Introduction

In this post we will see how we can write unit test cases for our WCF Service with a framework called NUnit. We will also be covering how to mock our dependencies in our test, here we will be using Rhino Mocks and Visual Studio 2015 for the development.

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Background

As a developer, we all writes lots of codes in our day to day life. It is more important to check whether the codes we have written works well. So for that we developer usually do unit testing, few developers are doing a manual testing to just check whether the functionality is working or not. I would say that it is wrong. In a TDD (Test Driven Development) unit testing is very important, where we actually writes the test cases before we start our coding. Let us see what exactly the “Unit Testing” is.

Unit Testing

Unit testing is the process of testing a unit, it can be a class, a block of code, function, a property. We can easily test our units independently. In dot net we have so many frameworks to do unit testing. But here we are going to use NUnit which is very easy to write tests. If you have Resharper installed in your machine, it will be more easier to execute and debug your tests.

Now it is time to set up our project and start our coding.

Setting up the project

To get started, please create an empty project in your Visual Studio.

empty_project

Now, we will add a WCF Service as follows.

create_a_wcf_service

Once you are done, you can see two files, an Interface(IMyService) and a class (MyService) with .svc extension. If you are completely new to WCF service, we strongly recommend you to read some basics here.

Now, it is time to set up our database and insert some data.

Creating database

Here we are creating a database with name “TrialDB”, you can always create a DB by running the query given below.

USE [master]
GO
  
/****** Object:  Database [TrialDB]    Script Date: 20-11-2016 03:54:53 PM ******/
CREATE DATABASE [TrialDB]
CONTAINMENT = NONE
ON  PRIMARY
( NAME = N'TrialDB', FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL13.SQLEXPRESS\MSSQL\DATA\TrialDB.mdf' , SIZE = 8192KB , MAXSIZE = UNLIMITED, FILEGROWTH = 65536KB )
LOG ON
( NAME = N'TrialDB_log', FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL13.SQLEXPRESS\MSSQL\DATA\TrialDB_log.ldf' , SIZE = 8192KB , MAXSIZE = 2048GB , FILEGROWTH = 65536KB )
GO
  
ALTER DATABASE [TrialDB] SET COMPATIBILITY_LEVEL = 130
GO
  
IF (1 = FULLTEXTSERVICEPROPERTY('IsFullTextInstalled'))
begin
EXEC [TrialDB].[dbo].[sp_fulltext_database] @action = 'enable'
end
GO
  
