Exercises

Try the following exercises:

1. Add a test to the CustomerForm test suite to specify that the error state is cleared when the form is submitted a second time with all validation errors corrected.
2. Update the AppointmentForm test suite to use jest.fn() and jest.spyOn().
3. Extend AppointmentForm so that it submits an appointment using a POST request to /appointments. The /appointments endpoint returns a 201 Created response without a body, so you don’t need to call json on the response object or send back any parameters to onSave.