Suppose I have a class like so:
public class StaticDude{
public static Object getGroove() {
// ... some complex logic which returns an object
};
}
How do I mock the static method call using easy mock? StaticDude.getGroove().
I am using easy mock 3.0
Not sure how to with pure EasyMock, but consider using the PowerMock extensions to EasyMock.
It has a lot of cool functions for doing just what you need -
https://github.com/jayway/powermock/wiki/MockStatic
Easymock is a testing framework for "for interfaces (and objects through the class extension)" so you can mock a class without an interface. Consider creating an interfaced object with an accessor for your static class and then mock that acessor instead.
EDIT: Btw, I wouldn't recommend doing static classes. It is better to have everything interfaced if you are doing TDD.
Just in Case PowerMock is unavailable for any reason:
You could move the static call to a method, override this method in the instantiation of the tested class in the test class, create a local interface in the test class and use its method in the overidden method:
private interface IMocker
{
boolean doSomething();
}
IMocker imocker = EasyMock.createMock(IMocker.class);
...
#Override
void doSomething()
{
imocker.doSomething();
}
...
EasyMock.expect(imocker.doSomething()).andReturn(true);
Generally speaking, it is not possible to mock a static method without using some sort of accessor, which seems to defeat the purpose of using a static method. It can be quite frustrating.
There is one tool that I know of called "TypeMock Isolator" which uses some sort of Satanic Magic to mock static methods, but that tool is quite expensive.
The problem is, I know of no way to override a static method. You can't declare it virtual. you can't include it in an interface.
Sorry to be a negative nelly.
Adding an exemple on how to implements static mock along regular mock of injected classes with EasyMock / PowerMock, since the linked exemple only shows static mock.
And with the PowerMockRunner the #Mock services are not wired on the #TestSubject service to test.
Let say we have a service we want to test, ServiceOne :
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
#Service
public class ServiceOne {
#Autowired
private ServiceTwo serviceTwo;
public String methodToTest() {
String returnServ2 = serviceTwo.methodToMock();
return ServiceUtils.addPlus(returnServ2);
}
}
Which calls another service that we will want to mock, ServiceTwo :
import org.springframework.stereotype.Service;
#Service
public class ServiceTwo {
public String methodToMock() {
return "ServiceTwoReturn";
}
}
And which calls a final class static method, ServiceUtils :
public final class ServiceUtils {
public static String addPlus(String pParam) {
return "+" + pParam;
}
}
When calling ServiceOne.methodToTest() we get "+ServiceTwoReturn" as a return.
Junit Test with EasyMock, mocking only the injected ServiceTwo Spring service :
import static org.easymock.EasyMock.expect;
import static org.easymock.EasyMock.replay;
import static org.easymock.EasyMock.verify;
import static org.junit.Assert.assertEquals;
import org.easymock.EasyMockRunner;
import org.easymock.Mock;
import org.easymock.TestSubject;
import org.junit.Test;
import org.junit.runner.RunWith;
#RunWith(EasyMockRunner.class)
public class ExempleTest {
#TestSubject
private ServiceOne serviceToTest = new ServiceOne();
#Mock
private ServiceTwo serviceMocked;
#Test
public void testMethodToTest() {
String mockedReturn = "return2";
expect(serviceMocked.methodToMock()).andReturn(mockedReturn);
replay(serviceMocked);
String result = serviceToTest.methodToTest();
verify(serviceMocked);
assertEquals("+" + mockedReturn, result);
}
}
Junit Test with EasyMock & PowerMock, mocking the injected ServiceTwo Spring service but also the final class and its Static method :
import static org.easymock.EasyMock.expect;
import static org.junit.Assert.assertEquals;
import static org.powermock.api.easymock.PowerMock.createMock;
import static org.powermock.api.easymock.PowerMock.mockStatic;
import static org.powermock.reflect.Whitebox.setInternalState;
import org.easymock.Mock;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.easymock.PowerMock;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
#RunWith(PowerMockRunner.class)
#PrepareForTest(ServiceUtils.class)
public class ExempleTest {
private ServiceOne serviceToTest;
private ServiceTwo serviceMocked;
#Before
public void setUp() {
serviceToTest = new ServiceOne();
serviceMocked = createMock(ServiceTwo.class);
// This will wire the serviced mocked into the service to test
setInternalState(serviceToTest, serviceMocked);
mockStatic(ServiceUtils.class);
}
#Test
public void testMethodToTest() {
String mockedReturn = "return2";
String mockedStaticReturn = "returnStatic";
expect(serviceMocked.methodToMock()).andReturn(mockedReturn);
expect(ServiceUtils.addPlus(mockedReturn)).andReturn(mockedStaticReturn);
PowerMock.replayAll();
String result = serviceToTest.methodToTest();
PowerMock.verifyAll();
assertEquals(mockedStaticReturn, result);
}
}
Related
I have a class for parsing a json response given from an API request, that was made using the restlet framework.
