The document discusses unit testing and provides examples of unit tests for different types of code including: - A simple unit test for a "User" class that tests getter and setter methods. - A more complex unit test for a "UserManager" class that tests for exceptions when saving duplicate users. - A database unit test using the DBUnit framework to test saving a user object to the database and validating the expected data.

1. Unit Testing The primary goal of unit testing is to take the smallest piece of testable software, isolate it from the remainder of the code, and determine whether it behaves exactly as you expect . by Bárbara Cabral Sofshore Software Engineering

2. Unit Testing What's important to know? The architecture of the system How to work with testing frameworks How to write good test-cases What is Good Unit Test? The test shall have a purpose to exist The test shall prioritize only the main problems, it means, the tester shall think about the better way to test the code.

3. TestNG TestNG is a testing framework inspired from JUnit and NUnit but introducing some new functionalities Writing a test is typically a three-step process: Write the business logic of your test and insert TestNG annotations in your code. Add the information about your test (e.g. the class name, the groups you wish to run, etc...) in a testng.xml file or in build.xml. Run TestNG.

4. TestNG package example1; import org.testng.annotations.*; public class SimpleTest { @BeforeClass public void setUp() { // code that will be invoked when this test is instantiated } @Test(groups = { "fast" }) public void aFastTest() { System.out.println("Fast test"); } @Test(groups = { "slow" }) public void aSlowTest() { System.out.println("Slow test"); } }

5. testng.xml <project default=&quot;test&quot;> <taskdef name=&quot; testng &quot; classpathref=&quot;cp&quot; classname=&quot; org.testng.TestNGAntTask &quot; /> <target name=&quot;test&quot;> <testng classpathref=&quot;cp&quot; groups=&quot; fast &quot;> <classfileset dir=&quot;build&quot; includes=&quot;example1/*.class&quot;/> </testng> </target> </project> <!DOCTYPE suite SYSTEM &quot;http://testng.org/testng-1.0.dtd&quot; > <suite name=&quot;Suite1&quot; verbose=&quot;1&quot; > <test name=&quot;Regression1&quot; > <packages> <package name=&quot;test.sample&quot; /> </packages> </test> </suite>

6. DBUnit DbUnit is a JUnit extension (also usable with Ant) targeted at database-driven projects that, among other things, puts your database into a known state between test runs. Best Pratices Use one database instance per developer Good setup don't need cleanup! Use multiple small datasets Connection management strategies

7. DBUnit Static data Testing can be simplified if you can get your database in a known state before a test is run. For this, we have the sql files to build the database: tables, columns and static data (ex: Cities of the Belgium). This kind of data rarely change! Dinamic data Most of your tests do not require the entire database to be re-initialized. So, instead of putting your entire database data in one large dataset, try to break it into many smaller chunks . This reduces the overhead caused by initializing your database for each test. This also facilitates team development since many developers working on different components can modify datasets independently. We can be have one dataSet to each class or to each test or to each group of tests. This kind of data is not commited in the database!

8. Strategy Run TestNG To create the static data To read the testng.xml file(s)

9. A very simple Unit Test class User { private String name; public String getName() { return name; } public void setName(String newName) { name = newName; } } class User Test extends TestSuite { public void testNameProperty() { User user = new User(); assertNull(user.getName()); String testName = &quot;test&quot;; user.setName(testName); assertEquals(testName, user.getName()); } }

10. A very simple Good Unit Test public class TestUser { Role userRole ; Role developerRole ; @BeforeClass public void beforeClass() throws Exception { userRole = UtilTestUser. getRole (RoleType. USER ); developerRole = UtilTestUser. getRole (RoleType. DEVELOPER ); } /** * 1. To create an user object * 2. Add the role(enum) to the role list of the user object * 3. Check if the role really was added * @throws InvalidNameException */ @Test (groups = { &quot;API&quot; }) public void testAddRole() throws InvalidNameException { User user = UserFactory. createUser ( &quot;asen&quot; , &quot;as12$as&quot; , &quot;Airton Senna&quot; ); user.addRole( userRole ); Assert. assertNotNull (user.getRoles()); Assert. assertEquals (user.getRoles().size(), 1); Assert. assertEquals (user.getRoles().iterator().next(), userRole ); } Test Script

11. Example: The Architecture of the User Management User <Interface> The contract to manipulate the object User We need generate a TestUser UserDAO <Interface> The contract to manipulate the object UserHibernateDAO The object UserHibernateDAO is responsible to provide a persistence layer to connect the object with the database UserManager <Interface> The contract to manipulate the object DefaultUserManager The object DefaultUserManager is responsible to provide some services as to load an user by its logon identifier and to save a new user or to save the object user updated.

12. TestUserManager public class TestUserManager extends DBUnitTestCase { UserManager userManager ; @BeforeClass public void beforeClass() throws Exception { userManager = UtilTestUser. getTestUserManager (); } /** * 1. A new user with an existent userId is created. * 2. The user is saved * 3. A UserIdExistsException is thrown */ @Test (groups = { &quot;API&quot; }, expectedExceptions = { UserAlreadyExistsException. class }) public void saveUserWithTheSameUserIdCausesException() throws InvalidNameException, UserAlreadyExistsException, DataAccessException, ServiceException { User user1 = UserFactory. createUser ( &quot;gkue&quot; , &quot;as12$as&quot; , &quot;Gustavo Kuerten&quot; ); userManager .saveUser(user1); User user2 = UserFactory. createUser ( &quot;gkue&quot; , &quot;as12$as&quot; , &quot;Gustavo Kuerten&quot; ); userManager .saveUser(user2); }

13. The database unit test public class TestUser DAO extends DBUnitTestCase { private static final String[] TABLES_CHECK_USER = { &quot;users&quot; , &quot;roles&quot; , &quot;user_roles&quot; }; //(...) --> a configuration code here /** * 1.The object user shall be created with all attributes and roles * 2.The object shall be saved in the database * 3.The dataSet expected shall be created to compare against the user object stored */ @Test (groups={ &quot;database&quot; }) public void testSaveUser() throws InvalidNameException, DatabaseUnitException, SQLException, IOException, UserAlreadyExistsException, DAOException, ServiceException { usesDataset( DATASET_BASE ); User user = UserFactory. createUser ( &quot;pcoe&quot; , &quot;pc910*pc&quot; , &quot;Paulo Coelho&quot; ); user.addRole( userRole ); user.addRole( adminRole ); userDao .saveUser(user); assertDataSet( &quot;saveUserExpected&quot; , TABLES_CHECK_USER ); }