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Rhino Mocks Fundamentals - Notes

Categories: Notes Testing

by Jim Cooper


A good unit test

  • Atomic
  • Deterministic (it should pass or fail)
  • Repeatable
  • Order Independent & Isolated
  • Fast
  • Easy to setup
var mockStudentRepository = MockRepository.GenerateMock<IStudentRepository>();
var student = new Student() { ... };
mockStudentRepository.AssertWasCalled(x => x.Save(student));

//using mocks to verify property setters
var mockStudentView = MockRepository.GenerateMock<IStudentView>();
mockstudentView.AssertWasCalled(x => x.WasStudentSaved = true);

//using stubs to control the program flow
var mockStudentValidator = MockRepository.GenerateMock<IStudentValidator>();
mockStudentValidator.Stub(x => x.ValidateStudent(Arg<Student>.Is.Anything)).Return(true);
mockStudentView.Stub(x => x.ShouldSaveStudent).Return(true);

//do not use GenerateStub cause it will not work for read-only properties
var mockStudentView = MockRepository.GenerateStub<IStudentView>();
mockstudentView.ShouldSaveStudent = true;
  • It's much easier to always use GenerateMock, you might need it anyway
  • Actualy generatemock actually is a generatetestdouble
  • Use Arrange,Act,Assert instead of Record,Replay¬†(legacy: Record, Playback, Expect.Call, ReplayAll, VerifyAll, DynamicMocks vs StrictMocks)
Arg<Student>.Matches(y => y.Id == expectedStudentId && y.FirstName == expectedFirstName)
Arg<Student>.Matches(y => IsCustomerMatching(student, expectedStudentId, expectedFirstName)
Arg<List<Student>>.List.ContainsAll(new List<Student> {student1, student2, student3})
//example custom constraint
mockStudentRepository.AssertWasCalled(x => x.Save(Arg<Student>.Matches(new StudentConstraint(expectedStudent))));
public class StudentConstraint : AbstractConstraint
public StudentContraint(Student expectedStudent) {}
public override bool Eval(object actual) {}
public override string Message { get; set; } //called if eval is false

Avoid using out & ref parameters
out Arg<Student>.Out(new Student()).Dummy
ref Arg<Student>.Ref(Rhino.Mocks.Constraints.Is.Anything, new Student()).Dummy