Trying to verify that my service has been invoked. I don't care about the arguments, just that it was called once. I tried this
A.CallTo(() => topicWriterFake.Write(A<string>.Ignored, A<string>.Ignored, A<IEnumerable<string>>.Ignored))
.Returns(Task.CompletedTask);
//code that causes message to be written to bus
// now i try to verify that it has been called, but it fails with a message " Expected to find it once exactly but didn't find it among the calls:"
A.CallTo(() => topicWriterFake.Write(A<string>.Ignored, A<string>.Ignored, A<IEnumerable<string>>.Ignored))
.MustHaveHappenedOnceExactly();