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Mock SignalR hub for testing dependent class

I'm trying to instantiate a class that handles a bunch of functionality, and is constructed using dependency injection. I mock two of my parameters, and the third is an in-memory database context. Now when asserting, it's throwing an error on the mockClientProxyParticipants.Verify() line:
System.NotSupportedException : Invalid verify on an extension method: proxy => proxy.SendAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>())
It is virtually impossible to not call the function, and calling Verify() with Times.Never() as parameter doesn't change anything.
I tried setting up the Linq argument of Verify() using normal strings like for mockClientProxyResults.Verify(), I tried using It.Is<string>(s => s == "some string") and I tried It.IsAny<string>().
I honestly don't understand what's wrong right now. Here's my test code, let me know if you want to see more:
var mockHub = new Mock<IHubContext<VoteHub>>();
var mockClients = new Mock<IHubClients>();
var mockClientProxyParticipants = new Mock<IClientProxy>();
var mockClientProxyResults = new Mock<IClientProxy>();
mockClients.Setup(clients => clients.Group("Participants")).Returns(mockClientProxyParticipants.Object);
mockClients.Setup(clients => clients.Group("Results")).Returns(mockClientProxyResults.Object);
mockHub.Setup(hub => hub.Clients).Returns(mockClients.Object);
var activeQuestionManagerMock = new Mock<IActiveQuestionManager>();
activeQuestionManagerMock.Setup(x => x.GetActiveQuestion())
.Returns(new ActiveQuestionModel(options));
QuestionHandler qm = new QuestionHandler(new VoteDbContext(options), mockHub.Object, activeQuestionManagerMock.Object);
//Act
qm.Ask(question);
//Assert
mockClientProxyParticipants.Verify(proxy => proxy.SendAsync(It.IsAny<string>(/*s => s == "AskQuestion"*/), It.IsAny<string>(/*s => s == qwaJSON*/), It.IsAny<CancellationToken>()), Times.Once());
mockClientProxyResults.Verify(proxy => proxy.SendAsync("UpdateCurrentQuestionProgress", It.IsAny<ActiveQuestionModel>(), default(CancellationToken)), Times.Once());

Turns out I misunderstood the error message and the issue is that IClientProxy.SendAsync() is an extension method, and Moq apparently doesn't like that. It's possible to use SendCoreAsync() instead, but you'll always have to pass an array as parameter, even if you want to send just one object or don't want to send any data at all.
credit to NKosi (see question comments)

Moq with same argument in Setup and Verify

All to often I write the same argument expression in Setup and Verify. Is there a way to make a reference of them?
What I write:
var mock = new Moq<IFoo>();
mock.Setup(m => m.MyMethod(It.Is.Any<string>());
...
mock.Verify(m => m.MyMethod(It.Is.Any<string>()), Times.Once);
Then I have the idea that as Setup and Verify share the same parameter it should/could be moved into a common reference like so:
var MyMethodCall = {WHAT SHOUD BE HERE?};
var mock = new Moq<IFoo>();
mock.Setup(m => MyMethodCall);
...
mock.Verify(m => MyMethodCall, Times.Once);

You can create a variable that holds the expression, so you can reuse it:
Expression<Action<IFoo>> expression = x => x.MyMethod(It.Is.Any<string>());
var mock = new Moq<IFoo>();
mock.Setup(expression);
...
mock.Verify(expression, Times.Once);

In this case, you could use Verifiable, then you don't need to specify parameters in Verify at all. It will verify that specific verifiable Setup has been invoked.
var mock = new Moq<IFoo>();
mock.Setup(m => m.MyMethod(It.Is.Any<string>()).Verifiable();
...
mock.Verify();
IMO Verifiable is better choice as Verify(Expression<>) doesn't work with setups but invocations internally. The explanation bellow:
public class Example
{
public bool IsValid { get; set; }
}
public interface IExample
{
bool Do(Example e);
}
// arrange
Expression<Func<IExample, bool>> expr = m => m.Do(It.Is<Example>(x => x.IsValid));
var mock = new Mock<IExample>();
mock.Setup(expr).Verifiable();
// act
var example = new Example {IsValid = true};
mock.Object.Do(example);
example.IsValid = false;
// assert
mock.Verify(expr, Times.Once);
What the outcome will be? The test will fail, since Verify will evaluate the expression after object has been changed. If you are using Verify then the invocation will be captured at the moment of invocation. However this is just a showcase should not happened that often :)

Can I test method call order with AAA syntax in Rhino-Mocks 3.6?

