Configure specific in memory database for testing purpose in Spring

Question

How do I configure my Spring Boot application so that when I run unit tests it will use in-memory database such as H2/HSQL but when I run Spring Boot application it will use

Answer 1

With @SpringBootTest magic, you just need to do following two changes.

1. Add 'h2' test dependency in pom.xml

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <scope>test</scope>
</dependency>

2. Use @AutoConfigureTestDatabase

@RunWith(SpringRunner.class)
@SpringBootTest(classes = MySpringBootApplication.class)
@AutoConfigureTestDatabase
public class SpringBootTest{

    @Autowired
    private RequestRepository requestRepository;
}

Now all the spring jpa bean/repositories used in test will use h2 as backing database.

2019-04-26 13:13:34.198 INFO 28627 --- [ main] beddedDataSourceBeanFactoryPostProcessor : Replacing 'dataSource' DataSource bean with embedded version

2019-04-26 13:13:34.199 INFO 28627 --- [ main] o.s.b.f.s.DefaultListableBeanFactory : Overriding bean definition for bean 'dataSource'

2019-04-26 13:13:36.194 INFO 28627 --- [ main] o.s.j.d.e.EmbeddedDatabaseFactory : Starting embedded database: url='jdbc:h2:mem:2784768e-f053-4bb3-ab88-edda34956893;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=false', username='sa'

Note: I still have 'spring-jpa' properties defined in 'application.properties' and I don't use any profiles. @AutoConfigureTestDatabase will override existing jpa configurations with test defaults AutoConfigureTestDatabase.Replace.