I would like to mock an object inside my class.
public class Controller{
private StandardEmailSender sender = new StandardEmailSender();
public void process() throws EmailException {
// do some stuff
sender.sendEmail(to, subject, body);
// do some stuff
}
}
I would like to mock sender.sendEmail(to, subject, body);. I've spent time finding a solution but I'm stuck. I tried to mock directly the object StandardEmailSender like this :
#Mock
StandardEmailSender sender;
#Before
public void setUp() throws EmailException {
MockitoAnnotations.initMocks(this);
doNothing().when(sender).sendEmail(anyString(), anyString(), anyString());
}
#Test
public void test() throws EmailException {
Controller controller= new Controller ();
controller.process();
//make some asserts
}
Would someone have a solution to my problem? Thanks!
You have two choices here:
make it possible for your test case to "manually" inject a (mocked) Sender object (for example by providing a constructor to set that field)
make use of Mockitos #InjectMocks annotation
A typical approach for option 1 is to use constructor telescoping, like this:
public class Controller {
private final Sender sender;
public Controller() { this(new StandardEmailSender()); }
Controller(Sender sender) { this.sender = sender; }
By doing so, clients can still create a Controller instance without worrying about providing a sender, and your unit tests can use that package protected constructor to provide a mocked sender instance.
Use a form of dependency injection, for example:
public class Controller{
private final EmailSender sender;
Controller(EmailSender emailSender) {
this.sender = Objects.requireNonNull(emailSender);
}
public Controller() {
this(new StandardEmailSender());
}
}
In your test:
#Test
public void test() throws EmailException {
Controller controller= new Controller(mockedSender);
controller.process();
}
Related
I have a class name ServiceLocator
public class ServiceLocator implements ApplicationContextAware {
private transient ApplicationContext _applicationContext;
private static ServiceLocator _instance = new ServiceLocator();
public void setApplicationContext(ApplicationContext applicationContext)
throws BeansException {
_instance._applicationContext = applicationContext;
}
public static ApplicationContext getApplicationContext() {
return _instance._applicationContext;
}
public static Object findService(String serviceName) {
return _instance._applicationContext.getBean(serviceName);
}
}
I am trying to use that class to find Service into Approver class methods
public class ApproverService extends AbstractDataService implements IApproverService {
public void updateCompletedInboxStatus(String status) {
IInboxService inboxService = (IInboxService)ServiceLocator.findService("inboxService");
InboxItem inboxItem = inboxService.getInboxItem("test");
inboxItem.setWorkItemStatus(status);
inboxService.saveInboxItem(inboxItem);
}
}
With that code i am trying to write Junit with PowerMockRunner
#RunWith(PowerMockRunner.class)
#PrepareForTest({ApproverService.class})
public class ApproverServiceTest {
#InjectMocks
ApproverService approverService;
#Mock
IInboxService inboxService;
#Mock
ServiceLocator serviceLocator;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
}
#Test
public void updateCompletedInboxStatus() {
RequestAccessHeader reqHdr = new RequestAccessHeader();
reqHdr.setRequestStatus(AccessConstants.REQ_STATUS_HOLD_INT);
String status = "test";
PowerMockito.mockStatic(ServiceLocator.class);
when(serviceLocator.findService("inboxService")).thenReturn(inboxService);
approverService.updateCompletedInboxStatus(status);
}
}
But I am getting null pointer
java.lang.NullPointerException
at com.alnt.fabric.common.ServiceLocator.findService(ServiceLocator.java:25)
at com.alnt.access.approver.service.ApproverServiceTest.updateCompletedInboxStatus(ApproverServiceTest.java:80)
Please help me to find the solution for that issue.
The static method is obviously not mocked.
The problem is most probably because you haven't add the to-be-mocked class in #PrepareForTest
Change it to #PrepareForTest({ApproverService.class, ServiceLocator.class})
Off-topics:
Although it compiles, calling static method by instance reference is not a good practice. Therefore the line should be when(ServiceLocator.findService(...)).thenReturn(inboxService).
Another problem is, you tried to use Singleton pattern but in wrong way. A singleton is suppose to return you an instance so the caller can call its instance method. Your findService is preferably an instance method and to be called as ServiceLocator.getInstance().findService(...). To further improve, unless you really need it to be a singleton, you should make it a normal object instance and inject to objects that need it (given you are already using Spring, I see no reason making a Singleton)
The setup for the static method is not mocked correctly
#RunWith(PowerMockRunner.class)
#PrepareForTest({ServiceLocator.class}) //Prepare static class for mock
public class ApproverServiceTest {
#Mock
IInboxService inboxService;
#Mock
InboxItem item;
#InjectMocks
ApproverService approverService;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
}
#Test
public void updateCompletedInboxStatus() {
//Arrange
String status = "test";
PowerMockito.mockStatic(ServiceLocator.class);
when(ServiceLocator.findService("inboxService")) //<-- NOTE static call
.thenReturn(inboxService);
when(inboxService.getInboxItem("test")).thenReturn(item);
//Act
approverService.updateCompletedInboxStatus(status);
//...
