Develop Reference

Testing a property set to an instance of a new object in Rhino Mocks 3.4.0

Background
I'm fixing unit tests which have been neglected for a long time for legacy code in our organisation. They're written using Rhino Mocks 3.4.0, and I'm struggling to find a way of making this test pass. Rhino Mocks documentation seems to have gone, and most answers here and blogs seem to be using updated 3.5 and 3.6 syntax.
I'm wary of updating the version of Rhino Mocks we're using, as we have several thousand unit tests which may or may not need updated if we update.
The scenario:
We have a Presenter and a View. When the Presenter is initialised, it sets some default filter properties in the View. In the past, both of these properties were enums and the test passed.
The last change updated one of the properties to be an instance of a class. The test was updated to expect a call to a static method which creates an instance with default values (matching the code under test), but the test now fails with the error Rhino.Mocks.Exceptions.ExpectationViolationException : Unordered method call.
Some sample code:
public enum FilterOptions { OptionA, OptionB, OptionC }
public class OtherFilterOptions
{
public bool Filter1 { get; set;}
public bool Filter2 { get; set; }
public OtherFilterOptions(bool filter1 = true, bool filter2 = false)
{
Filter1 = filter1;
Filter2 = filter2;
}
public static OtherFilterOptions DefaultFilterOptions()
{
return new OtherFilterOptions();
}
}
public interface IToTestView
{
FilterOptions Property1 { set; }
OtherFilterOptions Property2 { set; }
}
public class ToTestPresenter
{
public IToTestView View { get; set; }
public ToTestPresenter(IToTestView view)
{
View = view;
}
public void InitialiseView()
{
View.Property1 = FilterOptions.OptionA;
View.Property2 = OtherFilterOptions.DefaultFilterOptions();
}
}
And a failing test:
[TestFixture]
class Tests
{
[Test]
public void TestOne()
{
var mocks = new MockRepository();
var mockView = mocks.CreateMock<IToTestView>();
ToTestPresenter presenter = new ToTestPresenter(mockView);
using (mocks.Ordered())
{
mockView.Property1 = FilterOptions.OptionA;
mockView.Property2 = OtherFilterOptions.DefaultFilterOptions();
}
mocks.ReplayAll();
presenter.InitialiseView();
mocks.VerifyAll();
}
}
The full error is
Rhino.Mocks.Exceptions.ExpectationViolationException : Unordered method call! The expected call is: 'Ordered: { IToTestView.set_Property2(RhinoMocksTestApp.OtherFilterOptions); }' but was: 'IToTestView.set_Property2(RhinoMocksTestApp.OtherFilterOptions);'
I'm assuming that the test is failing because the value to be set is a method call rather than a concrete value. I've tried declaring a variable using mockView.Property2 = theVariable, but there's no change to the error.
Can I set an expectation that Property2 will be set to {some object with Values Filter1 = true, Filter2 = false}? I've seen examples doing similarly using Rhino Mocks 3.6, but is anything available using 3.4.0?
Edit:
As an example, this is an example test which passes in Rhino Mocks 3.6.1 - I'm hoping to find some syntax that works similarly for 3.4.0, if it exists.
[Test]
public void TestOne()
{
var mocks = new MockRepository();
var mockView = MockRepository.GenerateMock<IToTestView>();
ToTestPresenter presenter = new ToTestPresenter(mockView);
mocks.ReplayAll();
presenter.InitialiseView();
mockView.AssertWasCalled(v => v.Property1 = FilterOptions.OptionA);
mockView.AssertWasCalled(v => v.Property2 = Arg<OtherFilterOptions>.Matches(filters =>
(filters.Filter1 == true) && (filters.Filter2 == false)));
}

