This a repo for me to document the mocking issues I see while I am use. This is purely to show as code for displaying the error and not something anyone else to use.
I think the issue with this is with supertest not reinitializing express between tests. Therefore the new middleware mock is not called.
Use external variable that can be set during the test to change the behavior of middleware. It's not the best way but it's a simple fix for integration testing.