}
}
Reference Mocking Static Method
The subject under test should actually be refactored to avoid the service locator anit-pattern / code smell and should follow explicit dependency principle via constructor injection.
public class ApproverService extends AbstractDataService implements IApproverService {
private IInboxService inboxService;
#Autowired
public ApproverService(IInboxService inboxService){
this.inboxService = inboxService;
}
public void updateCompletedInboxStatus(String status) {
InboxItem inboxItem = inboxService.getInboxItem("test");
inboxItem.setWorkItemStatus(status);
inboxService.saveInboxItem(inboxItem);
}
}
That way the subject class is genuine about what it needs to perform its function correctly,
And the test can then be refactored accordingly
#RunWith(PowerMockRunner.class)
public class ApproverServiceTest {
#Mock
IInboxService inboxService;
#Mock
InboxItem item;
#InjectMocks
ApproverService approverService;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
}
#Test
public void updateCompletedInboxStatus() {
//Arrange
String status = "test";
when(inboxService.getInboxItem("test")).thenReturn(item);
//Act
approverService.updateCompletedInboxStatus(status);
//...
}
}
I have a test utility for with I need to have a fresh instance per test method (to prevent that state leaks between tests). So far, I was using the scope "prototype", but now I want to be able to wire the utility into another test utility, and the wired instances shall be the same per test.
This appears to be a standard problem, so I was wondering if there is a "test method" scope or something similar?
This is the structure of the test class and test utilities:
#RunWith(SpringRunner.class)
#SpringBootTest
public class MyTest {
#Autowired
private TestDriver driver;
#Autowired
private TestStateProvider state;
// ... state
// ... methods
}
#Component
#Scope("prototype") // not right because MyTest and TestStateProvider get separate instances
public class TestDriver {
// ...
}
#Component
public class TestStateProvider {
#Autowired
private TestDriver driver;
// ...
}
I'm aware that I could use #Scope("singleton") and #DirtiesContext(classMode = ClassMode.AFTER_EACH_TEST_METHOD) but this refreshes more than I need – a new TestDriver instance for each test would be enough. Also, this approach is error-prone because all tests using the TestDriver would need to know that they also need the #DirtiesContext annotation. So I'm looking for a better solution.
It is actually pretty easy to implement a testMethod scope:
public class TestMethodScope implements Scope {
public static final String NAME = "testMethod";
private Map<String, Object> scopedObjects = new HashMap<>();
private Map<String, Runnable> destructionCallbacks = new HashMap<>();
#Override
public Object get(String name, ObjectFactory<?> objectFactory) {
if (!scopedObjects.containsKey(name)) {
scopedObjects.put(name, objectFactory.getObject());
}
return scopedObjects.get(name);
}
#Override
public void registerDestructionCallback(String name, Runnable callback) {
destructionCallbacks.put(name, callback);
}
#Override
public Object remove(String name) {
throw new UnsupportedOperationException();
}
#Override
public String getConversationId() {
return null;
}
#Override
public Object resolveContextualObject(String key) {
return null;
}
public static class TestExecutionListener implements org.springframework.test.context.TestExecutionListener {
#Override
public void afterTestMethod(TestContext testContext) throws Exception {
ConfigurableApplicationContext applicationContext = (ConfigurableApplicationContext) testContext
.getApplicationContext();
TestMethodScope scope = (TestMethodScope) applicationContext.getBeanFactory().getRegisteredScope(NAME);
scope.destructionCallbacks.values().forEach(callback -> callback.run());
scope.destructionCallbacks.clear();
scope.scopedObjects.clear();
}
}
#Component
public static class ScopeRegistration implements BeanFactoryPostProcessor {
#Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory factory) throws BeansException {
factory.registerScope(NAME, new TestMethodScope());
}
}
}
Just register the test execution listener, and there will be one instance per test of all #Scope("testMethod") annotated types:
#RunWith(SpringRunner.class)
#SpringBootTest
#TestExecutionListeners(listeners = TestMethodScope.TestExecutionListener.class,
mergeMode = MergeMode.MERGE_WITH_DEFAULTS)
public class MyTest {
#Autowired
// ... types annotated with #Scope("testMethod")
}
I ran into the same problem some time ago and came to this solution:
Use Mocks
I wrote some methods to create specific mockito settings to add behavior to each mock.
So create a TestConfiguration class with following methods and bean definition.
private MockSettings createResetAfterMockSettings() {
return MockReset.withSettings(MockReset.AFTER);
}
private <T> T mockClass(Class<T> classToMock) {
return mock(classToMock, createResetAfterMockSettings());
}
and your bean definition will look like:
#Bean
public TestDriver testDriver() {
return mockClass(TestDriver .class);
}
MockReset.AFTER is used to reset the mock after the test method is run.
