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Semi-integration testing using mocks and application context

I need to write an e2e test on REST level, that sends real requests. So I want to use application context instead of mocking beans.
RestController.class has an autowired MyService.class, and this MyService.class is dependent on two repository classes. So I tried to mock repositories and inject them in the real Service in the following way:
#ExtendWith(SpringExtension.class)
#SpringBootTest(classes = MyService.class)
#AutoConfigureMockMvc
class MyControllerTest {
#Mock private MyRepository repository;
#Mock private AnotherRepository anotherRepository;
#Autowired #InjectMocks private MyService service;
#InjectMocks private MyController controller;
#RepeatedTest(1)
void someTest() throws Exception {
MockHttpServletResponse response =
mvc.perform(...); assertThat(...);
}
}
#Service
#RequiredArgsConstructor
public class MyService {
private final MyRepository repository;
private final AnotherRepository another; ...}
But I get the following error:
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myRepository'
I also tried to use #ContextConfiguration(classes = {MyConfig.class }) with no success:
#EnableWebMvc
#Configuration
public class MyConfig {
#Autowired private MyService service;
#Mock private MyRepository repository;
#Mock private AnotherRepository another;
}
Is there something I'm missing?

First off you should not use #Mock which is relevant for plain unit testing with mockito, use #MockBean instead. #MockBean "belongs" to the spring universe, it will create a bean (backed by mockito after all) but also will place it into the application context. If there is another bean of this type - it will substitute it.
I also don't think you should use #ExtendWith because #SpringBootTest in the relatively recent spring boot versions already has it defined (check the source code of #SpringBootTest annotation to make sure that's the case indeed.
Now other mistakes are more complicated.
To start with you don't need a spring boot test at all here. It also has a wrong parameter actually (which should point on a configuration class).
You should use #WebMvcTest instead. It seems that you only want to test the controller, and mock the service. #SpringBootTest in general tries to mimick the loading of the whole application, whereas the #WebMvcTest only tests a web layer. BTW, with this approach you don't need to even mock the Repository class because the controller will use the mock of the service, and since you don't load the whole application context there is no need to define a repository at all (the service being a mock doesn't use it anyway)

Add #RunWith(SpringRunner.class) to class MyControllerTest
#RunWith(SpringRunner.class)
class MyControllerTest {
}

Spring autowired dependency is null in class being tested

I'm trying to write a unit test for my PersonController class, which uses a dependency org.modelmapper.ModelMapper. The problem is that when the test calls a method of PersonController that uses the ModelMapper, the ModelMapper is null which results in an error. Clearly it is not being autowired correctly when running the test, but it works when running the application. I am hoping there is a way to fix this problem without needing to add the ModelMapper as a constructor parameter.
The code snippets are shown below:
#SpringBootTest
class PersonControllerTest {
#Mock
private IPersonService personService;
#InjectMocks
private PersonController underTest;
#BeforeEach
void setUp() {
underTest = new PersonController(personService);
}
...Tests...
}
And the relevant PersonController code is:
public class PersonController {
#Autowired
private ModelMapper _modelMapper;
private final IPersonService _personService;
public PersonController (IPersonService personService) {
_personService = personService;
}
...Code that calls _modelMapper...
}

One problem here is that you are creating a controller class manually using new PersonController(personService) so spring annotation #Autowired does not have any effect here (because spring is not creating the class is not configuring it).
Another issue is that you are using mockito #InjectMocks which basically injects mocks (for the unit test) but at the same time, you are using #SpringBootTest which is for integration test (application is started as normal but in test mode).
Based on your description is not clear to me if you are trying to code a unit test or an integration test. so:
If you are coding a unit test, remove #SpringBootTest add ModelMapper as a constructor parameter and instantiate a class with two mocks.
If you are coding an spring integration test, remove #InjectMocks and manual class instantiation of class and flag controller as #Autowire in test.

First of all you should annotate your class PersonControllerTest with
#ExtendWith(SpringExtension.class)
class PersonControllerTest {
or
#ExtendWith(MockitoExtension.class)
class PersonControllerTest {
depending on your use case. This should already fix your problem. If you are still using Junit4 you should use
#RunWith(Springrunner.class)
class PersonControllerTest {
but since you are using
#BeforeEach
that should not be the case :)
EDIT:
When you use ModelMapper via #Autowired you have to use #ExtendWith(SpringExtension.class) . You also have to annotate your class with #SpringBootTest or import the classes that should be available via dependency Injection manually using the #Import annotation.