Is it possible to test for the following example if the Method1 called 1st, then Method2 called after and then Method3 by using the AAA syntax, in Rhino-mocks 3.6 ?
// Assert
var mock = MockRepository.GenerateMock<ISomeService>();
// Act
myObject.Service = mock;
// How should I change this part to ensure that Rhino Mocks check the call order as well?
mock.AssertWasCalled(m=>m.Method1());
mock.AssertWasCalled(m=>m.Method2());
mock.AssertWasCalled(m=>m.Method3());

Here's one way to do it...
mock.AssertWasCalled(m=>m.Method1(), options => options.WhenCalled(w => mockService.AssertWasNotCalled(x=>x.Method2())));
mock.AssertWasCalled(m=>m.Method2(), options => options.WhenCalled(w => mockService.AssertWasNotCalled(x=>x.Method3())));
mock.AssertWasCalled(m=>m.Method3());

You can, but you really shouldn't. You should focus on testing the externall observable behaviors, rather than the implementation.
Method call order can change without affecting the contract with the client of the API. In that case, your test will fail, even when it shouldn't.
In short, testing implementation leads to brittle tests. Brittle tests lead to abandonment of the tests. You don't want to go there.
Hope this helps.

Here is how to do it nicely.
var mocks = new MockRepository();
var fooMock = mocks.DynamicMock<IFoo>();
using (mocks.Ordered())
{
fooMock.Expect(x => x.Method1());
fooMock.Expect(x => x.Method2());
}
fooMock.Replay();
var bar = new Bar(fooMock);
bar.DoWork();
fooMock.VerifyAllExpectations();
Found the answer from this blog post: Verifying the Order Of Method Execution With Rhino Mocks 3.5 by Philip Japikse

Here's how to do it by building assertions into each method invocation.
// Arrange - Build the necessary assertions into the stubbed method invocations.
var mock = MockRepository.GenerateMock<ISomeService>();
mock.Stub(m => m.Method1()).WhenCalled(inv => mock.AssertWasNotCalled(m => m.Method2()));
mock.Stub(m => m.Method2()).WhenCalled(inv => mock.AssertWasNotCalled(m => m.Method3()));
// Act
myObject.Service = mock;
// Assert - Ensure each expected method was called.
mock.AssertWasCalled(m => m.Method1());
mock.AssertWasCalled(m => m.Method2());
mock.AssertWasCalled(m => m.Method3());
Since this is mixes up normal arrange-act-assert pattern by running assertions in mid-act, I like to include very specific error messages for these instances to identify test failures more easily.
mock.Stub(m => m.Method1()).WhenCalled(inv =>
mock.AssertWasNotCalled(m => m.Method2(), opt =>
opt.Message("Method2 cannot be called before Method1.")));
You could also achieve a similar result by saving the result of each invocation in a variable during the act step, and then checking the variable states during the assert step. This better preserves the division of the arrange-act-assert pattern, but it is more plumbing code to write and maintain.
// Arrange - Build the necessary state variables into the stubbed method invocations.
bool wasMethod1Called;
bool wasMethod2Called;
bool wasMethod2CalledBeforeMethod1;
bool wasMethod3CalledBeforeMethod2;
var mock = MockRepository.GenerateMock<ISomeService>();
mock.Stub(m => m.Method1()).WhenCalled(inv =>
{
wasMethod1Called = true;
});
mock.Stub(m => m.Method2()).WhenCalled(inv =>
{
wasMethod2Called = true;
wasMethod2CalledBeforeMethod1 = !wasMethod1Called;
});
mock.Stub(m => m.Method3()).WhenCalled(inv =>
{
wasMethod3CalledBeforeMethod2 = !wasMethod2Called;
});
// Act
myObject.Service = mock;
// Assert - Ensure each expected method was called, and that they were called in the right order.
mock.AssertWasCalled(m => m.Method1());
mock.AssertWasCalled(m => m.Method2());
mock.AssertWasCalled(m => m.Method3());
Assert.That(wasMethod2CalledBeforeMethod1, Is.False, "Method2 cannot be called before Method1.");
Assert.That(wasMethod3CalledBeforeMethod2, Is.False, "Method3 cannot be called before Method2.");

