I'm trying to mock out a class in Moq with this method:
public virtual void Init(Context context, IPrincipal user)
{
_context = context;
_user = user;
var u = _context.Users.Include("Foo").First(x => x.Login == _user.Identity.Name);
My code that is calling this looks like this:
mockLoginState.CallBase = false;
mockLoginState.Setup(x => x.Init(It.IsAny<Context>(), It.IsAny<IPrincipal>()));
I don't want this method to actually be called because it will hit the database. From what I understand about Moq, this should be stubbed over because it's virtual and the code in the function shouldn't run, but this is not what I'm experiencing. Basically my problem is exactly as is described here:
"Short circuiting" void methods with Moq?
but the answer to that question didn't work for me.
How do I stop the function from being called?
Your code above looks correct. Are you sure you're calling the Init method on the Mock object? Have you tried using MockBehavior.Strict when constructing your Mock<LoginState>? This should throw an exception if any method that you haven't explicitly set up gets called.
Otherwise, you might have to provide more of your code for context.
Joe Taylor's answer was a clue.
Apparently the Init function was being called in the constructor of my LoginState object. When I created the Mock<LoginState> it was being called, and therefor my override was happening too late.
For more information on dealing with this constraint, see this question:
Use Moq to mock Constructor?
Related
I am trying to implement an audit trail on MVC project , by overriding the context by adding another peice of functionality (to so the audit).
The overriding of SaveChanges works fine, however the problem I have is with SaveChangesAsync.
Here is part the code from the context
public override Task<int> SaveChangesAsync()
{
throw new InvalidOperationException("User ID must be provided");
}
public override int SaveChanges()
{
throw new InvalidOperationException("User ID must be provided");
}
public async Task<int> SaveChangesAsync(int userId)
{
DecidSaveChanges(userId);
return await this.SaveChangesAsync(CancellationToken.None);
}
public int SaveChanges(int userId)
{
DecidSaveChanges(userId);
return base.SaveChanges();
}
The problem I have is with my controller
await db.SaveChangesAsync(1);
1 being a dummy user. I get the following error.
Error 1 The 'await' operator can only be used within an async method. Consider marking this method with the 'async' modifier and changing its return type to 'Task<System.Web.Mvc.ActionResult>'.
do you know what I am doing wrong here? and how to fix it?. I am using EF6 and MVC5
do you know what I am doing wrong here?
Yes, just look at your compiler error message:
The 'await' operator can only be used within an async method.
So, the controller action (that contains the call to SaveChangesAsync(1)) needs to be async.
and how to fix it?
Yes, just look at your compiler error message:
Consider marking this method with the 'async' modifier and changing its return type to 'Task<System.Web.Mvc.ActionResult>'.
So, you fix it by making the controller action async and changing its return type from ActionResult to Task<ActionResult>.
I have a typed factory interface as follows:
public interface ILogMessageFactory
{
ILogMessage Create(LogMessageType logMessageType, String text);
}
and I am registering it all follows:
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.AddFacility<TypedFactoryFacility>();
container.Register(
Component.For(typeof(ConsolePrompter)),
Component.For<ILogger>().ImplementedBy<ConsoleLogger>().LifeStyle.Transient,
Component.For<ILogMessageFactory>().AsFactory(),
Component.For<ILogMessage>().ImplementedBy<LogMessage>().LifeStyle.Transient
);
}
The problem is that I want to implement the ILogMessageFactory.Create method myself, to set a few things before I return.
