Regression: MethodNotFoundException

[andrei-ivanov]

Trying to upgrade from 1.6.4 to 1.6.6, I ran into this error:

org.powermock.reflect.exceptions.MethodNotFoundException: No methods matching the name(s) accept were found in the class hierarchy of class java.lang.Object.
	at org.powermock.reflect.internal.WhiteboxImpl.getMethods(WhiteboxImpl.java:1720)
	at org.powermock.reflect.internal.WhiteboxImpl.getMethods(WhiteboxImpl.java:1745)
	at org.powermock.reflect.internal.WhiteboxImpl.getBestMethodCandidate(WhiteboxImpl.java:983)
	at org.powermock.core.MockGateway$MockInvocation.findMethodToInvoke(MockGateway.java:317)
	at org.powermock.core.MockGateway$MockInvocation.init(MockGateway.java:356)
	at org.powermock.core.MockGateway$MockInvocation.<init>(MockGateway.java:307)
	at org.powermock.core.MockGateway.doMethodCall(MockGateway.java:142)
	at org.powermock.core.MockGateway.methodCall(MockGateway.java:125)
	at InstanceFacadeImplTest.pendingInstanceStatusProcessorShouldDoNothing(InstanceFacadeImplTest.java:91)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:68)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:316)
	at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:89)
	at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:97)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:300)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:131)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.access$100(PowerMockJUnit47RunnerDelegateImpl.java:59)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner$TestExecutorStatement.evaluate(PowerMockJUnit47RunnerDelegateImpl.java:147)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.evaluateStatement(PowerMockJUnit47RunnerDelegateImpl.java:107)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:288)
	at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:87)
	at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:50)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:208)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:147)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:121)
	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:123)
	at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:121)
	at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
	at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

public enum InstanceStatus {
	PENDING;
}

import java.util.function.Consumer;

public class InstanceFacadeImpl implements InstanceFacade {
	final Map<InstanceStatus, Consumer<Instance>> instanceStatusProcessors = new HashMap<>();

	{
		instanceStatusProcessors.put(InstanceStatus.PENDING, instance -> {
			// NOP
		});
	}
}

@RunWith(PowerMockRunner.class)
@PowerMockListener(AnnotationEnabler.class)
@PowerMockIgnore({ "javax.management.*" })
public class InstanceFacadeImplTest {

	private InstanceFacadeImpl instanceFacade;

	@Before
	public void setup() throws Exception {
		instanceFacade = new InstanceFacadeImpl();
	}

	@Test
	public void pendingInstanceStatusProcessorShouldDoNothing() throws Exception {
		replayAll();
		instanceFacade.instanceStatusProcessors.get(InstanceStatus.PENDING).accept(null);
		verifyAll();
	}
}

[andrei-ivanov]

As far as I see, it reaches org.powermock.reflect.internal.proxy.ProxyFrameworks.isCglibProxyClass(Class<?> clazz), which mistakes the lambda as a cglib proxy...

instance = InstanceFacadeImpl$$Lambda$1/1881218633@87b5b49
methodName = accept

This is from org.powermock.reflect.internal.proxy.ProxyFrameworks.getUnproxiedType(Class<?> type)
After that, the type becomes java.lang.Object, where it doesn't find the method.

[thekingn0thing]

Thank you for investigation! You're welcome to provide a pull request with fix :)

[andrei-ivanov]

Hmm, I'm not sure how the fix should look.
As far as I see on StackOverflow, there's no proper way to identify a lambda.
Looking for $$Lambda is not guaranteed to be portable or to be the same in the future versions.

I did however found an answer on how to properly identify cglib proxies.
It's actually done that way in another place in PowerMock: org.powermock.api.easymock.PowerMock.isEasyMocked(Object mock):

import net.sf.cglib.proxy.Enhancer;

private static boolean isEasyMocked(Object mock) {
    return Enhancer.isEnhanced(mock.getClass()) || Proxy.isProxyClass(mock.getClass());
}

This would mean that powermock-reflect would have a compile dependency on cglib-nodep, not just test, like it is now.

[thekingn0thing]

Unfortunately, we cannot introduce a new dependencies to powermock-reflect, because all other modules depends on it, and soon mockito module will not depend on cglib (Mockito 2 uses ByteBuddy instead CgLib).

I snooped the approach with CGLIB_CLASS_SEPARATOR from Spring.

Now, I think the right way will be to implement the same approach as in Enhancer.isEnhanced

    public boolean isCglibProxyClass(Class<?> clazz) {
        Method[] methods = class.getDeclaredMethod();
        for(Method m: method){
            if( "CGLIB$SET_THREAD_CALLBACKS".equals(m.getName() && m.getParameterTypes().lenght = 1)
                 return true;
        }
        return false;
    }

[andrei-ivanov]

Indeed, as I've already tried the Enhancer.isEnhanced approach and it fails for Mockito CgLib generated classes, as they've modified the parameters of CGLIB$SET_THREAD_CALLBACKS.

[andrei-ivanov]

I wonder how should I handle the unit test, as the project level is set to 1.6, which doesn't allow lambdas.

[thekingn0thing]

You can handle the test as it did in mockito case. Just create a new module junit4-java8-test and set language level to 1.8.

Thank you a lot for your help!