The mocks.Ordered() syntax specified by #craastad is the right way to do it, but I couldn't get it to work in RhinoMocks 3.5 - instead I had to tweak it to work without the instance of MockRepository that #craastad's solution used to call Ordered() on:
var fooMock = MockRepository.GenerateMock<IFoo>();
using (fooMock.GetMockRepository().Ordered())
{
fooMock.Expect(x => x.Method1());
fooMock.Expect(x => x.Method2());
}
var bar = new Bar(fooMock);
bar.DoWork();
fooMock.VerifyAllExpectations();
If you do it this way, it also appears to be unnecessary to call fooMock.Replay() either.

Different return values the first and second time with Moq

I have a test like this:
[TestCase("~/page/myaction")]
public void Page_With_Custom_Action(string path) {
// Arrange
var pathData = new Mock<IPathData>();
var pageModel = new Mock<IPageModel>();
var repository = new Mock<IPageRepository>();
var mapper = new Mock<IControllerMapper>();
var container = new Mock<IContainer>();
container.Setup(x => x.GetInstance<IPageRepository>()).Returns(repository.Object);
repository.Setup(x => x.GetPageByUrl<IPageModel>(path)).Returns(() => pageModel.Object);
pathData.Setup(x => x.Action).Returns("myaction");
pathData.Setup(x => x.Controller).Returns("page");
var resolver = new DashboardPathResolver(pathData.Object, repository.Object, mapper.Object, container.Object);
// Act
var data = resolver.ResolvePath(path);
// Assert
Assert.NotNull(data);
Assert.AreEqual("myaction", data.Action);
Assert.AreEqual("page", data.Controller);
}
GetPageByUrl runs twice in my DashboardPathResolver, how can I tell Moq to return null the first time and pageModel.Object the second?

With the latest version of Moq(4.2.1312.1622), you can setup a sequence of events using SetupSequence. Here's an example:
_mockClient.SetupSequence(m => m.Connect(It.IsAny<String>(), It.IsAny<int>(), It.IsAny<int>()))
.Throws(new SocketException())
.Throws(new SocketException())
.Returns(true)
.Throws(new SocketException())
.Returns(true);
Calling connect will only be successful on the third and fifth attempt otherwise an exception will be thrown.
So for your example it would just be something like:
repository.SetupSequence(x => x.GetPageByUrl<IPageModel>(virtualUrl))
.Returns(null)
.Returns(pageModel.Object);

The existing answers are great, but I thought I'd throw in my alternative which just uses System.Collections.Generic.Queue and doesn't require any special knowledge of the mocking framework - since I didn't have any when I wrote it! :)
var pageModel = new Mock<IPageModel>();
IPageModel pageModelNull = null;
var pageModels = new Queue<IPageModel>();
pageModels.Enqueue(pageModelNull);
pageModels.Enqueue(pageModel.Object);
Then...
repository.Setup(x => x.GetPageByUrl<IPageModel>(path)).Returns(pageModels.Dequeue);

Now you can use SetupSequence. See this post.
var mock = new Mock<IFoo>();
mock.SetupSequence(f => f.GetCount())
.Returns(3) // will be returned on 1st invocation
.Returns(2) // will be returned on 2nd invocation
.Returns(1) // will be returned on 3rd invocation
.Returns(0) // will be returned on 4th invocation
.Throws(new InvalidOperationException()); // will be thrown on 5th invocation