I've tried the obvious naïve solution without any success:
Component.For<ILogMessageFactory>().ImplementedBy<LogMessageFactory>().AsFactory()
Am I approaching this wrong? Should I just keep all initialization in the constructor of the given object?
use ITypedFactoryComponentSelector if this is something that really belongs to the factory. Alternatively use .OnCreate() on the component the factory resolves
I would like to be able to run tests on my fake repository (that uses a list)
and my real repository (that uses a database) to make sure that both my mocked up version works as expected and my actual production repository works as expected. I thought the easiest way would be to use TestCase
private readonly StandardKernel _kernel = new StandardKernel();
private readonly IPersonRepository fakePersonRepository;
private readonly IPersonRepository realPersonRepository;
[Inject]
public PersonRepositoryTests()
{
realPersonRepository = _kernel.Get<IPersonRepository>();
_kernel = new StandardKernel(new TestModule());
fakePersonRepository = _kernel.Get<IPersonRepository>();
}
[TestCase(fakePersonRepository)]
[TestCase(realPersonRepository)]
public void CheckRepositoryIsEmptyOnStart(IPersonRepository personRepository)
{
if (personRepository == null)
{
throw new NullReferenceException("Person Repostory never Injected : is Null");
}
var records = personRepository.GetAllPeople();
Assert.AreEqual(0, records.Count());
}
but it asks for a constant expression.
Attributes are a compile-time decoration for an attribute, so anything that you put in a TestCase attribute has to be a constant that the compiler can resolve.
You can try something like this (untested):
[TestCase(typeof(FakePersonRespository))]
[TestCase(typeof(PersonRespository))]
public void CheckRepositoryIsEmptyOnStart(Type personRepoType)
{
// do some reflection based Activator.CreateInstance() stuff here
// to instantiate the incoming type
}
However, this gets a bit ugly because I imagine that your two different implementation might have different constructor arguments. Plus, you really don't want all that dynamic type instantiation code cluttering the test.
A possible solution might be something like this:
[TestCase("FakePersonRepository")]
[TestCase("TestPersonRepository")]
public void CheckRepositoryIsEmptyOnStart(string repoType)
{
// Write a helper class that accepts a string and returns a properly
// instantiated repo instance.
var repo = PersonRepoTestFactory.Create(repoType);
// your test here
}
Bottom line is, the test case attribute has to take a constant expression. But you can achieve the desired result by shoving the instantiation code into a factory.
You might look at the TestCaseSource attribute, though that may fail with the same error. Otherwise, you may have to settle for two separate tests, which both call a third method to handle all of the common test logic.
This seems like a dumb question but I have looked through the docs for prism and searched the internet and can't find an example... Here is the deal.
I am using a DelegateCommand in Prism, it is working fine except when I assign a delegate to the can execute to the CanExecute method. in another view model I have a event that takes a bool that I am publishing too and I can see that the event is firing and that the bool is getting passed to my view model with the command in it no problem but this is what I don't understand... How does can execute know that the state has changed? Here is some code for the example.
from the view models ctor
eventAggregator.GetEvent<NavigationEnabledEvent>().Subscribe(OnNavigationEnabledChange, ThreadOption.UIThread);
NavigateCommand = new DelegateCommand(OnNavigate, () => nextButtonEnabled);
Now - here is the OnNavigationEnableChange event.
private void OnNavigationEnabledChange(bool navigationState)
{
nextButtonEnabled = navigationState;
}
enter code here
Like - I am totally missing something here - how does the command know that nextButtonEnabled is no true?
If someone could point me to a working example that would be awesome.
OK - thanks!
This is why I don't use the implementation of DelegateCommand in Prism. I've always hated the callback-based approach for enabling/disabling commands. It's entirely unnecessary, and as far as I can tell, its only (and rather doubtful) 'benefit' is that it's consistent with how execution itself is handled. But that has always seemed pointless to me because execution and enabling/disabling are clearly very different: a button knows when it wants to execute a command but doesn't know when the command's status might have changed.
So I always end up writing something like this:
public class RelayCommand : ICommand
{
private bool _isEnabled;
private Action _onExecute;
public RelayCommand(Action executeHandler)
{
_isEnabled = true;
_onExecute = executeHandler;
}
public bool IsEnabled
{
get { return _isEnabled; }
set
{
_isEnabled = value;
if (CanExecuteChanged != null)
{
CanExecuteChanged(this, EventArgs.Empty);
}
}
}
public bool CanExecute(object parameter)
{
return _isEnabled;
}
public event EventHandler CanExecuteChanged;
public void Execute(object parameter)
{
_onExecute();
}
}
(If necessary you could modify this to use weak references to execute change event handlers, like Prism does.)
