test: added unit-test for post editor

src/discussions/posts/post-editor/PostEditor.jsx

@@ -106,7 +106,7 @@ function PostEditor({
   const nonCoursewareIds = useSelector(enableInContext ? inContextCoursewareIds : selectNonCoursewareIds);
   const coursewareTopics = useSelector(enableInContext ? inContextCourseware : selectCoursewareTopics);
   const cohorts = useSelector(selectCourseCohorts);
-  const post = useSelector(selectThread(postId));
+  const post = useSelector(editExisting ? selectThread(postId) : () => ({}));
   const userHasModerationPrivileges = useSelector(selectUserHasModerationPrivileges);
   const userIsGroupTa = useSelector(selectUserIsGroupTa);
   const settings = useSelector(selectDivisionSettings);

src/discussions/posts/post-editor/PostEditor.test.jsx

@@ -141,6 +141,16 @@ describe('PostEditor', () => {
         }
       },
     );
+    test('selectThread is not called while creating a new post', async () => {
+      const mockSelectThread = jest.fn();
+      jest.mock('../data/selectors', () => ({
+        selectThread: mockSelectThread,
+      }));
+      await renderComponent();
+      expect(mockSelectThread)
+        .not
+        .toHaveBeenCalled();
+    });
   });
 
   describe('cohorting', () => {