Controlling Non-Public Method's Behavior Based on the Argument Value

Controlling Non-Public Methods Behavior Based on the Argument Value

You can control a fake Non public method's behavior based on call arguments by requiring all arguments to match the arguments used in the WhenCalled statement.

Syntax

C#

Isolate.NonPublic.WhenCalled(() => <method>).WithExactArguments(<Args_list>).<behavior>;

VB

Isolate.NonPublic.WhenCalled(Function() <method>).WithExactArguments(<Args_list>).<behavior>

Sample:

The following sample shows how to fake the method's return value as follows:

• The return value of MethodReturnInt is set to 10 only when the arguments are "typemock" and 1.

• The return value of MethodReturnInt is set to 50 only when the arguments are "unit tests" and 2.

C#

[TestMethod, Isolated]
public void FakeNonPublicMethod_BasedOn_ExactMethodArgs()
{
    // As we dont need to fake the object only its method we can use a live object.
    var liveDependency = new Dependency();
    Isolate.NonPublic.WhenCalled(liveDependency, "MethodReturnInt").WithExactArguments("typemock", 1).WillReturn(10);
    Isolate.NonPublic.WhenCalled(liveDependency, "MethodReturnInt").WithExactArguments("unit tests", 2).WillReturn(50);
    
    var result = new Tested().SimpleCalculation(liveDependency);
	
    Assert.AreEqual(60, result);
}

public class Tested
{
    public int SimpleCalculation(Dependency dependency)
    {
        return dependency.CallPrivate("typemock", 1) + dependency.CallPrivate("unit tests", 2);
    }
}

public class Dependency
{
    private int MethodReturnInt(string p, int p_2)
    {
        throw new NotImplementedException();
    }

    public int CallPrivate(string p, int p_2)
    {
        return MethodReturnInt(p, p_2);
    }
}

VB

<TestMethod(), Isolated()> _
Public Sub FakeNonPublicMethod_BasedOn_ExactMethodArgs()
    
    ' As we dont need to fake the object only its method we can use a live object.
    Dim liveDependency = New Dependency()
    Isolate.NonPublic.WhenCalled(liveDependency, "MethodReturnInt").WithExactArguments("typemock", 1).WillReturn(10)
    Isolate.NonPublic.WhenCalled(liveDependency, "MethodReturnInt").WithExactArguments("unit tests", 2).WillReturn(50)

    Dim result = New Tested().SimpleCalculation(liveDependency)
   
   Assert.AreEqual(60, result)
End Sub

Public Class Tested
    Public Function SimpleCalculation(dependency As Dependency) As Integer
        Return dependency.CallPrivate("typemock", 1) + dependency.CallPrivate("unit tests", 2)
    End Function
End Class

Public Class Dependency
    Private Function MethodReturnInt(p As String, p_2 As Integer) As Integer
        Throw New NotImplementedException()
    End Function

    Public Function CallPrivate(p As String, p_2 As Integer) As Integer
        Return MethodReturnInt(p, p_2)
    End Function
End Class