But to answer your question: how is the callback approach even meant to work? Prism's DelegateCommand offers a RaiseCanExecuteChanged method you can invoke to ask it to raise the event that'll cause command invokers to query your command's CanExecute. Given that you have to tell the DelegateCommand any time your enabled status changes, I don't see any meaningful benefit of a callback-based approach. (Sometimes you see a broadcast model though - arranging so that any change in status anywhere notifies all command invokers! In that case, a callback is useful because it means it doesn't matter if you don't know what actually changed. But requerying every single command seems unpleasant to me.)
Answering your question how does the command know that it is now enabled:
NavigateCommand = new DelegateCommand(OnNavigate, () => nextButtonEnabled);
This overload of the DelegateCommand constructor takes 2 parameters:
The first is the command action and the second is the CanExecute delegate that returns bool.
in your example your CanExecute action always returns nextButtonEnabled
eventAggregator.GetEvent<NavigationEnabledEvent>().Subscribe(OnNavigationEnabledChange, ThreadOption.UIThread);
triggers OnNavigationEnabledChange that changes nextButtonEnabled
this is how it works...
These three tests are identical, except that they use a different static function to create a StartInfo instance. I have this pattern coming up all trough my testcode, and would love
to be be able to simplify this using [TestCase], or any other way that reduces boilerplate code. To the best of my knowledge I'm not allowed to use a delegate as a [TestCase] argument, and I'm hoping people here have creative ideas on how to make the code below more terse.
[Test]
public void ResponseHeadersWorkinPlatform1()
{
DoResponseHeadersWorkTest(Platform1StartInfo.CreateOneRunning);
}
[Test]
public void ResponseHeadersWorkinPlatform2()
{
DoResponseHeadersWorkTest(Platform2StartInfo.CreateOneRunning);
}
[Test]
public void ResponseHeadersWorkinPlatform3()
{
DoResponseHeadersWorkTest(Platform3StartInfo.CreateOneRunning);
}
void DoResponseHeadersWorkTest(Func<ScriptResource,StartInfo> startInfoCreator)
{
ScriptResource sr = ScriptResource.Default;
var process = startInfoCreator(sr).Start();
//assert some things here
}
Firstly, I don't think the original is too bad. It's only messy if your assertions are different from test case to test case.
Anyway, you can use a test case, but it can't be done via a standard [TestCase] attribute due to using more complicated types. Instead, you need to use a public IEnumerable<> as the data provider and then tag your test method with a [TestCaseSource] attribute.
Try something like:
public IEnumerable<Func<ScriptResource, StartInfo>> TestCases
{
get
{
yield return Platform1StartInfo.CreateOneRunning;
yield return Platform2StartInfo.CreateOneRunning;
yield return Platform3StartInfo.CreateOneRunning;
}
}
[TestCaseSource("TestCases")]
public void MyDataDrivenTest(Func<ScriptResource, StartInfo> startInfoCreator)
{
ScriptResource sr = ScriptResource.Default;
var process = startInfoCreator(sr);
// do asserts
}
}
This is a more concise version of the standard pattern of yielding TestCaseData instances containing the parameters. If you yield instances of TestCaseData you can add more information and behaviours to each test (like expected exceptions, descriptions and so forth), but it is slightly more verbose.
Part of the reason I really like this stuff is that you can make one method for your 'act' and one method for your 'assert', then mix and match them independently. E.g. my friend was doing something yesterday where he used two Actions to say ("when method Blah is called, this method on the ViewModel should be triggered"). Very terse and effective!
It looks good. Are you looking to add a factory maybe ? Or you could add these methods to a Action List(in test setup) and call first action delegate, second action delegate and third action delegate.