How to set Arguments when mocking a "param" param function?

[Christiano]

Hi there!

Let's suppose I have a very simple class like this:

public class SimpleClass
{
public string GetFormatedString(string mask, params object[] par) 
{
return string.Format(mask, par);
}
}

I honestly have tried to Mock this method considering the fact that it may be called with an unpredictable number of arguments on "par" when running the tests. But I was unable to find something like this on JustMock documentation. I found many examples where you have to set exactly the number of arguments passed. Also mocking the second parameter as Args.IsAny<object[]>() doesnt work.

Can anyone help me on this question, please?

[Ricky]

Hi Christiano,
Thanks again for contacting us.

I wrote the test in the following way and it is working as expected.

var simpleClass = Mock.Create<SimpleClass>();

var expected ="expected";

Mock.Arrange(() => simpleClass.GetMessage("test", Arg.IsAny<object>())).Returns(() => expected);

Assert.AreEqual(expected, simpleClass.GetMessage("test", new Bar()));

As params argument can be passed separately, it is mocked the same way. The good thing is that you can mock a method based on different argument combination and you know for which it should your hit your mock instance.

This is something similar to other popular mocking tools like Moq / Rhino and in this way we adopt the best practices out there.
                  

Kind Regards
Ricky
the Telerik team

[Christiano]

Thank you for the answer, but I believe that I wasnt clear enough about the problem. My mistake, and I'm sorry about that. Maybe,a piece of code can explain it better:

[TestMethod]
public void TestMethod1()
{
  string expected = "crap";
  string tmp = string.Empty;
  SimpleLib.SimpleClass simple = Mock.Create<SimpleClass>();

  Mock.Arrange(() => simple.GetFormatedString(Arg.AnyString, Arg.IsAny<object>())).Returns(() => expected);
  tmp = simple.GetFormatedString("classe", 0);
  Assert.AreEqual( 0, string.Compare(tmp,expected)); //OK!

  tmp = simple.GetFormatedString("classe", 0,0);
  Assert.AreEqual(0, string.Compare(tmp, expected)); //NO!!!

  tmp = simple.GetFormatedString("classe", 0, 0, 0);
  Assert.AreEqual(0, string.Compare(tmp, expected)); //NO!!
}

As you can see, I have to arrange each call with a different number of parameters. And this is exactly what I want to avoid, because internally, this method can be invoked with an unpredictable number of arguments. Is it possible to define in a single Mock.Arrange any call?

Thank you!

[Ricky]

Hi Christiano,

Thanks again for contacting us. It is also possible to write the test in the following way:

[TestMethod]
public void TestMethod1()
{
    string expected = "crap";
    string tmp = string.Empty;
    SimpleClass simple = Mock.Create<SimpleClass>();

    Mock.Arrange(() => simple.GetFormatedString(string.Empty)).IgnoreArguments().Returns(() => expected);
    tmp = simple.GetFormatedString("classe", 0);
    Assert.AreEqual(0, string.Compare(tmp, expected)); //OK!

    tmp = simple.GetFormatedString("classe", 0, 0);
    Assert.AreEqual(0, string.Compare(tmp, expected)); //OK!!!

    tmp = simple.GetFormatedString("classe", 0, 0, 0);
    Assert.AreEqual(0, string.Compare(tmp, expected)); //OK!!
}

In this way , you don't have to specify each param separately.

Kind Regards
Ricky
the Telerik team

[Christiano]

This is what I was looking for. Thank you!