When targeting `browser` and `binaries.library()` ...

# javascript

[Edoardo Luppi]

When targeting browser and binaries.library() the Webpack task is not executed, is it expected?

[Artem Kobzar]

I feel, that in this case we generate only klib, so, there is no JS to process it with the Webpack

[Edoardo Luppi]

Mmh, you can run jsBrowserProductionLibraryDistribution, so there is some JS output

[Artem Kobzar]

Oh, so, in this case it's better to ask @Ilya Goncharov [JB].
Ilya what do we expect from the binaries.library() as an output?

[Edoardo Luppi]

To clarify also for @Ilya Goncharov [JB], this is related to the previous post.
Customizing the Webpack configuration might help me solve that issue.

[Edoardo Luppi]

Looked up the code and I can see

compilation.binaries
    .matching { it is Executable }

in KotlinBrowserJsIr.configureBuild, so to some degree it looks like it's done on purpose

[Ilya Goncharov [JB]]

Key idea in binaries.library to not prepare final bundle, but provide JavaScript library as set of files, webpack is expected to be executed on final phase in final application

[Edoardo Luppi]

@Ilya Goncharov [JB] thanks Ilya, that makes sense.
Related to the post above then, the right point where to modify the Webpack configuration is in the app that will bundle the Kotlin library.

[Edoardo Luppi]

Related to Webpack support, I have seen others create custom KotlinWebpack tasks. Is that supposed to be possible, or is it just a hack?

[Ilya Goncharov [JB]]

Yes, I think, the best place to configure webpack is in the final app project
But if you really need webpack for your library, it is better to use binaries.executable

As for custom KotlinWebpack task. Gradle is designed as system where there are many things are possible, so you can't forbidden create custom tasks of specific type. It is not designed by us for such purpose and we are not ready to deeply support such cases, but it is nature of Gradle, so I could not name it a hack, so users could create such tasks at their own risk

[Edoardo Luppi]

binaries.executable looks like the better approach to avoid too many customizations.
As far as I understand tho, executable doesn't output a package.json, so using it for a library is by default not possible.
Or did I not configure it correctly?

[Ilya Goncharov [JB]]

Yes, that's true. But there is a task named publicPackageJson which can produce it 🙂
But yes, for executable public package json was not supposed to be, because it is just working application

[Edoardo Luppi]

Thanks! Somehow we should put all those info into a K/JS "recipes" document.
I think other people will, or did have in the past, the same doubts. Haven't found any resource that groups everything together yet.