Embedded Postgres for Spring Boot Tests

Question

I'm building a Spring Boot app, backed by Postgres, using Flyway for database migrations. I've been bumping up against issues where I cannot produce a migration that generates the desired outcome in both Postgres, and the embedded unit test database (even with Postgres compatibility mode enabled). So I am looking at using embedded Postgres for unit tests.

I came across an embedded postgres implementation that looks promising, but don't really see how to set it up to run within Spring Boot's unit test framework only (for testing Spring Data repositories). How would one set this up using the mentioned tool or an alternative embedded version of Postgres?

Answer 1

I'm the author of the embedded-database-spring-test library that was mentioned by @MartinVolejnik. I think the library should meet all your needs (PostgreSQL + Spring Boot + Flyway + integration testing). I'm really sorry that you're having some trouble, so I've created a simple demo app that demonstrates the use of the library together with Spring Boot framework. Below I have summarized the basic steps that you need to do.

Maven configuration

Add the following maven dependency:

<dependency>
    <groupId>io.zonky.test</groupId>
    <artifactId>embedded-database-spring-test</artifactId>
    <version>1.5.2</version>
    <scope>test</scope>
</dependency>

Flyway configuration

Add the following property to your application configuration:

# Sets the schemas managed by Flyway -> change the xxx value to the name of your schema
# flyway.schemas=xxx // for spring boot 1.x.x
spring.flyway.schemas=xxx // for spring boot 2.x.x

Further, make sure that you do not use org.flywaydb.test.junit.FlywayTestExecutionListener. Because the library has its own test execution listener that can optimize database initialization and this optimization has no effect if the FlywayTestExecutionListener is applied.

Spring Boot 2 Configuration

Since Spring Boot 2, there is a compatibility issue with Hibernate and Postgres Driver. So you may need to add the following property to your application configuration to fix that:

# Workaround for a compatibility issue of Spring Boot 2 with Hibernate and Postgres Driver
# See https://github.com/spring-projects/spring-boot/issues/12007
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true

Example

An example of test class demonstrating the use of the embedded database:

@RunWith(SpringRunner.class)
@DataJpaTest
@AutoConfigureEmbeddedDatabase
public class SpringDataJpaAnnotationTest {

    @Autowired
    private PersonRepository personRepository;

    @Test
    public void testEmbeddedDatabase() {
        Optional<Person> personOptional = personRepository.findById(1L);

        assertThat(personOptional).hasValueSatisfying(person -> {
            assertThat(person.getId()).isNotNull();
            assertThat(person.getFirstName()).isEqualTo("Dave");
            assertThat(person.getLastName()).isEqualTo("Syer");
        });
    }
}