And finally add a TestExecutionListeners to your Test class:
#TestExecutionListeners({ResetMocksTestExecutionListener.class})
My FixValueConceptIntegration class has a constructor and it looks like this:
private ReferenceConceptHelper referenceConceptHelper;
private ConceptClientFacade conceptClientExternalFacade;
public FixValueConceptIntegration()
{
referenceConceptHelper = JournalSingletonFactory.getInstance().getSingletonInstance(ReferenceConceptHelper.class);
conceptClientExternalFacade = JournalSingletonFactory.getInstance().getSingletonInstance(ConceptClientFacade.class);
}
So now I'm going to test it using Mockito.
If we have a constructor like
public FixValueConceptIntegration(ReferenceConceptHelper referenceConceptHelper, ConceptClientFacade conceptClientExternalFacade)
{
this.referenceConceptHelper = referenceConceptHelper
this.conceptClientExternalFacade = conceptClientExternalFacade
}
I know it is easy to initialize when we are going to testing the class. Because we can just mock the ReferenceConceptHelper and ConceptClientFacade classes.
Then we can use it at the #BeforeMethod like this:
#BeforeMethod
public void beforeMethod()
{
MockitoAnnotations.initMocks(this);
fixValueConceptIntegration = new FixValueConceptIntegration(referenceConceptHelper, conceptClientExternalFacade);
}
Then all the dependencies will inject to the constructor and no worries.
So here the problem is I can't figure out how to inject these dependencies (by mocking) to the above testable class.
Just use the mock (org.mockito.Mockito.mock) method for the class and the when method to mock the method calls:
#Test
public void yourTest() {
ReferenceConceptHelper referenceConceptHelper = mock(ReferenceConceptHelper .class);
when(referenceConceptHelper.someMethod(any()).thenReturn("hello");
ConceptClientFacade conceptClientExternalFacade = mock(ConceptClientExternalFacade.class);
when(conceptClientExternalFacade.someMethod(any()).thenReturn("world");
FixValueConceptIntegration integration = new FixValueConceptIntegration(referenceConceptHelper, conceptClientExternalFacade);
assertEquals("hello world", integration.methodThatYouWouldLikeToTest());
}
In this case, you do not need to use the #BeforeMethod or call MockitoAnnotations.initMocks(this);. For unit tests, the initMocks are only useful if you do not have access directly to the class injected (typically when you are using field injection).
But if you would like to use the annotations (I personally don't like), you can do something like that:
#InjectMocks
private FixValueConceptIntegration integration;
#Mock
private ReferenceConceptHelper referenceConceptHelper;
#Mock
private ConceptClientFacade conceptClientFacade;
#Before
public void init() {
MockitoAnnotations.initMocks(this);
when(referenceConceptHelper.someMethod(any()).thenReturn("hello");
when(conceptClientExternalFacade.someMethod(any()).thenReturn("world");
}
#Test
public void yourTest() {
assertEquals("hello world", integration.methodThatYouWouldLikeToTest());
}
I extended my test class with TestNGBase which extends PowerMockTestCase.
And then add registerMockSingleton method to the TestNGBase class like this;
protected <E, I extends E> void registerMockSingleton(Class<E> typeInterface, I mock)
{
delegate.registerMockSingleton(typeInterface, mock);
}
Then inject mock dependencies to the constructor like this way;
#Override
public void performSetup() {
MockitoAnnotations.initMocks(this);
registerMockSingleton(ReferenceConceptHelper.class,mockReferenceConceptHelper);
registerMockSingleton(ConceptClientFacade.class,mockConceptClientExternalFacade);
fixValueConceptIntegration = new FixValueConceptIntegration();
}
#Override
protected void performTearDown() throws Exception
{
fixValueConceptIntegration = null;
}
All solved!!!
(My testable class constructor doesn't inject dependencies to with constructor
arguments.Thats why I solved my problem like this)
I have a method to test which is calling another class to get some information:
public ClassToTest {
public void methodToTest() {
AnotherClass ac = Factory.getInstance();
ResponseObj response = ac.anotherMethod();
}
}
AnotherClass is part of another JAR and I would like to mock the response from it(to be specific mock ResponseObj response)
How can I achieve that using Mockito?
First you need is to make your class testable. It means you need to extract object creation (AnotherClass ac = Factory.getInstance()) from your methodToTest to instance field or maybe separate method (to be able to mock it), or even better - create object outside of your class and pass it via constructor. As a result, your class under test should look like:
public class ClassToTest {
private AnotherClass ac;
public ClassToTest(AnotherClass ac) {
this.ac = ac;
}
public void methodToTest() {
ResponseObj response = ac.anotherMethod();
response.smth();
}
}
Then you need to declare AnotherClass and ResponseObj as fields in test class, and initialize them as a mocks.
