Mocking Static Methods with PowerMockito on Android

Question

I'm trying to stub out a static method so that I can unit test a REST Api interface.

I'm using...

PowerMockito 1.5 (to enable mocking of statics)
Roboelectric 1.2 (to stub out the rest of the android)
JUnit 4.10

Running the following code gives me the subsequent error

Any idea on what could fix this?

    @RunWith(RobolectricTestRunner.class)
    @PrepareForTest({Api.class})
    public class ApiTest extends TestCase {

        @Rule
        public PowerMockRule rule = new PowerMockRule();
        ...
        @Test
        public void testGet() throws Exception {
            Api.Response fakeResponse = PowerMockito.mock(Api.Response.class);
            PowerMockito.when(fakeResponse.getResult()).thenReturn(responseObj);
            mockStatic(Api.class);
            PowerMockito.when(Api.execute(any(HttpRequestBase.class))).thenReturn(fakeResponse);
            Api.get("/v1/contacts/");
        }
    }

However the stub on the static right before we call "Api.get" throws the following error...

java.lang.RuntimeException: java.lang.ClassNotFoundException: caught an exception while obtaining a class file for org.powermock.classloading.DeepCloner
    at org.powermock.api.support.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:68)
    at org.powermock.api.support.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:34)
    at org.powermock.classloading.ClassloaderExecutor.createDeepCloner(ClassloaderExecutor.java:106)
    at org.powermock.classloading.ClassloaderExecutor.execute(ClassloaderExecutor.java:88)
    at org.powermock.classloading.ClassloaderExecutor.execute(ClassloaderExecutor.java:78)
    at org.powermock.modules.junit4.rule.PowerMockStatement.evaluate(PowerMockRule.java:49)
    at com.xtremelabs.robolectric.RobolectricTestRunner$1.evaluate(RobolectricTestRunner.java:288)
    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.junit.runner.JUnitCore.run(JUnitCore.java:157)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:77)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:195)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:63)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: java.lang.ClassNotFoundException: caught an exception while obtaining a class file for org.powermock.classloading.DeepCloner
    at javassist.Loader.findClass(Loader.java:360)
    at com.xtremelabs.robolectric.bytecode.RobolectricClassLoader.findClass(RobolectricClassLoader.java:83)
    at javassist.Loader.loadClass(Loader.java:312)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    at com.xtremelabs.robolectric.bytecode.RobolectricClassLoader.loadClass(RobolectricClassLoader.java:59)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:247)
    at org.powermock.api.support.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:66)
    ... 24 more
Caused by: com.xtremelabs.robolectric.bytecode.IgnorableClassNotFoundException: msg because of javassist.NotFoundException: org.powermock.classloading.DeepCloner
    at com.xtremelabs.robolectric.bytecode.AndroidTranslator.onLoad(AndroidTranslator.java:92)
    at javassist.Loader.findClass(Loader.java:341)
    ... 31 more

score 1 · Answer 1 · answered Jun 06 '13 at 20:39

1

To have static mocking you have to use the PowerMockRunner, otherwise it does not work. See the documentation.

If possible i always avoid static mocking because of the classloading complications. If you would share the tested code, maybe I could suggest some workaround. Usually i create a non static method inside the class, which uses the static method, and i call the static method inside this non static one. Then i simply make a spy of the tested class, and i mock only this method. This way i do not need PowerMock.

answered Jun 06 '13 at 20:39

Gábor Lipták

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I just ran into this problem and this was the only reference to this bug I could eventually find - I kept thinking I must be doing something wrong. Where in the docs is this stated? I can confirm this is the case - after reducing my test to the bare essentials, static mocking stops working when switching from the runner to the rule. This is too bad, since it means you lose a lot of PowerMock's value when you have to run under a different runner. – Tom Tresansky Aug 21 '14 at 14:37
@Tom Tresansky: you can give a try to the agent based powermocking, which lets you to use a different runner. See https://code.google.com/p/powermock/wiki/PowerMockAgent – Gábor Lipták Aug 21 '14 at 21:20
I thought this was what we were already trying to do? I've asked a new question at: http://stackoverflow.com/questions/25850673/is-it-possible-to-mock-a-static-method-on-a-final-class-using-a-powermockrule-in to fully clarify this. – Tom Tresansky Sep 15 '14 at 14:53

Mocking Static Methods with PowerMockito on Android

1 Answers1