Adding configuration class to SpringBootTest breaks component scan - spring-boot

Question

I am trying to disable real Mongo connection and replace it with Fongo mock in tests.
Here is my test class:
#SpringBootTest
#RunWith(SpringRunner.class)
public class ControllerTest {
#Autowired
private WebApplicationContext wac;
#Autowired
private ObjectMapper objectMapper;
#MockBean
private MyService service;
private MockMvc mockMvc;
#Before
public void setup() {
this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
}
#Test
public void performTest() throws Exception {
... logic ...
}
}
It works fine unless I try to add my configuration file changing this line:
#SpringBootTest
to this:
#SpringBootTest(classes = TestConfig.class)
config class itself:
#Configuration
#ComponentScan
#EnableMongoRepositories
public class TestConfig extends AbstractMongoConfiguration {
#Override
protected String getDatabaseName() {
return "FongoDB";
}
#Override
public Mongo mongo() {
return new Fongo(getDatabaseName()).getMongo();
}
}
Then application fails to find beans and throws the next exception:
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.fasterxml.jackson.databind.ObjectMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1486)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
... 28 more
How can I fix it and apply additional configuration properly?

Answer 1

try use
#SpringBootTest
#Import(value = TestConfig.class)
instead of
#SpringBootTest(classes = TestConfig.class)

Answer 2

keep #SpringBootTest and then create a class using #TestConfiguration with the beans in as follows:
#TestConfiguration
public class TransactionManagerTestConfiguration {
#Bean
public String getDatabaseName() {
return "FongoDB";
}
#Bean
public Mongo mongo() {
return new Fongo(getDatabaseName()).getMongo();
}
}
As per the javadoc: Configuration that can be used to define additional beans or customizations for a test. Unlike regular Configuration classes the use of TestConfiguration does not prevent auto-detection of SpringBootConfiguration.