Documentation clarification around code splitting

[tstirrat15]

Looking at this section in under the code splitting header:

To support any code splitting library RHL uses a special tail update detection logic - if some components would be requested after initial HMR event - Application would be updated yet again to apply possible change. In this case you will see a message React-Hot-Loader: some components were updated out-of-bound. Updating your app to reconcile the changes..

I don't understand what this paragraph means. When does the warning show? Does it mean that something is wrong, or does it just indicate that a component on the other side of a code-splitting boundary has been updated?

I'm happy to submit an update to this section once I feel like I understand it.

[theKashey]

There was (and some issues says still is) an issue, which would be better described as I could see my update only after anther update.
Basically

• the client receives an update message
• it replaces old components by a new one
• it force-updates everything
• you still not see your update
• 😭🤔
• you do another update
• and now you see it - your first one

It could be caused by different reasons, but in terms of code splitting it was due the non-instant effect from dynamic import - "the new" component would be loaded after RHL force-updates everything and exits. As long as the call to that import would be caused by the force-update.

There was a special logic to handle React.lazy, some libraries were importing their stuff in their constructor... until "that change", which is just checking "is something updated" after "the update".
When I was rewriting imported-components I've failed to reimplement this logic for the custom React.lazy component, and had to stop using it to be RHL-compliant. Then I decided to fix the root cause, and here we are.

So, if RHL detects that something was updated after update just finished - it updates everything again. This change initial process:

• 😭🤔
• you do another update <--- it does this
• and now you see it - your first one 🥳

However, code splitting library still should detect HMR and call the importer again. Not all are doing that.

I hope now you have enought context to reword this sentence.

[tstirrat15]

I think so. Lemme submit a PR and see if I've got it. Thank you!

[brandon-pereira]

It would be nice if we could disable the warning, is this possible?

[theKashey]

Or "report it once"?

[brandon-pereira]

Well, the docs say "The warning is informational - it is a notice that this tail update logic is triggered, and does not indicate a problem in the configuration or usage of react-hot-loader.". I have a team of developers working with me, I'm managing the SSR/HMR setup. I don't think every developer should need to know about the inner works of a HMR. Ideally, I can set setConfig({ trackTailUpdates:true }). to suppress this warning since it's just informational and not an issue with the configuration. I'd like to keep our console logs to a minimal.

If this makes sense, I can try and see if I can implement the change.

[tstirrat15]

The idea being that if you're specifying the behavior, it shouldn't tell you that it's doing it? That makes sense to me.

[theKashey]

Sounds right

[brandon-pereira]

Opened #1386 where I'll implement this!