Using Moq to verify calls are made in the correct order

Question

I need to test the following method:

CreateOutput(IWriter writer)
{
    writer.Write(type);
    writer.Write(id);
    writer.Write(sender);

    // many more         


        

Answer 1

My scenario was methods without parameters:

public interface IWriter
    {
    void WriteA ();
    void WriteB ();
    void WriteC ();
    }

So I used Invocations property on the Mock to compare what was called:

var writer = new Mock ();

new SUT (writer.Object).Run ();

Assert.Equal (
    writer.Invocations.Select (invocation => invocation.Method.Name),
    new[]
        {
        nameof (IWriter.WriteB),
        nameof (IWriter.WriteA),
        nameof (IWriter.WriteC),
        });

You could also append the invocation.Arguments to check method calls with parameters.

Also the failure message is more clear than just expected 1 but was 5:

    expected
["WriteB", "WriteA", "WriteC"]
    but was
["WriteA", "WriteB"]