ALTER DATABASE [TrialDB] SET ANSI_NULL_DEFAULT OFF
GO
  
ALTER DATABASE [TrialDB] SET ANSI_NULLS OFF
GO
  
ALTER DATABASE [TrialDB] SET ANSI_PADDING OFF
GO
  
ALTER DATABASE [TrialDB] SET ANSI_WARNINGS OFF
GO
  
ALTER DATABASE [TrialDB] SET ARITHABORT OFF
GO
  
ALTER DATABASE [TrialDB] SET AUTO_CLOSE OFF
GO
  
ALTER DATABASE [TrialDB] SET AUTO_SHRINK OFF
GO
  
ALTER DATABASE [TrialDB] SET AUTO_UPDATE_STATISTICS ON
GO
  
ALTER DATABASE [TrialDB] SET CURSOR_CLOSE_ON_COMMIT OFF
GO
  
ALTER DATABASE [TrialDB] SET CURSOR_DEFAULT  GLOBAL
GO
  
ALTER DATABASE [TrialDB] SET CONCAT_NULL_YIELDS_NULL OFF
GO
  
ALTER DATABASE [TrialDB] SET NUMERIC_ROUNDABORT OFF
GO
  
ALTER DATABASE [TrialDB] SET QUOTED_IDENTIFIER OFF
GO
  
ALTER DATABASE [TrialDB] SET RECURSIVE_TRIGGERS OFF
GO
  
ALTER DATABASE [TrialDB] SET  DISABLE_BROKER
GO
  
ALTER DATABASE [TrialDB] SET AUTO_UPDATE_STATISTICS_ASYNC OFF
GO
  
ALTER DATABASE [TrialDB] SET DATE_CORRELATION_OPTIMIZATION OFF
GO
  
ALTER DATABASE [TrialDB] SET TRUSTWORTHY OFF
GO
  
ALTER DATABASE [TrialDB] SET ALLOW_SNAPSHOT_ISOLATION OFF
GO
  
ALTER DATABASE [TrialDB] SET PARAMETERIZATION SIMPLE
GO
  
ALTER DATABASE [TrialDB] SET READ_COMMITTED_SNAPSHOT OFF
GO
  
ALTER DATABASE [TrialDB] SET HONOR_BROKER_PRIORITY OFF
GO
  
ALTER DATABASE [TrialDB] SET RECOVERY SIMPLE
GO
  
ALTER DATABASE [TrialDB] SET  MULTI_USER
GO
  
ALTER DATABASE [TrialDB] SET PAGE_VERIFY CHECKSUM
GO
  
ALTER DATABASE [TrialDB] SET DB_CHAINING OFF
GO
  
ALTER DATABASE [TrialDB] SET FILESTREAM( NON_TRANSACTED_ACCESS = OFF )
GO
  
ALTER DATABASE [TrialDB] SET TARGET_RECOVERY_TIME = 60 SECONDS
GO
  
ALTER DATABASE [TrialDB] SET DELAYED_DURABILITY = DISABLED
GO
  
ALTER DATABASE [TrialDB] SET QUERY_STORE = OFF
GO
  
USE [TrialDB]
GO
  
ALTER DATABASE SCOPED CONFIGURATION SET MAXDOP = 0;
GO
  
ALTER DATABASE SCOPED CONFIGURATION FOR SECONDARY SET MAXDOP = PRIMARY;
GO
  
ALTER DATABASE SCOPED CONFIGURATION SET LEGACY_CARDINALITY_ESTIMATION = OFF;
GO
  
ALTER DATABASE SCOPED CONFIGURATION FOR SECONDARY SET LEGACY_CARDINALITY_ESTIMATION = PRIMARY;
GO
  
ALTER DATABASE SCOPED CONFIGURATION SET PARAMETER_SNIFFING = ON;
GO
  
ALTER DATABASE SCOPED CONFIGURATION FOR SECONDARY SET PARAMETER_SNIFFING = PRIMARY;
GO
  
ALTER DATABASE SCOPED CONFIGURATION SET QUERY_OPTIMIZER_HOTFIXES = OFF;
GO
  
ALTER DATABASE SCOPED CONFIGURATION FOR SECONDARY SET QUERY_OPTIMIZER_HOTFIXES = PRIMARY;
GO
  
ALTER DATABASE [TrialDB] SET  READ_WRITE
GO

 

Create a table and insert data in database

To create a table, you can run the query below.

USE [TrialDB]
GO
 
/****** Object:  Table [dbo].[Course]    Script Date: 20-11-2016 03:57:30 PM ******/
SET ANSI_NULLS ON
GO
 
SET QUOTED_IDENTIFIER ON
GO
 
CREATE TABLE [dbo].[Course](
    [CourseID] [int] NOT NULL,
    [CourseName] [nvarchar](50) NOT NULL,
    [CourseDescription] [nvarchar](100) NULL,
    CONSTRAINT [PK_Course] PRIMARY KEY CLUSTERED([CourseID] ASC)
    WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

 

Now we can insert few data to our newly created table.

USE [TrialDB]
GO
  
INSERT INTO [dbo].[Course]
           ([CourseID],[CourseName],[CourseDescription])
     VALUES
           (1,'C#','Learn C# in 7 days')
 INSERT INTO [dbo].[Course]
           ([CourseID],[CourseName],[CourseDescription])
     VALUES
           (2,'Asp.Net','Learn Asp.Net in 7 days')
INSERT INTO [dbo].[Course]
           ([CourseID],[CourseName],[CourseDescription])
     VALUES
           (3,'SQL','Learn SQL in 7 days')
INSERT INTO [dbo].[Course]
           ([CourseID],[CourseName],[CourseDescription])
     VALUES
           (4,'JavaScript','Learn JavaScript in 7 days')
GO

So our data is ready, that means we are all set to write our service and tests. Now go to your solution and create an entity data model.

entity_framework

So entity is also been created. Now please open your interface and that is where we start our coding. We can change the interface as follows.

using System;
  
using System.Collections.Generic;
  
using System.Linq;
  
using System.Runtime.Serialization;
  
using System.ServiceModel;
  
using System.Text;
  
   
  
namespace WCF_NUnit_Tests_Rheno_Mocks
  
{
  
    [ServiceContract]
  
    public interface IMyService
  
    {
  
        [OperationContract]
  
        Course GetCourseById(int courseId);
  
        [OperationContract]
  
        List<Course> GetAllCourses();
  
    }
  
}

Here we have created two operations, one to get a course by id and one to retrieve all the courses as a list. Now please go and implement these two operations in our service file. You can modify that class as follows.

using System;
  
using System.Collections.Generic;
  
using System.Linq;
  
using System.Runtime.Serialization;
  
using System.ServiceModel;
  
using System.Text;
  
   
  
namespace WCF_NUnit_Tests_Rheno_Mocks
  
{
  
    public class MyService : IMyService
  
    {
  
        private static MyEntity _myContext;
  
        private static IMyService _myIService;
  
   
  
        public MyService()
  
        {
  
               
  
        }
  
   
  
        public MyService(IMyService myIService)
  
        {
  
            _myContext = new MyEntity();
  
            _myIService = myIService;
  
        }
  
        public Course GetCourseById(int courseId)
  
        {
  
            var crse = _myContext.Courses.FirstOrDefault(dt => dt.CourseID == courseId);
  
            return crse;
  
        }
  
   
  
        public List<Course> GetAllCourses()
  
        {
  
            var courses = (from dt in _myContext.Courses select dt).ToList();
  
            return courses;
  
        }
  
    }
  
}

In the above code, as you can see we are creating two constructor one is without parameter and other is with parameter, and we are having IMyService as a parameter. In this way we can achieve the dependency injection when we write tests for our unit. So what we need to do all is, just pass the dependency, in this case it is IMyService.

