我正在使用NUnit和NSubstiture进行一些单元测试。
我有这门课:
public class Presenter
{
public Presenter()
{
}
private readonly IView _view;
public Presenter(IView view)
{
_view = view;
this._view.Loaded += OnLoaded;
}
private void OnLoaded()
{
_view.Render("Hello Word");
}
}
我有这个界面:
public interface IView
{
event Action Loaded;
void Render(string text);
}
我已经使用NSubstiture框架进行了单元测试,如下所示:
[Test]
public void ctor_WhenViewIsLoaded_CallsViewRender_WithMockingFramework()
{
var mockView = Substitute.For<IView>();
Presenter p = new Presenter(mockView);
mockView.Loaded += Raise.Event<Action>();
mockView.Received().Render(Arg.Is<string>(s => s.Contains("Hello World")));
}
但是现在我只想测试目的,编写相同的单元测试,但是没有NSubstiture框架:
[Test]
public void ctor_WhenViewIsLoaded_CallsViewRender_WithoutMockingFramework()
{
IView view;
Presenter MockingVIew = new Presenter(view);
}
但是怎么做呢?
谢谢
我试试这样:
public class FakePresenter : IView
{
public event Action Loaded;
public void Render(string text)
{
}
}
[Test]
public void ctor_WhenViewIsLoaded_CallsViewRender_WithoutMockingFramework()
{
//FakeMockingVIew = new Presenter(view);
FakePresenter fPresenter = new FakePresenter();
Presenter p = new Presenter(fPresenter);
fPresenter.Loaded += Raise.Event<Action>();
fPresenter.Received();
Assert.That(fPresenter, Is.EqualTo());
}
如果您不再想使用模拟框架,那么没有什么能阻止您自己创建一个从IView
派生的类并将其用作测试中的依赖项
public class MyTestClass {
public class FakePresenter : IView {
public event Action Loaded = delegate { };
public void Render(string text) {
RenderedText = text;
}
public string RenderedText { get; private set; }
public void Load() {
Loaded();
}
}
[Test]
public void ctor_WhenViewIsLoaded_CallsViewRender_WithoutMockingFramework() {
//Arrange
var fake = new FakePresenter();
var subject = new Presenter(fake);
var expected = "Hello Word";
//Act
fake.Load();
var actual = fake.RenderedText;
//Assert
Assert.AreEqual(expected, actual);
}
}
上面的依赖实现公开了一个Load()
方法来为所有订阅者引发事件,并且还有一个RenderedText
属性来捕获传递给Render
方法的文本,以便可以根据该值进行断言。
当你使用NSubstitute时,你必须告诉模拟视图引发一个事件。但由于IView接口不允许你触发事件,只添加一个事件监听器,NSubstitute做一个workaroud,通过附加一个特殊的事件处理程序,它实际上触发了一个事件(我不熟悉NSubstitute,但我假设这是发生的事情):
// Code here says "attact an event handler", but NSubstitute recognizes this
// special event handler and raises the event to the "real" hanlders instead
mockView.Loaded += Raise.Event<Action>();
因此,当你离开NSubstitute时,你需要从假视图类中以“正确”的方式触发事件:
public class FakeView : IView
{
private string RenderedText { get; private set; }
public event Action Loaded;
public void Render(string text)
{
renderedText = text;
}
public void RaiseLoaded() {
if (Loaded != null) Loaded();
}
}
现在,您可以轻松触发测试中的事件:
[Test]
public void ctor_WhenViewIsLoaded_CallsViewRender_WithoutMockingFramework()
{
FakeView view = new FakeView();
Presenter p = new Presenter(fPresenter);
view.RaiseLoaded();
Assert.That(view.RenderedText, Is.EqualTo("Hello World"));
}