How to set up unit test for service with dependency? - java

I have a service interface:
interface MyService
{
int getItem();
}
and a implementation:
#Service
class MyServiceImpl : implements MyService {
public MyServiceImpl(List<Loader> loaders) {
}
public int getItem() {
Loader loader = getTheLoader();
return loader.getItem();
}
}
I want to unit test MyServiceImpl. There's more to it then just forwarding the getItem() call to the loader, so I'd think I'd want to test the actual class. I don't think I'd want to test an actual loader, because that would be more of an integration test, yeah?
So, I'm not sure if this is the right approach? To create a real instance of the Impl class and then create a real instance of the TestLoader?
#TestInstance(TestInstance.Lifecycle.PER_CLASS)
public class MyServiceTests {
private MyService myService;
static class TestLoader implements Loader<String, Object> {
#Override
int getItem() {
}
}
#BeforeAll
void init() {
myService= new MyServiceImpl(List.of(new
TestLoader()));
}
I do want to capture call counts to the TestLoader::getItem, etc.
Kinda seems like I need to create a mock loader instead of a real loader to capture the call counts?
But its not clear how I would mock a Loader<String, Object> and override the getItem() class.

If you want to test both the class and the loader you have to do an integration test, you are right, but for unit test you have to mock other classes (that you are going to test next or you have already tested in other unit tests)
You can mock the loader (you can use mockito) and create a new list containing the mock
#TestInstance(TestInstance.Lifecycle.PER_CLASS)
public class MyServiceTests {
private MyService myService;
#Mock
private Loader loader;
#BeforeAll
void init() {
myService= new MyServiceImpl(List.of(loader));
}
}

Related

Mockito 3 mock method of an autowired class

I'm using spring-boot-starter-test 2.2.0 which includes Mockito 3.1.0.
I would like to test this class:
#RestController
public class MyClass {
#Autowired MyAutowired myAutowired;
public int myClassMethod(int i) {
return myAutowired.methodToMock(i);
}
}
Which use this one:
#Service
public class MyAutowired {
public int methodToMock(int i) {
return i;
}
}
In my test I would like to run myClassMethod but with a mocked behavior for methodToMock. Ideally I would like to check if methodToMock was called with the expected argument.
Here is what I tried so far:
#SpringJUnitConfig(Config.class)
#WebAppConfiguration
#ExtendWith(MockitoExtension.class)
class MyClassTest {
#Autowired MyClass myClass;
#Mock
private MyAutowired myAutowired;
#BeforeEach
public void initMocks(){
MockitoAnnotations.initMocks(this);
}
#Test
public void myTest() {
Mockito.when(myAutowired.methodToMock(any()).thenReturn(1);
int shouldBe1ButIs2 = myClass.myClassMethod(2);
}
}
What's wrong with that ? And how to make myClass.myClassMethod(2) return 1 ?
The issue is that your object MyClass is not referring to the right mock instance. The MyAutowired has to injected into MyClass.
You have two options:
Creating a setMyAutowired method in MyClass and pass the MyAutowired instance to it in your test class.
Replacing #Autowired with #InjectMocks annotation on MyClass. In this way, an instance of MyClass will be created and mocks objects which you declared in your test will be injected automatically in it.
I normally use the second option, which is more elegant.

Unable to mock a method which takes an interface

I have a service in my Spring Boot Project in which i have method which takes an interface.
interface IT {}
class AService {
public String method(IT it) {}
}
I have two classes which implements that interface.
class AIT implements IT {}
class BIT implements IT {}
I am using this service method in some other service passing the AIT/BIT class object according to my need.
Now, I am writing the test cases for other service mocking the Service
public class OtherServiceTests {
#MockBean
private Service service;
#Before
public void setUp() {
// none of these mocks working
Mockito.when(service.method(Mockito.any()))
.thenReturn("");
Mockito.when(service.method(Mockito.any(IT.class)))
.thenReturn("");
Mockito.when(service.method(Mockito.any(BIT.class)))
.thenReturn("");
Mockito.when(service.method(Mockito.any(AIT.class)))
.thenReturn("");
// all returing to NullPointerException
otherService = new OtherSerice();
}
}
None of these mocks are working for this method only. Other mocks are working fine. It is returning NullPointerException which makes the tests fail.
I am new to testing using mockito. If anyone can guide me for this solution than this will be very helpful for me.
Mock is not initialized and the annotation #MockBean should be replaced with #Mock.
Try to change it like this:
public class AServiceTest {
#Mock
AService service;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
}
#Test
public void myTest(){
Mockito.when(service.method(Mockito.any())).thenReturn("");
assertEquals("", service.method(new AIT()));
}
}

