Moq framework to test method execute times

Question

Please look at my code below, the verification always failed. Anyone can help?

public class ViewModel
{
    private IMyDataService dataService = null;

    public ViewModel(IMyDataService dataService)
    {
        this.dataService = dataService;
    }

    public Dictionary<string, string> filters {get; set;}

    public void ProcessFilters()
    {
        dataService.ProcessFilters(filters);
    }
}

[TestMethod]
public void ProcessFilters_Test()
{
    var mockService = new Mock<IMyDataService>();
    ViewModel vm = new ViewModel(mockService.Object);
    Dictionary<string,string> filters = null;
    vm.ProcessFilters(filters);
    mockService.Verify(x=>x.ProcessFilters(filters), Times.Once);
}

Your `filters`-variable stays allways null, I assume this is the problem — MakePeaceGreatAgain, May 30 '16 at 07:28
I only test if the dataService.ProcessFilters method executed. I don't care what the filters value. — Allen4Tech, May 30 '16 at 07:29
Without the code of this method we can only guess what goes whrong. Does your code throw an exception? Or does the assert-statement simply fail? — MakePeaceGreatAgain, May 30 '16 at 07:31
No, the code execute successfully. Just the Verify test method said: Expected invocation on the mock once, but was 0 times: x=>x.ProcessFilters(filters) — Allen4Tech, May 30 '16 at 07:33
Did you try to debug your test? Should be easy to identify the problem then. — MakePeaceGreatAgain, May 30 '16 at 07:37
Sure. in vm.ProcessFilters(filters) method, I can see dataService.ProcessFilters(filters) is executed. But, the verify method couldn't pass. — Allen4Tech, May 30 '16 at 07:41
Possible duplicate of [Verify a method call using Moq](http://stackoverflow.com/questions/9136674/verify-a-method-call-using-moq). You should setup the method to be verified first. — MakePeaceGreatAgain, May 30 '16 at 07:41
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/113299/discussion-between-allen4tech-and-himbrombeere). — Allen4Tech, May 30 '16 at 09:40

score 1 · Accepted Answer · edited May 23 '17 at 11:45

According to verify-a-method-call-using-moq you have to setup the method before you can verify it:

var mockService = new Mock<IMyDataService>();
mockService.Setup(mock => mock.ProcessFilter(null));
ViewModel vm = new ViewModel(mockService.Object);
Dictionary<string,string> filters = null;

// Act
vm.ProcessFilters(filters);

// Assert
mockService.Verify(x=>x.ProcessFilters(filters), Times.Once);

Furthermore the ProcessFilters-method in your ViewModel does not expect any parameter. However you have a filters-property within your class which is not set (at least not within your provided code). So you either have to add the appropriate parameter to the method-signature or set the property:

vm.Filters = filters;
vm.ProcessFilters();

Adriano · Answer 2 · 2016-05-30T09:17:25.397

0

Note that the ProcessFilters method belonging to the ViewModel class does not accept any arguments, so you're not actually calling the method. If you're trying to test whether or not the ProcessFilters method belonging to the ViewModel class calls the mocked IMyDataService exactly once with a filters argument that is null, then try something like:

[TestMethod]
public void ProcessFilters_Test()
{
    // Arrange.
    var mock = new Mock<IMyDataService>();
    var vm = new ViewModel(mock.Object);

    // Act.
    vm.ProcessFilters();

    // Assert.
    mock.Verify(s => s.ProcessFilters(null), Times.Once());
}

edited May 30 '16 at 09:17

answered May 30 '16 at 08:59

Adriano

1,697
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27

As far as I see this is exactly what OP already does, makes no difference if he provides `null` directly or via a variable (`filters`). – MakePeaceGreatAgain May 30 '16 at 10:52

Moq framework to test method execute times

2 Answers2