Let's say i have a controller class called UserController, and withing it there are 2 methods: getUserCount() and getLatestUser(), and getUserCount calls getLatestUser.
#Controller
class UserController{
public long getUserCount(){
#code
getLatestUser();
#code
}
public User getLatestUser(){}
}
i'm supposed to test each of these methods using Junit and Mockito, and thus i have something like this:
class UserControllerTest{
#Autowired
UserController userController;
#Test
public void testing_get_user_count(){
User user = new User();
when(userController.getLastestUser()).thenReturn(user);
}
}
My issue is that i can't mock UserController because i've autowired it, so i can't use when().thenReturn() on getLatestUser.
Is there a way for me to mock it anyways?
You can use #SpyBean instead of #Autowired. It applies Mockito spy on a bean.
class UserControllerTest {
#SpyBean
UserController userController;
#Test
public void testing_get_user_count(){
User user = new User();
when(userController.getLastestUser()).thenReturn(user);
}
}
Related
I have a singleton class (so private constructor) which needs to use a Spring Data repository during initialization. I have one injected as a constructor argument. Roughly:
#Controller
public class MyClass {
#Autowired
private MyClass(MyRepository repo) {
repo.findAll();
}
}
I want to unit test my class, so I need to have a mock repository initialized with mock values and then passed into my class before my class is initialized. How do I write my Mockito mocks in my JUnit test to make this possible?
You don't need Spring; this is an advantage of constructor injection. Just use MyRepository mockRepo = mock(MyRepository.class) and new MyClass(mockRepo).
(Your constructor should be public, by the way. You seem to be making the common mistake of confusing different senses of "singleton"; in the case of DI it simply means that the container only makes a single instance and shares it. Finally, if you only have one constructor you don't need #Autowired.)
Unit test should be independent. It means, we are not using real data from database even call any service from our test file.
Assuming you are using JUni5 and have findAllStudents() in your controller. So your test file approximately like this
#TestInstance(TestInstance.Lifecycle.PER_CLASS)
public class MyClassTest {
#Mock
private MyRepository repo;
#InjectMocks
private MyClass controller;
#BeforeAll
public void setup() {
MockitoAnnotations.initMocks(this);
}
#Test
public void testDataIsExist() {
List<String> expectednames = new ArrayList();
expectedNames.add("Foo");
expectedNames.add("Bar");
Mockito.when(myRepo.findAll()).thenReturn(expectedNames);
List<String> result = controller.findAllStudents();
Assertions.assertNotNull(result);
Assertions.assertEquals(expectednames, result);
}
}
So we are mock all the services we use in controller, then inject to controller itself. Then inside the test method we mock repo.findAll() to return expectedNames so if the controller find that function it will return what mock says to return.
After we call the function, we have to make it sure that the result is according to what we expected.
There is little value in a "unit test" for a #Controller implementation. If you use #WebMvcTest, then you can use #MockBean:
#WebMvcTest
class MyControllerTest {
#Autowired
private MockMvc mockMvc;
#MockBean
private MyRepository repository;
#Test
void testSomething() {
mockMvc.perform( ... );
}
}
I would like to know what is the best way to write unit tests in this context :
MyApi :
#RestController
public class MyApi{
#Autowired
MyAction myAction;
#PostMapping
public ResponseEntity addAction(#ResponseBody MyDto myDto){
return myAction.addAction(myDto);
}
}
MyAction :
#Service
public class MyAction{
#Autowired
private MyClient myClient;
public ResponseEntity<AuthenticationResponseDto> login(MyDto myDto{
return ResponseEntity.ok(myClient.addClient(myDto));
}
}
For example, is it mandatory to add constructor ?
Thanks
It's considered a good practice to use constructor injection, however if you don't want to use it you need to use #Mock and #InjectMocks. It uses reflection and constructor is not required to be defined.
#RunWith(MockitoJUnitRunner.class)
public class Test {
#Mock
private Client client;
#InjectMocks
private ServiceImpl plannerService = new ServiceImpl();
#Test
public void test() throws Exception {
....
