Java Extreme Programming Cookbook

Getting Started

Problem

You want to write unit tests with JUnit.

Solution

Create a subclass of junit.framework.TestCase. Each unit test is represented by a testXXX( ) method within the TestCase subclass.

Discussion

Example 4-1 shows an extremely simple test case. A test case is a subclass of TestCase and contains a collection of unit tests. Instances of TestCase are sometimes referred to as test fixtures, although we prefer to say “test case” since that matches the class name. Each unit test is a public, no-argument method beginning with “test”. If you do not follow this naming convention, JUnit will not be able to locate your test methods automatically. Instead, you would have to write a suite( ) method and construct instances of your test case, passing the test method name to the constructor.

Example 4-1. Simple test case

package com.oreilly.javaxp.common;

import junit.framework.TestCase;

/**
 * Sample unit tests for the {@link Person} class.
 */
public class TestPerson extends TestCase {

    /**
     * This constructor is only required in JUnit 3.7 and earlier.
     * @param testMethodName the name of the test method to execute.
     */
    public TestPerson(String testMethodName) {
        super(testMethodName);
    }

    /**
     * A unit test to verify the name is formatted correctly.
     */
    public void testGetFullName(  ) {
        Person p = new Person("Aidan", "Burke");
        assertEquals("Aidan Burke", p.getFullName(  )); } /** * A unit test to verify that nulls are handled properly. */ public void testNullsInName( ) { Person p = new Person(null, ...