I managed to make it work with KVision application...

# javascript

[Robert Jaros]

I managed to make it work with KVision applications, and I really wonder why HRM is not enabled by default? It makes app reload cycle at least twice as fast compared to the default configuration!

[Big Chungus]

Can you share a brief summary how?

[Ilya Goncharov [JB]]

Do you make some changes in your code for HMR with saving of state? Or do you just enable hot option?

[Robert Jaros]

config.devServer.hot = true;

in webpack.config.d

[Robert Jaros]

I had to make some changes in KVision, because the module.hot had to come from the application and not the library

[Robert Jaros]

but to enable HMR only this one option is required

[Big Chungus]

@Ilya Goncharov [JB], shouldn't that be default option for devRun?

[Robert Jaros]

it could be at least defined in KotlinWebpackConfig.DevServer class, and documented somewhere

[Ilya Goncharov [JB]]

So, usually feature of hmr is good option on module which contain hmr code in runtime
Usually, using of HMR in module without implementation of HMR interface should be without some changed in dev server (at least it was when I tested it on my project)
That’s why this option was not enabled by default in plugin

[Big Chungus]

Would be nice to have it on devRunTask, then as a configuration option

[Ilya Goncharov [JB]]

Yes, for now setting devServer is terribly, it should be dsl-like, but now it requires to create new instance
And yes, as for me it should represent all options of webpack dev server setting 🙂

[Robert Jaros]

There are probably not many options as useful as hot :-)

[turansky]

Library, plugins, rules, entry are useful too :)

[Robert Jaros]

I remember feeling slower reload cycle after migration from kotlin-frontend-plugin to the new plugin ... now I know why! :-)

[Ilya Goncharov [JB]]

I’ll investigate it, if there will no problems in different cases, I think it can be made hot by default

[Robert Jaros]

If something is wrong with HMR configuration webpack just falls back to live reload.

[Robert Jaros]

But it prints some warnings to the console, so at least we know there is something that can be fixed.

[Ilya Goncharov [JB]]

Personally for me, interesting why it faster even without any HMR code in your module

[Robert Jaros]

I was misunderstood

[Robert Jaros]

I have HMR code in KVision for years.

[Robert Jaros]

But the functions to pass state between reloads are optional.

[Robert Jaros]

and I personally don't use them

[Robert Jaros]

but today a user filled an issue about this not working

[Robert Jaros]

and I've started to investigate

[Ilya Goncharov [JB]]

Ohhh, so after adding hot there was nothing changed in experience, but then you fixed issues related with hmr code in KVision, and it works again, and it helps you to improve performance. Exactly HMR code in your library improve performance, not the just enabling of hot mode?

[Robert Jaros]

I don't think we can treat those two things separately :-)

[Robert Jaros]

If hot would be enabled by default, I would have fixed those errors months ago. And a lot of development time would be spared :)

[Robert Jaros]

I just didn't realize HMR was lost 🙂 I was sure it's just about reloading browser after code changes.

[Robert Jaros]

I've never used webpack nor hmr without Kotlin/JS :-)

[Ilya Goncharov [JB]]

Ok, thanks, I see point!
So honestly I know about HMR, but I thought it should be kinda optional, if user wants to use and write code to persist state. And yes, this option should be in dsl 🙂