If you choose to do end-to-end testing, you will want to do as little as possible. These are the top tier of tests and should be the least numerous type of test in your system. A recommendation is to only write as many tests as you have third-party connections to your application, that is, one test for each back-end server that you must communicate with. Additionally, use the simplest and most basic case which is not anticipated to change.

That completes integration testing from the front-end. There are still some things that can be done. We will leave them as an exercise for you. You might have noticed that the front-end and back-end are not fully in agreement for the model that is being passed back and forth. As an exercise, add or remove and refine the model that is being used by both systems so that they agree on the format.

Another task would be to set the base URL for the fetch service and run both applications locally to verify interconnectability.