NUnit With C#

1. Create another C# .Net Class Library project called UtilityLibtesting.

2. Then add a reference for the UnitTest.dll and NUnit framework DLL files that reside in the "\Program Files\NUnit 2.6.2\bin\framework\nunit.framework.dll" directory.
   
   Figure 1.3 Add references of NUnit framework and UnitTest.dll
3. Now add the namespace definition to the class library file as follows:

   using NUnit.Framework;  
   using UnitTest;

4. Now rename the class1.cs to TestCase.cs with TextFixture attribute.

5. It is time to write test case methods to verify whether the business logic stated in the DLL file is producing the expected result or not.

6. So we write another independent method for each corresponding function given in the DLL file with the [test] attribute and we also use the assert class to AreEqual() method in order to confirm the desired result. The AreEqual() method would take two arguments; the first is the expected result and the second specific method with an argument defined in the business logic class.

   // Test Case#1: Sales Amount is Greater or Equal than 1000 : Verification  
   [Test]  
   public void OneThousand_G_E() {  
       UtilityLib obj = new UtilityLib();  
       Assert.AreEqual(950, obj.calculateDiscount(1000));  
   }

7. We also put the condition for actual test cases by using the assert class AreNotEqual() method in which we pass any value as the first argument as in the following

   //______________Test for Actual Results____________  
   // Test Case#6: Sales Amount is not producing expected Result : Verification  
   [Test]  
   public void OneThousand() {  
       UtilityLib obj = new UtilityLib();  
       Assert.AreNotEqual(930, obj.calculateDiscount(1000));  
   }

8. Thereafter we specify the rest of the code for each condition as in the following

   using System;  
   using NUnit.Framework;  
   using UnitTest;  
   namespace UtilityLibTesting {  
       [TestFixture]  
       public classTestCase {  
           //__________Test for Expected Results__________  
           // Test Case#1: Sales Amount is Greater or Equal than 1000 : Verification  
           [Test]  
           public void OneThousand_G_E() {  
               UtilityLib obj = new UtilityLib();  
               Assert.AreEqual(950, obj.calculateDiscount(1000));  
           }  
           // Test Case#2: Sales Amount is Greater or Equal than 2000 : Verification  
           [Test]  
           public void TwoThousand_G_E() {  
               UtilityLib obj = new UtilityLib();  
               Assert.AreEqual(1800, obj.calculateDiscount(2000));  
           }  
           // Test Case#3: Sales Amount is Greater or Equal than 5000 : Verification  
           [Test]  
           public void FiveThousand_G_E() {  
               UtilityLib obj = new UtilityLib();  
               Assert.AreEqual(2500, obj.calculateDiscount(5000));  
           }  
           // Test Case#4: Sales Amount is 0 : Verification  
           [Test]  
           public void ZeroAmount() {  
               UtilityLib obj = new UtilityLib();  
               try {  
                   obj.calculateDiscount(0);  
               } catch (Exception e) {}  
           }  
           // Test Case#5: Sales Amount is below 1000 : Verification  
           [Test]  
           public void OneThousand_Below() {  
               UtilityLib obj = new UtilityLib();  
               Assert.AreEqual(999, obj.calculateDiscount(999));  
           }  
           //__________Test for Actual Results__________  
           // Test Case#6: Sales Amount is not producing expected Result : Verification  
           [Test]  
           public void OneThousand() {  
               UtilityLib obj = new UtilityLib();  
               Assert.AreNotEqual(930, obj.calculateDiscount(1000));  
           }  
           // Test Case#7: Sales Amount is not producing expected Result : Verification  
           [Test]  
           public void TwoThousand() {  
               UtilityLib obj = new UtilityLib();  
               Assert.AreNotEqual(1900, obj.calculateDiscount(2000));  
           }  
       }  
   }

9. Finally build the project and you will notice that the UtilityLibTesting.dll file is created in the project solution directory to be used later during the unit testing in the NUnit application.
   
   Figure 1.4 NUnitTesting.exe depict

Running Test Case

Until now we have seen the basics of the code, now it is time how to run your tests using the NUnit GUI. To use the GUI application, just simply run the software and target (open the project of) your test assembly where it resides. The test assembly is the class library (or executable) that contains the Test Fixtures. The application will then show you a graphical view of each class. To run the entire suite of tests, simply click the Run button. If you want to run only one Test Fixture or even just a single test, you can double-click it in the tree. After opening the project file, all the methods stated in the DLL file will show up in the left pane as in the following;

Figure 1.5 Test Method Loading

Now hit the Run button on the right side to start the Unit Automotive testing. It will take some time to verify all the conditions given in the test cases. If all the methods function properly as specified by the test condition then the GUI will produce the results in the Green Progress bar as in the following:

Figure 1.6 NUnit Test Report with No Error

In the scenario, if the code has some built-in programming glitches, then they are easily rectified during the NUnit Testing process. The following picture depicts a problem in the TwoThousand() method with the cross sign. Here the report indicates that all the method implementations are working properly except one method:

Figure 1.7 NUnit Test Fail output

We can go deeper into the error by using the Errors and Failure tab in the right bottom. This will display the exact error in the source code as in the following:

Figure 1.8 NUnit Detailed Test Report with Error