java - PowerMockito 的 UnfinishedStubbingException

Question

我想测试一个内部使用静态方法的方法，这就是我使用 PowerMockito 的原因。我想模拟对 Request.Get 的调用来自 Http 客户端 Fluent API。我设置了一个简单的测试，但出现了 UnfinishedStubbingException，我不明白为什么。

Mockito 2.8.9 和 Powermock 1.7.1

@RunWith(PowerMockRunner.class)
@PrepareForTest(Request.class)
public class MyApiServiceTest {

    @Test
    public void callTest() throws IOException, JSONException, URISyntaxException {
        PowerMockito.mockStatic(Request.class);
        Path path = Paths.get(getClass().getClassLoader().getResource("data.json").toURI());
        byte[] fileBytes = Files.readAllBytes(path);
        Content content = new Content(fileBytes, ContentType.APPLICATION_JSON);
        PowerMockito.doReturn(content).when(Request.Get(anyString()).execute().returnContent());
    }

}

堆栈跟踪

org.mockito.exceptions.misusing.UnfinishedStubbingException: 
Unfinished stubbing detected here:
-> at com.example.service.MyApiServiceTest.callTest(MyApiServiceTest.java:42)

E.g. thenReturn() may be missing.
Examples of correct stubbing:
    when(mock.isOk()).thenReturn(true);
    when(mock.isOk()).thenThrow(exception);
    doThrow(exception).when(mock).someVoidMethod();
Hints:
 1. missing thenReturn()
 2. you are trying to stub a final method, which is not supported
 3: you are stubbing the behaviour of another mock inside before 'thenReturn' instruction if completed


    at org.powermock.core.MockGateway.doMethodCall(MockGateway.java:182)
    at org.powermock.core.MockGateway.doMethodCall(MockGateway.java:164)
    at org.powermock.core.MockGateway.methodCall(MockGateway.java:141)
    at org.apache.http.client.fluent.Request.Get(Request.java)
    at com.example.service.MyApiServiceTest.callTest(MyApiServiceTest.java:42)
    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:326)
    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:310)
    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:298)
    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:218)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:160)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:134)
    at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
    at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:136)
    at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:121)
    at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:57)
    at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Answer 1

看来你试图同时 mock 太多的东西。

尝试独立地 stub execute() 和 returnContent() 方法:

@Test
    public void callTest() throws IOException, JSONException, URISyntaxException {
        // Arrange
        PowerMockito.mockStatic(Request.class);
        Request requestStub = Mockito.mock(Request.class);
        Response responseStub = Mockito.mock(Response.class);
        Path path = Paths.get(getClass().getClassLoader().getResource("data.json").toURI());
        byte[] fileBytes = Files.readAllBytes(path);
        Content content = new Content(fileBytes, ContentType.APPLICATION_JSON);

        Mockito.doReturn(responseStub).when(requestStub).execute();
        Mockito.doReturn(content).when(responseStub).returnContent();
        PowerMockito.doReturn(requestStub).when(Request.class, Mockito.anyString(), "Get");

        // Act and assert
    }

因此 powermockito 仅用于返回 requestStub 所有其余部分都可以使用普通的 mockito 完成。