit | Model | rental', function() {
+  setupModelTest('rental', {
+    needs: []
+  });
+  // Replace this with your real tests.
+  it('exists', function() {
+    let model = this.subject({num: 5, obj: {key: 'val'}, arr: [1,'two']});
+    expect(model).to.be.ok;
+  });
+});

__testfixtures__/fourteen-testing-api/setup-model-test2.output.js

@@ -0,0 +1,14 @@
+import { expect } from 'chai';
+import { describe, it } from 'mocha';
+import { setupTest } from 'ember-mocha';
+
+describe('Unit | Model | rental', function() {
+  setupTest();
+  // Replace this with your real tests.
+  it('exists', function() {
+    let model = Ember.run(
+      () => this.owner.lookup('service:store').createRecord('rental', {num: 5, obj: {key: 'val'}, arr: [1,'two']})
+    );
+    expect(model).to.be.ok;
+  });
+});

fourteen-testing-api.js

@@ -502,23 +502,52 @@ module.exports = function(file, api) {
               )
         );
       } else if (subjectType === 'model') {
-        p.replace(
-              j.callExpression(
-                j.memberExpression(
-                  j.callExpression(
-                    j.memberExpression(
-                      j.memberExpression(j.thisExpression(), j.identifier('owner')),
-                      j.identifier('lookup')
+        let createRecordArg = p.node.arguments[0], /* the argument provided to this.subject() */
+            emptyObjectExpression = j.objectExpression([]); /* empty object expression {} */
+
+        if( createRecordArg ){
+          // If there is an argument provided to this.subject, wrap it in a run loop
+          p.replace(
+            j.callExpression(
+              j.memberExpression(
+                j.identifier('Ember'), j.identifier('run')
+              ), [j.arrowFunctionExpression(
+                [],
+                j.callExpression(
+                  j.memberExpression(
+                    j.callExpression(
+                      j.memberExpression(
+                        j.memberExpression(j.thisExpression(), j.identifier('owner')),
+                        j.identifier('lookup')
+                      ),
+                      [j.literal('service:store')]
                     ),
-                    [j.literal('service:store')]
+                    j.identifier('createRecord')
                   ),
-                  j.identifier('createRecord')
+                  [j.literal(subjectName), createRecordArg].filter(Boolean)
+                )
+              )]
+            )
+          );
+        } else {
+          p.replace(
+            j.callExpression(
+              j.memberExpression(
+                j.callExpression(
+                  j.memberExpression(
+                    j.memberExpression(j.thisExpression(), j.identifier('owner')),
+                    j.identifier('lookup')
+                  ),
+                  [j.literal('service:store')]
                 ),
-                // creating an empty object expression {} as the 2nd argument here
-                // because setupModelTests shouldn't need store dependencies
-                [j.literal(subjectName), j.objectExpression([])].filter(Boolean)
-              )
-        );
+                j.identifier('createRecord')
+              ),
+              // creating an empty object expression {} as the 2nd argument here
+              [j.literal(subjectName), emptyObjectExpression].filter(Boolean)
+            )
+          );
+        }
+
       } else {
         p.replace(
           j.callExpression(