You can use a callback when setting up your mock object. Take a look at the example from the Moq Wiki (https://github.com/Moq/moq4/wiki/Quickstart).
// returning different values on each invocation
var mock = new Mock<IFoo>();
var calls = 0;
mock.Setup(foo => foo.GetCountThing())
.Returns(() => calls)
.Callback(() => calls++);
// returns 0 on first invocation, 1 on the next, and so on
Console.WriteLine(mock.Object.GetCountThing());
Your setup might look like this:
var pageObject = pageModel.Object;
repository.Setup(x => x.GetPageByUrl<IPageModel>(path)).Returns(() => pageObject).Callback(() =>
{
// assign new value for second call
pageObject = new PageModel();
});

Adding a callback did not work for me, I used this approach instead http://haacked.com/archive/2009/09/29/moq-sequences.aspx and I ended up with a test like this:
[TestCase("~/page/myaction")]
[TestCase("~/page/myaction/")]
public void Page_With_Custom_Action(string virtualUrl) {
// Arrange
var pathData = new Mock<IPathData>();
var pageModel = new Mock<IPageModel>();
var repository = new Mock<IPageRepository>();
var mapper = new Mock<IControllerMapper>();
var container = new Mock<IContainer>();
container.Setup(x => x.GetInstance<IPageRepository>()).Returns(repository.Object);
repository.Setup(x => x.GetPageByUrl<IPageModel>(virtualUrl)).ReturnsInOrder(null, pageModel.Object);
pathData.Setup(x => x.Action).Returns("myaction");
pathData.Setup(x => x.Controller).Returns("page");
var resolver = new DashboardPathResolver(pathData.Object, repository.Object, mapper.Object, container.Object);
// Act
var data = resolver.ResolvePath(virtualUrl);
// Assert
Assert.NotNull(data);
Assert.AreEqual("myaction", data.Action);
Assert.AreEqual("page", data.Controller);
}

The accepted answer, as well as the SetupSequence answer, handles returning constants.
Returns() has some useful overloads where you can return a value based on the parameters that were sent to the mocked method. Based on the solution given in the accepted answer, here is another extension method for those overloads.
public static class MoqExtensions
{
public static IReturnsResult<TMock> ReturnsInOrder<TMock, TResult, T1>(this ISetup<TMock, TResult> setup, params Func<T1, TResult>[] valueFunctions)
where TMock : class
{
var queue = new Queue<Func<T1, TResult>>(valueFunctions);
return setup.Returns<T1>(arg => queue.Dequeue()(arg));
}
}
Unfortunately, using the method requires you to specify some template parameters, but the result is still quite readable.
repository
.Setup(x => x.GetPageByUrl<IPageModel>(path))
.ReturnsInOrder(new Func<string, IPageModel>[]
{
p => null, // Here, the return value can depend on the path parameter
p => pageModel.Object,
});
Create overloads for the extension method with multiple parameters (T2, T3, etc) if needed.

Reached here for the same kind of problem with slightly different requirement.
I need to get different return values from mock based in different input values and found solution which IMO more readable as it uses Moq's declarative syntax (linq to Mocks).
public interface IDataAccess
{
DbValue GetFromDb(int accountId);
}
var dataAccessMock = Mock.Of<IDataAccess>
(da => da.GetFromDb(It.Is<int>(acctId => acctId == 0)) == new Account { AccountStatus = AccountStatus.None }
&& da.GetFromDb(It.Is<int>(acctId => acctId == 1)) == new DbValue { AccountStatus = AccountStatus.InActive }
&& da.GetFromDb(It.Is<int>(acctId => acctId == 2)) == new DbValue { AccountStatus = AccountStatus.Deleted });
var result1 = dataAccessMock.GetFromDb(0); // returns DbValue of "None" AccountStatus
var result2 = dataAccessMock.GetFromDb(1); // returns DbValue of "InActive" AccountStatus
var result3 = dataAccessMock.GetFromDb(2); // returns DbValue of "Deleted" AccountStatus

