Spring boot field injection with autowire not working in JUnit test

Question

I want to inject DeMorgenArticleScraper in a test.

@RunWith(SpringJUnit4ClassRunner.class)
public class DeMorgenArticleScraperTest {

    @Autowired
    private DeMorgenArticleScraper deMorgenArticleScraper;

    ...
}

The DeMorgenArticleScraper component has some configuration going on for itself, but the IDE/compiler is not complaining about them.

@Component
public class DeMorgenArticleScraper extends NewsPaperArticleScraper {

    @Autowired
    public DeMorgenArticleScraper(
            @Qualifier("deMorgenSelectorContainer") SelectorContainer selector,
            GenericArticleScraper genericArticleScraper,
            @Qualifier("deMorgenCompany") Company company) {
        super(selector, genericArticleScraper, company);
    }

    ...
}

The constructor parameters that are annotated with @Qualifier, are defined in a Config.class With @Bean. The class itself has @Configuration. I figure the problem is not situated here.

The IDE warns me already, no bean found...autowired members must be defined in a bean. But as far as I know, it is defined in a bean with the @Component annotation. All other bean wiring seems ok as the Spring boot application can start (when I comment out the test class).

Solution 1

@SpringBootTest is fairly heavyweight, and for all intents and purpose will load your entire application, https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-testing.html#boot-features-testing-spring-boot-applications, it's fairly heavyweight and dramatically affects test time. Depending on what you are trying to test you may want to look into

• Slice tests e.g. @JsonTest, @DataJpaTest, @WebMvcTest etc. , https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-testing.html#boot-features-testing-spring-boot-applications-testing-autoconfigured-tests. Benefit of these tests are not only will they not load everything, thus faster, but will try to hunt out the relevant configurations.
• Plain old @ContextConfigurationand point to the relevant @Configuration's required to load beans needed for the test https://docs.spring.io/spring/docs/current/spring-framework-reference/testing.html#contextconfiguration

Solution 2

I replaced

@RunWith(SpringJUnit4ClassRunner.class)

with

@SpringBootTest
@RunWith(SpringRunner.class)

This appears to be working fine: I see Spring boot firing up and loading beans. I'll keep this question open for a short while for better suggestions.

Solution 3

I ran into similar problem where my spring context was not getting initialized and therefore I was not able to inject the bean with @Autowired annotation. Then I came across this post and tried with the below annotations as suggested by @progonkpa and it started working.

@SpringBootTest
@RunWith(SpringRunner.class)

But then I realized that @SpringBootTest already contains @ExtendWith({SpringExtension.class}) annotation which is Junit5 equivalent of @RunWith(SpringRunner.class) thus it should load spring-context while running the test. Then I found out the silly mistake I made to import @Test annotation from junit4(i.e org.junit.Test;) instead of junit5(i.e org.junit.jupiter.api.Test;) library. I changed the @Test from junit5 library and it started working with a single annotation @SpringBootTest.

p.s : don't forget to exclude junit4 library from your dependency if you are using junit5