A teacher can use a single-item scale for rating

This test requires a forum containing several posts.

1. Log in as a teacher and create a single-item scale in the course e.g. 'Like'.
2. Update the forum and enable the single-item scale, setting the aggregate type to 'Average of ratings'.
3. Rate some posts in the forum.
4. After rating a post, click on the rating link and check that the popup window correctly displays the name of the user who rated the post, the rating and the time.
5. Check that it is possible to remove a rating.
6. Go to the gradebook and check that the ratings are listed correctly.
7. Check that you can no longer change the scale and a warning is displayed: "Some grades have already been awarded, so the grade type and scale cannot be changed."
8. Update the forum and set the aggregate type to 'No rating'.
9. Check that there is no longer the option to rate posts in the forum.
10. Go to the gradebook and check that the forum is no listed as a gradable item.