Problem creating mock using PowerMock

[Ali Gohar]

I am using following in my pom.xml

   <dependency> 
            <groupId>org.powermock.modules</groupId> 
            <artifactId>powermock-module-junit4</artifactId> 
            <version>1.4.5</version> 
            <scope>test</scope> 
        </dependency>
        <dependency>
		  <groupId>com.google.collections</groupId>
		  <artifactId>google-collections</artifactId>
		  <version>1.0</version>
		  <scope>test</scope>
	</dependency>	

        <dependency>
            <groupId>org.easymock</groupId>
            <artifactId>easymock</artifactId>
            <version>2.2</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.easymock</groupId>
            <artifactId>easymockclassextension</artifactId>
            <version>2.2</version>
            <scope>test</scope>
        </dependency>

I get this exception:

java.lang.IllegalStateException: Failed to transform class with name com.my.DroolsFlowManagerTest. Reason: 3
	at org.powermock.core.classloader.MockClassLoader.loadMockClass(MockClassLoader.java:208)
	at org.powermock.core.classloader.MockClassLoader.loadModifiedClass(MockClassLoader.java:146)
	at org.powermock.core.classloader.DeferSupportingClassLoader.loadClass(DeferSupportingClassLoader.java:65)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
	at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:247)
	at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.createDelegatorFromClassloader(JUnit4TestSuiteChunkerImpl.java:143)
	at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.createDelegatorFromClassloader(JUnit4TestSuiteChunkerImpl.java:49)
	at org.powermock.tests.utils.impl.AbstractTestSuiteChunkerImpl.createTestDelegators(AbstractTestSuiteChunkerImpl.java:231)
	at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.<init>(JUnit4TestSuiteChunkerImpl.java:69)
	at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.<init>(AbstractCommonPowerMockRunner.java:36)
	at org.powermock.modules.junit4.PowerMockRunner.<init>(PowerMockRunner.java:27)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
	at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:31)
	at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:24)
	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
	at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:29)
	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
	at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:24)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.<init>(JUnit4TestReference.java:29)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestClassReference.<init>(JUnit4TestClassReference.java:25)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createTest(JUnit4TestLoader.java:40)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.loadTests(JUnit4TestLoader.java:30)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:452)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 3
	at javassist.bytecode.ByteArray.write16bit(ByteArray.java:40)
	at javassist.bytecode.StackMapTable$Shifter.update(StackMapTable.java:744)
	at javassist.bytecode.StackMapTable$Shifter.sameFrame(StackMapTable.java:720)
	at javassist.bytecode.StackMapTable$Walker.stackMapFrames(StackMapTable.java:194)
	at javassist.bytecode.StackMapTable$Walker.parse(StackMapTable.java:179)
	at javassist.bytecode.StackMapTable$Shifter.doit(StackMapTable.java:714)
	at javassist.bytecode.StackMapTable.shiftPc(StackMapTable.java:693)
	at javassist.bytecode.CodeIterator.insertGap0(CodeIterator.java:676)
	at javassist.bytecode.CodeIterator.insertGap(CodeIterator.java:636)
	at javassist.bytecode.CodeIterator.insertGapCore(CodeIterator.java:467)
	at javassist.bytecode.CodeIterator.insertGap(CodeIterator.java:413)
	at javassist.expr.Expr.replace0(Expr.java:298)
	at javassist.expr.FieldAccess.replace(FieldAccess.java:213)
	at org.powermock.core.transformers.impl.MainMockTransformer$PowerMockExpressionEditor.edit(MainMockTransformer.java:233)
	at javassist.expr.ExprEditor.loopBody(ExprEditor.java:197)
	at javassist.expr.ExprEditor.doit(ExprEditor.java:90)
	at javassist.CtClassType.instrument(CtClassType.java:1289)
	at org.powermock.core.transformers.impl.MainMockTransformer.transform(MainMockTransformer.java:70)
	at org.powermock.core.classloader.MockClassLoader.loadMockClass(MockClassLoader.java:204)
	... 30 more

then i added javassist to my pom.xml like this:

	<dependency>
		  <groupId>javassist</groupId>
		  <artifactId>javassist</artifactId>
		  <version>3.10.0.GA</version>
		  <scope>test</scope>
		</dependency>

I've got rid of that problem but now I get another exception while trying to use PowerMock.createMock() method. Here is my code to create mock. its simple:

createMock(ByteArrayInputStream.class);

Exception i get is:

java.lang.IllegalArgumentException: java.io.ByteArrayInputStream is not an interface
	at java.lang.reflect.Proxy.getProxyClass(Proxy.java:362)
	at java.lang.reflect.Proxy.newProxyInstance(Proxy.java:581)
	at org.easymock.internal.JavaProxyFactory.createProxy(JavaProxyFactory.java:12)
	at org.easymock.internal.MocksControl.createMock(MocksControl.java:37)
	at org.powermock.api.easymock.PowerMock.doCreateMock(PowerMock.java:2211)
	at org.powermock.api.easymock.PowerMock.doMock(PowerMock.java:2162)
	at org.powermock.api.easymock.PowerMock.createMock(PowerMock.java:98)
	at net.plus.kbd.core.drools.DroolsFlowManagerTest.testReverseFlow(DroolsFlowManagerTest.java:103)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:66)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:322)
	at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:86)
	at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:94)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:309)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:112)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:73)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:297)
	at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:84)
	at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:222)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:161)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:135)
	at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
	at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:133)
	at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:112)
	at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:57)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Any idea what am i doing wrong?

Thanks

[David Newton]

Does PowerMock automatically take advantage of ClassExtension?

[Ali Gohar]

Thanks for your reply. Don't know to be honest I am still learning but looking at the example on their website, it looks like we can mock classes having final methods etc using PowerMock.createMock method. Have a look at http://code.google.com/p/powermock/wiki/MockFinal.

[Ali Gohar]

Fixed the problem It looks like PowerMock 1.4.5 is not compatible with easymock 2.2. It works with EasyMock 3.0 as easymock 3.0 doesn't use class extensions anymore separately it is built into it. Also it needs javassist 3.12.0.GA. Thanks.

[Jeanne Boyarsky]

Thanks for sharing the solution Ali.