What this PR does

• Fixes a state mutation issue in the fetchRevisionsPromise function that caused errors in Redux.
• Updates the logic to create a new course object with updated revisions instead of directly modifying the existing course object.
• Ensures Redux Toolkit's immutability rules are followed to prevent unexpected behavior.

Cause of the Mutation:

• The course.revisions property was being directly modified within the fetchRevisionsPromise function.
• Direct state mutation violates Redux’s immutability principles, which led to a detected mutation error.

Fix for the Mutation:

• Replaced the direct mutation of course.revisions with the creation of a new object:

const updatedCourse = {
  ...course,
  revisions: sortRevisionsByDate(revisions),
};

• This approach maintains immutability by ensuring the original course object remains unchanged.

Note:

For testing please set enableMutationChecks to true in create_store.js

Screenshots

Before:

After: