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org.powermock.api.mockito.ClassNotPreparedException in Static class mocking

I am writing a unit test to mock a static method in the verticle but getting ClassNotPreparedException always. I think that its only possible to mock this way if only the class is static, but i have non static class. What am i missing?
I have tried various solutions like using #rule or #PowerMockIgnore
//myVerticleTest.java
package com.blabla.me.verticles;
import static com.google.common.truth.Truth.assertThat;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import io.vertx.core.Vertx;
import io.vertx.junit5.VertxTestContext;
import io.vulpx.VulpxTestBase;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PowerMockIgnore;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.junit.runner.RunWith;
import com.blabla.me.verticles.AdditionalInformationCardVerticle;
import org.powermock.modules.junit4.rule.PowerMockRule;
import org.junit.Rule;
import com.blabla.me.verticles.st;
#RunWith(PowerMockRunner.class)
#PrepareForTest({ st.class })
#PowerMockIgnore({"org.mockito.*"})
public class myVerticleTest extends VulpxTestBase {
#Rule public PowerMockRule rule = new PowerMockRule();
private Vertx vertx;
private AdditionalInformationCardVerticle dummy;
#BeforeEach
#PrepareForTest({ st.class })
public void setUp(VertxTestContext testContext) throws Exception {
vertx = Vertx.vertx();
try {
PowerMockito.mockStatic(st.class);
PowerMockito.when(st.createClient()).thenReturn("kk");
//deploying verticle
dummy = new AdditionalInformationCardVerticle();
vertx.deployVerticle(dummy, testContext.completing());
} catch (Exception e) {
System.out.println("heyyy eroorrr : " + e);
}
}
#Test
#PrepareForTest({ st.class })
public void justnormaltest() {
cla ownclass = new cla();
String k = ownclass.createfromclass();
assertThat("kk").isEqualTo(k);
}
}
// st.java
public class st {
public static String createClient() {
return "kk";
}
}
// cla.java
public class cla {
public String createfromclass() {
return st.createClient();
}
}
I expect it to run the assertion but i always get below excpetion:
"org.powermock.api.mockito.ClassNotPreparedException:
The class com.sap.me.verticles.st not prepared for test.
To prepare this class, add class to the '#PrepareForTest' annotation.
In case if you don't use this annotation, add the annotation on class or method level. "

Here:
#PrepareForTest({ st.class })
That one goes to exactly one place: in front of your test class public class myVerticleTest.
And hint: instead of adding more and more "things" to not working code: pick any good documentation, and try to follow that to the last ; in the example code (instead of assuming that adding more and more things here or there would help).
One good starting point: the official documentation on static mocking.
And of course, the usual caveat: consider not learning about PowerMock in the first place. Instead focus on writing "easy to test" code. Far too often, people think PowerMock(ito) is the answer to their problem. When their problem in reality is their inability to write "easy to test" production code.

Proxy for abstract class without changing the usage

I have an abstract class (database mapping) implementing an interface where default implementations are injected at runtime (this is part of another library and cannot be changed).
I want to override one of the default implementation via a proxy (as that seems like the way to override this).
public abstract class Table1 implements Storable<Table1>
{
#Sequence("ID_SEQUENCE")
#Alias("ID")
public abstract String getID();
public abstract void setID(String ID);
#Alias("NAME")
public abstract String getAvailabilityZone();
public abstract void setAvailabilityZone(String value);
}
public interface Storable<S extends Storable<S>> {
//a bunch of method definition.
boolean tryLoad() throws Exception;
}
Let's say I want to override tryLoad() method to do my own things instead of what the generated code provides. Given the nature of the library, it is not something I can achieve by simple #Override.
The simple way this is currently used is as following:
public void method() {
Table1 t = Repository.storageFor(Table1.class).prepare();
t.setName( "temp" );
if (!t.tryLoad())
t.tryInsert();
}
I want to proxy tryLoad() without making changes in all the methods across the whole codebase - that would be to get proxied instance instead of actual one and perform the operation on that.
Is there any recommended way to achieve this?
Thanks!

