I’m writing a DNS authenticator plugin for certbot for Azure DNS. I’m wanting to write some tests as per the developer guidelines, but I’m trying to get my head around how to write tests that call an external service that requires configuration and security credentials? For a test to be effective, I would imagine the need to register an actual domain and Azure subscription, and supply credentials for this in the tests; however, it wouldn’t really be possible for anyone else to run the test without registering their own.
Certainly, I could write tests for other things (e.g. failed credentials), but I’m wondering how to handle testing the ‘real thing’?