Tutorial

1.                  Introduction

dotunit is a port of JUnit (www.junit.org) to the Microsoft .net platform. It provides a testing framework to support automated testing of applications, particularly to facilitate unit, function and regression testing.

2.                  Automated Testing

Testing is tedious and time consuming. As a result, it is not a popular chore among developers and few do it thoroughly, if at all. However, software must be tested to maintain quality and stability.

More often than not, a developer’s code does not work the first time (or the second, third…). The debugging process is often interactive and iterative. This requires the repeated testing of the same code.

The cost of testing does not stop with initial debugging unfortunately. As the system develops and is revised, regression testing is necessary to ensure previous sections still function properly as new ones are added.

Automated testing frameworks provide the developer with a method of capturing test cases and automate their execution, validation and the collection of results. The cost of testing goes down considerably and the developer can grow in confidence that the quality and stability of his code is high, without the excessive cost of traditional testing.

(For more on the value of automated testing, please see http://junit.sourceforge.net/doc/testinfected/testing.htm )

3.                  Getting Started

·         After installing dotunit, open the project you wish to test in the Visual Studio.net IDE.

·         Add a reference to dotunit.framework.dll (You may need to browse to locate the dll)

In general, tests are methods in a class that descends from dotUnit.Framework.TestCase. Each method that begins with the word Test (case matters) is a test case. Such functions take no arguments and should not return anything.

Each value that should be tested is done with either:

void AssertTrue(bool expression)

void AssertEquals(…)

(AssertEquals is overloaded for each simple data type (bool, string, int, double, etc.) The general format is

(optional string message, expected value, actual value)

4.                  Simple Tests

The following is a simple test case.

public class SimpleTest : dotUnit.Framework.TestCase

{

      public void TestSimpleCase()

{    

      AssertEquals(5, 2+3);

}

}

5.                  Fixtures

Fixtures are contexts for a series of tests. Many tests will use a common set of objects/state for testing. A fixture provides this common context. In order to establish a fixture, override the SetUp and TearDown (optional) methods.   SetUp will be called before any tests are run and TearDown will be called after the tests are run.

public class SimpleFixture: dotUnit.Framework.TestCase

{

      private m_nTestValue;

      protected override void SetUp()

{

      m_nTestValue = 5;

}

public void TestSimpleCase()

{    

      AssertEquals(m_nTestValue, 2+3);

}

}

6.                  Suites

Test Suites are collections of tests. You can arrange a hierarchy of test cases, as suites can contain other suites or test cases. Suites organize your tests.

In order to define a suite, create a class that implements a Suite property (return a TestSuite).

public class MySuite:

{

      public dotUnit.Framework.TestSuite Suite

{    

      get {

dotUnit.Framework.TestSuite suite = new

dotUnit.Framework.TestSuite(“My Tests”);

                  suite.AddTestSuite(typeof(SimpleTest));

                  suite.AddTestSuite(typeof(SimpleFixture));

      }

}

}

7.                  Running Tests

The dotunit GUI can be used to run your tests.

Simply browse to you compiled test cases (dll), select the class to test and click Go. You will see the results in the Errors window. You can browse the test hierarchy as well.

9.                  Testing Internal / Private Classes and Methods

Quite often, it is useful to unit test internal and private methods, that support the implementation of larger functionality. It is time consuming and error-prone to toggle access modifiers between “public” and “private”.

dotunit provides several utility functions to allow for the testing of non-public methods and classes. The following code snippet highlights the functions. (Please see the documentation for dotUnit.Utility.NonPublicType and the dotUnit.Tests.NonPublicTypeTest for more information.)  

public void TestMethods()

{

Type[] a = {typeof(int)};

object[] aValues={TEST_VALUE};

AssertEquals(TEST_VALUE+TEST_VALUE,

(int)NonPublicType.InvokeFunction(m_target,

"ProtectedAdd", a, aValues));

}

(In the above example, m_target is a reference to an object that has non-public methods.)    

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