JustMock partial class, mock private method

Question

I want to mock a partial class with a private method. But the arranged method is not called. Instead just the normal one. I don't get any errors. It's not relevant what GetAppleModel originally does since it shouldn't do anything in my Test Case. I want the complete body of GetAppleModel to do nothing and only return the task

Test Code:

Task<AppleModel> task = new Task<AppleModel>(() => appleModel);

var taskWorker = TaskWorkerFactory.Create(taskModel);

Mock.NonPublic
    .Arrange<Task<AppleModel>>((AppleTaskWorker) taskWorker, "GetAppleModel", ArgExpr.IsAny<Guid>())
    .DoInstead(() =>
    {
        //...
    })
    .Returns(task);

taskWorker.Start();
//Some Assertion

AppleTaskWorker Class:

public async void Start() {
    _appleModel = await GetAppleModel(_guid);
}

private async Task<AppleModel> GetAppleModel(Guid serviceGuid)
{
    var command = new ServiceCommand(serviceGuid);
    await HandlerService.Start(command);
    return command.GetResult();
}

---

I found an example from a JustMock developer:

Example:

public class Class1
{
    private bool Helper()
    {
        return true;
    }

    public bool TestMe()
    {
        if (Helper()) return true;

        return false;

    }

}

[TestMethod]
public void TestMethod1()
{
    var class1 = new Class1();
    Mock.NonPublic.Arrange<bool>(class1, "Helper").Returns(false);
    bool actual = class1.TestMe();
    Assert.IsFalse(actual);
}

Still can't get it work though...

Answer 1

I got it to work. You need to actually use a dynamic wrapper:

Task<AppleModel> task = new Task<AppleModel>(() => appleModel);

var taskWorker = TaskWorkerFactory.Create(taskModel);

dynamic taskWorkerWrapper = Mock.NonPublic.Wrap((AppleTaskWorker)taskWorker);

Mock.NonPublic
    .Arrange<Task<AppleModel>>(taskWorkerWrapper.GetAppleModel( ArgExpr.IsAny<Guid>())).Returns(task);

taskWorker.Start();
//Some Assertion