How to do integration testing using Fongo (Fake mongo) in Spring Boot

Question

I am working on spring boot application with mongodb as backend.

mongorepository for crud operation

I want to do integration testing using fake mongo (fongo)

I have taken reference from following link to do integration testing using fongo but no luck.

https://www.paradigmadigital.com/dev/tests-integrados-spring-boot-fongo/

INTEGRATION test is trying to connect to real database and IT fails

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = { ConfigServerWithFongoConfiguration.class }, properties = {
        "server.port=8980" }, webEnvironment = WebEnvironment.DEFINED_PORT)
@AutoConfigureMockMvc
@TestPropertySource(properties = { "spring.data.mongodb.database=test" })
@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
public class PersonControllerITest {

    @Autowired
    private MongoTemplate mongoTemplate;

    @Autowired
    private MockMvc mockMvc;

    private ObjectMapper jsonMapper;

    @Before
    public void setUp() {
        jsonMapper = new ObjectMapper();
    }

    @Test
    public void testGetPerson() throws Exception {

        Person personFongo = new Person();
        personFongo.setId(1);
        personFongo.setName("Name1");
        personFongo.setAddress("Address1");
        mongoTemplate.createCollection("person");
        mongoTemplate.insert(personFongo);

        ResultActions resultAction = mockMvc.perform(MockMvcRequestBuilders.get("http://localhost:8090/api/person/1"));
        resultAction.andExpect(MockMvcResultMatchers.status().is2xxSuccessful());
        MvcResult result = resultAction.andReturn();
        Person personResponse = jsonMapper.readValue(result.getResponse().getContentAsString(), Person.class);
        Assert.assertEquals(1, personResponse.getId());
        Assert.assertEquals("Name1", personResponse.getName());
        Assert.assertEquals("Address1", personResponse.getAddress());

    }

    @Test
    public void testCreatePerson() throws Exception {

        Person personRequest = new Person();
        personRequest.setId(1);
        personRequest.setName("Name1");
        personRequest.setAddress("Address1");

        String body = jsonMapper.writeValueAsString(personRequest);

        ResultActions resultAction = mockMvc.perform(MockMvcRequestBuilders.post("http://localhost:8090/api/person")
                .contentType(MediaType.APPLICATION_JSON).content(body));
        resultAction.andExpect(MockMvcResultMatchers.status().isCreated());

        Person personFongo = mongoTemplate.findOne(new Query(Criteria.where("id").is(1)), Person.class);
        Assert.assertEquals(personFongo.getName(), "Name1");
        Assert.assertEquals(personFongo.getAddress(), "Address1");
    }
}

I am getting following error while executing Integration test

   java.lang.IllegalStateException: Failed to load ApplicationContext
    
        at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)
        at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83)
        at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:117)
        at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
        at org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener.prepareTestInstance(SpringBootDependencyInjectionTestExecutionListener.java:44)
        at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230)
        at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228)
    
    Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'securityConfig': Unsatisfied dependency expressed through field 'entitlementsRepository'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entitlementsRepository': Cannot resolve reference to bean 'mongoTemplate' while setting bean property 'mongoOperations'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoTemplate' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.core.MongoTemplate]: Factory method 'mongoTemplate' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoDbFactory' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoClient' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mongodb.MongoClient]: Factory method 'mongoClient' threw exception; nested exception is java.lang.NullPointerException
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
        ... 25 more
    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entitlementsRepository': Cannot resolve reference to bean 'mongoTemplate' while setting bean property 'mongoOperations'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoTemplate' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.core.MongoTemplate]: Factory method 'mongoTemplate' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoDbFactory' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoClient' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mongodb.MongoClient]: Factory method 'mongoClient' threw exception; nested exception is java.lang.NullPointerException
        at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:359)
        at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:108)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1531)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1276)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
        
        ... 44 more
    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoTemplate' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.core.MongoTemplate]: Factory method 'mongoTemplate' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoDbFactory' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoClient' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mongodb.MongoClient]: Factory method 'mongoClient' threw exception; nested exception is java.lang.NullPointerException
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067)
        