I woke up last night and felt bored, so despite your lack of feedback I created a little Carbonado showcase project and shared it on GitHub. I made three commits:
Initial commit with Maven project already prepared for AspectJ and a JUnit test for me to find out how Carbonado actually works, because I had never used it before.
Add failing unit test for behaviour of tryLoad() expected to be provided by aspect.
Add aspect to make unit test pass. Aspect hooks into tryLoad() and auto-creates non-existent record. I do not know if I guessed right what you actually wanted to achieve, but if it was a different thing, just change the aspect implementation.
Sample code
Carbonado storable:
package de.scrum_master.app;
import com.amazon.carbonado.Nullable;
import com.amazon.carbonado.PrimaryKey;
import com.amazon.carbonado.Storable;
#PrimaryKey("ID")
public interface StoredMessage extends Storable<StoredMessage> {
long getID();
void setID(long id);
#Nullable String getMessage();
void setMessage(String message);
}
Aspect:
package de.scrum_master.aspect;
import com.amazon.carbonado.Storable;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
#Aspect
public class CarbonadoAspect {
#Around("call(boolean tryLoad()) && target(storable)")
public boolean tryInsertIfNotFound(ProceedingJoinPoint thisJoinPoint, Storable storable) throws Throwable {
System.out.println(thisJoinPoint);
if ((boolean) thisJoinPoint.proceed())
return true;
System.out.println("Not found: " + storable + " -> inserting");
return storable.tryInsert();
}
}
JUnit test:
package de.scrum_master.app;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.amazon.carbonado.FetchException;
import com.amazon.carbonado.PersistException;
import com.amazon.carbonado.Repository;
import com.amazon.carbonado.RepositoryException;
import com.amazon.carbonado.Storage;
import com.amazon.carbonado.SupportException;
import com.amazon.carbonado.repo.map.MapRepositoryBuilder;
import de.scrum_master.app.StoredMessage;
public class CarbonadoTest {
private Repository repo;
private Storage<StoredMessage> storage;
StoredMessage message;
#Before
public void setUp() throws Exception {
repo = MapRepositoryBuilder.newRepository();
storage = repo.storageFor(StoredMessage.class);
message = storage.prepare();
}
#After
public void tearDown() throws Exception {
repo.close();
repo = null;
storage = null;
message = null;
}
// (...)
#Test
public void aspectCreatesNonExistentRecord() throws SupportException, RepositoryException {
message.setID(1);
// Without the aspect this would be false
assertTrue(message.tryLoad());
assertEquals(message.getID(), 1);
assertEquals(message.getMessage(), null);
}
}
Enjoy!

Mock function not found in EasyMock

I am trying to build my first EasyMock test, however I have a trivial problem that the function "mock" is not found.
Here is my pretty straightforward code:
package homework;
import org.easymock.EasyMockSupport;
import org.junit.Before;
import org.junit.Test;
import com.locusenergy.homework.Elevator;
public class ElevatorTest extends EasyMockSupport{
private Elevator elevator;
#Before
public void setUp() {
elevator = mock(Elevator.class);
}
#Test
public void testCallElevator() {
elevator.requestFloor(5);
}
}
However, I am getting an error that mock is not found. I have no idea how to fix this issue.

Your code probably will work as it is when the next version of EasyMock is released.
The user guide refers to the mock method which can be found in the master branch but is not in the latest release (3.3.1).

Depending on Documentationof EasyMock the example should look like this:
package homework;
import org.easymock.EasyMockSupport;
import org.junit.Before;
import org.junit.Test;
import com.locusenergy.homework.Elevator;
public class ElevatorTest extends EasyMockSupport{
private Elevator elevator;
#Before
public void setUp() {
elevator = createMock(Elevator.class);
}
#Test
public void testCallElevator() {
elevator.requestFloor(5);
}
}
As described here: http://easymock.org/api/org/easymock/EasyMockSupport.html
The API Docs say the methods nameis createMock thats all.