Mockito when isn't replacing original method behaviour

I got 2 modules User and Email, both of them have 1 entry point which is a facade, rest is package scoped. The configuration is done in 2 classes
#Configuration
class UserConfiguration {
#Bean
UserFacade userFacade(UserRepository repository, EmailFacade emailFacade) {
return new UserFacade(repository, emailFacade);
}
}
#Configuration
class EmailConfiguration {
#Bean
EmailFacade emailFacade(EmailSender emailSender) {
return new EmailFacade(emailSender);
}
}
Now, I want to write tests that don't require Spring to start. I implemented a simple InMemoryRepository to make this happen
#RunWith(MockitoJUnitRunner.class)
public class RegisterUserTest {
#Mock
private EmailFacade emailFacade = new EmailFacade(new FakeEmailSender());
#InjectMocks
private UserFacade userFacade = new UserConfiguration().userFacade(new InMemoryUserRepository(), emailFacade);
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
}
}
I need some fake objects to instantiate EmailFacade so I wrote fake implementation
public class FakeEmailSender implements EmailSender {
#Override
public void sendEmail(EmailMessage emailMessage) throws RuntimeException {
}
}
In that scenario, I'm testing User domain, so I want to mock Email anyways.
I wrote a test to check if it works
#Test
public void shouldReturnSendingFailed() {
Mockito.when(emailFacade.sendUserVerificationEmail(Mockito.any())).thenReturn(Either.left(EmailError.SENDING_FAILED));
assertThat(userFacade.registerNewUser(RegisterUserDto.builder()
.username(USERNAME_4)
.email(VALID_EMAIL)
.password(VALID_PASSWORD).build()).getLeft(), is(EmailError.SENDING_FAILED));
}
But it isn't... after running this test I got
java.util.NoSuchElementException: getLeft() on Right
edit#
regiserNewUser() method
Either<DomainError, SuccessMessage> register(RegisterUserDto registerUserDto) {
if(userRepository.findUser(registerUserDto.getUsername()).isPresent())
return Either.left(UserError.USERNAME_ALREADY_EXISTS);
var userCreationResult = User.createUser(registerUserDto);
var savedUser = userCreationResult.map(this::saveUser);
var emailDto = savedUser.map(this::createVerificationEmail);
return emailDto.isRight() ? emailFacade.sendUserVerificationEmail(emailDto.get())
: Either.left(emailDto.getLeft());
}
Edit2#
With following test configuration
#RunWith(MockitoJUnitRunner.class)
public class RegisterUserTest {
#Mock
private EmailFacade emailFacade;
#InjectMocks
private UserFacade userFacade = new UserConfiguration().userFacade(new InMemoryUserRepository(), emailFacade);
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
}
}
I got nullpointer here, last line of registerNewUser().
Try running this code
#RunWith(MockitoJUnitRunner.class)
public class RegisterUserTest {
#Mock
private EmailFacade emailFacade;
private UserFacade userFacade;
#Before
public void setUp() {
userFacade = new UserConfiguration().userFacade(new InMemoryUserRepository(), emailFacade);
}
}
There are a few issues with your code:
You initialize your mocks twice. You don’t need to call initMocks in the setUp method if you are using Mockito runner
You are trying to inject mocks to already initialized object. But the field you are trying to inject is also passed to the constructor. Please read #InjectMocks doc, to check the strategies used to inject the mocks:
constructor (not used here, already initialized object)
setter (do you have one?)
field (is it not final)
There are details to each strategy (see my questions above). If no staregy is matched, Mockito will fail silently. The fact that you are passing an object in constructor, and rely on setter or field injection afterwards makes this code unnecesarily complex.

