[FIXED] @WebMvcTest with @Import does not work. Test context always asks for @Repository beans

Issue

Using Spring Boot 2.7.3 I can not create a simple integration test for my API using @WebMvcTest.

Here is my setup:

// GameServerApplicationTests.kt
@SpringBootTest
class GameServerApplicationTests {
    @Test
    fun contextLoads() { }
}

// CraftService.kt
@Service
class CraftService {
    fun getAll(): List<String> {
        return listOf("foo", "bar")
    }
}

// CraftApiTest.kt
@WebMvcTest
@Import(value = [CraftService::class])
class CraftApiTest {
    @Autowired
    private lateinit var testRestTemplate: TestRestTemplate

    @Test
    fun `should do accept craft all endpoint`() {
        val response = testRestTemplate.getForEntity("/craft/all", String::class.java)
        assertThat(response.statusCode).isEqualTo(HttpStatus.OK)
    }
}

When I run the test I see this exception:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'itemRepository' defined in com.gameserver.item.ItemRepository defined in @EnableJpaRepositories declared on GameServerApplication: Cannot create inner bean '(inner bean)#3fba233d' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#3fba233d': Cannot resolve reference to bean 'entityManagerFactory' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' available

I have no idea why it is looking for the itemRepository bean at all. I never asked for that.

I then added this

@WebMvcTest
@ComponentScan(excludeFilters = [ComponentScan.Filter(Repository::class)]) // <<
@Import(value = [CraftService::class])

Which resulted in this exception:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'playerRepository' defined in com.gameserver.player.PlayerRepository defined in @EnableJpaRepositories declared on GameServerApplication: Cannot create inner bean '(inner bean)#30c1da48' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#30c1da48': Cannot resolve reference to bean 'entityManagerFactory' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' available

Which confuses me even more. I explictly excluded all @Repository beans - but it just skipped ItemRepository and then asked for PlayerRepository now.

I am totally lost and have no idea why I am not able to setup a simple integration test for my API endpoint.

EDIT #1:

Other tests run just fine:

EDIT #2:

I tried to use a @Configuration bean for @Import.

// CraftApiTestConfiguration
@Configuration
class CraftApiTestConfiguration {
    @Bean
    fun getCraftService(): CraftService {
        return CraftService()
    }
}

// CraftApiTest.kt
@WebMvcTest
@Import(CraftApiTestConfiguration::class)
class CraftApiTest { // ... }

That did not help either. It just gave me the second exception mentioned above (the one asking for playerRepository)

Solution

I'll try to answer although without seeing the actual code it might not be correct.

So @WebMvcTest loads a "slice" of your application with all the beans annotated with @RestControllers. It doesn't load @Service or @Repository annotated beans.

When you run the test with @WebMvcTest annotation it will load all the controllers, and if, by accident the controller references others than the reference on the service (here I can't say for sure what it is), you might end up loading the stuff that you don't actually need.

Now when you use @WebMvcTest there are two things you can/should do:

1. Work with MockMvc instead of rest template that queries a web server, its not a full-fledged web layer test anyway.

2. Try using @WebMvcTest with your controller only:

@WebMvcTest(CraftApisController.class)

Also instead of injecting the real implementation of service, you can use @MockBean so that the real service implementation will be covered by a regular unit test (without spring at all, just plain JUnit/Mockito) and this test could check that your annotations are defined correctly

Answered By - Mark Bramnik
Answer Checked By - Terry (JavaFixing Volunteer)