Injecting non-mocks defined by a #Configuration class into a unit test

Java 8, JUnit 4 and Spring Boot 2.3 here. I have a situation where I have a #Component-annotated Spring Boot class that gets #Autowired with all its dependencies (the beans are defined in a #Configuration-annotated config class):
#Configuration
public class SomeConfig {
#Bean
public List<Fizz> fizzes() {
Fizz fizz = new Fizz(/*complex logic here*/);
return new Collections.singletonList(fizz);
}
#Bean
public Buzz buzz() {
return new Buzz(/*complex logic here*/);
}
}
#Component
public class ThingDoerinator {
#Autowired
private Lizz<Fizz> fizzes;
#Autowired
private Buzz buzz;
public String doStuff() {
// uses fizz and buzz extensively inside here...
}
}
I can easily write a unit test to inject all of these dependencies as mocks:
public class ThingDoerinatorTest extends AbstractBaseTest {
#Mock
private List<Fizz> fizzes;
#Mock
private Buzz buzz;
#InjectMocks
private ThingDoerinator thingDoerinator;
#Test
public void should_do_all_the_stuff() {
// given
// TODO: specify fizzes/buzz mock behavior here
// when
String theThing = thingDoerinator.doStuff();
// then
// TODO: make some assertions, verify mock behavior, etc.
}
}
And 80% of the time that works for me. However I am now trying to write some unit tests that are more like integration tests, where instead of injected mocks, I want the beans to be instantiated like normal and get wired into the ThingDoerinator class like they would be in production:
public class ThingDoerinatorTest extends AbstractBaseTest {
#Mock
private List<Fizz> fizzes;
#Mock
private Buzz buzz;
#InjectMocks
private ThingDoerinator thingDoerinator;
#Test
public void should_do_all_the_stuff() {
// given
// how do I grab the same Fizz and Buzz beans
// that are defined in SomeConfig?
// when -- now instead of mocks, fizzes and buzz are actually being called
String theThing = thingDoerinator.doStuff();
// then
// TODO: make some assertions, verify mock behavior, etc.
}
}
How can I accomplish this?

You can use SpringBootTest.
#SpringBootTest(classes = {Fizz.class, Buzz.class, ThingDoerinator.class})
#RunWith(SpringRunner.class)
public class ThingDoerinatorTest {
#Autowired
private Fizz fizz;
#Autowired
private Buzz buzz;
#Autowired
private ThingDoerinator thingDoerinator;
}

