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Tag Archives: unit test

Unit Test Internal Members

Applies to .Net application in Visual Studio 2010 and up.

Say I have C# project (call it QC project). In the project, I have class that has internal member(s) like this:

namespace QC
{
    public class PersonService
    {
        public bool PromotePerson(string userName)
        {
        }

        internal bool FindPerson(string userName)
        {
        }
    }
}

For unit test, I’d created separate project (call it QCTest project). Because internal members can only be accessed in same assembly, I won’t be able to invoke `QC.PersonService.FindPerson(string userName)` method from QCTest project.

To overcome this issue, in `AssemblyInfo.cs` of project being tested (in my case, QC project), simply add

[assembly: InternalsVisibleTo("QCTest")]

After rebuilding my solution, I am able to access `QC.PersonService.FindPerson(string userName)` in my QCTest project.

As an added bonus, if you use mock library like Moq or Rhino and try to mock internal members, you most likely need to add:

[assembly: InternalsVisibleTo("DynamicProxyGenAssembly2")]

What is `DynamicProxyGenAssembly2` ?

DynamicProxyGenAssembly2 is a temporary assembly built by mocking systems that use CastleProxy like Moq or NSubsitute. It is generated when the mock is needed and disposed of after the tests are finished.

Reference: https://stackoverflow.com/a/17179923

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Posted by on January 18, 2019 in General

 

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Unit Testing DTO Classes

Reason why I unit test my DTO (Data Transfer Object) classes are because I pass these classes to client app and client app might use them and expect certain properties in response. Sometimes I change DTO properties that I used in client app and forget to refactor client app.
By unit testing my DTO classes, it acts as reminder for me to refactor client app whenever DTO properties (or its name) changes.

For example, I have Person DTO.

Person.cs

public class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Age { get; set; }
}

To unit test, I would create PersonMirror DTO.

public class PersonMirror
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Age { get; set; }
}

Then use following helper class to unit test my DTO.

public class TestHelper
{
    public static void CompareType()
    {
        var errorMessage = "Type: {0}; Property: {1}";

        var instance = Activator.CreateInstance(typeof(T));
        var instanceType = instance.GetType();
        var mirror = Activator.CreateInstance(typeof(TMirror));
        var mirrorType = mirror.GetType();
        var mirrorProperties = mirrorType.GetProperties();

        // Remove 'Mirror' convention
        var mirrorTypeName = mirrorType.Name;
        if (mirrorType.Name.IndexOf("Mirror") > 0)
        {
            mirrorTypeName = mirrorType.Name.Substring(0, mirrorType.Name.IndexOf("Mirror"));
        }

        // Compare type name
        Assert.AreEqual(mirrorTypeName, instanceType.Name);

        // Compare properties
        foreach (var mirrorProperty in mirrorProperties)
        {
            var instanceProperty = instanceType.GetProperty(mirrorProperty.Name);

            Assert.IsNotNull(instanceProperty, string.Format(errorMessage, instanceType.FullName, mirrorProperty.Name));
        }
    }
}

Usage (using MS Test):
PersonTest.cs

[TestClass]
public class PersonTest
{
    [TestMethod]
    public void TestPersonDto()
    {
        TestHelper.CompareType<Person, PersonMirror>();
    }    
}
 
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Posted by on January 18, 2019 in General

 

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Karma: Only Run 1 Test

Useful hack to only run 1 test in Karma.

Instead of ‘it’, change test declaration to ‘fit’.
Example:

    fit('should create', () => {
        expect(component).toBeTruthy();
    });

This will force Karma to only run ‘should create’ test.

 
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Posted by on October 22, 2018 in General

 

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Mocking Generic Method with NSubstitute

The generic method:


public interface ICacheService
{
    T Get<T>(string id);
}

User object in NSubstitute to mock the generic method.


private ICacheService MockICacheService()
{
    var service = Substitute.For<ICacheService>();

    // Return Models
    object returnForAny = null;

    // Mock
    service.Get<object>(Arg.Any<string>()).ReturnsForAnyArgs(returnForAny);

    return service;
}

 
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Posted by on September 13, 2017 in General

 

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Return Null in NSubstitute Mock Framework

The API is not intuitive, at least not for me. So, I have to figure out how to return null with this mocking framework I have never used before.

var service = Substitute.For<ISomethingService>();

// Mock
service.Get<IEnumerable<SomeDomain>>(Arg.Any<string>()).ReturnsForAnyArgs(x => null);

Normally, I would just to .ReturnsForAnyArgs(null), not the case with NSubstitute.

 
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Posted by on May 27, 2015 in General

 

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Unit Testing WIF’s ClaimsPrincipalPermission.CheckAccess

WIF 4.5 has ClaimsPrincipalPermission.CheckAccess method, very useful to check user’s authorization. You can use this as method call or attribute.

// Imperative method call
using System.IdentityModel.Services;
public ActionResult Index()
{
    ClaimsPrincipalPermission.CheckAccess("foo", "bar");

    return View();
}

// Attribute
[ClaimsPrincipalPermission(SecurityAction.Demand, Operation="foo", Resource="bar")]
public ActionResult ViewFoobar()
{
    return View();
}

Either way, how do we unit test this? My approach is to first abstract out ClaimsPrincipalPermission and create a new wrapper class that will be injected to the dependent class.

Abstract Out

using System.IdentityModel.Services;

public class ClaimsPrincipalWrapper : IClaimsPrincipalWrapper
{
    public void CheckAccess(string resource, string action)
    {
        ClaimsPrincipalPermission.CheckAccess(resource, action);
    }
}

Dependency Injection

using System.IdentityModel.Services;

public class HomeController : Controller
{
    private readonly IClaimsPrincipalWrapper _ClaimsPrincipalWrapper;

    public HomeController(IClaimsPrincipalWrapper claimsPrincipalWrapper)
    {
        _ClaimsPrincipalWrapper = claimsPrincipalWrapper;
    }

    public ActionResult Index()
    {
        _ClaimsPrincipalWrapper.CheckAccess("foo", "bar");

        return View();
    }
}

Unit Test

[TestMethod]
public void TestIndex()
{
    // Arrange
    var _claimsPrincipal = new Mock<IClaimsPrincipalWrapper>();
    _claimsPrincipal.Setup(m => m.CheckAccess(It.IsAny<string>, It.IsAny<string>));
    var _controller = new HomeController(_claimsPrincipalMock.Object);

    // Act
    var _result = _controller.Index() as ViewResult;

    // Assert
    Assert.IsTrue(_result.View != null);
}
 
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Posted by on May 4, 2015 in General

 

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Visual Studio 2012: Debugging Unit Tests Doesn’t Work

There’s a problem in Visual Studio 2012 where debugging unit tests doesn’t work. This often happens when you enable code coverage.

The solution is fairly simple, un-check any selected test setting file under Test > Test Settings.

This behavior is expected, at least according to Microsoft, they just don’t support debugging for code coverage.

 
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Posted by on May 1, 2015 in General

 

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