In software engineering, dependency injection is a software design pattern that implements inversion of control for resolving dependencies. A dependency is an object that can be used (a service). An injection is the passing of a dependency to a dependent object (a client) that would use it. Source: WikiPedia

If you need to know more on dependency injection, please read here. Now we will build and check whether our service is working fine or not. Please press CTRL+F5.

invoking_wcf_service

As our services are ready, we can now create the tests for those operations. For that we can create a new class library in our project and name it UnitTest.Service. Please add a class MyServiceTests in the class library where we can add our tests. And please do not forget to add our application reference too.

add_project_reference

Installing and configuring NUnit

Now we can install NUnit to our test project from NuGet Package. Once you add the package, you will be able to add the preceding namespace in our MyServiceTests class.

using NUnit.Framework;

In NUnit we have so many attributes that can be used for different purposes, but now we are going to use only four among them.

  •   TestFixture


testfixture_in_nunit

  •   OneTimeSetUp


one_time_setup_attribute_in_nunit

In previous versions, we were using TestFixtureSetUp, as the TestFixtureSetUp is obsolete, now we are using OneTimeSetUp


testfixturesetup_attribute_is_obsolete

  •   TearDown

This attribute is used to identify a method that is called immediately after each tests, it will be called even if there is any error, this is the place we can dispose our objects.

  •   Test

This attribute is used to make a method callable from NUnit test runner. This can not be inherited.

Now we can see all these attributes in action. So let us write some tests, but the real problem is we need to mock the IMyService right as the parameterized constructor of the class MyService expecting it. Remember, we have discussed about setting up our services in the way which can be injected the dependencies? No worries, we can install Rhino Mock for that now.


rhino_mocks_in_nuget_package

So we can add the tests are dependencies as follows in our test class.

using NUnit.Framework;
 
using Rhino.Mocks;
 
using WCF_NUnit_Tests_Rhino_Mocks;
 
  
 
namespace UnitTest.Service
 
{
 
    [TestFixture]
 
    public class MyServiceTests
 
    {
 
        private static MyService _myService;
 
        private IMyService _myIservice;
 
        [OneTimeSetUp]
 
        public void SetUp()
 
        {
 
            _myIservice = MockRepository.GenerateMock<IMyService>();
 
            _myService = new MyService(_myIservice);
 
              
 
        }
 
  
 
        [TearDown]
 
        public void Clean()
 
        {
 
             
 
        }
 
  
 
        [Test(Description = "A test to check whether the returned value is null")]
 
        public void GetCourseById_Return_NotNull_Pass()
 
        {
 
            //Set Up
 
            var crs = new Course
 
            {
 
                CourseID = 1,
 
                CourseName = "C#",
 
                CourseDescription = "Learn course in 7 days"
 
            };
 
            _myIservice.Stub(dt => dt.GetCourseById(1)).IgnoreArguments().Return(crs);
 
  
 
            //Act
 
            crs = _myService.GetCourseById(1);
 
  
 
            //Assert
 
            Assert.IsNotNull(crs,"The returned value is null");
 
        }
 
  
 
        [Test(Description = "A test to check we get all the courses")]
 
        public void GetAllCourses_Return_List_Count_Pass()
 
        {
 
            //Act
 
            var crs = _myService.GetAllCourses();
 
  
 
            //Assert
 
            Assert.AreEqual(4, crs.Count,"The count of retrieved data doesn't match");
 
            _myIservice.VerifyAllExpectations();
 
        }
 
  
 
    }
 
}

As you can see we have mocked our IMyService as follows.

_myIservice = MockRepository.GenerateMock<IMyService>();


generate_mock_with_rhino

And, in the test GetCourseById_Return_NotNull_Pass we have also used a method called Stub. Stub actually tell the mock object to perform a certain action when a matching method is called, and it doesn’t create an expectation for the same. So you might be thinking, how can we create an expectation? For that we have a method called Expect.


expect_in_rhino_mock

It is always recommended to verify your expectation when you use Expect as we used it in our test GetAllCourses_Return_List_Count_Pass.

_myIservice.VerifyAllExpectations();

As it is already said, we are using Resharper, we have so many shortcuts to run our tests, now if you right click on your TestFixture. You can see a run all option as preceding.


run_all_test_option_in_resharper

If you are getting an error as “No connection string named ‘Entity’ could be found in the application config file”, you may need to install the entity framework in my test project and also add a new config file with the connection string like we have in our web config file.

If everything goes fine and you don’t have any errors, you will get a screen as preceding.


nunit_output

Happy coding!.

See also

Conclusion

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