Echte Abhängigkeiten mit Testcontainers

Why Testcontainers

Adding the Dependency

// build.gradle
testImplementation "org.testcontainers:junit-jupiter"
testImplementation "org.testcontainers:postgresql"

The @Testcontainers Annotation

@Testcontainers
@SpringBootTest
class UserRepositoryIT {
    // containers declared here
}

Declaring a PostgreSQLContainer

@Container
static PostgreSQLContainer<?> postgres =
    new PostgreSQLContainer<>("postgres:16")
        .withDatabaseName("testdb")
        .withUsername("test")
        .withPassword("test");

Wiring the Datasource

@DynamicPropertySource
static void props(DynamicPropertyRegistry registry) {
    registry.add("spring.datasource.url",
        postgres::getJdbcUrl);
    registry.add("spring.datasource.username",
        postgres::getUsername);
    registry.add("spring.datasource.password",
        postgres::getPassword);
}

A Full Repository Test

@Test
void savesAndReads() {
    User saved = repository.save(new User("Alice"));
    assertThat(repository.findById(saved.getId()))
        .isPresent();
}

Static vs Instance Containers

Other Container Types

@Container
static GenericContainer<?> redis =
    new GenericContainer<>("redis:7")
        .withExposedPorts(6379);

Reusing Containers

@Container
static PostgreSQLContainer<?> postgres =
    new PostgreSQLContainer<>("postgres:16")
        .withReuse(true);

Spring Boot Service Connections

@Container
@ServiceConnection
static PostgreSQLContainer<?> postgres =
    new PostgreSQLContainer<>("postgres:16");

Docker Requirement

Quick Check

Recap