What is Unit TestingWhen is it Performed ?Who performs it? Why do we need Unit TestingWhat are tips should be followedHow do I do Unit Testing?Types of unit testingExample of Nunit Test cases

What Is Unit TestingUnit Testingis alevel of software testingwhere individual units/ components of a software are tested. The purpose is to validate that each unit of the software performs as designed.

A unit is the smallest testable part of software. It usually has one or a few inputs and usually a single output.

What Is Unit Testing Cont..

What Is Unit Testing Cont..Integration TestingIt is alevel of software testing where individual units are combined and tested as a group.System Testing :

It is a level of software testing where a complete and integrated software is tested.The purpose of this test is to evaluate the systems compliance with the specified requirements.Example: During the process of manufacturing a ballpoint pen, the cap, the body, the tail, the ink cartridge and the ballpoint are produced separately and unit tested separately. When two or more units are ready, they are assembled and Integration Testing is performed. When the complete pen is integrated, System Testing is performed.

What Is Unit Testing Cont..ACCEPTANCE TESTING:

Acceptance Testingis alevel of software testingwhere a system is tested for acceptability.The purpose of this test is to evaluate the systems compliance with the business requirements and assess whether it is acceptable for delivery.

What Is Unit Testing Continue..When is it performed?

Unit Testing is the first level of testing and is performed prior to Integration Testing

Who performs it?Unit Testing is normally performed by software developers themselves or their peers. In rare cases it may also be performed by independent software testers.

Why should we have Unit Testing in Project ?Unit testing increases confidence in changing/ maintaining code. If good unit tests are written and if they are run every time any code is changed, we will be able topromptly catchany defects introduced due to the change. Also, if codes are already made less interdependent to make unit testing possible, the unintended impact of changes to any code is less.

Why should we have Unit Testing in Project ?Codes are more reusable. In order to make unit testing possible, codes need to be modular. This means that codes are easier to reuse.The cost of fixing a defect detected during unit testing is lesser in comparison to that of defects detected at higher levels. Compare the cost (time, effort, destruction, humiliation) of a defect detected during acceptance testing or when the software is live.

TIPSFind a tool/ framework for your language.Do not create test cases for everything. Instead, focus on the tests that impact the behavior of the system.Isolate the development environment from the test environment.Use test data that is close to that of production.

TIPSBefore fixing a defect, write a test that exposes the defect. Why? First, you will later be able to catch the defect if you do not fix it properly. Second, your test suite is now more comprehensive. Third, you will most probably be too lazy to write the test after you have already fixed the defect.

TIPSAim at covering all paths through the unit. Pay particular attention to loop conditions.Make sure you are using a version control system to keep track of your test scripts.Perform unit tests continuously and frequently.In addition to writing cases to verify the behavior, write cases to ensure performance of the code.

How do I do Unit Testing?The first step is to decide how to test the method in questionbefore writing the code itself. With at least a rough idea ofhow to proceed, you can then write the test code itself, eitherbefore or concurrently with the implementation code. If yourewriting unit tests for existing code, thats fine too, but you mayfind you need to refactor it more often than with new code inorder to make things testable.

How Do I Do Unit Testing?you run the test itself, and probably all the other testsin that part of the system, or even the entire systems tests ifthat can be done relatively quickly. Its important that all thetests pass, not just the new one. This kind of basic regressiontesting helps you avoid any collateral damage as well as anyimmediate, local bugs.

Something about nUnitThere are many different types of Unit testing framework such as Mstest,Nunit, Xunit, Junit.

Something about nUnitNunit is a unit-testing framework for all .Net languages.It has been written entirely in C#.

Important nUnit Linkshttp://www.nunit.orghttp://nunit.org/download.htmlhttp://sourceforge.net/projects/nunit/

The Input & Output of nUnitnUnit Dll, exe file XML file (Optional)Processing details on the GUI or Command prompt

Things to do before testingDownload Nunit.msi from http://nunit.org/download.html and install nunit.

Things to do before testing cont.Add nunit.frameworks.dll to your project references. This dll resides in nunit\bin folder.The next few screen shots show how to add this dll file if your project has been opened as a classlibrary.

Select the Solution explorer mode

Right click references and select Add reference

Select Browse

Goto the nunit\bin directory, choose nunit.framework.dll and press open.

Now press ok in the Add reference page

The dll has been added to your reference list.

In your code, add using nunit.framework.

