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Check whether RxJs subscriptions in Angular component are complete or unsubscribed

See original GitHub issue

Is there a way to validate that all RxJs subscriptions are either complete or unsubscribed by the end of the life cycle of Angular component (when ngOnDestroy is called)?

My understanding is that rxjs-tslint-rules doesn’t support it at the moment. However, I’d like to see your take on

  • whether it is possible? and
  • is rxjs-tslint-rules the right tool for that?

Issue Analytics

  • State:closed
  • Created 4 years ago
  • Comments:8 (4 by maintainers)

github_iconTop GitHub Comments

cartantcommented, Apr 26, 2019

I don’t use Angular much, these days, but I talk often with developers who do.

rxjs-prefer-async-pipe is not a rule that I’ve ever used. There are rules in the package that enforce different opinions.

I think it’s more than just subscriptions, though. What would you be doing in this.http.get(url).subscribe(...)? I often see people doing this sort of thing, putting a slab of imperative code in the function passed to subscribe and then assigning something to this - to be picked up by change detection.

IMO, that’s all rather horrid. And it would be better implemented as a composed observable - using map, etc. to transform the reponse - and that observable could be used with an async pipe. When I did use Angular, I only ever used OnPush change detection and that plays nicely with the async pipe.

So I think it’s more than just subscriptions. It’s about implementing components in a manner that as declarative a possible. And with OnPush change detection rather than the ‘magic’ stuff that, IMO, should never have been brought over from AngularJS.

cartantcommented, Apr 23, 2019

BTW, I’ve made a note of your question, as I think it would be a great feature to add to the DevTools and - hopefully - it will be fairly straightforward.

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