EventHandlers的单元测试和代码覆盖率

Question

I'm trying to do a unit test on the eventHandler in the class and I'm not exactly sure how to get valid data to put in the tests. Thanks in advance!

public class BriefAssociation
    {

        public static event EventHandler<AssociationEventArgs> BriefAssociationChanged;
        public static event EventHandler<AssociationEventArgs> BriefAssociationChangedEvent;

        public static void OnBriefAssociationChanged(AssociationEventArgs e)
        {
            BriefAssociationChanged(null, e);
        }

        public static bool HasListener(EventHandler<AssociationEventArgs> TestCheck)
        {
            if ((BriefAssociationChangedEvent != null))
                if ((BriefAssociationChangedEvent.GetInvocationList().Length > 0))
                {
                    return true;
                }

            return false;
        }
    }


    public class AssociationEventArgs
    { 
        public int CustomerID;
    }

CHANGES The following edit is for an error which is discussed in the comments

public class BriefAssociation
{

    public static event EventHandler<AssociationEventArg> BriefAssociationChanged;
    public static event EventHandler<AssociationEventArg> BriefAssociationChangedEvent;

    public static void OnBriefAssociationChanged(AssociationEventArg e)
    {
        BriefAssociationChanged(null, e);
    }


    public static bool HasListener(EventHandler<AssociationEventArg> TestCheck)
    {
        if ((BriefAssociationChangedEvent != null))
            if ((BriefAssociationChangedEvent.GetInvocationList().Length > 0))
            {
                return true;
            }

        return false;
    }
}
public class AssociationEventArg
{ 
    public int CustomerID;
}

Answer 1

For the second method "HasListener" I have a test that gives it a null value to test the if statement but I need to give it something that has a value of length grater than 0 to test the rest of the function. I hope it makes sense.

This is a simple test that might help

[Test]
public void should_raise_event()
{
    BriefAssociation.BriefAssociationChangedEvent += BriefAssociationChanged;
    bool result = BriefAssociation.HasListener(null);
    Assert.True(result);
}

public void BriefAssociationChanged(Object obj, AssociationEventArgs associationEventArgs)
{ }

Answer 2

Here's all the test you need for the 1st method:

    [Test]
    public void OnBriefAssociationCHanged_ShouldRaiseBriefAssociationChangedEvent()
    {
        // Data
        object resultSender = null;
        AssociationEventArgs resultArgs = null;
        AssociationEventArgs testArgs = new AssociationEventArgs();

        // Setup
        BriefAssociation.BriefAssociationChanged += (sender, args) =>
        {
            resultSender = sender;
            resultArgs = args;
        };

        // Test
        BriefAssociation.OnBriefAssociationChanged(testArgs);

        // Analysis
        Assert.IsNull(resultSender);
        Assert.AreSame(resultArgs, testArgs);
    }