Spring Boot properties in 'application.yml' not loading from JUnit Test

What am I doing wrong? I'm using this little standalone App which runs and finds my src/main/resources/config/application.yml. The same configuration doesn't work from JUnit, see below:

@Configuration
@ComponentScan
@EnableConfigurationProperties

public class TestApplication {

    public static void main(String[] args) {

        SpringApplication.run(TestApplication.class);
    }
}


@Component
@ConfigurationProperties

public class Bean{
    ...
}

The following doesn't work, the same properties in application.yml are not loaded and Bean has only null values:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = TestApplication.class)

public class SomeTestClass {
    ...
}

Try this:

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = TestApplication.class, 
    initializers = ConfigFileApplicationContextInitializer.class)
public class SomeTestClass {
    ...
}

EDIT:

For Spring Boot version 1.5+, SpringApplicationConfiguration was removed in favour of SpringBootTest or direct use of SpringBootContextLoader.

You can still use initializers parameter with ContextConfiguration annotation.

The trick to load any custom yml file in SpringBoot 2.0 w/o using @SpringBootTest

• create some yml file in test\resources
• Use ConfigFileApplicationContextInitializer and spring.config.location property

Example Code:

@RunWith(SpringRunner.class)
@ContextConfiguration(
    classes = { MyConfiguration.class, AnotherDependancy.class },
    initializers = {ConfigFileApplicationContextInitializer.class} )
@TestPropertySource(properties = { "spring.config.location=classpath:myApp-test.yml" })
public class ConfigProviderTest {
    @Autowired
    private MyConfiguration myConfiguration; //this will be filled with myApp-test.yml 

   @Value("${my.config-yml-string}")
   private String someSrting; //will get value from the yml file.

}

For JUnit 5 use the @ExtendWith(SpringExtension.class) annotation instead of @RunWith(SpringRunner.class)

Alternative in February 2017:

@SpringBootTest
@ContextConfiguration(classes = { TestApplication.class })
@RunWith(SpringRunner.class)
public class SomeTestClass {
   ...
}

the lean variant (withouth @SpringBootTest):

@ContextConfiguration(classes = { TestApplication.class },
                 initializers = { ConfigFileApplicationContextInitializer.class })
@RunWith(SpringRunner.class)
public class SomeTestClass {

Here's another way: [Spring Boot v1.4.x]

@Configuration
@ConfigurationProperties(prefix = "own")
public class OwnSettings {

    private String name;
    Getter & setters...

}

import org.springframework.boot.test.context.SpringBootTestContextBootstrapper;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@BootstrapWith(SpringBootTestContextBootstrapper.class)
public class OwnSettingsTest {

  @Autowired
  private OwnSettings bean;

  @Test
  public void test() {
    bean.getName();
  }
}

This works ONLY if also 'application.properties' file exists.

e.g. maven project:

src/main/resources/application.properties [ The file can be empty but it's mandatory! ]
src/main/resources/application.yml [here's your real config file]