Android 单元测试中的RxJava Schedules.io（）NullPointerException

我正试图在标准JUnit测试中测试这个类，但是，我遇到了Schedulers.io（）的NullPointerException。可以模拟Schedulers.io（）吗

这是一个Android应用程序，我正在尝试使用travis ci提供完整的代码覆盖率，以实现持续集成，并使用coverage.io提供报告覆盖率

待测类别：

public class GetLiveStreamsList extends UseCase {

    private final String filename;
    private final ContentRepository contentRepository;

    public GetLiveStreamsList( final String filename, final ContentRepository contentRepository, ThreadExecutor threadExecutor, PostExecutionThread postExecutionThread ) {
        super( threadExecutor, postExecutionThread );

        this.filename = filename;
        this.contentRepository = contentRepository;

    }

    @Override
    protected Observable buildUseCaseObservable() {

        Action1<List<LiveStreamInfo>> onNextAction = new Action1<List<LiveStreamInfo>>() {

            @Override
            public void call( List<LiveStreamInfo> liveStreamInfos ) {

                try {
                    Thread.sleep( 5000 );
                } catch( InterruptedException e ) { }

            }

        };

        return this.contentRepository.liveStreamInfos( this.filename )
                .repeat( Schedulers.io() )
                .doOnNext( onNextAction );
    }

}

以下是stacktrace：

java.lang.NullPointerException
    at org.mythtv.android.domain.interactor.GetLiveStreamsList.buildUseCaseObservable(GetLiveStreamsList.java:47)
    at org.mythtv.android.domain.interactor.GetLiveStreamsListTest.testGetLiveStreamsListUseCaseObservableHappyCase(GetLiveStreamsListTest.java:48)
    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.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.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
    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:69)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:234)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:74)
    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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)


Process finished with exit code 255

---

您忘记设置

contentRepository.liveStreamInfos

的返回值。默认为

null

您需要如下设置返回值：

when(contentRepository.liveStreamInfos()).thenReturn(...);

---

你能发布堆栈跟踪吗？@zsxwing我添加了堆栈跟踪。这是我唯一一个这样做的测试。另一个类似的不会这样做。我相信这与repeat（）中的schedulers.io（）有关。其他搜索表明我应该使用schedulers.immediate（），但是，当运行应用程序时，它会崩溃。那么，如果您有模拟线程执行器，您希望实际执行如何发生？只需切换到包含实际线程的集成测试…@TassosBassoukos你能提供一个例子吗？顺便问一下，哪一行是第47行？谢谢。我重构了它，以消除重复调用的需要。嗨，wing，我也设置了它，但我面临NPE，请检查

when(contentRepository.liveStreamInfos()).thenReturn(...);