You don't need to mock anything, just inject your class in your test and your configuration will provide the beans to your ThingDoerinator class and your test case will work as if you are calling the ThingDoerinator. doStuff() method from some controller or other service.
TL;DR
I think, you are confused with tests running whole spring context and unit test which just test the function/logic we wrote without running whole context. Unit tests are written to test the piece of function, if that function would behave as expected with given set of inputs.
Ideal unit test is that which doesn't require a mock, we just pass the input and it produces the output (pure function) but often in real application this is not the case, we may find ourselves in situation when we interact with some other object in our application. As we are not about to test that object interaction but concerned about our function, we mock that object behaviours.
It seems, you have no issue with unit test, so you could mock your List of bean in your test class ThingDoerinator and inject them in your test case and your test case worked fine.
Now, you want to do the same thing with #SpringBootTest, so I am taking a hypothetical example to demonstrate that you don't need to mock object now, as spring context will have them, when #springBootTest will load whole context to run your single test case.
Let's say I have a service FizzService and it has one method getFizzes()
#Service
public class FizzService {
private final List<Fizz> fizzes;
public FizzService(List<Fizz> fizzes) {
this.fizzes = fizzes;
}
public List<Fizz> getFizzes() {
return Collections.unmodifiableList(fizzes);
}
}
Using constructor injection here1
Now, my List<Fizzes would be created through a configuration (similar to your case) and been told to spring context to inject them as required.
#Profile("dev")
#Configuration
public class FizzConfig {
#Bean
public List<Fizz> allFizzes() {
return asList(Fizz.of("Batman"), Fizz.of("Aquaman"), Fizz.of("Wonder Woman"));
}
}
Ignore the #Profile annotation for now2
Now I would have spring boot test to check that if this service will give same list of fizzes which I provided to the context, when it will run in production
#ActiveProfiles("test")
#SpringBootTest
class FizzServiceTest {
#Autowired
private FizzService service;
#Test
void shouldGiveAllTheFizzesInContext() {
List<Fizz> fizzes = service.getFizzes();
assertThat(fizzes).isNotNull().isNotEmpty().hasSize(3);
assertThat(fizzes).extracting("name")
.contains("Wonder Woman", "Aquaman");
}
}
Now, when I ran the test, I saw it works, so how did it work, let's understand this. So when I run the test with #SpringBootTest annotation, it will run similar like it runs in production with embedded server.
So, my config class which I created earlier, will be scanned and then beans created there would be loaded into the context, also my service class annotated with #Service annotation, so that would be loaded as well and spring will identify that it needs List<Fizz> and then it will look into it's context that if it has that bean so it will find and inject it, because we are supplying it from our config class.
In my test, I am auto wiring the service class, so spring will inject the FizzService object it has and it would have my List<Fizz> as well (explained in previous para).
So, you don't have to do anything, if you have your config defined and those are being loaded and working in production, those should work in your spring boot test the same way unless you have some custom setup than default spring boot application.
Now, let's look at a case, when you may want to have different List<Fizz> in your test, in that case you will have to exclude the production config and include some test config.
In my example to do that I would create another FizzConfig in my test folder and annotate it with #TestConfiguration
#TestConfiguration
public class FizzConfig {
#Bean
public List<Fizz> allFizzes() {
return asList(Fizz.of("Flash"), Fizz.of("Mera"), Fizz.of("Superman"));
}
}
And I would change my test a little
#ActiveProfiles("test")
#SpringBootTest
#Import(FizzConfig.class)
class FizzServiceTest {
#Autowired
private FizzService service;
#Test
void shouldGiveAllTheFizzesInContext() {
List<Fizz> fizzes = service.getFizzes();
assertThat(fizzes).extracting("name")
.contains("Flash", "Superman");
}
}
Using different profile for tests, hence #ActiveProfile annotation, otherwise the default profile set is dev which will load the production FizzConfig class as it would scan all the packages ( 2Remember the #Profile annotation above, this will make sure that earlier config only runs in production/dev env ). Here is my application.yml to make it work.
spring:
profiles:
active: dev
---
spring:
profiles: test
Also, notice that I am importing my FizzConfiguration with #Import annotation here, you can also do same thing with #SpringBootTest(classes = FizzConfig.class).
So, you can see test case has different values than in production code.
Edit
As commented out, since you don't want test to connect to database in this test, you would have to disable auto configuration for spring data JPA, which spring boot by default does that.
3You can create a another configuration class like
#Configuration
#EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class, DataSourceTransactionManagerAutoConfiguration.class, HibernateJpaAutoConfiguration.class})
public TestDataSourceConfiguration {}
And then include that with your #SpringBootTest, this will disable default database setup and then you would be left with last piece of puzzle which is any repository interaction you might be having in your class.
Because now, you don't have auto configuration in your test case, those repository are just interfaces, which you can easily mock inside your test class
#ActiveProfiles("test")
#SpringBootTest
#Import(FizzConfig.class, TestDataSourceConfiguration.class)
class FizzServiceTest {
#MockBean
SomeRepository repository;
#Autowired
private FizzService service;
#Test
void shouldGiveAllTheFizzesInContext() {
// Use Mockito to mock behaviour of repository
Mockito.when(repository.findById(any(), any()).thenReturn(Optional.of(new SomeObject));
List<Fizz> fizzes = service.getFizzes();
assertThat(fizzes).extracting("name")
.contains("Flash", "Superman");
}
}
1Constructor injection is advisable instead of `#Autowired` in production code, if your dependencies are really required for that class to work, so please avoid it if possible.
3Please note that you create such configuration only in test package or mark with some profile, do not create it in your production packages, otherwise it will disable database for your running code.

How to run a unit test using the SpringBoot 2

I have the following test:
#SpringBootTest
#ExtendWith(SpringExtension.class)
class BookServiceImplTest {
#MockBean
private BookRepository bookRepository;
#MockBean
private LibraryService libraryService;
#Autowired
private BookServiceImpl bookService;
#Test
void create() {
BookRequestDTO bookRequestDTO = new BookRequestDTO();
Library library = new Library();
Book expectedBook = new Book();
when(libraryService.getById(bookRequestDTO.getLibraryId()))
.thenReturn(library);
when(bookRepository.save(any(Book.class)))
.thenReturn(expectedBook);
Book actualBook = bookService.create(bookRequestDTO);
assertEquals(expectedBook, actualBook);
}
}
It is okay, and it runs, but I was wondering is there a way to run this as a Unit test instead of a Integration tests and still use #MockBean #Autowired. Or am I missing some point?
I tried leaving only #ExtendWith(SpringExtension.class), but I get an Exception about BookServiceImpl bean not found.
I know how to do it using MockitoExtension and #Mock, #InjectMocks, but I was wondering if there is a more SpringBoot way of doing it?

