Is starting a KMM Kotlin/JS project worth it?

Indeed! Yes .

As google moves towards future by bringing most of it’s Android/ Kotlin libraries to KMM . We ponder how easy it is to setup for Kotlin -> JS .

How does the Kotlin/JS work? Similar to other hybrid tech like flutter,React Native,Xamarin the code is compiled to the bytecode or language the underlying platform supports.

KMM compiler

Kotlin has two compilers Frontend and Backend . The frontend compiler converts the kotlin code to PSI and then to an intermediate representation . The backend compiler converts the IR to the desired language or bytecode.

I have added the basic steps to create a Kotlin/Js project in this repo readme.

KotlinJSApp/README.md

The sample uses Webpack server which comes by default in the KMM plugin. You could disable it or use a specified version through gradle.

For adding any webpack configuration create an webpack.config.d folder and add .js files which will be merged to the output webpack.config.js file

In case you would like to run a backend server using NodeJs . It is also possible by changing the KotlinJsTarget to nodejs

kotlin {
    js(IR) {
        nodejs {
        }
        binaries.executable()
    }
}

You can include NPM dependencies using gradle like

dependencies {
    implementation(npm("react", "> 14.0.0 <=16.9.0"))
}

And finally . to run your project you can use

.gradlew jsRun

.gradlew jsNodeDevelopmentRun

Conclusion:

For developers who are coming from android/java/kotlin background it would be a great boon to target web clients. The documentation in official webpages may not be sufficient for spinning up a new project yet. Hopefully as Google is committed to provide support for KMM , we can expect that the initial friction in adaption reduce.

Thats all folks !

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