Testing a method called many times in moq

Question

I have an interface like this:

Interface IWriteFile { string FileName {get;set;} void Open(); void WriteData(string dataToWrite); void Close(); } 

I want to test a class that will use this interface to populate a file. It will call WriteData a bunch of times, and I just want to check the final output. Is there a way to introduce a new private field for the Mock object that will be added each time WriteData (Data) is called?

I just want to see what the file will look like at the end of the day. Is there a better approach to this?

Answer 1

So, do you need some kind of count of the number of times it is called?

 int count = 0; List<string> items = new List<string>(); var mock = new Mock<IWriteFile>(); mock.Setup(m => m.WriteData(It.IsAny<string>())) .Callback((string data) => { items.Add(data); count++; });