l08 unit testing

L08  Unit  Testing

Reading

▪ Optional  – http://www.junit.org  – JUnit  Test  Infected:  Programmers  Love  Writing  Tests

▪ Extreame  Programming  Philosophy:  – “Build  a  little,  test  a  little”  

▪ All  classes  have  unit  testing  classes  – Run  on  regular  basis  

▪ Unit  test  – A  structured  set  of  tests  that  exercises  the  methods  of  a  class  

▪ Test  Driven  Development  –  TDD  

Background

▪ Is  this  your  code?  Big  ball  of  MudBackground

▪ Why  is  unit  testing  a  good  idea?  ▪ Reasons:  – Gives  the  developer  confidence  that  the  class  is  working  properly  

– Quickly  finds  the  source  of  bugs  – Focuses  the  developer  on  the  design  of  a  class  – Helps  define  the  requirements  of  the  individual  classes

Why Unit Testing

▪ Why  is  unit  testing  a  good  idea?  ▪ And  the  really  good  reason:  

– In  large  application,  changes  and  re-­‐factoring  are  possible

Why Unit Testing

1. Build  a  unit  test  to  test  a  class  during  design  This  will  test  the  design  Focuses  the  developer  on  the  design  of  a  class  

2. Stub  out  the  class  All  tests  will  fail  since  there  is  no  code!  

3. Write  the  functionality  in  the  class  Until  the  test  will  pass

Building the Tests

▪ An  open  source  Java  unit  testing  tool  – Developed  by  Erich  Gamma  and  Kent  Beck  

▪ Location:    – www.junit.org    

▪ JUnit  tests  does  not:  – Take  the  place  of  functional  testing  – Separate  data  from  test  code  (look  at  JUnit++)  – Can’t  unit  test  Swing  GUIs,  JSPs    or  HTML  (look  at  JUnit  extensions)

JUnit

▪ Java  based  testing  framework  to  make  writing  and  maintaining  unit  tests  easier  

▪ Uses  testcases  and  testsuits  to  build  a    hierarchy  of  tests  which  can  be  run  to  test  the  whole  system  or  individual  modules/classes  

▪ The  developer  creates  the  unit  tests  using  JUnit  utilities,  extends  JUnit  test  classes  and  uses  a  test  runner  to  run  them

What is JUnit?

package test;

import junit.framework.TestCase; import junit.framework.Assert; import domain.Money;

public class MoneyTestCase extends TestCase { private Money f12CHF; private Money f14CHF;

protected void setUp () { f12CHF = new Money(12, "CHF"); f14CHF = new Money(14, "CHF"); } public void testSimpleAdd() { Money expected = new Money(26,"CHF"); Money results = f12CHF.add(f14CHF); Assert.assertTrue(expected.equals(results)); }

Test Case

public void testEquals () { Assert.assertTrue(!f12CHF.equals(null)); Assert.assertEquals(f12CHF, f12CHF); Assert.assertEquals(f12CHF, new Money (12, "CHF")); Assert.assertTrue(!f12CHF.equals(f14CHF)); } }

Test Case

@Test public void multiplicationOfZeroIntegersShouldReturnZero() {

// MyClass is tested MyClass tester = new MyClass();

// Tests assertEquals("10 x 0 must be 0", 0, tester.multiply(10, 0)); assertEquals("0 x 10 must be 0", 0, tester.multiply(0, 10)); assertEquals("0 x 0 must be 0", 0, tester.multiply(0, 0)); }

Annotations

package test; import junit.framework.TestSuite; public class TestRunner { public static void main(String[] args) { // the testcase String[] testCaseName = { MoneyTestCase.class.getName()}; // testrunner junit.swingui.TestRunner.main(testCaseName); //junit.textui.TestRunner.main(testCaseName); } }

Test Case Runner

junit.textui.TestRunner.main(testCaseName);

junit.swingui.TestRunner.main(testCaseName);

Running the Tests

public class TestContent extends TestCase { ContentServicecontentService; protected void setUp() throws Exception { contentService = new ContentService(); contentService.setMailGateway(new MailServerStub()); contentService.setContentDataGateway(new ContentDataGatewayStub()); } public void testService() throws ServiceException { contentService.addContent(new Content(1, "Video 1", "http", "", new Date(), "")); List<Content> list = contentService.getContents(); assertEquals(list.size(), 1); }

Example

Player Example▪ Spring  Test  Framework  ▪ JUnit  

▪ PlayerService

<dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency>

<dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>4.2.1.RELEASE</version> </dependency>

Player Examplepom.xml

package is.ru.honn.rufan.domain; public class Player { protected int playerId; protected String username; protected String name; public Player() { } public Player(int playerId, String username, String name) { this.playerId = playerId; this.username = username; this.name = name; }...

Player Example

package is.ru.honn.rufan.service; import is.ru.honn.rufan.domain.Player; public interface PlayerService { public int addPlayer(Player player) throws ServiceException; public Player getPlayer(int playerId); }

Player Example

package is.ru.honn.rufan.service; import is.ru.honn.rufan.domain.Player; import java.util.ArrayList; import java.util.List; import java.util.logging.Logger; public class PlayerServiceStub implements PlayerService { Logger log = Logger.getLogger(PlayerServiceStub.class.getName()); private List<Player> players = new ArrayList<Player>();

Player Example

public int addPlayer(Player player) throws ServiceException { for(Player p: players) { if (p.getUsername() == player.getUsername()) { String msg = "Username: '" + player.getUsername() + "' already exists."; log.info(msg); throw new ServiceException(msg); } } players.add(player); return players.size()-1; }

Player Example

public Player getPlayer(int playerId) { for(Player p: players) { if (p.getPlayerId() == playerId) return p; } return null; }}

Player Example

Demo

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

<bean id="service" class="is.ru.honn.rufan.service.PlayerServiceStub" />

</beans>

Player Example

@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration("classpath:app-test-stub.xml")

public class testPlayerService extends TestCase { Logger log = Logger.getLogger(testPlayerService.class.getName());

@Autowired private PlayerService service;

@Before public void setUp() { }

Player Example

@Test public void testUser() { Player player0 = new Player(0, "messi", "Messi"); Player player1 = new Player(1, "ronaldo", "Ronaldo");

service.addPlayer(player0); service.addPlayer(player1);

// Test if add works Player playerNew = service.getPlayer(1); assertSame(playerNew, player1);

Player Example

// Test if same username fails try { service.addPlayer(player1); } catch (ServiceException s) { assertSame(ServiceException.class, s.getClass()); }

}

}

Player Example