}
}
I'm sure there is a way to avoid using an autowired constructor and just autowiring a field, however I use constructors as I consider it a good practice. It also makes it easy to inject a mocked object like so
#Mock
MyAction myAction;
MyApi myApi;
ResponseEntity<AuthenticationResponseDto> testResponse = ResponseEntity.ok
(new AuthenticationResponseDto());
#Before
public void setup(){
myApi = new MyApi(myAction);
}
#Test
public void simpleMyApiTestExample (){
when(myAction.login(any())).thenAnswer(i-> testRespone);
ResponseEntity<?> actualResponse = myApi.addAction(new MyDto());
assertThat(actualResponse).isSameAs(testResponse);
}
Just to give you an idea. I just wrote this example in the SO text editor, so appologies for any typos/mistakes. But hopefully this shows why having constructors is useful for testing things that are autowired. It allows you to mock the objects necessary for instantiation by adding them to the constructor. In this example this would probably also apply to MyDto and AuthenticationResponseDto objects as well.
I'm having a problem injecting mock into one class I need for testing. I'm trying to mock a Dao class and had no problem doing so using ReflectionTestUtils in various services I'm using, however this one just does not want to work, it keeps calling the Dao class and getting errors from the database.
This is the test class:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration
#WebAppConfiguration
public class DedicationControllerTest extends AbstractRestTest {
#Mock
UserDaoImpl userDao;
#Autowired
#InjectMocks
GrantedAuthoritiesLevelsHolder grantedAuthoritiesLevelsHolder;
#Test
public void shouldTest() throws Exception {
//given
String json = this.getJsonFromFile("json/my.json");
Mockito.when(userDao.getUser(Mockito.anyString())).thenReturn(new User(1l, "mock"));
ReflectionTestUtils.setField(grantedAuthoritiesLevelsHolder, "userDao", userDao);
ResultActions result = mockMvc.perform(post( controllerUrl + "/action")
.contentType(MediaType.APPLICATION_JSON_UTF8)
.content(json));
// then
result
.andExpect(status().isOk());
}
}
And this is the class I'm trying to inject mock into:
#Component
#Scope(value="session", proxyMode = ScopedProxyMode.TARGET_CLASS)
public class GrantedAuthoritiesLevelsHolder {
#Autowired
private UserDao userDao;
// some methods
}
You will have to register mocked bean as UserDao when the context is getting loaded. You can register it as shown below. Put this in any class annotated with #Configuration
#Bean
#Primary
public UserDao UserDao() {
return mock(UserDao.class);
}
I believe that your configuration may be not enough to put a mock into Spring context.
My advice:
#MockBean(answer=Answers.RETURNS_SMART_NULLS)
UserDao userDao;
#Autowired
GrantedAuthoritiesLevelsHolder grantedAuthoritiesLevelsHolder;
It should put a mock into Spring context, moreover it should give you hints with incorrect/missing stubbing.
I'm trying to write a simple unit test for a service in Spring Boot.
The service calls a method on a repository which returns an instance of User.
I'm trying to mock the repository, because I want to test only the service.
So, the code for Repository:
public interface UserRepository extends MongoRepository<User, String> {
User findByEmail(String email);
}
Service interface:
public interface UserService {
#Async
CompletableFuture<User> findByEmail(String email) throws InterruptedException;
}
Service implementation:
#Service
public class UserServiceImpl implements UserService {
private UserRepository userRepository;
// dependency injection
// don't need Autowire here
// https://docs.spring.io/spring-boot/docs/current/reference/html/using-boot-spring-beans-and-dependency-injection.html
public UserServiceImpl(UserRepository userRepository) {
this.userRepository = userRepository;
}
#Async
public CompletableFuture<User> findByEmail(String email) throws InterruptedException {
User user = userRepository.findByEmail(email);
return CompletableFuture.completedFuture(user);
}
}
Unit Test:
#RunWith(SpringRunner.class)
#SpringBootTest
public class UserServiceTest {
#InjectMocks
UserService userService;
#Mock
UserRepository mockUserRepository;
#Before
public void setUp() {
MockitoAnnotations.initMock(this);
}
#Test
public void mustReturnUser() throws InterruptedException {
String emailTest = "foo#bar.com";
User fakeUser = new User();
fakeUser.setEmail(emailTest);
when(mockUserRepository.findByEmail(emailTest)).thenReturn(fakeUser);
User user = userService.findByEmail(emailTest).join();
assertThat(user).isEqualTo(fakeUser);
verify(mockUserRepository).findByEmail(emailTest);
}
}
When I run this test, I got a MockitoException:
org.mockito.exceptions.base.MockitoException:
Cannot instantiate #InjectMocks field named 'userService'.