The method responsible for reading the json takes an object from this framework, a Representation,
public QueryResponse readResponse(Representation repr), and I would like to test the functionality of this
My question is, how do I pass a valid Representation object into this method in my JUnit test, considering I do not know how it is constructed from the API call, will I have to implement the call itself within the test to retrieve a workable object or is there another method?
For a unit test, use a mocking framework like mockito:
import org.hamcrest.Matchers;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;
import org.restlet.representation.Representation;
import static org.junit.Assert.assertThat;
import static org.mockito.Mockito.when;
#ExtendWith(MockitoExtension.class)
public class RestletTest {
#Mock
private Representation representation;
#Test
public void demonstrateMock() {
when(representation.getAvailableSize()).thenReturn(1024l);
ClassToTest t = new ClassToTest();
assertThat(t.callRepresentation(representation), Matchers.is(1024l));
}
}
class ClassToTest {
public long callRepresentation(Representation representation) {
return representation.getAvailableSize();
}
}
I want to mock a static method using PowerMockito,
public class DepedencyService {
public static int getImportantValue() {
return -4;
}
}
public class Component {
public int componentMethod() {
return DepedencyService.getImportantValue();
}
}
but it is giving me an exception.
import static org.testng.Assert.assertEquals;
import org.easymock.EasyMock;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
#RunWith(PowerMockRunner.class)
#PrepareForTest(DepedencyService.class)
public class ComponentTest {
#Test
public void testComponentMethod() {
Component c = new Component();
PowerMockito.mockStatic(DepedencyService.class);
EasyMock.expect(DepedencyService.getImportantValue()).andReturn(1);
assertEquals(1, c.componentMethod());
}
}
The exception :-
java.lang.IllegalStateException: no last call on a mock available at
org.easymock.EasyMock.getControlForLastCall(EasyMock.java:520) at
org.easymock.EasyMock.expect(EasyMock.java:498)
Can anyone please help me? Why is this failing? I am new to PowerMockito and does not know what to do here!
Your main problem is that you're writing STUPID code (like most of us did at the beginning) where you rather should write SOLID code.
Using Powermock is just a surrender to this bad design.
Yes, classes having only static methods are called utility classes.
But you should get over this misconception that classes providing common behavior should have (only) static methods.
As a rule of thumb there should be only one non private static method in your entire program, and this is main().
You appear to be mixing mocking frameworks.
You need to properly arrange the static dependencies before exercising the test
Since PowerMockito is used to mock the static class then you should use Mockito to arrange the expected behavior
For example
#RunWith(PowerMockRunner.class)
#PrepareForTest(DepedencyService.class)
public class ComponentTest {
#Test
public void testComponentMethod() {
//Arrange
int expected = 1;
PowerMockito.mockStatic(DepedencyService.class);
Mockito.when(DepedencyService.getImportantValue()).thenReturn(expected);
Component subject = new Component();
//Act
int actual = subject.componentMethod();
//Assert
assertEquals(expected, actual);
}
}
That said, I would advise not having your code tightly coupled to static dependencies. It makes for difficult to test code.
I am trying to Unit Test a class in Java.
Code for this class: ToBeTested
public class ToBeTested {
private Collaborator collaborator;
public ToBeTested() {
System.out.println("ToBeTested: Constructor");
}
public void start() {
System.out.println("ToBeTested: Start");
collaborator = new Collaborator();
}
}
This class ToBeTested depends on another class, Collaborator.
Code for class: Collaborator
public class Collaborator {
Collaborator() {
System.out.println("Collaborator: Constructor");
}
}
While testing the class ToBeTested, I want to stub instantiation of Collaborator. That's a dependency I want to mock and I don't want it's constructor to be called.
I'm using Junit (v4.12) and PowerMock (v1.6.1).
Code for Test Class: TestToBeTested
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.easymock.annotation.Mock;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import static org.powermock.api.easymock.PowerMock.*;
#RunWith(PowerMockRunner.class)
#PrepareForTest({ToBeTested.class, Collaborator.class})
public class TestToBeTested {
#Mock
private Collaborator collaborator;
private ToBeTested toBeTested;
#Before
public void setUp() throws Exception {
collaborator = createMock(Collaborator.class);
expectNew(collaborator.getClass()).andReturn(null);
toBeTested = new ToBeTested();
}
#Test
public void test() {
replayAll();
toBeTested.start();
verifyAll();
}
}
My understanding is that this will mock or stub out Collaborator and it's constructor should not be called. However, when I run the test, I notice that original constructor of Collaborator is called.
Output of test run:
ToBeTested: Constructor
ToBeTested: Start
Collaborator: Constructor
I'm very new to Java and Unit Testing in Java, so I apologize if I'm doing a very fundamental mistake here.