AnotherClass ac = Mockito.mock(AnotherClass.class);
ResponseObj responseMock = Mockito.mock(ResponseObj.class);
After that you can mock method call:
when(anotherClassMock.anotherMethod()).thenReturn(responseMock);
At the end your test class should look like:
public class ClassToTestTest {
private AnotherClass anotherClassMock = mock(AnotherClass.class);
private ResponseObj responseMock = mock(ResponseObj.class);
private ClassToTest classToTest = new ClassToTest(anotherClassMock);
#Test
public void test() {
when(anotherClassMock.anotherMethod()).thenReturn(responseMock);
classToTest.methodToTest();
verify(responseMock, only()).smth();
}
}
And in case you couldn't change public API of your ClassToTest, you can use approach with Mockito spy and protected method.
public class ClassToTest {
public void methodToTest() {
AnotherClass ac = constructAnotherClassObj();
ResponseObj response = ac.anotherMethod();
response.smth();
}
protected AnotherClass constructAnotherClassObj() {
return Factory.getInstance();
}
}
public class ClassToTestTest {
private AnotherClass anotherClassMock = mock(AnotherClass.class);
private ResponseObj responseMock = mock(ResponseObj.class);
private ClassToTest classToTest = spy(new ClassToTest());
#Test
public void test() {
when(anotherClassMock.anotherMethod()).thenReturn(responseMock);
when(classToTest.constructAnotherClassObj()).thenReturn(anotherClassMock);
classToTest.methodToTest();
verify(responseMock, only()).smth();
}
}
Although the answer by #arsen_adzhiametov is correct and up to the mark I would like to contribute how I do it.
In this case, I am mocking the value of HomeClient which internally is a WebClient that calls out another service for some values.
TestClass.java (Please name it better)
...
import org.mockito.Mockito;
...
class TestClass {
HomeClient mockHomeClient;
#BeforeEach
void setup() {
mockHomeClient = Mockito.mock(HomeClient.class);
// Axon specific test code. Can ignore if not using Axon.
fixture = new AggregateTestFixture<>(SomeAgreegate.class);
fixture.registerInjectableResource(mockHomeClient);
}
#Test
void testOpenOperation() throws HomeClientException {
Mockito.when(mockHomeClient.getXYZ("nice")).thenReturn(2);
// Do what you will with your code and call the method which you want to test
// Mockito will mock the `HomeClient` in this case and `getXYZ` will return `2`
// You can also change the mock response any time in the same function
Mockito.when(mockHomeClient.getXYZ("nice")).thenReturn(-100);
// Or specify different results on mock when different values are provided
Mockito.when(mockHomeClient.getXYZ("nice")).thenReturn(1);
Mockito.when(mockHomeClient.getXYZ("foo")).thenReturn(100);
Mockito.when(mockHomeClient.getXYZ("bar")).thenReturn(0);
}
}
I have this code in my Subject Under Test:
public class Widget {
private Set<Thing> things;
public Set<Thing> getThings() { return things; }
public void setThings(Set<Thing> things) { this.things = things; }
public void performAction(PerformingVisitor performer) {
for (Thing thing: getThings())
{
thing.perform(performer);
}
}
}
My JUnit/Mockito test looks like:
#RunWith(MockitoJUnitRunner.class)
public class WidgetTest {
#Mock private PerformingVisitor performer;
#Mock private Thing thing;
#InjectMocks private Widget widget;
#Before
public void setUp() throws Exception {
Set<Thing> things = new HashSet<Thing>();
things.add(thing);
widget.setThings(things);
MockitoAnnotations.initMocks(this);
}
#Test
public void shouldPerformThing() {
Mockito.when(thing.perform(Mockito.any(PerformingVisitor.class))).thenReturn(true);
widget.performAction(performer);
Mockito.verify(thing).perform(Mockito.any(PerformingVisitor.class));
}
}
However, this gives me the error:
Wanted but not invoked:
thing.perform(<any>);
-> at com.myclass.ThingTest.shouldPerformThing(WidgetTest.java:132)
I've verified that the code enters the for loop and should be calling the actual thing.perform(performer); line, but my mock does not seem to be recording a call.
I think you need initMocks before the mock injection.
Could you try to change your setUp method for this:
#Before
public void setUp() throws Exception {
MockitoAnnotations.initMocks(this);
Set<Thing> things = new HashSet<Thing>();
things.add(thing);
widget.setThings(things);
}
Hope it works
From the MockitoJUnitRunner javadoc:
Initializes mocks annotated with Mock, so that explicit usage of MockitoAnnotations.initMocks(Object) is not necessary.
So, if you remove
MockitoAnnotations.initMocks(this)
from your setUp method, the test pass.