Mocking an NHibernate ISession with Moq
I am starting a new project with NHibernate, ASP.NET MVC 2.0 and StructureMap and using NUnit and Moq for testing. For each of my controllers I have a single public constructor into which an ISession is being injected. The application itself works just fine, but in terms of unit testing I essentially have to mock an ISession in order to test the controllers.
When I attempt to Mock the ISession with MOQ i get the following error message:
Only property accesses are supported in intermediate invocations
It appears that my problem is expecting List of users from the framework CreateQuery method but after googling the issue I am now clearer.
I have two questions:
1) Is this the WRONG way to mock dependency injection of an ISession
2) Is there a way to modify the code so that it can successfully return my list
[Test]
public void DummyTest()
{
var mock = new Mock<ISession>();
var loc = new Mock<User>();
loc.SetupGet(x => x.ID).Returns(2);
loc.SetupGet(x => x.FirstName).Returns("John");
loc.SetupGet(x => x.LastName).Returns("Peterson");
var lst = new List<User> {loc.Object};
mock.Setup(framework => framework.CreateQuery("from User").List<User>()).Returns(lst);
var controller = new UsersController(mock.Object);
var result = controller.Index() as ViewResult;
Assert.IsNotNull(result.ViewData);
}
Please note, I am pretty sure I could just create a hard-coded list of users (rather than mocking an individual User and adding it to a list) but figured I'd leave the code as I have it right now.
Also, the Index action of this particular controller esse开发者_StackOverflow社区ntially executes the CreateQuery call mimicked above to return all users in the database. This is a contrived example - don't read anything into the details.
Thanks in advance for your help
Edit: In reply to the below comment, I am adding the stacktrace for the error. Also, all properties on the User class are virtual.
TestCase 'Beta.Tests.Unit.Controllers.UserControllerTest.Details_InValidIndex_ReturnsNotFoundView' failed: System.NotSupportedException : Only property accesses are supported in intermediate invocations on a setup. Unsupported expression framework.CreateQuery("from User"). at Moq.Mock.AutoMockPropertiesVisitor.VisitMethodCall(MethodCallExpression m) at Moq.ExpressionVisitor.Visit(Expression exp) at Moq.Mock.AutoMockPropertiesVisitor.VisitMethodCall(MethodCallExpression m) at Moq.ExpressionVisitor.Visit(Expression exp) at Moq.Mock.AutoMockPropertiesVisitor.SetupMocks(Expression expression) at Moq.Mock.GetInterceptor(LambdaExpression lambda, Mock mock) at Moq.Mock.<>c__DisplayClass12
2.<Setup>b__11() at Moq.PexProtector.Invoke[T](Func
1 function) at Moq.Mock.Setup[T1,TResult](Mock mock, Expression1 expression) at Moq.Mock
1.Setup[TResult](Expression`1 expression) Controllers\UserControllerTest.cs(29,0): at Beta.Tests.Unit.Controllers.UserControllerTest.Details_InValidIndex_ReturnsNotFoundView()
Below is the solution I came up with which seems to work perfectly. Again, I am not testing NHibernate and I am not testing the database - I simply want to test the controllers which depend on NHibernate. The issue with the initial solution appears to be the fact that I was calling a Method as well as reading the List member of the session in the MOQ setup call. I broke up these calls by breaking the solution into a QueryMock and a Session Mock (create query returns an IQuery object). A transaction mock was also necessary as it is a dependency (in my case) of the session...
[Test]
public void DummyTest()
{
var userList = new List<User>() { new User() { ID = 2, FirstName = "John", LastName = "Peterson" } };
var sessionMock = new Mock<ISession>();
var queryMock = new Mock<IQuery>();
var transactionMock = new Mock<ITransaction>();
sessionMock.SetupGet(x => x.Transaction).Returns(transactionMock.Object);
sessionMock.Setup(session => session.CreateQuery("from User")).Returns(queryMock.Object);
queryMock.Setup(x => x.List<User>()).Returns(userList);
var controller = new UsersController(sessionMock.Object);
var result = controller.Index() as ViewResult;
Assert.IsNotNull(result.ViewData);
}
Rather than mocking the Session
, one might consider setting up a different Configuration
for unit-tests. This unit-testing Configuration
uses a fast, in-process database like SQLite or Firebird. In the fixture setup, you create a new test database completely from scratch, run the scripts to set up the tables, and create a set of initial records. In the per-test setup, you open a transaction and in the post-test teardown, you rollback the transaction to restore the database to its previous state. In a sense, you are not mocking the Session
, because that gets tricky, but you are mocking the actual database.
精彩评论