To begin, download the following to your local machine:
C:\> javac -classpath .:junit.jar BinaryTreeTest.javaIf the test suite compiled correctly, you should now have three .class files: BinaryTree.class, BinaryTree$Node.class, and BinaryTreeTest.class. Now start the JUnit GUI with
C:\> java -cp .:junit.jar junit.swingui.TestRunnerClick the button labeled "..." to select the BinaryTreeTest class, then click "Ok". To run the test suite, click "Run". Make sure that the "Reload classes every run" option is selected so that JUnit will pick up new versions of the test suite as you make changes and recompile.
There is a bug in BinaryTree.java. Add new unit tests to BinaryTreeTest.java until you find it. Visit the Getting Started page to learn more about JUnit.