订阅只有onNext处理程序的RxJs Observable会给出"this._subscribe不是一个函数“

Question

我正在尝试订阅从Subject创建的Observable，每当我订阅时没有错误处理程序，我就会得到错误this._subscribe is not a function。我发现this问题描述了类似的错误；但答案似乎不适合我的情况。下面是我的代码：

const subject = new Rx.Subject();
subject
    .withLatestFrom(otherObservable)
    .subscribe(
        values => {
            // some logic
       }
    );

我也试过了：

const subject = new Rx.Subject();
subject
    .withLatestFrom(otherObservable)
    .subscribeOnNext(
        values => {
            // some logic
       }
    ); 

我得到了同样的错误。下面是我仅尝试使用subscribe时的堆栈跟踪

  Observable.Rx.Observable.observableProto.subscribe.observableProto.forEach (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:2034:19)                                                                        
WithLatestFromObservable.subscribeCore (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:4084:33)                                                                                                              
WithLatestFromObservable.tryCatcher (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:63:31)                                                                                                                   
setDisposable [as action] (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:2082:46)                                                                                                                           
ScheduledItem.invokeCore (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:896:33)                                                                                                                             
ScheduledItem.invoke (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:884:40)                                                                                                                                 
runTrampoline (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:1125:37)                                                                                                                                       
tryCatcher (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:63:31)                                                                                                                                            
CurrentThreadScheduler.schedule (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:1141:45)                                                                                                                     
WithLatestFromObservable.Rx.ObservableBase.ObservableBase._subscribe (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:2095:32)                                                                                
WithLatestFromObservable.Rx.Observable.observableProto.subscribe.observableProto.forEach (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:2034:19)  

这是我尝试subscribeOnNext时的堆栈跟踪

Observable.Rx.Observable.observableProto.subscribe.observableProto.forEach (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:2034:19)
    WithLatestFromObservable.subscribeCore (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:4084:33)
    WithLatestFromObservable.tryCatcher (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:63:31)
    setDisposable [as action] (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:2082:46)
    ScheduledItem.invokeCore (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:896:33)
    ScheduledItem.invoke (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:884:40)
    runTrampoline (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:1125:37)
    tryCatcher (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:63:31)
    CurrentThreadScheduler.schedule (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:1141:45)
    WithLatestFromObservable.Rx.ObservableBase.ObservableBase._subscribe (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:2095:32)
    WithLatestFromObservable.Rx.Observable.observableProto.subscribeOnNext (/home/ryan/code/redurx/node_modules/rx/dist/rx.js:2046:19)

如果我向subscribe传递一个像() => null这样的小错误处理程序，我就得不到错误。有什么想法吗？

Answer 1

多亏了user3743222 ，我想通了。事实证明(实际上在逻辑上)，你不能订阅一个普通的可观察对象。它需要以这样一种方式构建，即它有值得观察的价值。我在单元测试中将otherObservable的初始化从new Rx.Observable()更改为Rx.Observable.just(1)，现在可以订阅它了。不过，我有点困惑，当我同时传递onNext和onError处理程序时，它为什么没有抛出相同的错误。但我还是要买下它。