Unit Test & Log4net

Question

I have unit test testing an action in my controller, the action writes to log4net.

When I run my action it works well - writes to log4net .

However , When I run the unit test - the action doesn't write to log4net but doesn't throw any exception.

Does anyone have a solution?

Answer 1

// ARRANGE
var memoryAppender = new MemoryAppender();
BasicConfigurator.Configure(memoryAppender);

// ACT
_sut.DoWhatever();

// ASSERT - using xunit - change the expression to fit your purposes
Assert.True(memoryAppender.GetEvents().Any(le => le.Level == Level.Warn), "Expected warning messages in the logs");

You don't need to add in another layer of indirection by using a logging interface (if you don't want to). I have used the abstracted way for years, but now am moving towards just using the MemoryAppender as it is testing what is actually happening. Just be sure to .Clear() the appender after each test.