why is spring boot's DataJpaTest scanning #Component - spring

Question

Confident this hasn't been asked but reading through the Spring docs and testing utilities I found this annotation and thought I'd start using it. Reading through the fine print I read:
Regular #Component beans will not be loaded into the ApplicationContext.
That sounded good and I even liked the idea of using H2 except from what I found the entity I wanted to use had catalog and schema modifiers to it and the default H2 I couldn't figure out how to support that. I made an H2 datasource for the test branch and use that and override the replace. I wound up with
#RunWith(SpringRunner.class)
#ContextConfiguration(classes=ABCH2Congfiguration.class)
#DataJpaTest
#AutoConfigureTestDatabase(replace= AutoConfigureTestDatabase.Replace.NONE)
public class StatusRepositoryTest {
}
However my tests fails fro Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type.
which leads to:
Error creating bean with name 'customerServiceImpl': Unsatisfied dependency.
However the customerServiceImpl is this bean:
#Component
public class CustomerServiceImpl implements CustomerService {
}
That says #Component. The fine print for DataJpaTest says it doesn't load #Components. Why is it doing that and thus failing the test?
As Kyle and Eugene asked below here's the rest:
package com.xxx.abc.triage;
#Component
public interface CustomerService {
}
Configuration
#ComponentScan("com.xxx.abc")
#EnableJpaRepositories("com.xxx.abc")
//#Profile("h2")
public class ABMH2Congfiguration {
#Primary
#Bean(name = "h2source")
public DataSource dataSource() {
EmbeddedDatabase build = new EmbeddedDatabaseBuilder().setType(EmbeddedDatabaseType.H2).setName("ABC").addScript("init.sql").build();
return build;
}
#Bean
public JpaVendorAdapter jpaVendorAdapter() {
HibernateJpaVendorAdapter bean = new HibernateJpaVendorAdapter();
bean.setDatabase(Database.H2);
bean.setShowSql(true);
bean.setGenerateDdl(true);
return bean;
}
#Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory(
DataSource dataSource, JpaVendorAdapter jpaVendorAdapter) {
LocalContainerEntityManagerFactoryBean bean = new LocalContainerEntityManagerFactoryBean();
bean.setDataSource(dataSource);
bean.setJpaVendorAdapter(jpaVendorAdapter);
bean.setPackagesToScan("com.xxx.abc");
return bean;
}
#Bean
public JpaTransactionManager transactionManager(EntityManagerFactory emf) {
return new JpaTransactionManager(emf);
}
}
And just to clarify the question, why is #Component being loaded into the context within a #DataJpaTest?

Answer 1

#ComponentScan automatically inject all found #Component and #Service into context. You could override it by separate #Bean:
#Bean
CustomerService customerService{
return null;
}
Or remove #Component annotation from CustomerService and CustomerServiceImpl, but you should add #Bean at your production #Configuration

Answer 2

#DataJpaTest does not load #Component, #Service... by default, only #Repository and internal things needed to configure Spring data JPA.
In your test, you can load any #Configuration you need, and in your case, you load #ABMH2Congfiguration which performs a #ComponentScan that's why Spring try to load your CustomerService.
You should only scanning the #Repository in this configuration class, and scan others #Component, #Service... in another #Configuration like DomainConfiguration. It's always a good practice to separate different types of configurations.