How to test asp.net core built-in Ilogger

Question

I want to verify some logs logged. I am using the asp.net core built-in ILogger, and inject it with the asp.net core built-in DI:

private readonly ILogger<         


        

Answer 1

LogError is an extension method (static) not an instance method. You can't "directly" mock static methods (hence extension method) with a mocking framework therefore Moq is unable to mock and hence verify that method. I have seen suggestions online about adapting/wrapping the target interface and doing your mocks on that but that would mean rewrites if you have used the default ILogger throughout your code in many places. You would have to create 2 new types, one for the wrapper class and the other for the mockable interface.