        ... 57 more
    Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.core.MongoTemplate]: Factory method 'mongoTemplate' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoDbFactory' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoClient' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mongodb.MongoClient]: Factory method 'mongoClient' threw exception; nested exception is java.lang.NullPointerException
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
        ... 66 more
    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoDbFactory' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoClient' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mongodb.MongoClient]: Factory method 'mongoClient' threw exception; nested exception is java.lang.NullPointerException
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
        
        ... 67 more
    Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoClient' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mongodb.MongoClient]: Factory method 'mongoClient' threw exception; nested exception is java.lang.NullPointerException
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
        ... 89 more
    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoClient' defined in class path resource [com/company/myapp/configs/MongoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mongodb.MongoClient]: Factory method 'mongoClient' threw exception; nested exception is java.lang.NullPointerException
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.obtainBeanInstanceFromFactory(ConfigurationClassEnhancer.java:389)
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:361)
        at com.company.myapp.configs.MongoConfig$$EnhancerBySpringCGLIB$$33034a08.mongoClient(<generated>)
        at com.company.myapp.configs.MongoConfig.mongoDbFactory(MongoConfig.java:73)
        at com.company.myapp.configs.MongoConfig$$EnhancerBySpringCGLIB$$33034a08.CGLIB$mongoDbFactory$1(<generated>)
        at com.company.myapp.configs.MongoConfig$$EnhancerBySpringCGLIB$$33034a08$$FastClassBySpringCGLIB$$50ee8948.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:358)
        at com.company.myapp.configs.MongoConfig$$EnhancerBySpringCGLIB$$33034a08.mongoDbFactory(<generated>)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
        ... 90 more
    Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mongodb.MongoClient]: Factory method 'mongoClient' threw exception; nested exception is java.lang.NullPointerException
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
        ... 112 more
    Caused by: java.lang.NullPointerException
        at java.util.Hashtable.put(Hashtable.java:460)
        at java.util.Properties.setProperty(Properties.java:166)
        at java.lang.System.setProperty(System.java:796)
        at com.company.myapp.configs.MongoConfig.mongoClient(MongoConfig.java:78)
        at com.company.myapp.configs.MongoConfig$$EnhancerBySpringCGLIB$$33034a08.CGLIB$mongoClient$3(<generated>)
        at com.company.myapp.configs.MongoConfig$$EnhancerBySpringCGLIB$$33034a08$$FastClassBySpringCGLIB$$50ee8948.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:358)
        at com.company.myapp.configs.MongoConfig$$EnhancerBySpringCGLIB$$33034a08.mongoClient(<generated>)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
        ... 113 more

My main Application.java

@SpringBootApplication(exclude = {MongoDataAutoConfiguration.class, MongoAutoConfiguration.class})
@EntityScan(basePackageClasses = Jsr310Converters.class)
@ComponentScan(basePackages = {"com.company.myapp", "com.company.myapp.repository"})
@AutoConfigureAfter(MongoConfig.class)
@EnableSwagger2
@EnableScheduling
public class Application
{
public class Application
{
    private static final Logger logger = LoggerFactory.getLogger(Application.class);

    @Value("${http.port}")
    int httpPort;

    @Value("${ssl.port}")
    int sslPort;

    @Value("${ssl.keystore.file}")
    String keyStoreFile;

    @Value("${ssl.keystore.password}")
    String keyStorePassword;

    @Autowired
    FileUtil fileUtil;

    public static void main(String[] args)
    {
        Runtime.getRuntime().addShutdownHook(new Thread() {                       
            @Override
            public void run() {
                logger.info("myapp server shutdown initiated");
                LogManager.shutdown();
                logger.info("myapp server shutdown completed");
            }
        });
        SpringApplication.run(Application.class, args);                          
    }

    @Bean
    public CompressingFilter compressingFilter()
    {
        return new CompressingFilter();
    }

    @Bean
    public EmbeddedServletContainerFactory servletContainer()
    {
        String keystore = "dev";

