- Test Driven Development (TDD) uses JUnit to write test cases before writing code to remove fear factors and clearly depict what the code is doing. - The three steps of TDD are Red (a failed test case), Green (the test passes), and Refactor (change code to meet design principles). - An example walks through writing tests for a Book class, making the tests fail, making them pass, and refactoring the code using TDD principles.

1. Test Driven Development vis-à-vis JUnit by Somenath Mukhopadhyay [email_address] Somenath Mukhopadhyay

22. The JUnit Code import junit.framework.Test; import junit.framework.TestCase; import junit.framework.TestSuite; public class BookTest extends TestCase { private Book book1; public BookTest(String name) { super(name); } protected void setUp() throws Exception { super.setUp(); book1 = new Book("Som", 10.11); book2 = new Book("Reema", 12.33); book3 = new Book("Som", 10.11); } Contd..... Somenath Mukhopadhyay

23. The JUnit Code protected void tearDown() throws Exception { super.tearDown(); book1 = null; book2 = null; book3 = null; } public void testEquals() { assertFalse(book2.equalsBook(book1)); assertTrue(book1.equalsBook(book1)); assertTrue(book1.equalsBook(book3)); } public void testGetPrice() { double price = book1.getPrice(); assertTrue(price == 10.11); } Contd... Somenath Mukhopadhyay

24. The JUnit Code public void testSetPrice() { book1.setPrice(15.15); double price = book1.getPrice(); assertTrue(price == 15.15); } public void testGetTitle() { String title = book2.getTitle(); boolean result = title.equals("Reema"); assertTrue(result == true); } public static Test suite(){ TestSuite suite = new TestSuite(); suite.addTest(new BookTest("testEquals")); suite.addTest(new BookTest("testGetTitle")); suite.addTest(new BookTest("testSetPrice")); return suite; } Somenath Mukhopadhyay

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