The answer I was looking for was in the LastCall.Constraints() method. Passing arguments to Constraints allows you to specify property values of an argument:
[Test]
public void TestOne()
{
var mocks = new MockRepository();
var mockView = mocks.CreateMock<IToTestView>();
ToTestPresenter presenter = new ToTestPresenter(mockView);
using (mocks.Ordered())
{
mockView.Property1 = FilterOptions.OptionA;
mockView.Property2 = OtherFilterOptions.DefaultFilterOptions();
LastCall.Constraints(
Property.Value("Filter1", true)
& Property.Value("Filter2", false));
}
mocks.ReplayAll();
presenter.InitialiseView();
mocks.VerifyAll();
}
There are a large number of options that can be passed in to the Constraints() method. Details on some of them on this CodeProject page
Another option is LastCall.IgnoreArguments() if you don't care what the property is actually set to.

Validator ignoring MaxLength attributes

Problem:
I am trying to manually Validate some c# objects, and the Validator is ignoring string length related validations.
Test Case:
extending this example which uses the [Required] attribute, i also wanted to validate that strings were not too long, as follows.
public class Recipe
{
//[Required]
public string Name { get; set; }
[MaxLength(1)] public string difficulty = "a_string_that_is_too_long";
}
public static void Main(string[] args)
{
var recipe = new Recipe();
var context = new ValidationContext(recipe, serviceProvider: null, items: null);
var results = new List<ValidationResult>();
var isValid = Validator.TryValidateObject(recipe, context, results);
if (!isValid)
{
foreach (var validationResult in results)
{
Console.WriteLine(validationResult.ErrorMessage);
}
} else {
Console.WriteLine("is valid");
}
}
Expected result: an error: "difficulty is too long."
Actual result: 'is valid'
other things tested:
the validator is working, uncommenting the [Required] results in the message "The Name field is required."
using [StringLength] instead (as noted
at https://stackoverflow.com/a/6802739/432976 ) made no difference.

You need to make 2 changes to have the validation work the way you expect:
1. You have to change the difficulty field to a property.
The Validator class only validates properties, so change the difficulty definition to a property like this:
[MaxLength(1)] public string difficulty { get; set; } = "a_string_that_is_too_long";
2. Specify the validateAllProperties: true parameter to the Validator.TryValidateObject call.
The documentation for Validator.TryValidateObject is not very forthcoming about the fact that, unless you use the overload with validateAllProperties: true, only the Required attribute will be checked. So modify the call like this:
var isValid = Validator.TryValidateObject(recipe,
context,
results,
validateAllProperties: true);

Unit Test for two classes inherit an Interface

I have two classes that implement an interface, but both classes have a parameter passed into the constructor to identify what class the application would need. I am trying to test one (GetAvailablity) method on (AvailablityRepoData) class when I create an instance of AvailablityRepoData I am getting an error for non-virtual method. I would really appreciate if someone can point me to the right direction.
public interface IAvailablityRepo
{
string GetAvailablity(Availablity availablity);
}
public class AvailablityRepoData: IAvailablityRepo
{
public AvailablityRepoData(string websetting) {
}
public string GetAvailablity(Availablity availablity) {
return "Data";
}
}
public class AvailablityRepoWeb:IAvailablityRepo
{
public AvailablityRepoWeb(string DataSetting) {
}
public string GetAvailablity(Availablity availablity) {
return "Web";
}
}
public class Availablity
{
public virtual string Id {
get;
set;
}
public virtual string Status {
get;
set;
}
}
var a = new Availablity() { Id = "111", Status = "A"};
Mock<IAvailablityRepo> mockRepo = new Mock<IAvailablityRepo>();
Mock<IAvailablityRepo> RepoData = new Mock<IAvailablityRepo>();
RepoData.Setup(x => x.GetAvailablity(It.IsAny<Availablity> ())).Returns("pass");
var result = RepoData.Object.GetAvailablity(a);

