by David Björkevik
An RxJS operator that causes an observable to complete early if/when another controlling observable completes.
This is very useful to easliy limit the lifetime of a pipe, for instance when
writing user interface modules: Set up a simple Subject called "destroyed" for
your UI component and call its .complete()-method upon component destruction.
Now you may use .pipe(completeWhen(destroyed)) to make sure your subscriptions
are cancelled when your component is destroyed.
npm install rxjs-complete-when