Testing with mock objects - JUnit in Action - page 117

The next section demonstrates the use of some of the most popular open source
mocking frameworks—they're powerful enough for our needs, and we don't need to
implement our mocks from the beginning.

7.6 Introducing mock frameworks

So far we've been implementing the mock objects we need from scratch. As you can
see, it's not a tedious task but rather a recurring one. You might guess that we don't
need to reinvent the wheel every time we need a mock. And you're right—there are
many good projects already written that can help us facilitate the usage of mocks in
our projects. In this section we take a closer look at two of the most widely used mock
frameworks: the EasyMock and the JM ock. We try to rework the example HTTP con-
nection application so that we can demonstrate how to use the two frameworks.

7.6.1 Using EasyMock

EasyMock ( http://easymock.org/ ) is an open source framework that provides useful
classes for mocking objects. To use the framework you need to download the zip
archive from the website of the project, unpack it somewhere, and include the con-
tained easymock.jar in your classpath.
To show you how easy it is to construct mock objects in your test cases using Easy-
Mock, we revise some of the mocks we constructed in the previous sections. We start
with a simple one: reworking the AccountService test from listing 7.2. See listing 7.15.

Listing 7.15 Reworking the TestAccountService test using EasyMock

[...]
import static org.easymock.EasyMock.createMock;
import static org.easymock.EasyMock.replay;
import static org.easymock.EasyMock.expect;
import static org.easymock.EasyMock.verify;

B

public class TestAccountServiceEasyMock
{
private AccountManager mockAccountManager;

C

@Before
public void setUp()
{
mockAccountManager = createMock( "mockAccountManager",
AccountManager.class );
}

D

@Test
public void testTransferOk()
{
Account senderAccount = new Account( "1", 200 );
Account beneficiaryAccount = new Account( "2", 100 );

E

// Start defining the expectations
mockAccountManager.updateAccount( senderAccount );
mockAccountManager.updateAccount( beneficiaryAccount );

F