As has already been said in the comments, it's not clear from the code you've posted what your error is. If I copy and past it straight into visual studio (wrapping the test code in a test), the test passes fine. I'm going to suggest that when you experienced the error, you test code was actually closer to this:
[TestMethod]
public void TestMethod1() {
var a = new Availablity() { Id = "111", Status = "A" };
Mock<IAvailablityRepo> mockRepo = new Mock<IAvailablityRepo>();
Mock<AvailablityRepoData> RepoData = new Mock<AvailablityRepoData>();
RepoData.Setup(x => x.GetAvailablity(It.IsAny<Availablity>())).Returns("pass");
var result = RepoData.Object.GetAvailablity(a);
}
This results in an error when the test is run:
System.NotSupportedException:Invalid setup on a non-virtual (overridable in VB) member:
x => x.GetAvailablity(It.IsAny<Availablity>())
The difference between this test and your original test is that I've changed the Mocked type from the interface IAvailabilityRepo to AvailabilityRepoData which is the concrete class. Since Moq only supports mocking of interfaces / virtual methods it's naturally getting upset.
As has been mentioned by #prgmtc, your test as it stands doesn't really testing much of anything.
With your current code, it doesn't actually look like you need to be using Mocks at all. Something like this might be a more appropriate test:
[TestMethod]
public void TestDataRepoReturnsDataAvailability() {
var someImportantSetting = "thisShouldBeSomethingMeaningful";
var availability = new Availablity() { Id = "111", Status = "A" };
var sut = new AvailablityRepoData(someImportantSetting);
var returnedAvailability = sut.GetAvailablity(availability);
Assert.AreEqual("Data", returnedAvailability);
}
Assuming your actual code is more complex the string passed into your data repo would presumably need to be rather more meaningful...
As a general rule of thumb, you shouldn't be mocking the system under test. If you find yourself creating a mock for the system you're testing it's a good indication that you've got to much functionality in one class and/or you're trying to test the wrong thing...
As an asside, you may want to look into something like the builder pattern to create your different repos rather than passing the type into the constructor for each of the repos as you seem to be suggesting.

Example of how to use AutoFixture with NSubstitute

I use NSubstitute a lot. And I love it.
I am just looking into AutoFixture. It seems great!
I have seen AutoFixture for NSubstitute and seen a few examples in Moq on how to use this feature.
But I can't seem to translate it into NSubstitute.
I tried this:
var fixture = new Fixture().Customize(new AutoNSubstituteCustomization());
var addDest = Substitute.For<IPerson>();
Using:
public interface IPersonEntity
{
int ID { get; set; }
string FirstName { get; set;}
string LastName { get; set;}
DateTime DateOfBirth { get; set; }
char Gender { get; set; }
}
And I get an object, but none of the properties are populated (kind of the point of AutoFixture).
I also tried:
var fixture = new Fixture().Customize(new AutoNSubstituteCustomization());
var result = fixture.Create<IPersonEntity>();
That also gave me an object with no populated properties. (Note if I do the above with a PersonEntity class, then the properties are all populated.)
I am sure that there is a way to make this work, but I can't seem to find it.
So, given my IPersonEntity interface above, does anyone know how to use AutoFixture and NSubstitute to give me a populated IPersonEntity object?

Instead of customizing the Fixture instance with the AutoNSubstituteCustomization you may use the customization below:
var fixture = new Fixture().Customize(
new AutoPopulatedNSubstitutePropertiesCustomization());
var result = fixture.Create<IPersonEntity>();
// -> All properties should be populated now.
The AutoPopulatedNSubstitutePropertiesCustomization is defined as:
internal class AutoPopulatedNSubstitutePropertiesCustomization
: ICustomization
{
public void Customize(IFixture fixture)
{
fixture.ResidueCollectors.Add(
new Postprocessor(
new NSubstituteBuilder(
new MethodInvoker(
new NSubstituteMethodQuery())),
new AutoPropertiesCommand(
new PropertiesOnlySpecification())));
}
private class PropertiesOnlySpecification : IRequestSpecification
{
public bool IsSatisfiedBy(object request)
{
return request is PropertyInfo;
}
}
}
The difference with the AutoNSubstituteCustomization is that the above customization is also decorated with a Postprocessor instance to automatically set values for all the public properties of the requested type.
References:
The above solution is inspired by the following blog articles by Mark Seemann:
How to configure AutoMoq to set up all properties
How to automatically populate properties with AutoMoq