...
Caused by: org.mockito.exceptions.base.MockitoException: the type 'UserService' is an interface.
Instead of using the interface, I tried to use the real implementation; changing the test like this:
#InjectMocks
UserServiceImpl userService;
Now, the test passes with success, but this don't appear be right (at least for me).
I like to test the UserService that Spring Boot is using (suppose that in a new version of my system, I implement a new UserServicePostgreSQLImpl - now I'm using MongoDB).
(edit: see the bottom edit in the question)
I changed the Unit Test as follows:
#Autowired
#InjectMocks
UserService userService;
but now I got a test failure:
Expected :model.User#383caf89
Actual :null
For some reason, when I use #Autowired, the UserRepository mock doesn't work.
If I change the emailTest to use a real email in my database,
the test passes.
When I use #Autowired,
the test is using the real UserRepository and not a Mock version of UserRepository.
Any help?
Edit: looking at the answers from #msfoster and #dunni, and thinking better, I believe that the correct way is to test every implementation (in my example, use UserServiceImpl userService).
In order for your UserServiceImpl to be autowired when annotating it with #InjectMocks then it needs to registered as a Spring bean itself. You can do this most simply by annotating your UserServiceImpl class with #Service.
This will ensure it is picked up by the component scan in your Spring boot configuration. (As long as the scan includes the package your service class is in!)
You are running your tests with SpringRunner but for mocks you don't really need spring context. Try following code
// Using mockito runner
#RunWith(MockitoJUnitRunner.class)
public class UserServiceTest {
#Mock
UserRepository mockUserRepository;
// Mockito will auto inject mockUserRepository mock to userService via constructor injection
#InjectMocks
UserService userService;
#Test
public void mustReturnUser() throws InterruptedException {
String emailTest = "foo#bar.com";
User fakeUser = new User();
fakeUser.setEmail(emailTest);
when(mockUserRepository.findByEmail(emailTest)).thenReturn(fakeUser);
User user = userService.findByEmail(emailTest).join();
assertThat(user).isEqualTo(fakeUser);
verify(mockUserRepository).findByEmail(emailTest);
}
}
This is just a variation on the #Yogesh Badke answer.
Although you are using spring at runtime,
there is no need to use spring during the unit test.
Instead,
you can mock all the dependencies and set them to the mocks during test setup
(using reflection or setters, if you have them).
Here is some example code:
import org.springframework.test.util.ReflectionTestUtils;
public class TestUserService
{
private static final String VALUE_EMAIL = "test email value";
private UserService classToTest;
#Mock
private User mockUser;
#Mock
private UserRepository mockUserRepository;
#Before
public void beforeTest()
{
MockitoAnnotations.initMock(this);
classToTest = new UserService();
doReturn(mockUser).when(mockUserRepository).findByEmail(VALUE_EMAIL);
ReflectionTestUtils.setField(
classToTest,
"userRepository",
mockUserRepository);
}
#Test
public void findByEmail_goodEmailInput_returnsCorrectUser()
{
final User actualResult;
actualResult = classToTest.findByEmail(VALUE_EMAIL);
assertSame(
mockUser,
actualResult);
}
}
If interface is implemented by more than one class, then use the qualifier name (example below) in Junit beans.xml file to run the respective Junit test case.
