Control doesn't go to the virtual method while debugging

Question

I have a class with few methods. For these methods, I'm creating Unit Test cases using MSTest.

public class Class1
{
    public virtual async Task<bool> GetData()
    {
        string var1 ="dsfs", var2 ="eer";
        bool retVal = await DoSomething(var1, var2);
        // some business logic
        return true;
    }
    public virtual async Task<bool> DoSomething(string var1, string var2)
    {
        return true;
    }
}

The test cases for method GetData() looks like this.

[TestClass()]
public class Class1Test
{
    [TestMethod()]
    public async Task GetDataTest()
    {
        var mockService = new Mock<Class1>();
        var isTrue = ReturnTrue(); // this function returns true
        mockService.Setup(x => x.DoSomething(It.IsAny<string>(), It.IsAny<string>())).Returns(isTrue);
        var result = await mockService.Object.GetData();
        Assert.IsTrue(result);
    }
}

Now, the problem I'm facing is,

var result = await mockService.Object.GetData();

From this line the control doesn't go to the actual GetData() method in Class1 . If I remove virtual keyword from the method definition, then the control goes to the method, ie, if I make the method like this.

public async Task<bool> GetData()
{
    bool retVal = await DoSomething(var1, var2);
    // some business logic
    return true;
}

I need to make this method virtual because, this method is called in some other method say " XYZMethod " and for writing test case "XYZMethod", I had mocked GetData() method there.

So is there anyway I can solve this problem without removing virtual keyword.

PS: Writing interfaces is not an option as this is a very heavy code which I'm working on and introducing Interface at this stage is not practical.

Answer 1

Enable CallBase on the mock so that it will invoke base members that have not been overridden by a setup expectation.

Also use ReturnsAsync when configuring asynchronous mocked members to allow them to flow correctly when invoked.

[TestClass()]
public class Class1Test {
    [TestMethod()]
    public async Task GetDataTest() {
        //Arrange
        var mockService = new Mock<Class1>(){
            CallBase = true
        };
        var expected = ReturnTrue(); // this function returns true
        mockService
            .Setup(x => x.DoSomething(It.IsAny<string>(), It.IsAny<string>()))
            .ReturnsAsync(expected);

        //Act
        var actual = await mockService.Object.GetData();

        //Assert
        Assert.IsTrue(actual);
    }
}