测试此命令

Question

我premit我是很新的单元测试，我已经得到了一些麻烦testign此命令

internal async Task OnDeleteTreasurerCommandExecute(TesorieraItemResult tesoriera) 
    { 
     try 
     { 
      if (await MessageService.ShowAsync("Confermare l'operazione?", string.Empty, MessageButton.YesNo, MessageImage.Question) == MessageResult.Yes) 
      { 
       await repository.DeleteTesorieraItemAsync(tesoriera.ID_ISTITUTO,tesoriera.ID_DIVISA,tesoriera.PROGRESSIVO); 

       await MessageService.ShowInformationAsync("Operazione completata"); 

       if (SelectedInstitute != null) 
        await OnLoadDataCommandExecute(); 
      } 
     } 
     catch (Exception ex) 
     { 
      ErrorService.HandleError(GetType(), ex); 
     } 
    } 

我使用Catel MVVM作为框架

我怎么模拟是/否答案？ 谢谢

Answer 1

您需要将MessageService替换为可以返回yes或no answer的类。以下是使用NSubstitute的示例。

1. Install-Package NSubstitute

2. Install-Package NUnit

3. 让我们说你有一个有 需要有一个方法的类，然后编号：

   public class AccountViewModel 
   { 
       readonly IMessageService _messageService; 
       readonly ICustomerRepository _customerRepository; 
   
       public AccountViewModel(IMessageService messageService, ICustomerRepository customerRepository) 
       { 
        _messageService = messageService; 
        _customerRepository = customerRepository; 
       } 
   
       public async Task OnDeleteCustomer(Customer customer) 
       { 
        if (await MessageService.ShowAsync(
         "Confirm?", 
         string.Empty, 
         MessageButton.YesNo, 
         MessageImage.Question) == MessageResult.Yes) 
        { 
         _customerRepository.Delete(customer); 
         await MessageService.ShowInformationAsync("Completed"); 
        } 
       } 
   } 
   

然后你测试用例如下所示：

public class TestAccountViewModel 
{ 
    [TestCase] 
    public class TestDeleteCustomer() 
    { 
     // arrange 
     var messageService = Substitute.For<IMessageService>(); 
     messageService 
      .ShowAsync(
       Arg.Any<string>(), 
       Arg.Any<string>(), 
       Arg.Any<MessageButton>(), 
       Arg.Any<MessageImage>()) 
      .Returns(Task.FromResult(MessageResult.Yes); 

     messageService 
      .ShowInformationAsync(Arg.Any<string>()) 
      .Returns(Task.FromResult<object>(null)); 

     var customerRepository = Substitute.For<ICustomerRepository>(); 

     // act 
     var sut = new AccountViewModel(messageService, customerRepository); 
     var customer = new Customer(); 
     sut.OnDeleteCustomer(customer); 

     // assert 
     Assert.IsTrue(customerRepository.Received().DeleteCustomer(customer)); 
    } 
} 

Answer 2

在过去的版本中，Catel提供了IMessageService的测试实现，它允许您对预期结果进行排队，以便可以测试命令中的不同路径。

我刚刚注意到这个类不再可用，但你可以很容易地实现一个测试存根（使用嘲讽等）。或者你可以贡献给Catel并重新实现测试。