Spring-Automocker

Compatible with Spring >= 4.3 (so spring-boot >= 1.4)

PoC of automatic IO mocking tool for Spring's JavaConfig.

Load your entire Production configuration into a JUnit test.

The purpose of this project is to test functionalities of applications on real code without heavy glue code.

Currently the project supports mocking of

• @PropertySource
• Spring-web example
• JDBC examples
• JMS example

Use SpringJUnit4ClassRunner in conjunction with @Automocker

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = MyApplication.class)
@Automocker
public class MyApplicationTest {

	@Autowired
	private MockMvc mockMvc;

	@Test
	public void user_creation_api() {
		mvc.perform(MockMvcRequestBuilders.get("/create_user?firstName=Alyson&lastName=Hannigan"))
			.andExpect(MockMvcResultMatchers.status().isOk());

		mvc.perform(MockMvcRequestBuilders.get("/list_users"))
			.andExpect(MockMvcResultMatchers.status().isOk())
			.andExpect(MockMvcResultMatchers.content().string("[\"Alyson Hannigan\"]"));
	}
}

Mocking strategies

Spring-web

There is nothing to mock here. However some things are nonetheless being taken care of

• If any bean annotated with spring-context @Controller is present, spring-test MockMvc is configured and added to the test context

JDBC

All beans implementing javax.sql.DataSource are replaced with distinct org.h2.jdbcx.JdbcDataSource. A DataSourceLocator bean is supplied to easily access multiple dataSources.

JMS

• All beans implementing javax.jms.ConnectionFactory are replaced by a mockrunner MockConnectionFactory. Each factory is built with its own DestinationManager
• If any bean implementing javax.jms.ConnectionFactory is present, a custom JmsMock is configured and added to the test context
• If any bean implementing spring-jms JmsListenerContainerFactory is present, a wrapper is set around its ErrorHandler and can be accessed through JmsMock
• A JmsMockLocator bean is supplied to easily access multiple JmsMock.

Extending Spring-Automocker

@AfterBeanRegistration extension

A test class meta-annotated with @AfterBeanRegistration will trigger specific behavior through the indicated AfterBeanRegistrationExecutable implementation. This annotation can only be used on an annotation as the AfterBeanRegistrationExecutable#execute will be supplied with the annotation annotated with AfterBeanRegistration. Doing so the developper can defined specific arguments in the annotation, such as @MockJdbc#url() and used them in the AfterBeanRegistrationExecutable implementation.

For example, replacing user-defined beans by Mockito mocks can be done like this:

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@AfterBeanRegistration(MockBeans.MockBeansExecutable.class)
public @interface MockBeans {

    Class<?>[] classes();

    class MockBeansExecutable implements AfterBeanRegistrationExecutable<MockBeans> {

        @Override
        public void execute(MockBeans annotation, ExtendedBeanDefinitionRegistry extendedBeanDefinitionRegistry) {
            String mockCreatorBeanName = extendedBeanDefinitionRegistry.registerBeanDefinition(MockCreator.class);
            Arrays.stream(annotation.classes())
                    .map(extendedBeanDefinitionRegistry::getBeanDefinitionsForClass)
                    .flatMap(Set::stream)
                    .forEach(bean -> replaceDefinitionByMock(mockCreatorBeanName, bean));
        }

        private static void replaceDefinitionByMock(String mockCreatorBeanName, BeanDefinitionMetadata beanDefinitionMetadata) {
            beanDefinitionMetadata.beanDefinitionModifier()
                    .setFactoryBeanName(mockCreatorBeanName)
                    .setFactoryMethodName("createMock")
                    .addIndexedArgumentValue(0, beanDefinitionMetadata.beanClass());
        }
    }

    class MockCreator {
        @Bean
        public <T> T createMock(Class<T> clazz) {
            return Mockito.mock(clazz);
        }
    }
}

Usage is then pretty simple:

@ContextConfiguration(classes = SimpleApplication.class)
@RunWith(SpringJUnit4ClassRunner.class)
@MockBeans(classes = MyBean.class)
public class SimpleApplicationTest {

    @Autowired
    private MyBean myMock;
...