Nested asynchronous functions are not executed

[tahirahmed76]

While mocking an object that have a synchronous method which internally executes an asynchronous method is not returning correct results. Eventhough, the setup was configured correctly, it didn't execute the nested asynchronous methods that returns a Task. Following is my object to mock.

public class ServiceClient
{
    private readonly Uri baseUri;

    public ServiceClient(string baseUri)
    {
        this.baseUri = new Uri(baseUri);
    }

    public void Process()
    {
        Console.WriteLine("Process has been started");

        DoSomething();

        // this is not working as well..
        // DoSomething().Wait();

        Console.WriteLine("Process has been completed");
    }

    public virtual Task DoSomething()
    {
        Console.WriteLine("DoSomething has been started");
        return DoSomethingMore();
    }

    public virtual Task DoSomethingMore()
    {
        Console.WriteLine("DoSomethingMore has been started");
        return Task.CompletedTask;
    }
}

And following is my unit test.

public void TestMethod1()
{
    var client = new Mock<MoqTesting.ServiceClient>(@''http://localhost:9000/service'');
    client.Setup(s => s.DoSomethingMore()).Returns(Task.CompletedTask);
    client.Object.Process();
    client.Verify(f => f.DoSomethingMore(), Times.Once);
}

This test fails and verify confirms that DoSomethingMore() method was never executed.
Complete source code is also attached to easily reproduce the issue.
MoqTesting.zip

[stakx]

The problem here is that Moq also mocks the DoSomething method. Because you haven't provided a setup for DoSomething, it will just return the default empty value for Task, which is a completed task. Your logic in DoSomething will never run.

You can get Moq to call your logic in DoSomething by setting client.CallBase to true:

var client = new Mock<ServiceClient>(…) { CallBase = true };
//                                      ^^^^^^^^^^^^^^^^^^^