rxjs

- **observable (Symbol):** `observable` (the `Symbol.observable` symbol instance) is no longer exported. Use a polyfill like `symbol-observable`, or use `Symbol.observable ?? '@@observable'` as a workaround." - **Subject.create:** Removed the deprecated `Subject.create` method. If you need to create an object that is "half Observable, half Observer", you'll need to either bolt `next`, `error`, and `complete` handlers onto an `Observable` and property type the return... or you'll need to create your own class that is backed by an `Observable`. In any case, if the `Observer` and the `Observable` are so unrelated that you have to bolt them together, you're probably better off with those two objects separately. This is why `Subject.create` has been deprecated for so long. - **WebSocketSubject:** `WebSocketSubject` is no longer `instanceof Subject`. Check for `instanceof WebSocketSubject` instead.

source ↗