During my quest to find out the root cause, I have referred to following SO questions:
PowerMock's expectNew() isn't mocking a constructor as expected
PowerMock expectNew how to specify the type of the parameters
Not able to mock constructor using PowerMock
https://dzone.com/articles/using-powermock-mock
Thank you very much in advance for help/suggestions/feedback.
One possible reason that it might not be working could be this line:
expectNew(collaborator.getClass()).andReturn(null);
collaborator is a mocked instance which means it's "getClass()" method is going to return Collaborator$CGLIBMockedWithPowermock or something like that -- not the Collaborator class you want it to be. So you might get it to work simply by changing that line to:
expectNew(Collaborator.class).andReturn(null);
I want to test my Service class method testB1Method2 by mocking overridden method a1Method2 of class B1. I do not want to change anything in class A1 and B1. I am using mockito 1.9.0 and powermockito 1.4.12. The following code I am trying:
UnitTestService class:
import static org.mockito.Mockito.*;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.MockitoAnnotations;
import org.powermock.api.mockito.PowerMockito;
import org.testng.Assert;
import org.testng.annotations.Test;
public class UnitTestService {
#Mock
B1 b1;
#InjectMocks
Service service = new Service();
#Test
public void testB1Method2() throws Exception {
MockitoAnnotations.initMocks(this);
when(b1.a1Method2()).thenReturn("mockvalue");
PowerMockito.whenNew(B1.class).withArguments(Mockito.any()).thenReturn(b1);
String output = service.serviceMethod();
System.out.println("=====" + output);
Assert.assertTrue("mockvalue".equalsIgnoreCase(output), "testA1Method2 failed!");
}
}
Service class:
public class Service {
public String serviceMethod() {
B1 b1 = new B1("some data");
return b1.a1Method2();
}
}
class A1:
public abstract class A1 {
public A1(String data) {
//doing many thing with data
}
public String a1Method1() {
return "from a1Method1";
}
public String a1Method2() {
return "from a1Method2";
}
}
B1 class:
public class B1 extends A1 {
public B1(String data) {
super(data);
}
#Override
public String a1Method1() {
return "a1Method1 from B1 class";
}
}
I am running class UnitTestService using testNG in eclipse. And here actual method in class B1 a1Method2 is getting called as it is printing "=====from a1Method2" in console. ie: here it seems mockito is not able to mock this method.
What code change should I make in UnitTestService class to mock class B1 a1Method2 ?
You created hard to test code there, for absolutely no good reason.
What is breaking your neck is that small little call to new B1 in your service class.
If you would be using dependency injection for that object; then you would absolutely not need to deal with powermock and mocking inherited methods. Because then you could simply create a "mock" B1; pass that to your service; and then you have full control over what will be happening during your test.
So, the viable alternative here might be to avoid complex test setup by simply improving your production code to be easier to test.
Watch those videos to better understand what I am talking about!
Description:
I cannot seem to have my stubs or mocks take affect in the class I have under test. I am trying to use the whenNew action so I can mock a return object and then mock a operation on that object with a returned value.
I imagine its something simple I am missing but not seeing it.
SOLUTION: Originally I was running with MockitoRunner.class and it required being changed to PowerMockRunner.class. Code below reflects the solution.
Jars on the classpath:
powermock-mockito-1.4.11-full.jar
mockoito-all-1.9.0.jar
javassist-3.15.0-GA.jar
junit-4.8.2.jaf
objensis-1.2.jar
cglib-nodep-2.2.2.jar
TEST CLASS
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import static org.powermock.api.mockito.PowerMockito.*;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import static org.mockito.Matchers.any;
#RunWith(PowerMockRunner.class)
#PrepareForTest(ClassA.class)
public class ClassATest {
#Test
public void test() throws Exception
{
String[] returnSomeValue = {"PowerMockTest"};
String[] inputValue = {"Test1"};
ClassB mockedClassB = mock(ClassB.class);
whenNew( ClassB.class).withNoArguments().thenReturn( mockedClassB );
when( mockedClassB, "getResult", any(String[].class) ).thenReturn(returnSomeValue);
IClassA classUnderTest = new ClassA();
String[] expectedValue = classUnderTest.runTest(inputValue);
}
}
Class A Implementation
public class ClassA implements IClassA {
#Override
public String[] runTest(String[] inputValues) {
String[] result;
IClassB classB = new ClassB();
result = classB.getResult(inputValues);
return result;
}
}
Since you are using powermock features (#PrepareForTest, PowerMockito.whenNew etc.), you have to run your test with the PowerMockRunner.
#RunWith(PowerMockRunner.class)
Because ClassB#geResult is not private, you may also simplify your code and replace
when( mockedClassB, "getResult", any(String[].class) ).thenReturn(someValue);
by
when(mockedClassB.getResult(any(String[].class))).thenReturn(someValue);