Integration Tests

The point of integration testing, as the name suggests, is to test whether many separately developed modules work together as expected.

Martin Fowler

class CustomerService {
	....
	public boolean saveOrUpdateCustomer(final Customer customer) {
		final Optional<Customer> result = customerRepository.findById(customer.getId());

		if (result.isPresent())) {
			customerRepository.update(customer);
			return true;
		} else {
			customerRepository.save(customer);
			return false;
		}
	}
}
						

class CustomerServiceTest {
	@Test
	public void testSaveOrUpdateCustomer() {
		final Customer testCustomer = new Customer(1, "John", "Doe");

		final customerRepositoryMock = mock(CustomerRepository.class);
		given(customerRepositoryMock.findCustomerById(testCustomer.getId()))
			.willReturn(Optional.empty());
		given(customerRepositoryMock.update(testCustomer))
			.doNothing();

		final CustomerService service = new CustomerService(customerRepositoryMock);
		assertThat(service.saveOrUpdateCustomer(customer)).equalsTo(true);
	}
}
						

H2 in memory database vs PostgreSQL

TestContainers

Testcontainers is a Java library that supports JUnit tests, providing lightweight, throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container.

testcontainers.org

Some of Databases supported

And many other Modules

TestContainers is supported

Growing Ecosystem

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class DrTests {
    @BeforeEach
    void setup() {
      Testcontainers.exposeHostPorts(port);
      drHEADerContainer = new GenericContainer(
        new ImageFromDockerfile("drheader", true)
          .withDockerfileFromBuilder(builder ->
          builder.from("python:3.7.4")
            .run("git clone https://github.com/Santandersecurityresearch/DrHeader.git")
            .run("cd DrHeader && git checkout master && git pull && pip install .")
            .entryPoint("tail -f /dev/null")
            .build()));
      drHEADerContainer.start();
    }

    @AfterEach
    void tearDown() {
       drHEADerContainer.stop();
    }	
}

						

private void drHEADer(final String url) throws Exception {
  final String testUrl = String.format(TEST_CONTAINERS_INTERNAL_URL, port, url);
  final ExecResult execResult = drHEADerContainer.
    execInContainer("drheader", "scan", "single", testUrl);
  
  if (execResult.getExitCode() != 0) {
    throw new AssertionError(String.format("Error on drHEADer analysis : \n%s", 
     execResult.getStdout()));
  }
}

@Test
@DisplayName("Index should not have drHEADer errors")
void IndexShouldNotHaveDrHEADerErrors() throws Exception {
	drHEADer("/index.html");
}
						

@Test
void whenShouldRecover() throws Exception {
	stopDatabase();
	assertServiceIsReady(false);

	startDatabase();
	loadInitData();
	assertServiceIsReady(true);
	assertOffersAre(INITIAL_OFFERS);

	stopDatabase();
	assertServiceIsReady(true);
	assertOffersAre(INITIAL_OFFERS);

	startDatabase();
	loadInitData();
	addVanillaCookies();
	assertServiceIsReady(true);
	assertOffersAre(ADDITIONAL_OFFERS);
}