我正在了解Rx
Java.我开始在我的一个个人应用程序中使用它,并希望单元测试代码,但有一些困难,并希望得到一些帮助.
场景很简单.
>我通过进行REST调用来获取UserInfo对象
>如果重新调整的UserInfo对象不为null,则返回true,否则返回false.
对于上面的场景,我的RxJava代码看起来像这样
public LiveData<Boolean> doesUserExists(String userName) {
UserExistsObserver observer= new UserExistsObserver ();
getUserInfo(userName).subscribeWith(subscriber);
disposable.add(observer);
return userExists;
}
public Observable<Boolean> getUserInfo(String userName) {
return repository.getUserInfo(userName)
.flatMap(new Function<UserInfo,Observable<Boolean>>() {
@Override
public Observable<Boolean> apply(UserInfo userInfo) throws Exception {
return Observable.just(userInfo != null);
}
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread());
}
所以我想编写一个简单的单元测试来检查getUserInfo()是否返回正确的布尔值.以下是我的单元测试.
@Test
public void getUserInfo_returns_true(){
UserInfo userInfo = new UserInfo(); //Dummy data - non null userInfo object
when(repository.getUserInfo("username")).thenReturn(Observable.just(userInfo));
TestObserver<Boolean> testObserver = new TestObserver<>();
//the flatMap operator should return true since userInfo is not null
viewmodel.getUserInfo("username").subscribeWith(testObserver);
testObserver.assertValue(true);
}
以下是我的日志
java.lang.AssertionError: Expected: true (class: Boolean),Actual: [] (latch = 1,values = 0,errors = 0,completions = 0) at io.reactivex.observers.BaseTestConsumer.fail(BaseTestConsumer.java:163) at io.reactivex.observers.BaseTestConsumer.assertValue(BaseTestConsumer.java:328) at com.ik.githubbrowser.search_user.SearchUserviewmodelTest.getUserInfo_returns_true(SearchUserviewmodelTest.java:51) 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:50) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27) at org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:55) at org.junit.rules.RunRules.evaluate(RunRules.java:20) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325) at org.junit.runners.BlockJUnit4ClassRunner.runchild(BlockJUnit4ClassRunner.java:78) at org.junit.runners.BlockJUnit4ClassRunner.runchild(BlockJUnit4ClassRunner.java:57) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) at org.junit.runners.ParentRunner.runchildren(ParentRunner.java:288) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37) at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62) at org.junit.runner.JUnitCore.run(JUnitCore.java:137) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:117) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:262) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:84) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147) java.lang.NullPointerException at io.reactivex.android.schedulers.HandlerScheduler$HandlerWorker.schedule(HandlerScheduler.java:70) at io.reactivex.Scheduler$Worker.schedule(Scheduler.java:272) at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.schedule(ObservableObserveOn.java:161) at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.onNext(ObservableObserveOn.java:119) at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeOnObserver.onNext(ObservableSubscribeOn.java:58) at io.reactivex.internal.operators.observable.ObservableScalarXMap$Scalardisposable.run(ObservableScalarXMap.java:248) at io.reactivex.internal.operators.observable.ObservableScalarXMap$ScalarXMapObservable.subscribeActual(ObservableScalarXMap.java:164) at io.reactivex.Observable.subscribe(Observable.java:10903) at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeTask.run(ObservableSubscribeOn.java:96) at io.reactivex.Scheduler$disposeTask.run(Scheduler.java:452) at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:61) at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:52) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Exception in thread "RxCachedThreadScheduler-1" java.lang.NullPointerException at io.reactivex.android.schedulers.HandlerScheduler$HandlerWorker.schedule(HandlerScheduler.java:70) at io.reactivex.Scheduler$Worker.schedule(Scheduler.java:272) at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.schedule(ObservableObserveOn.java:161) at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.onNext(ObservableObserveOn.java:119) at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeOnObserver.onNext(ObservableSubscribeOn.java:58) at io.reactivex.internal.operators.observable.ObservableScalarXMap$Scalardisposable.run(ObservableScalarXMap.java:248) at io.reactivex.internal.operators.observable.ObservableScalarXMap$ScalarXMapObservable.subscribeActual(ObservableScalarXMap.java:164) at io.reactivex.Observable.subscribe(Observable.java:10903) at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeTask.run(ObservableSubscribeOn.java:96) at io.reactivex.Scheduler$disposeTask.run(Scheduler.java:452) at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:61) at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:52) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Process finished with exit code -1
解决方法
您的方法必须通过2个不同的线程来生成结果(由于subscribeOn和observeOn调用).这意味着观察者需要时间来实际产生结果.在检查assertValue之前使用TestObserver.awaitTerminalEvent()以确保observable实际生成了一个值.
或者,您应该在测试代码时使用不同的调度程序,因为Android调度程序可能需要额外的代码才能在测试环境中正常运行.