Java™ Application Development on Linux - Dator

13.5 Writing Test Cases303It prints a period for each test that it runs. (Yes, there are 119 periodsthere. Go ahead; count them if you must.) The command-line version is usefulfor incorporating JUnit tests into shell scripts (e.g., for testing nightly builds,e-mailing the results) and is used by ant when it invokes JUnit.13.5WRITING TEST CASESWriting a test case for your own Java code consists, at its simplest, of writing anew class for each class that you want to test. But this class that you create isbuilt in a special way so that the test harness of JUnit can execute it. That is,the test case class that you create should meet certain naming conventions, sothat the JUnit test runners can find what they need in order to run your tests.More specifically, your test cases will extend the JUnit class TestCase.Now, TestCase is an abstract class, meaning there are parts that you have tofill in (i.e., methods that you must write) to make it a working class. Moreover,TestCase implements (in the Java sense of the word) the Test interface. Canyou begin to see how the TestCase class is a framework? It defines the roughoutline of how the test cases will look so that a common test runner can runany test case, no matter who wrote it.Let’s look at a simple example, to see what such a test case looks like.Example 13.2 shows one for testing our Account class.Example 13.2 Simple test casepackage net.multitool.core;import java.util.*;import net.multitool.util.*;import junit.framework.*;// needed by our class// needed by our class// needed by JUnit/*** for JUnit testing of Account.java*/public classAccountTestextends TestCase{// our test instrumentation:Account base;