Change flush mode in Spring Boot tests when @DataJpaTest in use?

Question

How do you get Spring tests using @DataJpaTest to use COMMIT flush mode? This is not working for my Spock unit tests:

@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
@DataJpaTest(properties = "spring.jpa.properties.org.hibernate.flushMode=COMMIT")
class MyJpaTestSpec extends Specification {
    @Autowired
    EntityManager entityManager

    def "test flush mode"() {
        expect:
        // confirming that flushMode is still AUTO even though I configured COMMIT
        entityManager.flushMode == FlushModeType.AUTO
    }
}

entityManager.getFlushMode() continues to return AUTO.

This is with Spring Boot 2.2.2 with a dependency on spring-test:5.2.2.RELEASE.

I also have a configuration class:

@AutoConfigurationPackage
@SpringBootConfiguration
class MyConfiguration {
}

And src/test/resources/application.yml (Gradle) appears to being read because certain configurations are being picked up (such as the datasource), but the spring.jpa.properties.org.hibernate.flushMode property appears to be ignored from the config file while executing the @DataJpaTest tests.

spring:
  datasource:
    driver-class-name: org.h2.Driver
    url: jdbc:h2:mem:mydb;DB_CLOSE_DELAY=-1
    username: sa
    password: sa
  jpa:
    # seems to be ignored for @DataJpaTests
    properties:
        org.hibernate.flushMode: COMMIT

I've tried hacks like adding a @PostConstruct in MyConfiguration to call setFlushMode() on the entityManager but that doesn't work either. By the time the test is run, it has reverted back to AUTO flush mode. (I'm guessing it reverts back to AUTO for every new session.)

Answer 1

I should have tried this before even posting the question, but it turns out this appears to be a Spring bug that has recently been fixed. I upgraded to Spring Boot v2.2.6 (which uses spring-test v5.2.5). When I posted my question, I was using Spring Boot v2.2.2. The upgrade from v2.2.2 to v2.2.6 has solved the problem. On v2.2.6, spring.jpa.properties.org.hibernate.flushMode is not ignored in my test like it was with v2.2.2.