使用PowerMock和Robolectric - IncompatibleClassChangeError

Question

我想在Android Robolectric測試中使用PowerMockito來模擬一些靜態方法。我正在按照指導here使用JUnit 4.8.2，Robolectric 2.2，Mockito 1.9.5和PowerMock 1.9.5。由於我必須使用RoboElectricTestRunner，因此我試圖使用PowerMockRule來引導PowerMock。但是，當使用PowerMock進行測試時，我遇到了不幸java.lang.IncompatibleClassChangeError。

java.lang.reflect.InvocationTargetException
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 sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:323) at sun.instrument.InstrumentationImpl.loadClassAndCallAgentmain(InstrumentationImpl.java:348)

Caused by: java.lang.IncompatibleClassChangeError: Implementing class at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637) at java.lang.ClassLoader.defineClass(ClassLoader.java:621) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)

如果我把org.ow2.asm的org.powermock庫我拿到後：

java.lang.IncompatibleClassChangeError: class org.objectweb.asm.tree.ClassNode has interface org.objectweb.asm.ClassVisitor as super class at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637) at java.lang.ClassLoader.defineClass(ClassLoader.java:621) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at java.net.URLClassLoader.defineClass(URLClassLoader.java:283) at java.net.URLClassLoader.access$000(URLClassLoader.java:58) at java.net.URLClassLoader$1.run(URLClassLoader.java:197) at java.security.AccessController.doPrivileged(Native Method)

上每單元測試。

根據Maven的依賴：樹Robolectric和PowerMock不共享任何依賴關係。 但顯然org.powermock：powermock模塊，javaagent包一些組織/ ObjectWeb聯盟/ ASM類和Robolectric依靠org.ow2.asm：ASM：罐子：4.1導致衝突。

---

@RunWith(RobolectricTestRunner.class) 
@PrepareForTest(Helper.class) 
@PowerMockIgnore({"com.sun.jmx.*", "javax.management.*"}) 
public class HelpFragTest { 

    @Rule 
    public PowerMockRule rule = new PowerMockRule(); 

    static { 
     PowerMockAgent.initializeIfNeeded(); 
    } 

    FragmentActivity fragmentActivity; 
    FragmentManager fragmentManager; 
    ActionBarManager actionBarManager; 

    @Before 
    public void setup(){ 
     actionBarManager = mock(ActionBarManager.class); 
     LowesApplication.instance().setActionBarManager(actionBarManager); 
     fragmentActivity = Robolectric.buildActivity(FragmentActivity.class).create().start().resume().get(); 
     fragmentManager = fragmentActivity.getSupportFragmentManager(); 
    } 

    @Test 
    public void testShow(){ 
     mockStatic(Helper.class); 

     HelpFrag helpFrag = HelpFrag.newInstance(); 
     FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction(); 

     fragmentTransaction.add(helpFrag, null); 
     fragmentTransaction.commit(); 

     assertTrue(helpFrag.isVisible()); 
    } 
} 

Answer 1

我找到了一種方法與Robolectric一起使用PowerMock。

除了標準的PowerMock罐子，還需要PowerMock Junit Rule。這是描述here如何抓住它。我使用xstream classloading版本，因爲objenesis其中一個很麻煩。這與PowerMock 1.5.5和Robolectric 2.3一起工作，我不能談論舊版本。另請注意，不應該包含Java代理，因爲根據我的經驗，它會導致問題。

所以如果你正在使用maven，這些依賴應該聲明：

<dependency> 
    <groupId>org.powermock</groupId> 
    <artifactId>powermock-module-junit4</artifactId> 
    <version>${powermock.version}</version> 
    <scope>test</scope> 
</dependency> 
<dependency> 
    <groupId>org.powermock</groupId> 
    <artifactId>powermock-module-junit4-rule</artifactId> 
    <version>${powermock.version}</version> 
    <scope>test</scope> 
</dependency> 
<dependency> 
    <groupId>org.powermock</groupId> 
    <artifactId>powermock-api-mockito</artifactId> 
    <version>${powermock.version}</version> 
    <scope>test</scope> 
</dependency> 
<dependency> 
    <groupId>org.powermock</groupId> 
    <artifactId>powermock-classloading-xstream</artifactId> 
    <version>${powermock.version}</version> 
    <scope>test</scope> 
</dependency> 

然後，你必須設置你的測試類是這樣的：

@RunWith(RobolectricTestRunner.class) 
@PowerMockIgnore({ "org.mockito.*", "org.robolectric.*", "android.*" }) 
@PrepareForTest(Static.class) 
public class MyTest { 

    @Rule 
    public PowerMockRule rule = new PowerMockRule(); 

    private MyActivity activity; 

    @Before 
    public void setup() { 
     activity = Robolectric.buildActivity(MyActivity.class).create().get(); 
    } 

    @Test 
    public void test() throws Exception { 
     PowerMockito.mockStatic(Static.class); 
     Mockito.when(Static.getCurrentTime()).thenReturn(1); 

     Assert.assertEquals(1, activity.getId()); 
    } 
}