Test Driven Development and NUnit Testing -Adam Main

What is Test Driven Development? b 2 Rules Write new code only when a test failsWrite new code only when a test fails Eliminate duplicationEliminate duplication b Failing to compile is failing a test

Basic Process 1. Write a test that fails 2. Write code to pass the test 3. Refactor the code 4. If the program isn’t finished, goto 1

Advantages b Concise and simple b Less manual testing b Know specs and requirements b Higher percent code coverage b Highly testable code b Coupling and cohesion

Disadvantages b High number of compiles Wastes timeWastes time Less thoughtLess thought b Very little design minutes15-20 minutes LanguageLanguage HardwareHardware

What is NUnit? b Based off of xUnit JUnit -JavaJUnit -Java b Basic testing framework b.NET environment b Uses metadata b Console and GUI testing apps

Why NUnit? b Simple Interface b Constant Feedback b XML results b Configurable SubsetsSubsets PackagesPackages SolutionsSolutions

How do you use NUnit? b Metadata attribute tags b Assert library calls b GUI or console application

What are Attribute tags? b.NET b [Attribute] b Metadata b “Compilable comments”

Attribute Tags b [TestFixture] b [Test] b [TestFixtureSetUp] b [TestFixtureTearDown]

More Attribute Tags b [ExpectedException(typeof(ExceptionType))] b [Category("Category Name")] b [Explicit] b [Ignore(“reason”)]

What is the Assert Library b Created by NUnit team b Static functions b Assert class

Assert Functions b 3 Basic Overloads -Assert.IsFalse( bool condition); -Assert.IsFalse( bool condition, string message ); -Assert.IsFalse( bool condition, string message, object[] parms ); b One Assert per test Short circuitShort circuit Simple and concise testsSimple and concise tests

Assert Functions  AreEqual(int actual, int expected)  AreEqual(double actual, double expected)  AreEqual(float actual, float expected)  AreEqual(decimal actual, decimal expected)  AreEqual(object actual, object expected)  AreSame (object actual, object expected)

Assert Functions  IsTrue( bool condition)  IsFalse( bool condition)  IsNull( object obj)  IsNotNull( object obj)  Fail()  Ignore()

Projects b Load VS projects/solutions b Save selected tests b.nunit

Demo b Create a simple b Use TDD b Use NUnit

Sources b [1] NUnit - Documentation. Retrieved March 28, 2005, from b [2] George, Boby and Laurie Williams. An Initial Investigation of Test Driven Development in Industry. Retrieved March 30, 2005, from b [3] Ganssle, Jack. XP Deconstructed. Dec 10, b [4] Provost, Peter. Test Driven Development in.NET. b [5] Introduction to Test Drive Development (TDD). Retreived April 1, 2005, from b [6] Mugridge, Rick. Test Driven Development and the Scientific Method.