Mock code in ASP.NET

There you are testing that: Having an "AudioBookApiController" that receives an "AudioService", when you call the "Get" method on the AudioBookApiController object (apiController), it returns an AudioBook instance.

To do so: On the test you seem to be testing just the AudioBookApiController, not the service, so you create a Mock of the service (audioServiceMock) and then you configure the apiController instance with that mock (during the construction of the AudioBookApiController).

You also tell what will audioServiceMock return when "GetById" is called, --> it must return the variable audioBook.

Finally, you tell the apiController to Get the audioBook related with a Guid and you check (Assert.Equal) that the audioBook returned is the expected.

#1 audioServiceMock.Setup(x => x.GetById(It.IsAny<Guid>())).Returns(audioBook);

Does it initialize the audioServiceMock with audioBook ?

#2 var apiController = new AudioBookApiController(audioServiceMock.Object);
Does it return the audioBook object ?

Thx