Easy Mock - How to? - testing

Question

I am trying easyMock test few classes / interface methods. Methods with parameters, trying to capture the parameter, but getting one or other error. If I manage to only record one expectation, it doesn't even capture anything in the parameter pipe, where if i use the following approach, I am getting error as follows the code.
#Test
public void testFireChannelInitializer() throws Exception
{
expect(c.pipeline()).andReturn(pipeline).times(1);
channelListener.fireChannelInitializer(EasyMock.capture(pipe), serverHandler);
EasyMock.replay(c, pipeline, channelListener);
initializer.initChannel(c);
verifyAll();
assertEquals(4, pipe.getValues().size());
assertTrue(pipe.getValues().get(0) instanceof LoggingHandler);
assertTrue(pipe.getValues().get(0) instanceof ObjectEncoder);
assertTrue(pipe.getValues().get(0) instanceof ObjectDecoder);
assertTrue(pipe.getValues().get(0) instanceof ServerHandler);
}
Results in Error
testFireChannelInitializer(com.obolus.generic.impl.DefaultChannelListenerTest)
Time elapsed: 3.812 sec <<< ERROR! java.lang.IllegalStateException: 2
matchers expected, 1 recorded. This exception usually occurs when
matchers are mixed with raw values when recording a method: foo(5,
eq(6)); // wrong You need to use no matcher at all or a matcher for
every single param: foo(eq(5), eq(6)); // right foo(5, 6); // also
right at
org.easymock.internal.ExpectedInvocation.createMissingMatchers(ExpectedInvocation.java:51)
at
org.easymock.internal.ExpectedInvocation.(ExpectedInvocation.java:40)
at org.easymock.internal.RecordState.invoke(RecordState.java:78) at
org.easymock.internal.MockInvocationHandler.invoke(MockInvocationHandler.java:40)
at
org.easymock.internal.ObjectMethodsFilter.invoke(ObjectMethodsFilter.java:94)
at
org.easymock.internal.ClassProxyFactory$MockMethodInterceptor.intercept(ClassProxyFactory.java:97)
at
com.obolus.generic.impl.DefaultChannelListener$$EnhancerByCGLIB$$2da02970.fireChannelInitializer()
at
com.obolus.generic.impl.DefaultChannelListenerTest.testFireChannelInitializer(DefaultChannelListenerTest.java:63)
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:483) at
org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
at
org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
at
org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263) at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231) at
org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60) at
org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229) at
org.junit.runners.ParentRunner.access$000(ParentRunner.java:50) at
org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222) at
org.junit.runners.ParentRunner.run(ParentRunner.java:300) at
org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:242)
at
org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:137)
at
org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483) at
org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at
org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at
org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at
org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at
org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Any idea whats wrong or How to use easy mock? No good documentation or examples around.

Answer 1

The easymock website has a user guide but they redid their website recently and the guide isn't as complete as it used to be.
I think your problem might be you have to do a capture AND an argument matcher.
From the user guide:
Matches any value but captures it in the Capture parameter for later access. You can do and(someMatcher(...), capture(c)) to capture a parameter from a specific call to the method. You can also specify a CaptureType telling that a given Capture should keep the first, the last, all or no captured values.
So you might need to do an and( capture(..), paramMatcher)
Also EasyMock has an annoying API "feature" where if you use one argument matcher in a method call, then all the arguments must also be wrapped in matchers even if it's eq(). I think that's what your exception is complaining about. So I think those are your two problems.
I'm not sure what your method signature looks like so I will assume it's
void fireChannelInitializer(Object, ServerHandler);
after using static imports to import EasyMock.*
channelListener.fireChannelInitializer(
and(capture(pipe), isA(Object.class)), //captures the argument to `pipe` Capture object
eq(serverHandler));