You can make it unit test in four steps:
Remove #SpringBootTest annotation, as it is spinning up the entire Spring context ―not useful for unit tests where all collaborators are mocked
Remove #Autowired annotation from BookServiceImpl declaration and add a #BeforeEach setup method where you initialize bookService passing bookRepository and libraryService as parameters
Use MockitoExtension instead of SpringExtension in the ExtendWith annotation. Here I'm assuming you are able to use a library like Mockito for mocking your collaborators
Use Mockito's #Mock instead of #MockBean, as we are manually initializing bookService so there is no need to deal with Spring beans
To add a bit more on your first question: #Mockbean and #Autowired are annotations that make sense for integration tests as they handle the mocking and injection of beans. Unit tests should consider this class in isolation, mocking interactions with other classes, so there is no need to spin up the application context and set up beans.

Remove #SpringBootTest, this will load whole context and slow down your tests. The role of #MockBean is to create a mock from the specified bean and add it to the context. Since there's no context running, There's not point in using #MockBean
Annotate your unit test class with #RunWith(SpringRunner.class)
For injecting dependencies, this is a good practice to create a configuration file and mock beans explicitly and create the target bean using them. Assuming you're using constructor-based injection:
#Profile("test")
#Configuration
public class BookServiceTestConfiguration {
#Bean
public BookRepository bookRepository() {
return Mockito.mock(BookRepository.class);
}
#Bean
public LibraryService libraryService() {
return Mockito.mock(LibraryService.class);
}
#Bean
public BookService bookService() {
BookServiceImpl bookService = new BookServiceImpl(
bookRepository(), libraryService()
);
return userGroupService;
}
}
Then write your test class as:
#ActiveProfiles("test")
#Import(BookServiceTestConfiguration .class)
#RunWith(SpringRunner.class)
public class BookServiceUnitTest {
#Autowired
private BookService bookService;
// write unit tests
}
for further information, read this article

#RefreshScope seems to ignore Mockito's mocks

I'm implementing a service using Spring Boot and Spring Cloud Config service to provide the configuration values. In my Service I have a couple of config values which need to refresh when the value changes in the remote Git repo, and I was using #RefreshScope to enable that feature.
The problem comes when I try to inject a mock for RestTemplate in that service, it appears to ignore it and use the autowired instance instead. If I comment out the annotation it seems to work fine.
Here's the code for the Service:
#Service
#RefreshScope
public class MyServiceImpl implements MyService {
private static final Logger LOG = Logger.getLogger(MyServiceImpl.class);
#Autowired
public RestTemplate restTemplate;
#Value("${opts.default}")
private String default;
#Value("${opts.address}")
private String address;
#Value("${opts.separator}")
private String separator;
...
}
Test source code:
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(classes = Application.class)
public class ServiceTest {
#Mock
private RestTemplate restTemplate;
#Autowired
#InjectMocks
private MyServiceImpl service;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
}
public void testMethod() throws Exception {
when(restTemplate.postForObject(anyString(), any(), eq(ServiceResponse.class), anyMap())).thenReturn(getSuccessfulResponse());
ServiceResponse response = service.doYourStuff();
Assert.assertNotNull(response);
Assert.assertTrue(response.isSuccessful());
}
...
}

When adding the #RefreshScope the bean becomes a proxy instead of an actual raw implementation. Currently the RestTemplate is set on the proxy rather then the underlying instance. (If you debug you would see that your MyServiceImpl is actually more like an instance of MyServiceImpl$SpringCgLib#353234).
To fix you need to manually set the dependency using ReflectionTestUtils and AopTestUtils. The latter is to obtain the actual proxy.
Remove the #InjectMocks annotation and add the following to your setup method after the initialization of the mocks:
Object actualTarget = AopTestUtils.getUltimateTargetObject(service);
ReflectionTestUtils.setfield(actualTarget, "restTemplate", restTemplate);
For versions earlier as 4.2 the following might do the trick
Object actualTarget = (service instanceof Advised) ? ((Advised) service).getTargetSource().getTarget() : service;
The problem is that Mockito doesn't detect the proxy and just sets the field. The ReflectionTestUtils doesn't detect the proxy either hence the manual unwrapping. I actually stepped into this trap a couple of times before, which led me to create SPR-14050 this morning to have it embedded in the ReflectionTestUtils to easy the pain a little.