Please see the following image:
It is a common scenario when integrating with 3rd party app, that we want to evaluate the API call status. If it result in error then do A, otherwise do B.
However, since we don’t own that app, we can’t dictate the response of that API call. And currently it is quite impossible to test the flow for API call error scenario.
Ideally, I would like to be able to provide mock data to every 3rd party piece, so that I can test my flow if the status is 2xx, 4xx, 5xx