We can simply declare one variable with int as a datatype. initialize it to zero, and then increase it's value as follows:
int firstTime = 0;
repository.Setup(_ => _.GetPageByUrl<IPageModel>(path)).Returns(() =>
{
if (firstTime == 0)
{
firstTime = 1;
return null;
}
else if(firstTime == 1)
{
firstTime = 2;
return pageModel.Object;
}
else
{
return null;
}
});

In some cases one needs to have the called function return different types of data based on conditions you cannot impose via the function itself. If the function accepts parameters then those can be used as conditionals to get different data.
In my case, I had a webapi call which I need to mock; earlier it was working out fine based on the input parameter, however one fine day, those parameters were converted to request headers. So since I couldn't provide a callback (no function parameters) so came up with another approach as follows
[Earlier one, when API had parameters]
this.mockedMasterAPICalls.Setup(m => m.GetCountries(It.Is<int>(ou => ou == 2), It.Is<int>(lan => lan == 1))).Returns(Task.FromResult(countryResponse));
[New one, when API had headers... The headers were getting injected into another dictionary of the API caller]
this.mockedMasterAPICalls.Setup(m => m.RequestHeaders).Returns(new Dictionary<string, string>());
this.mockedMasterAPICalls.Setup(m => m.GetCountries()).Returns(() =>
{
if (this.mockedMasterAPICalls.Object.RequestHeaders[GlobalConstants.HeaderOUInstance] == "2")
return Task.FromResult(countryResponse);
else return Task.FromResult(new GetCountryResponse() { Countries = null });
});
Note the use of the mocked object itself to make any decisions required

Verifying a specific parameter with Moq

public void SubmitMessagesToQueue_OneMessage_SubmitSuccessfully()
{
var messageServiceClientMock = new Mock<IMessageServiceClient>();
var queueableMessage = CreateSingleQueueableMessage();
var message = queueableMessage[0];
var xml = QueueableMessageAsXml(queueableMessage);
messageServiceClientMock.Setup(proxy => proxy.SubmitMessage(xml)).Verifiable();
//messageServiceClientMock.Setup(proxy => proxy.SubmitMessage(It.IsAny<XmlElement>())).Verifiable();
var serviceProxyFactoryStub = new Mock<IMessageServiceClientFactory>();
serviceProxyFactoryStub.Setup(proxyFactory => proxyFactory.CreateProxy()).Returns(essageServiceClientMock.Object);
var loggerStub = new Mock<ILogger>();
var client = new MessageClient(serviceProxyFactoryStub.Object, loggerStub.Object);
client.SubmitMessagesToQueue(new List<IMessageRequestDTO> {message});
//messageServiceClientMock.Verify(proxy => proxy.SubmitMessage(xml), Times.Once());
messageServiceClientMock.Verify();
}
I'm starting using Moq and struggling a bit.
I'm trying to verify that messageServiceClient is receiving the right parameter, which is an XmlElement, but I can't find any way to make it work. It works only when I don't check a particular value.
Any ideas?
Partial answer:
I've found a way to test that the xml sent to the proxy is correct, but I still don't think it's the right way to do it.
public void SubmitMessagesToQueue_OneMessage_SubmitSuccessfully()
{
var messageServiceClientMock = new Mock<IMessageServiceClient>();
messageServiceClientMock.Setup(proxy => proxy.SubmitMessage(It.IsAny<XmlElement>())).Verifiable();
var serviceProxyFactoryStub = new Mock<IMessageServiceClientFactory>();
serviceProxyFactoryStub.Setup(proxyFactory => proxyFactory.CreateProxy()).Returns(messageServiceClientMock.Object);
var loggerStub = new Mock<ILogger>();
var client = new MessageClient(serviceProxyFactoryStub.Object, loggerStub.Object);
var message = CreateMessage();
client.SubmitMessagesToQueue(new List<IMessageRequestDTO> {message});
messageServiceClientMock.Verify(proxy => proxy.SubmitMessage(It.Is<XmlElement>(xmlElement => XMLDeserializer<QueueableMessage>.Deserialize(xmlElement).Messages.Contains(message))), Times.Once());
}
By the way, how could I extract the expression from the Verify call?