Just sharing another approach...
You can use org.easymock.IMocksControl.
Your code will look something like below
....
#Before
public void setUp() {
IMocksControl mocksControl = createControl();
elevator = = mocksControl.createMock(Elevator.class);
}
.....
I prefer using IMocksControl. As the name\api suggest controls the behavior of its associated mock object.
Note : I am using easymock version 3.1
Regards,
MB

Mocking CGLIB enhanced objects

Is it true that mockito can't mock objects that were already enhanced by CGLIB?
public class Article {
#Autowired
private dbRequestHandler
#Autowired
private filesystemRequestHandler
#Transactional
public ArticleDTO getArticleContents() {
//extractText() and then save the data in DTO
//extractImages() and then save the data in DTO
// some other calls to other databases to save data in dto
return articleDTO;
}
public void extractText() {
//call to DB
}
public void extractImages() {
// call to file system
}
}
public class IntegrationTest {
#Autowired
private Article article;
//setup method {
articleMock = Mockito.spy(article);
doNothing().when(articleMock).extractImages();
}
}
In the above example when it comes to doNothing().when(articleMock).extractImages(); it actually calls the real function. On a closer look articleMock gets enhanced two times. One cause of autowiring and second time cause of spying.
If I can't spy on enhaced objects, then how can I test the getArticle() method in my Integration test, so that I can verify a proper DTO is returned.
Note : I actually don't want to test the method which does filesystem calls. just the DB ones. thats why I need to test the getArticle method.

If I understand correctly your class is wired by Spring. Spring uses CGLIB to ensure transactional behaviour only if there is no interface, which is implemented by your object. If there is an interface, it uses simple JDK Dynamic Proxies. (see http://docs.spring.io/spring/docs/3.0.0.M3/reference/html/ch08s06.html)
Maybe you could try to extract an interface, and let Spring to use dynamic proxies. Maybe then Mockito could perform better.

If you run as a true unit test and not as an integration test, you need not run in a container having Spring autowire for you. In one of your comments, I think you alluded to trying this, and you noted that there was an endless set of chained object references which you would have to provide as well. But there is a way around that. Mockito provides some predefined Answer classes that you can initialize your mock with. You may want to look at RETURNS_DEEP_STUBS, which will possibly get you around this problem.

Will you please update your question with ready-to-go compilable code. Here's some code review suggestions:
Issues with this question code:
Article.java missing import: org.springframework.beans.factory.annotation.Autowired
Article.java missing import: org.springframework.transaction.annotation.Transactional
Article.java attribute syntax issue: dbRequestHandler
Article.java attribute syntax issue: filesystemRequestHandler
Article.java method has no initialized return statement: articleDTO
Here's what you maybe should use as you questionCode with the above issues fixed:
Article.java
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
public class Article {
#Autowired
private Object dbRequestHandler;
#Autowired
private Object filesystemRequestHandler;
#Transactional
public ArticleDTO getArticleContents() {
// extractText() and then save the data in DTO
// extractImages() and then save the data in DTO
// some other calls to other databases to save data in dto
ArticleDTO articleDTO = null;
return articleDTO;
}
public void extractText() {
// call to DB
}
public void extractImages() {
// call to file system
}
}
IntegrationTest.java is a poor name for a testClass because it's to generic. I would suggest ArticleTest for a java unit test.
ArticleTest.java
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.springframework.beans.factory.annotation.Autowired;
#RunWith(PowerMockRunner.class)
#PrepareForTest(ClassWithPrivate.class)
public class ArticleTest {
#InjectMocks
private Article cut;
#Mock
private Object dbRequestHandler;
#Mock
private Object filesystemRequestHandler;
#Test
public void testeExtractImages() {
/* Initialization */
Article articleMock = Mockito.spy(cut);
/* Mock Setup */
Mockito.doNothing().when(articleMock).extractImages();
/* Test Method */
ArticleDTO result = cut.getArticleContents();
/* Asserts */
Assert.assertNull(result);
}
}

You can utilize AdditionalAnswers.delegatesTo method. In following example, the secondProxyDoingMocking declaration creates something like a spy (compare with implementation of spy() method) except it uses "lightweight" method delegation.
import org.mockito.AdditionalAnswers;
public class ArticleTest {
#Autowired
private Article firstProxyDoingAutowiring;
#Test
public void testExtractImages() {
Article secondProxyDoingMocking = Mockito.mock(Article.class,
Mockito.withSettings().defaultAnswer(
AdditionalAnswers.delegatesTo(firstProxyDoingAutowiring)
)
);
Mockito.doNothing().when(secondProxyDoingMocking).extractImages();
...
}
}
I didn't test this example, however I assembled it from my working code. My use case was similar: return constant value for given method, call real method for all remaining methods of Spring #Transactional-annotated bean.

How do I mock static methods in a class with easymock?

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);
}
}