Comment editor tests pass even when they should fail

[chia-yh]

Describe the bug
As mentioned in #1197 (comment), some of the expect statements in the async tests in comment-editor.component.spec.ts seem to never execute, leading to tests passing even when they should fail.

To Reproduce
Steps to reproduce the behavior:

1. Locate one of the async tests, e.g.

    it('should allow users to input text', async () => {

2. Edit the expect statement to intentionally fail, e.g.

      fixture.whenStable().then(() => {
        expect(textBox.value).toEqual('');
      });

4. npm run test
5. All tests are executed successfully

Expected behavior
The expect statement edited to fail should cause the particular test to fail

Desktop (please complete the following information):

• OS: Windows 10
• Browser: Chrome
• Version [e.g. 22]