Example:
#Autowired
#Qualifier("animal")
private Animal animals;
In Junit beans.xml
<bean id="animal" class="com.example.abc.Lion"/>
where Lion is the implementation class for the Interface Animal.
You need to #InjectMocks for the implementation class. Not the interface class.
Example:
#RunWith(SpringRunner.class)
#SpringBootTest
public class UserServiceTest {
#Mock
UserRepository mockUserRepository;
#InjectMocks
UserServiceImpl userServiceImpl; ------> This is important
}
I have a component setup that is essentially a launcher for an application. It is configured like so:
#Component
public class MyLauncher {
#Autowired
MyService myService;
//other methods
}
MyService is annotated with the #Service Spring annotation and is autowired into my launcher class without any issues.
I would like to write some jUnit test cases for MyLauncher, to do so I started a class like this:
public class MyLauncherTest
private MyLauncher myLauncher = new MyLauncher();
#Test
public void someTest() {
}
}
Can I create a Mock object for MyService and inject it into myLauncher in my test class? I currently don't have a getter or setter in myLauncher as Spring is handling the autowiring. If possible, I'd like to not have to add getters and setters. Can I tell the test case to inject a mock object into the autowired variable using an #Before init method?
If I'm going about this completely wrong, feel free to say that. I'm still new to this. My main goal is to just have some Java code or annotation that puts a mock object in that #Autowired variable without me having to write a setter method or having to use an applicationContext-test.xml file. I would much rather maintain everything for the test cases in the .java file instead of having to maintain a separate application content just for my tests.
I am hoping to use Mockito for the mock objects. In the past I have done this by using org.mockito.Mockito and creating my objects with Mockito.mock(MyClass.class).
You can absolutely inject mocks on MyLauncher in your test. I am sure if you show what mocking framework you are using someone would be quick to provide an answer. With mockito I would look into using #RunWith(MockitoJUnitRunner.class) and using annotations for myLauncher. It would look something like what is below.
#RunWith(MockitoJUnitRunner.class)
public class MyLauncherTest
#InjectMocks
private MyLauncher myLauncher = new MyLauncher();
#Mock
private MyService myService;
#Test
public void someTest() {
}
}
The accepted answer (use MockitoJUnitRunner and #InjectMocks) is great. But if you want something a little more lightweight (no special JUnit runner), and less "magical" (more transparent) especially for occasional use, you could just set the private fields directly using introspection.
If you use Spring, you already have a utility class for this : org.springframework.test.util.ReflectionTestUtils
The use is quite straightforward :
ReflectionTestUtils.setField(myLauncher, "myService", myService);
The first argument is your target bean, the second is the name of the (usually private) field, and the last is the value to inject.
If you don't use Spring, it is quite trivial to implement such a utility method. Here is the code I used before I found this Spring class :
public static void setPrivateField(Object target, String fieldName, Object value){
try{
Field privateField = target.getClass().getDeclaredField(fieldName);
privateField.setAccessible(true);
privateField.set(target, value);
}catch(Exception e){
throw new RuntimeException(e);
}
}
Sometimes you can refactor your #Component to use constructor or setter based injection to setup your testcase (you can and still rely on #Autowired). Now, you can create your test entirely without a mocking framework by implementing test stubs instead (e.g. Martin Fowler's MailServiceStub):
#Component
public class MyLauncher {
private MyService myService;
#Autowired
MyLauncher(MyService myService) {
this.myService = myService;
}
// other methods
}
public class MyServiceStub implements MyService {
// ...
}
public class MyLauncherTest
private MyLauncher myLauncher;
private MyServiceStub myServiceStub;
#Before
public void setUp() {
myServiceStub = new MyServiceStub();
myLauncher = new MyLauncher(myServiceStub);
}
#Test
public void someTest() {
}
}
This technique especially useful if the test and the class under test is located in the same package because then you can use the default, package-private access modifier to prevent other classes from accessing it. Note that you can still have your production code in src/main/java but your tests in src/main/test directories.
