Snippet to show how you can emulate server-side logic in a Mock Service Worker handler

emulatingServerSideLogic.js

rest.post(`/assignment`, async (req, res, ctx) => {
  // The newly created assignment in this test should have only 1 class and 3 students assigned
  const numberOfClassesAssigned = req.body.assignments.length;
  const numberOfStudentsAssigned = req.body.assignments[0].students.length;
  if (numberOfClassesAssigned === 1 && numberOfStudentsAssigned === 3) {
    return res(
      ctx.status(200),
      ctx.json({ assignments: [{ refId: 'mockRefId' }] }),
    );
  }
  return res(ctx.status(404));
});