add new test to assert that course creation will populate default tabs as expected. Also update factory to not override defaults on tabs array. Also simplfy self.tab test condition.

cms/djangoapps/contentstore/tests/test_contentstore.py

@@ -312,6 +312,23 @@ class ContentStoreToyCourseTest(ModuleStoreTestCase):
 
         self.assertGreater(len(course.textbooks), 0)
 
+    def test_default_tabs_on_create_course(self):
+        module_store = modulestore('direct')
+        CourseFactory.create(org='edX', course='999', display_name='Robot Super Course')
+        course_location = Location(['i4x', 'edX', '999', 'course', 'Robot_Super_Course', None])
+
+        course = module_store.get_item(course_location)
+
+        expected_tabs = []
+        expected_tabs.append({u'type': u'courseware'})
+        expected_tabs.append({u'type': u'course_info', u'name': u'Course Info'})
+        expected_tabs.append({u'type': u'textbooks'})
+        expected_tabs.append({u'type': u'discussion', u'name': u'Discussion'})
+        expected_tabs.append({u'type': u'wiki', u'name': u'Wiki'})
+        expected_tabs.append({u'type': u'progress', u'name': u'Progress'})
+
+        self.assertEqual(course.tabs, expected_tabs)
+
     def test_static_tab_reordering(self):
         module_store = modulestore('direct')
         CourseFactory.create(org='edX', course='999', display_name='Robot Super Course')

common/lib/xmodule/xmodule/course_module.py

@@ -410,7 +410,7 @@ class CourseDescriptor(CourseFields, SequenceDescriptor):
                     continue
 
         # TODO check that this is still needed here and can't be by defaults.
-        if not self.tabs or (isinstance(self.tabs, list) and len(self.tabs) == 0):
+        if not self.tabs:
             # When calling the various _tab methods, can omit the 'type':'blah' from the
             # first arg, since that's only used for dispatch
             tabs = []

common/lib/xmodule/xmodule/modulestore/tests/factories.py

@@ -38,16 +38,6 @@ class XModuleCourseFactory(Factory):
             new_course.display_name = display_name
 
         new_course.lms.start = datetime.datetime.now(UTC).replace(microsecond=0)
-        new_course.tabs = kwargs.pop(
-            'tabs',
-            [
-                {"type": "courseware"},
-                {"type": "course_info", "name": "Course Info"},
-                {"type": "discussion", "name": "Discussion"},
-                {"type": "wiki", "name": "Wiki"},
-                {"type": "progress", "name": "Progress"}
-            ]
-        )
 
         # The rest of kwargs become attributes on the course:
         for k, v in kwargs.iteritems():