If you like Mockito then you will appreciate the MockitoJUnitRunner. It allows you to do "magic" things like #Manuel showed you:
#RunWith(MockitoJUnitRunner.class)
public class MyLauncherTest
#InjectMocks
private MyLauncher myLauncher; // no need to call the constructor
#Mock
private MyService myService;
#Test
public void someTest() {
}
}
Alternatively, you can use the default JUnit runner and call the MockitoAnnotations.initMocks() in a setUp() method to let Mockito initialize the annotated values. You can find more information in the javadoc of #InjectMocks and in a blog post that I have written.
I believe in order to have auto-wiring work on your MyLauncher class (for myService), you will need to let Spring initialize it instead of calling the constructor, by auto-wiring myLauncher. Once that is being auto-wired (and myService is also getting auto-wired), Spring (1.4.0 and up) provides a #MockBean annotation you can put in your test. This will replace a matching single beans in context with a mock of that type. You can then further define what mocking you want, in a #Before method.
public class MyLauncherTest
#MockBean
private MyService myService;
#Autowired
private MyLauncher myLauncher;
#Before
private void setupMockBean() {
doNothing().when(myService).someVoidMethod();
doReturn("Some Value").when(myService).someStringMethod();
}
#Test
public void someTest() {
myLauncher.doSomething();
}
}
Your MyLauncher class can then remain unmodified, and your MyService bean will be a mock whose methods return values as you defined:
#Component
public class MyLauncher {
#Autowired
MyService myService;
public void doSomething() {
myService.someVoidMethod();
myService.someMethodThatCallsSomeStringMethod();
}
//other methods
}
A couple advantages of this over other methods mentioned is that:
You don't need to manually inject myService.
You don't need use the Mockito runner or rules.
I'm a new user for Spring. I found a different solution for this. Using reflection and making public necessary fields and assign mock objects.
This is my auth controller and it has some Autowired private properties.
#RestController
public class AuthController {
#Autowired
private UsersDAOInterface usersDao;
#Autowired
private TokensDAOInterface tokensDao;
#RequestMapping(path = "/auth/getToken", method = RequestMethod.POST)
public #ResponseBody Object getToken(#RequestParam String username,
#RequestParam String password) {
User user = usersDao.getLoginUser(username, password);
if (user == null)
return new ErrorResult("Kullanıcıadı veya şifre hatalı");
Token token = new Token();
token.setTokenId("aergaerg");
token.setUserId(1);
token.setInsertDatetime(new Date());
return token;
}
}
And this is my Junit test for AuthController. I'm making public needed private properties and assign mock objects to them and rock :)
public class AuthControllerTest {
#Test
public void getToken() {
try {
UsersDAO mockUsersDao = mock(UsersDAO.class);
TokensDAO mockTokensDao = mock(TokensDAO.class);
User dummyUser = new User();
dummyUser.setId(10);
dummyUser.setUsername("nixarsoft");
dummyUser.setTopId(0);
when(mockUsersDao.getLoginUser(Matchers.anyString(), Matchers.anyString())) //
.thenReturn(dummyUser);
AuthController ctrl = new AuthController();
Field usersDaoField = ctrl.getClass().getDeclaredField("usersDao");
usersDaoField.setAccessible(true);
usersDaoField.set(ctrl, mockUsersDao);
Field tokensDaoField = ctrl.getClass().getDeclaredField("tokensDao");
tokensDaoField.setAccessible(true);
tokensDaoField.set(ctrl, mockTokensDao);
Token t = (Token) ctrl.getToken("test", "aergaeg");
Assert.assertNotNull(t);
} catch (Exception ex) {
System.out.println(ex);
}
}
}
I don't know advantages and disadvantages for this way but this is working. This technic has a little bit more code but these codes can be seperated by different methods etc. There are more good answers for this question but I want to point to different solution. Sorry for my bad english. Have a good java to everybody :)
Look at this link
Then write your test case as
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration({"/applicationContext.xml"})
public class MyLauncherTest{
#Resource
private MyLauncher myLauncher ;
#Test
public void someTest() {
//test code
}
}