Is @react-rxjs/core@0.6.0-1 a significant breaking change from 0.5.0?

Upgrading to @react-rxjs/core@0.6.0-1 I can’t get the most basic PoC to work.

import React from "react";
import { bind, shareLatest } from "@react-rxjs/core";
import { timer } from "rxjs";
import { startWith } from 'rxjs/operators';

const [useTimer] = bind(() => timer(0, 1000).pipe(startWith(0), shareLatest()));

export default function App() {
  const timer = useTimer();
  return <div className="App">{timer}</div>;
}

Error
Missing subscription

Code

If this is due to breaking changes, a suggestion would be to expand this exception message to give more detail. Plus, to add a demo package with a few working examples to provide end users with a sanity check.

If it is a regression, perhaps there can be some integration tests added.

[voliva]

Hey @ilikejames - glad that you’re finding a solution.

A quick note however, just to clarify:

const [useTimer, timer$] = bind(
  timer(0, 1000).pipe(shareLatest())
, 0);

const [useTimerSum, timerSum$] = bind(
  timer$.pipe(scan((a,b) => a+b))
);

In this example, useTimer can be used without needing a <Subscribe /> boundary, but useTimerSum does, even if theoretically it wouldn’t dispatch suspense, so it will throw “Missing subscription” if used straight away.

This is because bind can’t really know if a stream is doing something that would become asynchronous. To avoid this (without using <Subscribe />), useTimerSum also would need a defaultValue.

Edit: Also, the shareLatest() in this example is redundant, you shouldn’t need it.

[ilikejames]

No need to apologise, though perhaps in future 0.6.0 could have been released as a prerelease version before the docs were updated 😉

I follow your last part and see that…

const [useTimer, timer$] = bind(
  timer(0, 1000).pipe(shareLatest())
, 0);

…works.

And after discussion with @voliva, using a default value in this way bypasses Suspense completely. So this is an option for the majority of our streams, and then we only need to use <Subscribe/> on the few stream that should trigger suspenseful behaviour in the ui.

Ok. Thanks!