        TomcatEmbeddedServletContainerFactory tomcat = new TomcatEmbeddedServletContainerFactory();
        tomcat.addConnectorCustomizers((TomcatConnectorCustomizer) con -> {
                    //if ("true".equalsIgnoreCase(sslEnabled)) {
                    logger.info("----------------------------------------- Initialising ssl endpoint -------------------------------------");
                    Http11NioProtocol proto = (Http11NioProtocol) con.getProtocolHandler();
                    proto.setSSLEnabled(true);
                    con.setScheme("https");
                    con.setSecure(true);
                    con.setPort(sslPort);
                    proto.setKeystoreFile(fileUtil.getConfigFilePath(keyStoreFile));
                    proto.setKeystorePass(keystore);
                    proto.setKeyPass(keystore);
                    logger.info("---------------------------------------- Initialised ssl endpoint ----------------------------------------");
                    //}
                });

        tomcat.addAdditionalTomcatConnectors(createStandardConnector());
        return tomcat;
    }

    private Connector createStandardConnector()
    {
        Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");
        connector.setPort(httpPort);
        return connector;
    }
}

AbstractFongoBaseConfiguration.java

@EnableAutoConfiguration(exclude={MongoAutoConfiguration.class, MongoDataAutoConfiguration.class})
public abstract class AbstractFongoBaseConfiguration extends AbstractMongoConfiguration{

    @Autowired
    private Environment env;

    @Override
    protected String getDatabaseName() {
        return env.getRequiredProperty("spring.data.mongodb.database");
    }

    @Override
    public Mongo mongo() throws Exception {
        return new Fongo(getDatabaseName()).getMongo();
    }
}

ConfigServerWithFongoConfiguration.java

@EnableAutoConfiguration(exclude = { EmbeddedMongoAutoConfiguration.class, MongoAutoConfiguration.class,
        MongoDataAutoConfiguration.class })
@Configuration
@ComponentScan(basePackages = { "com.company.myapp" }, excludeFilters = {
        @ComponentScan.Filter(classes = { SpringBootApplication.class }) })
public class ConfigServerWithFongoConfiguration extends AbstractFongoBaseConfiguration {

}

Could you please suggest , what needs to be done to resolve this issue ?

Answer 1

Fongo doesn't seem to be maintained anymore. I would switch to Test Containers if feasible https://www.testcontainers.org/modules/databases/mongodb/

This is a better reference for what you are trying to do: https://www.baeldung.com/spring-boot-embedded-mongodb

You need to add @AutoConfigureDataMongo on the test.

Answer 2

I had tried with your code for Integration Test and Same config file.

But for AbstractFongoBaseConfiguration.class i had provided below code.

I had removed that @EnableAutoConfiguration(exclude={MongoAutoConfiguration.class, MongoDataAutoConfiguration.class}) line. It's working fine for me.

package com.company.myapp;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.data.mongodb.config.AbstractMongoConfiguration;

import com.github.fakemongo.Fongo;
import com.mongodb.Mongo;
//this exclude i had removed
public abstract class AbstractFongoBaseConfiguration extends AbstractMongoConfiguration{

    @Autowired
    private Environment env;

    @Override
    protected String getDatabaseName() {
        return env.getRequiredProperty("spring.data.mongodb.database");
    }

    @Override
    public Mongo mongo() throws Exception {
        return new Fongo(getDatabaseName()).getMongo();
    }
}

Here I had attached video with same code.

Also one point i want to inform you both make your ConfigServerWithFongoConfiguration and AbstractFongoBaseConfiguration are with same package of Test directory as PersonControllerITest class.

I had also pre-assumed that your application run fine and you only have problem with Integration Test.

Here i had attached successfully run test case screen as well.

Answer 3

In your stacktrace, the exception occurs in the "MongoConfig" class. As seen here:

com.company.myapp.configs.MongoConfig.mongoClient(MongoConfig.java:78)

It indicates to me that your Spring configuration chain is not set up as you intend it to be. It looks like the actual MongoConfig class intended to be used in the actual application environment is still being loaded.

Without having your full project (or the Config class that is actually causing the NullPointer), it is near impossible to give a detailed answer to your issue. However, I would advise you to create a specific TestConfig spring configuration class, so you can include only the main config classes that you want to be part of your test context.

TLDR: take a look at your config set-up, and figure out why your MongoConfig.java is loaded. If it is intended to be loaded, include it here so people can figure out what the problem is.