Merge pull request #9731 from edx/waheed/fix-discusion-get-course

Fixed discussion module get_course.

common/lib/xmodule/xmodule/discussion_module.py

@@ -97,13 +97,10 @@ class DiscussionModule(DiscussionFields, XModule):
 
     def get_course(self):
         """
-        Return the CourseDescriptor at the root of the tree we're in.
+        Return CourseDescriptor by course id.
         """
-        block = self
-        while block.parent:
-            block = block.get_parent()
-
-        return block
+        course = self.runtime.modulestore.get_course(self.course_id)
+        return course
 
 
 class DiscussionDescriptor(DiscussionFields, MetadataOnlyEditingDescriptor, RawDescriptor):

lms/djangoapps/courseware/tests/test_discussion_module.py

 # -*- coding: utf-8 -*-
 """Test for Discussion Xmodule functional logic."""
+import ddt
 from mock import Mock
 from . import BaseTestXmodule
 from courseware.module_render import get_module_for_descriptor_internal
+from xmodule.discussion_module import DiscussionModule
+from xmodule.modulestore import ModuleStoreEnum
+from xmodule.modulestore.django import modulestore
+from student.tests.factories import UserFactory
 
 
+@ddt.ddt
 class DiscussionModuleTest(BaseTestXmodule):
     """Logic tests for Discussion Xmodule."""
     CATEGORY = "discussion"
@@ -24,3 +30,63 @@ class DiscussionModuleTest(BaseTestXmodule):
         html = fragment.content
         self.assertIn('data-user-create-comment="false"', html)
         self.assertIn('data-user-create-subcomment="false"', html)
+
+    @ddt.data(ModuleStoreEnum.Type.mongo, ModuleStoreEnum.Type.split)
+    def test_discussion_render_successfully_with_orphan_parent(self, default_store):
+        """
+        Test that discussion module render successfully
+        if discussion module is child of an orphan.
+        """
+        user = UserFactory.create()
+        store = modulestore()
+        with store.default_store(default_store):
+            course = store.create_course('testX', 'orphan', '123X', user.id)
+            orphan_sequential = store.create_item(self.user.id, course.id, 'sequential')
+
+            vertical = store.create_child(
+                user.id,
+                orphan_sequential.location,
+                'vertical',
+                block_id=course.location.block_id
+            )
+
+            discussion = store.create_child(
+                user.id,
+                vertical.location,
+                'discussion',
+                block_id=course.location.block_id
+            )
+
+            discussion = store.get_item(discussion.location)
+
+            root = self.get_root(discussion)
+            # Assert that orphan sequential is root of the discussion module.
+            self.assertEqual(orphan_sequential.location.block_type, root.location.block_type)
+            self.assertEqual(orphan_sequential.location.block_id, root.location.block_id)
+
+            # Get module system bound to a user and a descriptor.
+            discussion_module = get_module_for_descriptor_internal(
+                user=user,
+                descriptor=discussion,
+                student_data=Mock(name='student_data'),
+                course_id=course.id,
+                track_function=Mock(name='track_function'),
+                xqueue_callback_url_prefix=Mock(name='xqueue_callback_url_prefix'),
+                request_token='request_token',
+            )
+
+            fragment = discussion_module.render('student_view')
+            html = fragment.content
+
+            self.assertIsInstance(discussion_module._xmodule, DiscussionModule)     # pylint: disable=protected-access
+            self.assertIn('data-user-create-comment="false"', html)
+            self.assertIn('data-user-create-subcomment="false"', html)
+
+    def get_root(self, block):
+        """
+        Return root of the block.
+        """
+        while block.parent:
+            block = block.get_parent()
+
+        return block