JUnit HowTo (by Yonggang Lu, edited by Clinton Jeffery)

1. Before using Junit

First, add your working directory (with Java files to test) and /net/faculty/jeffery/junit4.4/junit.jar to your CLASSPATH in your .cshrc, .bashrc, or .profile (or Control Panel) for example:

 in junit 3.8.1, useful on current UI CS lab machines...
setenv CLASSPATH .:/net/faculty/jeffery/junit-3.8.1.jar
or
export CLASSPATH=.:/net/faculty/jeffery/junit-3.8.1.jar

 in junit 4.4, useful on a newer java version on a local machine... 
setenv CLASSPATH .:/net/faculty/jeffery/junit4.4/junit.jar
or
export CLASSPATH=.:/net/faculty/jeffery/junit4.4/junit.jar

Of course, you might substitute your correct pathname for the /net/faculty/jeffery/... part.

Read the documentation of Junit at:
- http://junit.sourceforge.net/doc/testinfected/testing.htm
- http://junit.sourceforge.net/doc/cookbook/cookbook.htm

2. There are two ways to test a class file:

(1). Use the same class file but inherit the TestCase class.

First, make the following changes to your class file:

Add a line at the beginning of the file:

import junit.framework.*;

Change the class declaration to:

public class yourclass extends TestCase {
...
}

Then, write test methods. Those methods should have names starting with "test". The assertTrue() and assertEquals() are to be used in those methods.

For example:

	public void testAdd() {
		double result= fValue1 + fValue2;
		assertTrue(result == 6);
	}
	public void testEquals() {
		assertEquals(12, 12);
		assertEquals(12L, 12L);
		assertEquals(new Long(12), new Long(12));
		assertEquals("Size", 12, 13);
		assertEquals("Capacity", 12.0, 11.99, 0.0);
	}

Then add a suite method if you want to use suite:

public static Test suite() {
   return new TestSuite(SimpleTest.class);
}

Finally, add the following line to main() method:

junit.textui.TestRunner.run(suite());  #if you use suite

or,

junit.textui.TestRunner.run(.class); # if you don't use suite

which can run the Junit in the text mode if you excute the class with java.

(2). Use a different class file to test existing class files.

This is very similar with (1) except that you write a different class file for testing purposes.

This has a big advantage: you don't need to make any changes to the existing class files, so they aren't cluttered up by testing code. In your new test file, the following is still necessary:

import junit.framework.*;
public class yourclass_tester extends TestCase {
...
}

In the new class, you need to create the variables and instances of the classes you want to test, and then write the test methods (the names must start with "test"; JUnit automatically calls those methods), also create suite method if needed. Then add a main method:

	public static void main(String args[]) {
		junit.textui.TestRunner.run(yourclass_tester.class);
	}

or,

	public static void main(String args[]) {
		junit.textui.TestRunner.run(suite());
	}

if you use suite.

You may refer to the /net/faculty/jeffery/junit4.4/junit/samples/money/MoneyTest.java file for more details.

3. The test suites can be run together in one file:

The following example is from: .../junit4.4/junit/samples/AllTests.java

import junit.framework.*;

/**
 * TestSuite that runs all the sample tests
 *
 */
public class AllTests {

	public static void main (String[] args) {
		junit.textui.TestRunner.run (suite());
	}
	public static Test suite ( ) {
	    TestSuite suite= new TestSuite("All JUnit Tests");

	    suite.addTest(VectorTest.suite());
	    suite.addTest(SimpleTest.suite());
	    suite.addTest(new TestSuite(junit.samples.money.MoneyTest.class));
	    suite.addTest(junit.tests.AllTests.suite());
	    return suite;
	}
	}

4. Use the graphical interface:

This can be done by typing "java junit.awtui.TestRunner" or "junit.swingui.TestRunner" on the command line. After a window appears, you can input a test class name to run the test.