Though the other answer has been marked as correct back then, I just wanted to add for completeness that you can indeed use AutoNSubstituteCustomization:
var fixture = new Fixture().Customize(new AutoNSubstituteCustomization() { ConfigureMembers = true});
var result = fixture.Create<IPersonEntity>();
This will result in the properties being populated.

How can I unit test my custom validation attribute

I have a custom asp.net mvc class validation attribute.
My question is how can I unit test it?
It would be one thing to test that the class has the attribute but this would not actually test that the logic inside it. This is what I want to test.
[Serializable]
[EligabilityStudentDebtsAttribute(ErrorMessage = "You must answer yes or no to all questions")]
public class Eligability
{
[BooleanRequiredToBeTrue(ErrorMessage = "You must agree to the statements listed")]
public bool StatementAgree { get; set; }
[Required(ErrorMessage = "Please choose an option")]
public bool? Income { get; set; }
.....removed for brevity
}
[AttributeUsage(AttributeTargets.Class)]
public class EligabilityStudentDebtsAttribute : ValidationAttribute
{
// If AnyDebts is true then
// StudentDebts must be true or false
public override bool IsValid(object value)
{
Eligability elig = (Eligability)value;
bool ok = true;
if (elig.AnyDebts == true)
{
if (elig.StudentDebts == null)
{
ok = false;
}
}
return ok;
}
}
I have tried to write a test as follows but this does not work:
[TestMethod]
public void Eligability_model_StudentDebts_is_required_if_AnyDebts_is_true()
{
// Arrange
var eligability = new Eligability();
var controller = new ApplicationController();
// Act
controller.ModelState.Clear();
controller.ValidateModel(eligability);
var actionResult = controller.Section2(eligability,null,string.Empty);
// Assert
Assert.IsInstanceOfType(actionResult, typeof(ViewResult));
Assert.AreEqual(string.Empty, ((ViewResult)actionResult).ViewName);
Assert.AreEqual(eligability, ((ViewResult)actionResult).ViewData.Model);
Assert.IsFalse(((ViewResult)actionResult).ViewData.ModelState.IsValid);
}
The ModelStateDictionary does not contain the key for this custom attribute.
It only contains the attributes for the standard validation attributes.
Why is this?
What is the best way to test these custom attributes?

Your attribute EligabilityStudentDebtsAttribute is just a standard class, like everything else, just unit test the IsValid() method. If it works OK, trust to Framework that attribute works OK.
So:
[Test]
public void AttibuteTest()
{
// arrange
var value = //.. value to test - new Eligability() ;
var attrib = new EligabilityStudentDebtsAttribute();
// act
var result = attrib.IsValid(value);
// assert
Assert.That(result, Is.True)
}

Your custom validation attribute might be dependent on the state of other properties. In this case you can use the System.ComponentModel.DataAnnotations.Validator static methods, for example:
var model = ...
var context = new ValidationContext(model);
var results = new List<ValidationResult>();
var isValid = Validator.TryValidateObject(model, context, results, true);
Assert.True(isValid);

I have found out that IsValid does not work well on simple types like string. E.g. if you have a validation on a string query parameter that is not an object. Additionally it's easier to test a value directly on the attribute without having to provide a whole object. It also allows to check the error message. This is how it works:
string input = "myteststring";
var myAttribute = new MyAttribute()
var result = attribute.GetValidationResult(input, new ValidationContext(input));
var isSuccess = result == ValidationResult.Success;
var errorMessage = result?.ErrorMessage;
This code tests only the validation of your input value and nothing else.
P.S. I have tested this in dotnet core, but I would think this works for ordinary dotnet as well.