卡利EventAggregator MOQ验证PublishOnUIThreadAsync异步方法

Question

我有一个事件如下

namespace MyProject 
{ 
    public class MyEvent 
    { 
     public MyEvent(int favoriteNumber) 
     { 
      this.FavoriteNumber = favoriteNumber; 
     } 

     public int FavoriteNumber { get; private set; } 
    } 
} 

我具有引发此事件的方法。

using Caliburn.Micro; 
//please assume the rest like initializing etc. 
namespace MyProject 
{ 
    private IEventAggregator eventAggregator; 

    public void Navigate() 
    { 
     eventAggregator.PublishOnUIThreadAsync(new MyEvent(5)); 
    } 
} 

如果我只使用PublishOnUIThread，下面的代码（在一个单元测试）工作正常。

eventAggregatorMock.Verify(item => item.Publish(It.IsAny<MyEvent>(), Execute.OnUIThread), Times.Once); 

但是我该如何检查异步版本？

eventAggregatorMock.Verify(item => item.Publish(It.IsAny<MyEvent>(), Execute.OnUIThreadAsync), Times.Once); 

面临验证异步方法的麻烦。假设private Mock<IEventAggregator> eventAggregatorMock;。部分Execute.OnUIThreadAsync给出错误'Task Execute.OnUIThreadAsync' has the wrong return type。

我也试过

eventAggregatorMock.Verify(item => item.Publish(It.IsAny<MyEvent>(), action => Execute.OnUIThreadAsync(action)), Times.Once); 

，但是他说，System.NotSupportedException: Unsupported expression: action => action.OnUIThreadAsync()

在此先感谢。

Answer 1

IEvenAggregator.Publish被定义为

void Publish(object message, Action<System.Action> marshal); 

因此，你需要提供正确的表达式匹配的定义。

eventAggregatorMock.Verify(_ => _.Publish(It.IsAny<MyEvent>(), 
           It.IsAny<Action<System.Action>>()), Times.Once); 

而且PublishOnUIThreadAsync扩展方法返回一个任务

/// <summary> 
/// Publishes a message on the UI thread asynchrone. 
/// </summary> 
/// <param name="eventAggregator">The event aggregator.</param> 
/// <param name="message">The message instance.</param> 
public static Task PublishOnUIThreadAsync(this IEventAggregator eventAggregator, object message) { 
    Task task = null; 
    eventAggregator.Publish(message, action => task = action.OnUIThreadAsync()); 
    return task; 
} 

所以应该等待

public async Task Navigate() { 
    await eventAggregator.PublishOnUIThreadAsync(new MyEvent(5)); 
}