Integration testing for Java developers.

1. TestContainers
Integration testing without the hassle

2. Anton Arhipov
@antonarhipov

3. Why integration testing?

10. 1. # of tests per time unit

11. 1. # of tests per time unit
2. Complex setup

13. 1. Reproducible environment

14. 1. Reproducible environment
2. Both for development and CI

15. 1. Reproducible environment
2. Both for development and CI
3. Isolated

16. 1. Reproducible environment
2. Both for development and CI
3. Isolated
4. As real as possible

17. 1. Reproducible environment
2. Both for development and CI
3. Isolated
4. As real as possible
5. Cross-platform

18. 1. Reproducible environment
2. Both for development and CI
3. Isolated
4. As real as possible
5. Cross-platform
6. Easy to set up, use & maintain

24. TestContainers to the rescue!

25. How does it work?
https://github.com/docker-java/docker-java
Docker environment discovery
Will start docker machine if it’s not started yet
Containers cleanup on JVM shutdown

26. GenericContainer redis =
new GenericContainer("redis:3.0.6")
.withExposedPorts(6379);

27. GenericContainer redis =
new GenericContainer("redis:3.0.6")
.withExposedPorts(6379);
PostgreSQLContainer postgreSQLContainer =
new PostgreSQLContainer("postgres:9.6.2")
.withUsername(POSTGRES_USERNAME)
.withPassword(POSTGRES_PASSWORD);

28. https://github.com/testcontainers/testcontainers-java

29. Microservices!11
REST service
Java, Spring Boot
Redis & PostgreSQL
Calls to some other application

30. @RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = DemoApplication.class,
webEnvironment = WebEnvironment.RANDOM_PORT)
@ContextConfiguration(initializers = AbstractIntegrationTest.Initializer.class)
public abstract class AbstractIntegrationTest {
@ClassRule
public static PostgreSQLContainer postgreSql = new PostgreSQLContainer();
@ClassRule
public static GenericContainer redis = new GenericContainer("redis:3.0.6")
.withExposedPorts(6379);
@ClassRule
public static MockServerContainer mockServer = new MockServerContainer();

31. @RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = DemoApplication.class,
webEnvironment = WebEnvironment.RANDOM_PORT)
@ContextConfiguration(initializers = AbstractIntegrationTest.Initializer.class)
public abstract class AbstractIntegrationTest {
@ClassRule
public static PostgreSQLContainer postgreSql = new PostgreSQLContainer();
@ClassRule
public static GenericContainer redis = new GenericContainer("redis:3.0.6")
.withExposedPorts(6379);
@ClassRule
public static MockServerContainer mockServer = new MockServerContainer();
Still using all the
Spring goodies!

32. @RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = DemoApplication.class,
webEnvironment = WebEnvironment.RANDOM_PORT)
@ContextConfiguration(initializers = AbstractIntegrationTest.Initializer.class)
public abstract class AbstractIntegrationTest {
@ClassRule
public static PostgreSQLContainer postgreSql = new PostgreSQLContainer();
@ClassRule
public static GenericContainer redis = new GenericContainer("redis:3.0.6")
.withExposedPorts(6379);
@ClassRule
public static MockServerContainer mockServer = new MockServerContainer();
External
dependencies

34. public class MockServerContainer<SELF extends MockServerContainer<SELF>>
extends GenericContainer<SELF> {
public MockServerContainer() {
super("jamesdbloom/mockserver:latest");
addExposedPorts(8080);
}
private MockServerClient client;
@Override
protected void containerIsStarted(InspectContainerResponse containerInfo) {
super.containerIsStarted(containerInfo);
client = new MockServerClient(getContainerIpAddress(),
getMappedPort(getExposedPorts().get(0)));
}
}

35. public class MockServerContainer<SELF extends MockServerContainer<SELF>>
extends GenericContainer<SELF> {
public MockServerContainer() {
super("jamesdbloom/mockserver:latest");
addExposedPorts(8080);
}
private MockServerClient client;
@Override
protected void containerIsStarted(InspectContainerResponse containerInfo) {
super.containerIsStarted(containerInfo);
client = new MockServerClient(getContainerIpAddress(),
getMappedPort(getExposedPorts().get(0)));
}
}

36. MockServerClient client = …
client.when(
HttpRequest.request("/analytics/issues/" +
project.projectId + "/app").withMethod("GET"),
Times.unlimited())
.respond(singleIssueResponse());

37. https://github.com/bsideup/testcontainers-microservices-example

40. How to test Java agents?

41. https://github.com/bsideup/javaagent-boilerplate

42. https://www.testcontainers.org
https://twitter.com/testcontainers
https://github.com/testcontainers
https://testcontainers.slack.com

43. anton@zeroturnaround.com
@antonarhipov
slideshare.net/arhan