fix: fix topic info for course-wide discussion topics (#458)

* fix: fix topic info for course-wide discussion topics

* refactor: removed const and used url directly

* test: adds test cases for topic info

* test: updated test cases

src/discussions/posts/data/__factories__/threads.factory.js

@@ -7,7 +7,7 @@ Factory.define('thread')
   .sequence('rendered_body', (idx) => `Some contents for <b>thread number ${idx}</b>.`)
   .sequence('type', (idx) => (idx % 2 === 1 ? 'discussion' : 'question'))
   .sequence('pinned', idx => (idx < 3))
-  .sequence('topic_id', idx => `some-topic-${(idx % 3)}`)
+  .sequence('topic_id', idx => `test-topic-${(idx % 3)}`)
   .sequence('closed', idx => Boolean(idx % 3 === 2)) // Mark every 3rd post closed
   .attr('comment_list_url', ['id'], (threadId) => `http://test.site/api/discussion/v1/comments/?thread_id=${threadId}`)
   .attrs({

src/discussions/posts/data/redux.test.js

@@ -102,7 +102,7 @@ describe('Threads/Posts data layer tests', () => {
     expect(store.getState().threads.threadsById['thread-1'])
       .toHaveProperty('topicId');
     expect(store.getState().threads.threadsById['thread-1'].topicId)
-      .toEqual('some-topic-1');
+      .toEqual('test-topic-1');
   });
 
   test('successfully handles thread creation', async () => {