bug: `Channel` remounts its `children` when changing channels

[ginnymin]

Describe the bug

Any children inside of Channel get remounted when switching channels

To Reproduce

Steps to reproduce the behavior:

1. Include any component inside of Channel: <Channel><Component /></Channel>
2. Switch to another active channel (via setActiveChannel
3. Notice inner component remounts

Expected behavior

Children of Channel do not remount.

Example repro code

const Component = () => {
  useState(() => {
    console.log("Component mount");
  });
  return null;
}

// stream client and channelId (string) passed in
const Example = ({ channelId, streamClient }) => {
  const { setActiveChannel } = useChatContext();

  useEffect(() => {
    if (!streamClient) return;
    const channel = streamClient.channel("messaging", channelId);
    setActiveChannel(channel);
  }, [streamClient, setActiveChannel, channelId]);

  return (
    <Channel>
      <Component />
    </Channel>
  );
};

Package version

• stream-chat-react: 13.14.4
• stream-chat-css:
• stream-chat-js: 9.38.0

Desktop (please complete the following information):

• OS: MacOS
• Browser: Chrome and Safari

[mjcampagna]

Also, it's not fixed in v14. The same pattern exists — v14's Channel still renders:

return <ChannelInner {...props} channel={channel} key={channel.cid} />;

The key={channel.cid} on ChannelInner is the root cause — when you switch channels, the cid changes, React sees a different key, and unmounts/remounts the entire subtree including all children.

[MartinCupela]

Unfortunately this key could not be removed with v14. We plan state layer re-write for v15 (end of this year), where the key will not be necessary anymore. I suppose this key was introduced 5 years ago in order the SDK reflects the state updates. Removing the key would break the state.

To have an idea, here is a PR in progress that works on using reactive state layer independent from React components:

#2909

[ginnymin]

@MartinCupela Is it possible to only remount Stream's internal components when the key changes and not affect consumer components here?