Because I am using bypass. According to my understanding, I cannot use bypass for both the external service or my app (since they would have different ports).
If you are aware on how to do this, please do provide an example, using HTTPoison to access your server’s app, and bypass to simulate a response from an external service.
It has come to my attention that perhaps the best way to achieve my goal is to test the controller directly and use something like Mox or Hammox to simulate the external service.
This is due to the fact that my original plan, of doing an integration test using bypass to simulate a response from a 3rd party service together with an HTTPoison call to my actual application are not compatible, since bypass will intersect calls to my application, preventing the 3rd party service of being called.
With this in mind I have now changed the direction of my search:
And will leave this as concluded.