테스트 컨테이너: Testcontainers

// build.gradle
testImplementation 'org.springframework.boot:spring-boot-testcontainers'
testImplementation 'org.testcontainers:postgresql'
testImplementation 'org.testcontainers:junit-jupiter'

@SpringBootTest
@Testcontainers
@ActiveProfiles("test")
class UserRepositoryTest {

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

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

    @Autowired UserRepository userRepository;

    @Test
    void save_and_find() {
        User user = User.builder()
            .email("alice@example.com")
            .name("Alice")
            .build();
        userRepository.save(user);

        Optional<User> found = userRepository.findByEmail("alice@example.com");
        assertTrue(found.isPresent());
        assertEquals("Alice", found.get().getName());
    }
}

// 더 간단 — 자동 연결
@SpringBootTest
@Testcontainers
class UserRepositoryTest {

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

    // application 설정 자동 주입 — DynamicPropertySource 불필요
}

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


@Test
void cache_test() {
    redisTemplate.opsForValue().set("key", "value");
    assertEquals("value", redisTemplate.opsForValue().get("key"));
}

@Container
@ServiceConnection
static ComposeContainer compose = new ComposeContainer(
    new File("src/test/resources/docker-compose-test.yml")
).withExposedService("postgres", 5432)
 .withExposedService("redis", 6379)
 .withExposedService("kafka", 9092);

# ~/.testcontainers.properties
testcontainers.reuse.enable=true

static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:16-alpine")
    .withReuse(true);  // 테스트 사이에 재사용