单元测试的模拟 Gtk# 控件

Question

Edit : Fixed the problem

My problem (TL;DR)

I am trying to test my Gtk# control wrapper implementation, but when I try to create my object using a mock of Gtk.Button as a parameter, I get a

System.MissingMethodException : Method 'MyNameSpace.GUI.GTKSharp.GtkSharpButton..ctor' not found.
    at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&)
    at System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00038] in /build/mono/src/mono-4.6.1/mcs/class/corlib/System.Reflection/MonoMethod.cs:305 

The test code:

[TestFixture]
public class GtkSharpButtonTests
{
    private Mock<Gtk.Button> _buttonMock;

    [TestFixtureSetUp]
    public void BeforeAllSetUp()
    {
        _buttonMock = new Mock<Gtk.Button>();
    }

    [Test]
    public void My_Test()
    {
        var called = false;            
        // ---> System.MissingMethodException
        var button = new GtkSharpButton(_buttonMock.Object);

        // .... rest of the test           
    }
}

My guess is that when it tries to create the GtkSharpButton (my implementation) it creates it with a Castle proxy object , but it does not find a GtkSharpButton constructor which expects this type.

It also might be a problem with mocking a concrete class, maybe I am doing this wrong.

I have tested the other layers with the same technique, but the others rely on interface, so easier to mock.

Packages used:

• Moq v4.5.23
• NUnit v2.6.4
• Castle.Core v3.3.3
• gtk-sharp v3.0.0 (from gtk-sharp-3.0 v2.99.3 )
• glib-sharp v3.0.0 (from gtk-sharp-3.0 v2.99.3 )
• atk-sharp v3.0.0 (from gtk-sharp-3.0 v2.99.3 )

I am on linux using mono v4.6.1.3 in Monodevelop v5.10.1 . But this also happens with the nunit-console v2.4.8 .

More information about what I am doing

I am currently creating a C# app and I want to abstract the View layer.

To do so when I create my Controller I pass a view interface (ex. IMainWindowView ).

This way I can mix and match different implementations:

IMainWindowView view = new GtkSharpMainWindowView();
IMainWindowView view = new WPFMainWindowView();

var mainWindowController = new MainWindowController(view);

Example of IMainWindowView:

public interface IMainWindowView
{
    IButton ExampleButtonName { get; }

    IButton ExampleButtonName2 { get; }

    // ....
}

Code behind these

Interfaces:

public interface IControl
{
    string Tooltip { get; set; }
}

public interface IButton : IControl
{
    event ButtonClickEventHandler Triggered;

    void Trigger();
}

Wrapper implementations:

public abstract class GtkSharpControl : IControl
{
    protected Widget BaseWidget { get; private set; }

    public string Tooltip
    {
        get { return BaseWidget.TooltipText; }
        set { BaseWidget.TooltipText = value; }
    }

    protected GtkSharpControl(Widget widget)
    {
        if (widget == null)
            throw new ArgumentNullException(nameof(widget));

        BaseWidget = widget;
    }
}

public class GtkSharpButton : GtkSharpControl, IButton
{
    public event ButtonClickEventHandler Triggered;

    protected Button BaseWidget
    {
        get { return base.BaseWidget as Button; }
    }

    public GtkSharpButton(Button button)
        : base(button)
    {
        BaseWidget.Clicked += Button_Clicked;
    }

    private void Button_Clicked(object sender, EventArgs e)
    {
        if (Triggered != null)
            Triggered(this, new ButtonEventArgs());
    }

    public void Trigger()
    {
        BaseWidget.Click();
    }
}

This implementation is currently working well, but I can't currently test the GtkSharp controls implementation layer.

If you need more information, ask.

Answer 1

I fixed my problem.

It was simply a problem of using different library versions. I was not using the same gtk-sharp library version for my tests and implementation.

The Code project was using gtk-sharp2 (v2.12.29)

The Test project was using gtk-sharp3 (v2.99.3)

So when it created a mock, it created a gtk-sharp3 button mock, but my class constructor was expecting a gtk-sharp2 button, so it failed.

Thanks knocte for helping me figure it out by asking how I installed my gtk-sharp lib.