Question

I have these mocks:

_processWrapperMock = new Mock<IProcessWrapper>(MockBehavior.Strict);
_processStartInfoMock = new Mock<IProcessStartInfo>();

and a setup for the Start() method:

_processWrapperMock.Setup(m => m.Start(_processStartInfoMock.Object))
                   .Returns(new Process());

and my _processWrapperMock instance is passed to the constructor for the object which contains the method I’m testing.

var wrapper = new WrapperClassImTesting(_processWrapperMock.Object);

I then execute the method which I’m testing:

byte[] output = wrapper.MethodImTesting(someParams);

Within MethodImTesting, the Start method of the _processWrapperMock is executed however my previous setup doesn’t seem to be taken into account. The error I get is at the line:

using (var process = _processWrapper.Start(processStartInfo))

throwing:

Mock Exception was unhandled by user code

IProcessWrapper.Start(GraphVizWrapper.ProcessStartInfo) invocation
failed with mock behavior Strict. All invocations on the mock must
have a corresponding setup.

What am I doing / not doing, that I need to for this to work as I expect?

Answer 1

Why bother creating a mock at all … can’t you just do this?

_processWrapperMock.Setup(m => m.Start(It.IsAny<IProcessStartInfo>)).Returns(new Process());

Are you sure there isn’t some other method or property that’s being accessed?