If the verification logic is non-trivial, it will be messy to write a large lambda method (as your example shows). You could put all the test statements in a separate method, but I don't like to do this because it disrupts the flow of reading the test code.
Another option is to use a callback on the Setup call to store the value that was passed into the mocked method, and then write standard Assert methods to validate it. For example:
// Arrange
MyObject saveObject;
mock.Setup(c => c.Method(It.IsAny<int>(), It.IsAny<MyObject>()))
.Callback<int, MyObject>((i, obj) => saveObject = obj)
.Returns("xyzzy");
// Act
// ...
// Assert
// Verify Method was called once only
mock.Verify(c => c.Method(It.IsAny<int>(), It.IsAny<MyObject>()), Times.Once());
// Assert about saveObject
Assert.That(saveObject.TheProperty, Is.EqualTo(2));

I've been verifying calls in the same manner - I believe it is the right way to do it.
mockSomething.Verify(ms => ms.Method(
It.IsAny<int>(),
It.Is<MyObject>(mo => mo.Id == 5 && mo.description == "test")
), Times.Once());
If your lambda expression becomes unwieldy, you could create a function that takes MyObject as input and outputs true/false...
mockSomething.Verify(ms => ms.Method(
It.IsAny<int>(),
It.Is<MyObject>(mo => MyObjectFunc(mo))
), Times.Once());
private bool MyObjectFunc(MyObject myObject)
{
return myObject.Id == 5 && myObject.description == "test";
}
Also, be aware of a bug with Mock where the error message states that the method was called multiple times when it wasn't called at all. They might have fixed it by now - but if you see that message you might consider verifying that the method was actually called.
EDIT: Here is an example of calling verify multiple times for those scenarios where you want to verify that you call a function for each object in a list (for example).
foreach (var item in myList)
mockRepository.Verify(mr => mr.Update(
It.Is<MyObject>(i => i.Id == item.Id && i.LastUpdated == item.LastUpdated),
Times.Once());
Same approach for setup...
foreach (var item in myList) {
var stuff = ... // some result specific to the item
this.mockRepository
.Setup(mr => mr.GetStuff(item.itemId))
.Returns(stuff);
}
So each time GetStuff is called for that itemId, it will return stuff specific to that item. Alternatively, you could use a function that takes itemId as input and returns stuff.
this.mockRepository
.Setup(mr => mr.GetStuff(It.IsAny<int>()))
.Returns((int id) => SomeFunctionThatReturnsStuff(id));
One other method I saw on a blog some time back (Phil Haack perhaps?) had setup returning from some kind of dequeue object - each time the function was called it would pull an item from a queue.

A simpler way would be to do:
ObjectA.Verify(
a => a.Execute(
It.Is<Params>(p => p.Id == 7)
)
);

I believe that the problem in the fact that Moq will check for equality. And, since XmlElement does not override Equals, it's implementation will check for reference equality.
Can't you use a custom object, so you can override equals?

Had one of these as well, but the parameter of the action was an interface with no public properties. Ended up using It.Is() with a seperate method and within this method had to do some mocking of the interface
public interface IQuery
{
IQuery SetSomeFields(string info);
}
void DoSomeQuerying(Action<IQuery> queryThing);
mockedObject.Setup(m => m.DoSomeQuerying(It.Is<Action<IQuery>>(q => MyCheckingMethod(q)));
private bool MyCheckingMethod(Action<IQuery> queryAction)
{
var mockQuery = new Mock<IQuery>();
mockQuery.Setup(m => m.SetSomeFields(It.Is<string>(s => s.MeetsSomeCondition())
queryAction.Invoke(mockQuery.Object);
mockQuery.Verify(m => m.SetSomeFields(It.Is<string>(s => s.MeetsSomeCondition(), Times.Once)
return true
}