Obtaining JUnit

Alternatively, you can download it from www.junit.org. Just be sure you download version 3.8.1, because that is the version this document is based on. Major changes were made starting with version 4.0

Configuring jGRASP to work with JUnit

1. From the Settings menu, select PATH/CLASSPATH, then Workspace.
   
2. Select the CLASSPATHS tab from the resulting dialog box, it not already selected. It should look like this:
   
   
   
   
3. Click New and browse to the junit.jar you previously copied to your csc205 folder. Ignore the Documentation Path field. It will look something like this:
   
   
   
4. Click OK, to get back to the original dialog box. The file path you just entered will be listed and the dialog box will look like this:
   
   
   
5. Click Apply then OK.
   
6. The dialog boxes are gone. From the Settings menu, select Compiler Settings, then Workspace.
   
7. Select the Compiler tab from the resulting dialog box, if not already selected, then the Flags/Args/Main subtab. It should look like this:
   
   
   
8. Click the black square in row Run and column Flags2, then enter junit.swingui.TestRunner into the text field. The result should look like this:
   
   
   
9. Click Apply then OK.
   
10. IMPORTANT! With this setting, the JUnit tester will run every time you you want to run a program, even if you are no longer using JUnit! To "suspend" the setting, follow steps 6-9 again. This time, when you click the box, the word junit.swingui.TestRunner disappears. It will be recovered the next time you click the box; it is only in suspension.

Writing the Test Driver using JUnit

The purpose of unit testing is to test the various methods of a class under development. Your test driver must be a separate public Java class that looks something like this. The bolded text will change for your specific class but the rest is standard.

import junit.framework.*;
   
public class MyTestDriver extends TestCase {
   ///////////////////////////////////////////////
   //  Define any instance variables, constructors
   //  or helper methods needed by the driver here.
   
   public MyTestDriver() {
   }
   
   ///////////////////////////////////////////////
   //  Place your test methods here.  A test method 
   //  must meet these requirements:
   //    1. public void
   //    2. no parameters
   //    3. name starts with "test"
   //    4. calls the method(s) being tested
   //    5. contains a pass/fail test, usually in form of an assertion
   
   public void testFirstMethod() {
   }
   
   public void testSecondMethod() {
   }
   
   // Define additional tests as needed...
   
   /////////////////////////////////////////////////
   // These are standard, except the test class name
   // has to go into the TestSuite constructor call.
	
   public static junit.framework.Test suite() { 
      return new TestSuite(MyTestDriver.class); 
   }
   
   public static void main(String args[]) { 
      junit.textui.TestRunner.run(suite());
   }
}

   public void testEmptyArrayList() {
      ArrayList a = new ArrayList();
      assertEquals("Size of empty list is not 0", 0, a.size() );
   }

   public void testForException() {
         ArrayList a = new ArrayList();
      try { 
         Object obj = a.get(0); 
         fail("expected IndexOutOfBoundsException");
      } 
         catch (IndexOutOfBoundsException success) {} 
   }

Running the Test

Here's an example of a successful test:

If you get a RED bar, check to see which test(s) failed. Then the debugging starts!

If the test results show up in the JGRASP text output window instead, this just means that the compile flags configuration (steps 6-9 under Configuring jGRASP) did not work. Here's the same example with text output: