How to embed in memory MariaDB4j to replace default Spring DataSource in JUnit Tests?

Question

I am writing tests for Service that uses several data Jpa repositories. The problem is that some repositories use a lot of native queries with MySQL specific functions such as str_to_date(). So when I tried to test the service's method using H2 I got an error saying that H2 doesn't recognize function. I have tried using H2 in MySQL mode, but got the same error.

here mariaDB4j was proposed as a work-around. I have added dependency into Maven

<dependency>
    <groupId>ch.vorburger.mariaDB4j</groupId>
    <artifactId>mariaDB4j</artifactId>
    <version>2.3.0</version>
    <scope>test</scope>
</dependency>

But getting IllegalStateException : Failed to replace DataSource with an embedded database for tests. If you want an embedded database please put a supported one on the classpath or tune the replace attribute of @AutoConfigureTestDatabase.

My Test file looks this way:

@RunWith(SpringRunner.class)
@DataJpaTest
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.ANY)
public class TestPay {

    @TestConfiguration
    static class PaymentServiceTestContextConfiguration {
        @Bean
        public PaymentService paymentService(){
            return new PaymentService();
        }
    }

    @Autowired
    private PaymentService paymentService;
    @Autowired
    private TarifRepository firstRepository;
    @Autowired
    private BuildingRepository secondRepository;
    @Autowired
    private ApartmentRepository thirdRepository;

    /* Test cases here*/
}

The project is build with Annotation driven Spring Boot.

Answer 1

I build the following class that I reuse in every integration test that requires database access to mariadb. It could probably be improved (and I'd be happy for suggestions), but it works so far:

@RunWith(SpringRunner.class)
@SpringBootTest
@TestPropertySource(locations="classpath:application-junit.properties")
@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_CLASS) //otherwise mariadb is not cleaned up between tests
public abstract class MyIntegrationTest {

    private static MariaDB4jSpringService DB;

    @BeforeClass
    public static void init() throws ManagedProcessException {
        DB = new MariaDB4jSpringService();
        DB.setDefaultPort(1234);
        DB.start();
        DB.getDB().createDB("yourtables");
        DB.getDB().source("schema.sql"); // init scripts from /src/test/resources/schema.sql
    }

    @AfterClass
    public static void cleanup() {
        if (DB != null) DB.stop();
    }
}

application-junit.properties:

spring.datasource.url=jdbc:mariadb://localhost:1234/yourtables
spring.datasource.username=root
spring.datasource.password=

Answer 2

It sounds like you need to explicitly declare your DataSource for tests. In the case of h2, there is likely already a datasource bean declared by a spring test dependency, but there may not be an off-the-shelf one provided by ch.vorburger.mariaDB4j.

Here's an example of an embedded MariaDB DataSource that I stole from elsewhere on the internet

import ch.vorburger.mariadb4j.DBConfigurationBuilder
import ch.vorburger.mariadb4j.springframework.MariaDB4jSpringService
import org.springframework.beans.factory.annotation.Value
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.context.annotation.Profile

import javax.sql.DataSource

@Configuration
@Profile(['local', 'integrationTest'])
class EmbeddedMariaDbConfig {

    @Bean
    MariaDB4jSpringService mariaDB4jSpringService() {
        new MariaDB4jSpringService()
    }

    @Bean
    DataSource dataSource(MariaDB4jSpringService mariaDB4jSpringService,
                          @Value('${app.mariaDB4j.databaseName}') String databaseName,
                          @Value('${spring.datasource.username}') String datasourceUsername,
                          @Value('${spring.datasource.password}') String datasourcePassword,
                          @Value('${spring.datasource.driver-class-name}') String datasourceDriver) {
        //Create our database with default root user and no password
        mariaDB4jSpringService.getDB().createDB(databaseName)

        DBConfigurationBuilder config = mariaDB4jSpringService.getConfiguration()

        DataSourceBuilder
                .create()
                .username(datasourceUsername)
                .password(datasourcePassword)
                .url(config.getURL(databaseName))
                .driverClassName(datasourceDriver)
                .build();
    }
}