Unable to find a @SpringBootConfiguration, you need to use @ContextConfiguration or @SpringBootTest(classes=...) with your test

I am using Spring Data JPA and Spring Boot. The layout of the application is this

main
    +-- java
        +-- com/lapots/game/monolith
            +-- repository/relational
                +--RelationalPlayerRepository.java
            +-- web
                +--GrandJourneyMonolithApplication.java
                +-- config
                    +-- RelationalDBConfiguration.java
test
    +-- java
        +-- com/lapots/game/monolith
            +-- repository/relational
                +-- RelationalPlayerRepositoryTests.java
            +-- web
                +-- GrandJourneyMonolithApplicationTests.java

The repository for my object looks like this

public interface RelationalPlayerRepository extends JpaRepository<Player, Long> {
}

Additionally for the repositories I provided a configuration

@Configuration
@EnableJpaRepositories(basePackages = "com.lapots.game.monolith.repository.relational")
@EntityScan("com.lapots.game.monolith.domain")
public class RelationalDBConfiguration {
}

My main application looks like this

@SpringBootApplication
@ComponentScan("com.lapots.game.monolith")
public class GrandJourneyMonolithApplication {

    @Autowired
    private RelationalPlayerRepository relationalPlayerRepository;

    public static void main(String[] args) {
        SpringApplication.run(GrandJourneyMonolithApplication.class, args);
    }

    @Bean
    public CommandLineRunner initPlayers() {
        return (args) -> {
            Player p = new Player();
            p.setLevel(10);
            p.setName("Master1909");
            p.setClazz("warrior");

            relationalPlayerRepository.save(p);
        };
    }
}

Test for application looks like this

@RunWith(SpringRunner.class)
@SpringBootTest
public class GrandJourneyMonolithApplicationTests {

    @Test
    public void contextLoads() {
    }

}

The test for repository looks like this

@RunWith(SpringRunner.class)
@DataJpaTest
public class RelationalPlayerRepositoryTests {

    @Autowired
    private TestEntityManager entityManager;

    @Autowired
    private RelationalPlayerRepository repository;

    @Test
    public void testBasic() {
        Player expected = createPlayer("Master12", "warrior", 10);
        this.entityManager.persist(expected);
        List<Player> players = repository.findAll();
        assertThat(repository.findAll()).isNotEmpty();
        assertEquals(expected, players.get(0));
    }

    private Player createPlayer(String name, String clazz, int level) {
        Player p = new Player();
        p.setId(1L);
        p.setName(name);
        p.setClazz(clazz);
        p.setLevel(level);
        return p;
    }
}

But when I try to run the tests I get the error

Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.041 sec <<< FAILURE! - in com.lapots.game.monolith.repository.relational.RelationalPlayerRepositoryTests
initializationError(com.lapots.game.monolith.repository.relational.RelationalPlayerRepositoryTests)  Time elapsed: 0.006 sec  <<< ERROR!
java.lang.IllegalStateException: Unable to find a @SpringBootConfiguration, you need to use @ContextConfiguration or @SpringBootTest(classes=...) with your test
at org.springframework.util.Assert.state(Assert.java:70)
at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.getOrFindConfigurationClasses(SpringBootTestContextBootstrapper.java:202)
at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.processMergedContextConfiguration(SpringBootTestContextBootstrapper.java:137)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:409)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildDefaultMergedContextConfiguration(AbstractTestContextBootstrapper.java:323)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:277)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildTestContext(AbstractTestContextBootstrapper.java:112)
at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.buildTestContext(SpringBootTestContextBootstrapper.java:82)
at org.springframework.test.context.TestContextManager.<init>(TestContextManager.java:120)
at org.springframework.test.context.TestContextManager.<init>(TestContextManager.java:105)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTestContextManager(SpringJUnit4ClassRunner.java:152)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.<init>(SpringJUnit4ClassRunner.java:143)
at org.springframework.test.context.junit4.SpringRunner.<init>(SpringRunner.java:49)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:104)
at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:33)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:283)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:173)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:128)
at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:203)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:155)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)

What is the problem? Domain Player loooks like this

@Data
@Entity
@Table(schema = "app", name = "players")
public class Player {
    @Id
    @GeneratedValue
    private Long id;

    @Transient
    Set<Player> comrades;

    @Column(unique = true)
    private String name;

    private int level;

    @Column(name = "class")
    private String clazz;
}

src/test/java packages and src/main/java packages should match. I had same issue where

• my src/main/java packages were starting with com.comp.example but
• src/test/java packages were starting with com.sample.example

Because of this spring boot application was not able to pickup the configuration of the application, which it picks up from @SpringBootApplication class. So test case should fall under the same packages where @SpringBootApplication in src/main/java is written.

When the Spring Boot starts, it scans the classpath from the top to the bottom of the project to find the config file. Your config is under another files and that is a reason of the problem. Move you config upper to the monolith package and everything gonna be fine.

@SpringBootTest has a parameter named classes. It accepts an array of classes for configuration. Add the class for the config file to it, for example:

@SpringBootTest(classes={com.lapots.game.monolith.web.GrandJourneyMonolithApplication.class})

The Test src/test/java files should also follow the same directory structure as in src/main/java.

In my case this was due to some [move|copy/paste] of classes. For some, the package clause was either [not updated correctly|not present] and the changes were not picked up but the IDE.

Anyways, review your project packaging.

I was able to resolve this problem only after including in the @SpringBootTest classes both the context configuration class and the application class.

Delete the file module-info.java. This worked for me.