NUnit Testing Framework AttributeTextFixture Attribute

The TestFixture attribute is an indication that a class contains test methods. When you mention this attribute to a class in your project, the Test Runner application will scan it for test methods. The following code illustrates the usage of this attribute as in the following: usingSystem; usingNUnit.Framework; usingSystem.Text; namespaceUNitTesting { [TestFixture] publicclassProgram { } }

NUnit Testing Framework AttributeTest Attribute The Test attribute indicates that a method within a test fixture should be run by the Test Runner application. The method must be public, return void, and will not be run when the Test Fixture is run. The following code depicts the use of this attribute as in the following: [TestFixture] publicclassProgram { [Test] publicvoidTest() { ... } }

NUnit Testing Framework AttributeAssert Class the Assert class is used to confirm whether the test cases is producing the expected result or not using its auxiliary methods such as AreEqual() or AreNotEqual().

NUnit Testing Framework AttributeExpectedException Attribute You could fortify your code to handle various exceptions by using try...Catch blocks. But sometimes you have some circumstances where you actually want to ensure that an exception occurs. To overcome such a problem you should use the ExpectedException attribute as in the following; [TestFixture] publicclassProgram { [Test] [ExpectedException(typeof(DivideByZeroException))] publicvoidTest() { inti=10,j=0,x; x = i / j; } } In the previous code, we are intentionally committing a divide by zeroexception that is to be detected during the NUnit Test execution.

NUnit Testing Framework AttributeIgnore Attribute The Ignore attribute is required to indicate that a test should not be run on a particular method. Use the Ignore attribute as in the following: [TestFixture] publicclassProgram { [Test] [Ignore("This method is skipping")] publicvoidTest() { ... } }

NUnit Testing Framework AttributeSetUpThis attribute is used inside aTestFixtureto provide a common set of functions that are performed just before each test method is called.TearDownThis attribute is used inside a TestFixture to provide a common set of functions that are performed after each test method is run.

[TestFixture] public class NUnit { MyTest test=null; [SetUp] public void Initialize() { test = new MyTest(); } [TearDown] public void CleanUp() { test = null; }

Add testfixture to your program

TestFixture Example[TestFixture]public class calcTest{[Test]public void AdditionTests(){calculator cal=new calculator();cal.Addition(5,10); //CASE 1 Assert.AreEqual(15,cal.output());cal.Addition(-5,10); // CASE 2 Assert.AreEqual(15,cal.output());}

[Test]public void DivisionTests(){calculator cal=new calculator();cal.Division(10,2); // CASE 1 Assert.AreEqual(5,cal.output());

cal.Division(10,0); //CASE 2 Assert.AreEqual(2,cal.output());}}//for testfixture

How to write your test codeSuppose you want to test the functions in a class, your testfixture(test stub) should look somewhat like this

using NUnit.Framework;Namespace sample1{public class sampleclass(){public void func1(){} }//for sampleclass

[TestFixture]public class sampleTest(){[Test]public void test1(){testcase1;testcase2;}//for test1()}//for sampleTest textfixture}//for namespace

Calculator Exampleusing System;using NUnit.Framework; namespace ClassLibrary1{public class calculator{private int result;

public void Addition(int num1,int num2){result=num1+num2;}

public int output(){return result;}

public void Division(int num1,int num2){if(num2==0){throw new DivideByZeroException(); }result = num1/num2;}}

Calculator Example cont[TestFixture]public class calcTest{[Test]public void AdditionTests(){calculator cal=new calculator();cal.Addition(5,10);Console.Write("TESTING 5+10\n"); Assert.AreEqual(15,cal.output());cal.Addition(-5,10);Console.Write("TESTING -5+10\n"); Assert.AreEqual(5,cal.output());}

[Test]public void DivisionTests(){calculator cal=new calculator();cal.Division(10,2); Console.Write("TESTING 10div2\n"); Assert.AreEqual(5,cal.output());

cal.Division(10,0); Console.Write("TESTING 10div0\n"); Assert.AreEqual(0,cal.output());}}//for testfixture}//for namespace

Build the ProjectAfter the testfixture is complete, build the project. This will create a dll file which will reside in projectname\bin\debug folder.

LOCATION of dllIn this example I am copying the dll file from projectname\bin\debug folder to nunit\bin folder for my convenience. But this is not a requirement when we are testing and the dll can be run from projectname\bin\debug folder.

Location of exe files

Starting the GUI from console The GUI can be started from the console by executing nunit-gui.exe [inputfilename][options] Ex: nunit-gui.exe nunit.tests.dll run This option will load the dll file and run the test. * Options with their values are separated by an equal, colon or a space.

