I’m trying to use Kotlin for firebase functions. I...

# javascript

[spierce7]

I’m trying to use Kotlin for firebase functions. I’m getting problems because Kotlin is exporting other keys as well, which makes firebase throw an error. Here are the additional keys it has that it shouldn’t:

$$importsForInline$$,com,firebase

Firebase basically expects a node file with only firebase functions exported. How can I achieve this?

[turansky]

com, firebase - package names?

[anton.bannykh]

I don't think there is a way to limit exports in the Kotlin/JS compiler output. What you could do is have all the functions you want to export in a separate module. I am not familiar with firebase, but I suppose splitting code into a few JS modules shouldn't be an issue for it. Am I wrong?

[turansky]

I don't think there is a way to limit exports in the Kotlin/JS compiler output.

It can be modified via Webpack configuration.

[turansky]

If package is problem - it can be "removed" via webpack output.libraryExport property or via Gradle plugin - https://github.com/turansky/kfc-plugins#component

[anton.bannykh]

Thank you for pointing this out.

Doesn't this solve a different issue though? Correct me if I'm wrong, but it seems that output.libraryExport may be used to modify the package (require('foo').org.blah.A -> require('foo').A), but cannot be used to remove some exports, while keeping the others.

I suspect there should be some JS tool to remove some exports from a module, but I don't think that's it.

[anton.bannykh]

If you don't need to test those "additinal functions" you could make them internal and pass the -Xfriend-modules-disabled flag to the compiler. That would prevent the compiler from exporting internal declarations.

[turansky]

but cannot be used to remove some exports

@anton.bannykh I have example for this theme. I use DCE to keep only required, but in common case output.libraryExport does the same job.

Example

// exported
aaa.ComponentA
bbb.ComponentB
ccc.ComponentC

+

output.libraryExport = ["bbb"]

=

// exported
ComponentB

https://github.com/turansky/kfc-plugins/tree/master/examples/component-extension

[Ilya Goncharov [JB]]

@spierce7 So, if TL;DR you can put all necessarily declarations on one package org.example
And then you can tell webpack to export only this package via output.libraryExport=['org', example'] , it means that your object will contain only declarations from package org.example
You can set libraryExport manually with webpack.config.d/library.js :

// it will be redundant in 1.3.70
config.output = config.output || {}
config.output.library = <module-name>
config.output.libraryTarget = 'umd'

// it is necessary both before 1.3.70 and in 1.3.70
config.output.libraryExport = ['org', example']

[spierce7]

Does the node.js application packaging use web pack?

[Ilya Goncharov [JB]]

No, nodejs has no bundle yet, we have feature request, you can describe your use case here https://youtrack.jetbrains.com/issue/KT-35620
Seems that it makes sense (not sure that webpack, but maybe some analogues for js packaging)

[anton.bannykh]

@turansky My bad, thank you for clarifying how it works! 🙂 🙏

[Ilya Goncharov [JB]]

but in common case output.libraryExport does the same job.

@turansky I just want to tell about difference, that it is correct only for export, you’re right, that from export point of view effect is the similar, but the main difference, that in fact libraryExport don’t remove signature, and they are in the code anyway, but DCE really remove declarations, and reduce file size

[turansky]

@spierce7 Possibly this will help you
https://webpack.js.org/configuration/output/#outputglobalobject

[spierce7]

@Ilya Goncharov [JB] Is how the app behaves in terms of exports going to change in 1.4? I remember hearing that right now it’s assumed that everything is open and can be accessed, and in 1.4 its assumed everything is closed except explicitly annotated otherwise

My problem is that kotlin packages are being exported. Is that changing in 1.4?