Using Mock Obects in Spring Integration Tests

Delegate.java

package com.jayway.example;

public interface Delegate {

    String doSomething();

    String doSomethingElse();
}

easymock-test-config.xml

<beans...>
    <context:component-scan base-package="com.jayway.example"/>

    <bean id="delegateMock" class="com.jayway.springmock.EasyMockFactoryBean">
        <constructor-arg name="classToBeMocked" value="com.jayway.example.Delegate" />
    </bean>
</beans>

EasyMockFacadeTest.java

package com.jayway.example;

import org.junit.After;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import static org.easymock.EasyMock.expect;
import static org.easymock.EasyMock.replay;
import static org.easymock.EasyMock.reset;
import static org.easymock.EasyMock.verify;
import static org.hamcrest.core.Is.is;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertThat;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("easymock-test-config.xml")
public class EasyMockFacadeTest {

    @Autowired
    Facade facade;

    @Autowired
    Delegate delegateMock;

    @Before
    public void setUp() {
        reset(delegateMock);
    }

    @Test
    public void shouldAutowireDependencies() {
        assertNotNull(facade);
        assertNotNull(delegateMock);
    }

    @Test
    public void shouldDelegateToDoSomething() {
        String expected = "hello";

        expect(delegateMock.doSomething()).andReturn(expected);

        replay(delegateMock);

        String actual = facade.firstMethod();
        assertThat(actual, is(expected));

        verify(delegateMock);
    }

    @Test
    public void shouldDelegateToDoSomethingElse() {
        String expected = "goodbye";
        
        expect(delegateMock.doSomethingElse()).andReturn(expected);

        replay(delegateMock);

        String actual = facade.secondMethod();
        assertThat(actual, is(expected));

        verify(delegateMock);
    }
}

Facade.java

package com.jayway.example;

@Component
public class Facade {

    @Autowired
    private Delegate delegate;

    public String firstMethod() {
        return delegate.doSomething();
    }

    public String secondMethod() {
        return delegate.doSomethingElse();
    }
}

InitialTest.java

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("test-config.xml")
public class FacadeTest {

    @Autowired
    Facade facade;

    @Autowired
    Delegate delegateMock;

    @Test
    public void shouldAutowireDependencies() {
        assertNotNull(facade);
        assertNotNull(delegateMock);
    }
}

MockitoFacadeTest.java

package com.jayway.example;

import org.junit.After;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import static org.hamcrest.core.Is.is;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertThat;
import static org.mockito.Mockito.reset;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("mockito-test-config.xml")
public class MockitoFacadeTest {

    @Autowired
    Facade facade;

    @Autowired
    Delegate delegateMock;

    @Before
    public void setUp() {
        reset(delegateMock);
    }

    @Test
    public void shouldWireDependencies() {
        assertNotNull(facade);
        assertNotNull(delegateMock);
    }
    
    @Test
    public void shouldDelegateToDoSomething() {
        String expected = "hello";

        when(delegateMock.doSomething()).thenReturn(expected);

        String actual = facade.firstMethod();
        assertThat(actual, is(expected));

        verify(delegateMock).doSomething();
    }

    @Test
    public void shouldDelegateToDoSomethingElse() {
        String expected = "goodbye";

        when(delegateMock.doSomethingElse()).thenReturn(expected);

        String actual = facade.secondMethod();
        assertThat(actual, is(expected));

        verify(delegateMock).doSomethingElse();
    }
}

movkito-test-config.xml

<beans...>
    <context:component-scan base-package="com.jayway.example"/>

    <bean id="delegateMock" class="com.jayway.springmock.MockitoFactoryBean">
        <constructor-arg name="classToBeMocked" value="com.jayway.example.Delegate" />
    </bean>
</beans>

SecondTest.java

@Test
public void shouldDelegateToDoSomething() {
    String expected = "hello";

    when(delegateMock.doSomething()).thenReturn(expected);

    String actual = facade.firstMethod();
    assertThat(actual, is(expected));

    verify(delegateMock).doSomething();
}

SetUp.java

@Before
public void setUp() {
    reset(delegateMock);
}

ThirdTest.java

 @Test
 public void shouldDelegateToDoSomethingElse() {
    String expected = "goodbye";
        
    expect(delegateMock.doSomethingElse()).andReturn(expected);

    replay(delegateMock);

    String actual = facade.secondMethod();
    assertThat(actual, is(expected));

    verify(delegateMock);
}

The code in this gist is used to demonstrate how mock objects can be used when developing Spring integration tests. For details, read the blog post at http://blog.jayway.com/2011/12/12/spring-integration-tests-part-ii-using-mock-objects/ .