Starting the GUI from consolenunit-gui.exe [inputfilename][options]Options:/help short format: /?/config=STR project config to load/noload suppress loading of last proj/run Automatically run after load/fixture=STR Fixture to test

Starting the GUI from consoleSpecifying an Assemblynunit-gui nunit.tests.dllThe following will start the forms interface loading the same assembly through its Visual Studio project definition:nunit-gui nunit.tests.csproj

Starting the GUI from consoleSpecifying an Assembly and a FixtureWhen specifying a a fixture, you must give the full name of the test fixture along with the containing assembly. For example, to load only the NUnit.Tests.AssertionTests in the nunit.tests.dll assembly use the following command:nunit-gui /fixture:NUnit.Tests.AssertionTests nunit.tests.dll

GUI MODEThe steps to be followed areLoad the Dll file.Select Run.View the errors if any on the GUI screen.Save the output XML if necessary.

create a new projectnamespace TestNUnit { public class MyTest { public int Add(int a, int b) { return a + b; } public int Substract(int a, int b) { return a - b; } public int Divide(int a, int b) { return a / b; } } }

Add referencenunit.framework.dll

Add a class inside the newly created project to write the test methodsusing System.Web; using NUnit.Framework; using TestNUnit; namespace UnitTest { [TestFixture] public class Nunit { MyTest test=null; [SetUp] public void Initialize() { test = new MyTest(); } [TearDown] public void CleanUp() { test = null; }

Add a class inside the newly created project to write the test methods Cont..[Test] public void Addition() { Assert.AreEqual(5, test.Add(2, 3)); } [Test] public void Substraction() { Assert.AreEqual(0, test.Substract(2, 2)); } [Test] public void Divide() { Assert.AreEqual(1, test.Devide(2, 2)); }

Compile the project and openNUnit.exefrom the Start menu.

Select open in the NUNIT GUI

Select the dll which you want to test(In this case, we have moved the dll to the nunit\bin folder)

From the File menu, click on Open project, locate the.dllfile, and load into NUnit.

The following screen loads all test methods.

Runs Perfectly

Tests Fail

To save the output in an XML file

Writing in the output fileIn the GUI mode, the user must specify that he/she wants to save the output. No xml output file is automatically created on the users behalf.But in Console mode, a XML file is created even if not specified by the user.

Console modeThe command to execute the exe in console mode is nunit-console.exe [filename] [option]

Example: nunit-console.exe classlibrary1.dll -XML=ourfile.xml

The different options areNunit-console [inputfiles][options]Options

/Fixture=STR Fixture to test/config=STR project configuration to load/XML=STR Name of XML output file/transform=STR name of transform file/xmlConsole display XML to the console/output=STR File to receive test output (short :/out=STR) /err=STR File to receive test error output/labels Label each test in stdout/include = STR list of categories to include/exclude = STR list of categories to exclude/noshadow disable shadow option/thread runs thread on a separate thread/wait wait for input before closing console window /nologo Do not display the logo/help Display help (short format: /?)

Runs Perfectly

Test Fails

Output fileAs mentioned earlier, in console mode the xml file is automatically created as testresult.xml in the nunit\bin folder.The user can change the name of the output file by saying -XML = newfilename.xml as shown in the previous slide.

Now lets Examine the Output file (test passed)

Test Failed

Failure message(1 message)

Test Failure(2 tests)

Some of the frequently used Assert methods are:Method DescriptionAssert.AreEqual Verifies the two objects are equal.Ex. Assert.AreEqual(expected, actual)Assert.AreEqual(expected, actual, "The expected and actual are not equal.") Assert.AreNotEqual Verifies that two objects are not equal.Ex.Assert.AreNotEqual(expected, actual) Assert.AreNotEqual(expected, actual, "The expected and actual are equal.")

Some of the frequently used Assert methods are:Assert.IsNull Verifies the passed object is null.Ex.Assert.IsNull(actual) Assert.IsNull(actual, "The actual is not null.") Assert.IsNotNull Verifies the passed object is not null.Ex.Assert.IsNotNull(actual) Assert.IsNotNull(actual, "The actual is null.")

Some of the frequently used Assert methods are:Assert.IsEmpty Verifies the passed string is empty.Ex.Assert.IsEmpty(actual) Assert.IsEmpty(actual, "The passed string is not empty.")Assert.IsTrue Verifies the passed condition is true or not.Ex.Assert.IsTrue(actual) Assert.IsTrue(actual, "The passed condition is not true.")

Some of the frequently used Assert methods are:Assert.IsFalse Verifies the passed condition is false or not. Ex.Assert.IsFalse(actual) Assert.IsFalse(actual, "The passed string is not false.") Assert.IsInstanceOf Verifies the passed object is of the particular type.Ex.Assert.IsInstanceOf(typeof(Employee), actual) Assert.IsInstanceOf(typeof(Employee), actual, "The object is of not type Employee.")

NUNIT

Thank you

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