Observable似乎不适用于Chrome 41

Question

I am currently trying to make my Angular 7 app to get crawled by Google properly, but unfortunately it seems like using HttpClient creates some trouble when I subscribe to it or attempt to convert it to a promise.

When using HttpClient, chrome 41 throws the following error:

TypeError: Cannot read property 'call' of undefined {stack: (...), message: "Cannot read property 'call' of undefined"}
errors.ts:35defaultErrorLogger
error_handler.ts:51push../node_modules/@angular/core/fesm5/core.js.ErrorHandler.handleError
application_ref.ts:230next
event_emitter.ts:110push../node_modules/@angular/core/fesm5/core.js.EventEmitter.subscribe.schedulerFn
Subscriber.ts:266push../node_modules/rxjs/_esm5/internal/Subscriber.js.SafeSubscriber.__tryOrUnsub
Subscriber.ts:208push../node_modules/rxjs/_esm5/internal/Subscriber.js.SafeSubscriber.next
Subscriber.ts:140push../node_modules/rxjs/_esm5/internal/Subscriber.js.Subscriber._next
Subscriber.ts:100push../node_modules/rxjs/_esm5/internal/Subscriber.js.Subscriber.next
Subject.ts:71push../node_modules/rxjs/_esm5/internal/Subject.js.Subject.next
event_emitter.ts:92push../node_modules/@angular/core/fesm5/core.js.EventEmitter.emit
ng_zone.ts:296(anonymous function)
zone.js:391push../node_modules/zone.js/dist/zone.js.ZoneDelegate.invoke
zone.js:150push../node_modules/zone.js/dist/zone.js.Zone.run
ng_zone.ts:218push../node_modules/@angular/core/fesm5/core.js.NgZone.runOutsideAngular
ng_zone.ts:296onHandleError
zone.js:395push../node_modules/zone.js/dist/zone.js.ZoneDelegate.handleError
zone.js:245push../node_modules/zone.js/dist/zone.js.Zone.scheduleTask
zone.js:261push../node_modules/zone.js/dist/zone.js.Zone.scheduleMacroTask
zone.js:1194scheduleMacroTaskWithCurrentZone
zone.js:3371(anonymous function)
zone.js:1518push../node_modules/zone.js/dist/zone.js.proto.(anonymous function)
xhr.ts:319push../node_modules/@angular/common/fesm5/http.js.HttpXhrBackend.handle
Observable.ts:239push../node_modules/rxjs/_esm5/internal/Observable.js.Observable._trySubscribe
Observable.ts:221push../node_modules/rxjs/_esm5/internal/Observable.js.Observable.subscribe
subscribeToResult.ts:29subscribeToResult
mergeMap.ts:156push../node_modules/rxjs/_esm5/internal/operators/mergeMap.js.MergeMapSubscriber._innerSub
mergeMap.ts:149push../node_modules/rxjs/_esm5/internal/operators/mergeMap.js.MergeMapSubscriber._tryNext
mergeMap.ts:132push../node_modules/rxjs/_esm5/internal/operators/mergeMap.js.MergeMapSubscriber._next
Subscriber.ts:100push../node_modules/rxjs/_esm5/internal/Subscriber.js.Subscriber.next
subscribeToArray.ts:11push../node_modules/rxjs/_esm5/internal/util/subscribeToArray.js.subscribeToArray
Observable.ts:239push../node_modules/rxjs/_esm5/internal/Observable.js.Observable._trySubscribe
Observable.ts:221push../node_modules/rxjs/_esm5/internal/Observable.js.Observable.subscribe
mergeMap.ts:111push../node_modules/rxjs/_esm5/internal/operators/mergeMap.js.MergeMapOperator.call
Observable.ts:215push../node_modules/rxjs/_esm5/internal/Observable.js.Observable.subscribe
filter.ts:72push../node_modules/rxjs/_esm5/internal/operators/filter.js.FilterOperator.call
Observable.ts:215push../node_modules/rxjs/_esm5/internal/Observable.js.Observable.subscribe
map.ts:60push../node_modules/rxjs/_esm5/internal/operators/map.js.MapOperator.call
Observable.ts:215push../node_modules/rxjs/_esm5/internal/Observable.js.Observable.subscribe
...
...
...

I did a simple check by replacing this:

  this.http.get(endpoint, this.requestHeaders).toPromise()

by this:

  this.http.get(endpoint, this.requestHeaders)

The error went away, but I can't resolve my promise inside the tap so it's not really useful for me. Any idea what's going wrong?

Answer 1

I am pretty sure that your subscribe function has incorrect parameters..

it should receive a function like below.

return this.http.get(filename, {responseType: 'text'})
    .subscribe(
        data => { 
            this.log(filename, data);
        },
        error => { 
            this.logError(filename, error);
        });

Update:

Please see compatibility of Promise in versions of browser at caniuse.com . According to that, Promise classes are not supported in Chrome 41 and support is from Chrome 63 only.

Another point is that ES6 classes are not supported in Chrome versions 4-41 as well.