Inject mocks to Abstract class using mockito

I am mocking an abstract class like below:
myAbstractClass = Mockito.mock(MyAbstractClass.class, Mockito.CALLS_REAL_METHODS);
the problem is that MyAbstractClass has some dependencies injected via EJB annotations and there are not setters. Is there a way to inject the dependencies?
#InjectMocks does not work with Abstract classes.
I am using junit5 for this.
What I did is instantiate the abstract class with a new abstractClass() in #BeforeEach and call the methods by super if the method is not abstract(using this because I have protected methods), after this I use ReflectionUtils.setField() to set the mocks in the abstract class and test every method and works pretty well. I leave a simple example that works.
AbstractClass
public abstract class AbstractClass {
#Autowired
private Environment environment;
protected String getProperty(String property){
return environment.getRequiredProperty(property);
}
}
AbstractClassTest
#ExtendWith(MockitoExtension.class)
class AbstractClassTest {
AbstractClass abstractClass;
#Mock
Environment environment;
#BeforeEach
void setUp() {
abstractClass = new AbstractClass() {
#Override
public String getProperty(String property) {
return super.getProperty(property);
}
};
ReflectionTestUtils.setField(abstractClass, "environment", environment);
}
#Test
void shouldReturnProperty() {
String propertyValue = "this property";
when(environment.getRequiredProperty("property")).thenReturn(propertyValue);
String property = abstractClass.getProperty("property");
assertEquals(propertyValue, property);
}
}
This is just using mockito and junit5 to test.
Remember to call ReflectionUtils after you instantiate the class with new AbstractClass() or the mocks won't be injected.
Any improve on this implementation is welcome :D.
Since you cannot instantiate an Abstract class there is nothing to test. I would recommend that you create child class (it could be a nested class inside your test class), and then run your tests that way. Then you can use the #Mock, #InjectMocks as you would normally.
You can use the Powermock library to inject mocks in myAbstractClass using Whitebox.setInternalState(myAbstractClass, mock(MockedClass.class));
Junit 4 specific solution
Abstract class that need to be tested
#Slf4j
public abstract class AdhocNotificationEmail {
#Autowired
protected CustomerNotificationRepository customerNotificationRepository;
protected abstract Map<String, String> abstractMethod(AdhocNotificationDTO adhocNotificationDTO);
public JSONObject concreteMethod(){
// some stuff that needs to be tested and common to all subclasses
}
}
Test Class:
#RunWith(SpringJUnit4ClassRunner.class)
public class AdhocNotificationEmailTest{
#Mock
protected CustomerNotificationRepository customerNotificationRepository;
private AdhocNotificationEmail unit;
#Before
public void setUp() {
unit = new AdhocNotificationEmail() {
#Override
protected Map<String, String> abstractMethod(AdhocNotificationDTO notificationDTO) {
return null;
}
};
unit.customerNotificationRepository = customerNotificationRepository;
}
#Test
public void concreteMethod_greenPath() {
final String templateName = "NOTIFICATION_TEMPLATE";
final AdhocNotificationDTO adhocNotificationDTOStub = getAdhocNotificationDTOStub(templateName);
final CustomerNotification customerNotificationStub = getCustomerNotificationStub(templateName);
when(customerNotificationRepository.findByIdAndTemplateName(id, templateName)).thenReturn(customerNotificationStub);
final JSONObject response = unit.concreteMethod(adhocNotificationDTOStub);
assertNotNull(response);
}
Personally, what I like to do is to extend the abstract with an anonymous class declared in the #Before (or #BeforeEach in junit.jupiter). This way I can achieve the following:
Don't mock the class that I want to test (like you are doing with Mockito.mock(MyAbstractClass.class, Mockito.CALLS_REAL_METHODS)), since that is kind of an anti-pattern. You only want to Mock the dependencies of the class you are testing;
You can provide Mocks for the dependencies of the abstract class, and that are called by non-abstract methods;
You can test non-abstract methods that call abstract methods
Example:
class TestAbstractClass {
#Mock
private ServiceDependency dependency;
private AbstractClass abstractClass;
#BeforeEach
void setUp() {
abstractClass= new AbstractClass (dependency) { };
}
#Test
void test(){
Mockito.when(dependency.someMethod()).thenReturn(something);
var result = abstractclass.someNonAbstractMethod();
// assertions
}
}
Good practice is to write unit tests for all possible classes which inherits from this abstract class. Because in theory it is possible situation. This dependency should be mocked and you should forget about mocking dependencies of this EJB component.
Maybe some code snippets would help to clarify what you try to achieve here.

Mocking subclass items with mockito in java

I have written a testclass for a baseclass that uses a factory. I #Mocked the factory to return a Mock object.
It looks sort of like this.
class BaseClass{
SomeFactory factory;
public BaseClass(SomeFactory factory){
this.factory=factory;
}
public void parse(){
factory.createSomething();
}
}
Now my (working) testclass looks like this.
#RunWith(MockitoJUnitRunner.class)
public class BaseTest {
#Mock
SomeFactory factory;
#Mock
SomeCreation crateation;
BaseClass subject;
#Before
public void setUp(){
when(factory.createSomething()).thenReturn(someCreation);
subject = new BaseClass(factory);
}
#Test
testParse(){
subject.Parse();
verify(factory).createSomething();
}
}
This all works fine, but now i have extended BaseClass (lets call it SubClass) and added some functionality. My SubClass also uses an extended factory (SubFactory). So i also want to extend BaseTest and run the same tests, because it does the exact same thing and something extra.
so i overrode the setUp() like so:
class SubTest extends BaseTest{
#Mock
SubFactory subFactory;
#Mock
Something something;
#Override
public void setUp(){
when(subFactory.createSomething()).thenReturn(
factory = subFactory;
subject = new SubClass(subFactory);
}
}
This however doesn't work, because in the baseclass it throws an UnfinishedVerificationException saying:
Missing method call for verify(mock) here:
pointing to the verify in the BaseClass.
Any ideas on how to structure my test-cases that allows me to test the SubClass with the same tests as BaseClass?
Thank you,
Do not extend test cases! Even though there will be (lots of) duplicated code, it's easier to be read and followed.
So, the subclass test should not extend the BaseClass test, but rather re-use the tests on the functionality, which will not be overwritten in the subclass. Also, a getter for the factory would be needed to better customize the behavior on the mocked factory:
class SubClass extends BaseClass {
SubClass(SubFactory factory) {
super(factory);
}
SubFactory getFactory() { return factory; }
public void parse() {
getFactory().createSomething();
}
}
class SubTest {
#Mock
SubFactory subFactory;
#Mock
Something something;
#Mock
SubCreation someSubCreation;
SubClass subject = new SubClass(subFactory);
public void setUp() {
when(subFactory.createSomething()).thenReturn(someSubCreation);
}
}

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