Kotlin Programming: The Big Nerd Ranch Guide, 2nd Edition

Declaring Support for Kotlin/JS

Your first step is to declare a new target in your code for JavaScript. This will once again involve updating your build.gradle file.

Listing 26.1  Declaring a JavaScript target (build.gradle)

...
kotlin {
    jvm()
    macosX64() {
        binaries {
            executable()
        }
    }
    js {
        browser()
        binaries {
            executable()
        }
    }
    sourceSets {
        ...
    }
}
...

The only thing new here is the browser function call. This specifies that you intend to run your JavaScript inside a browser. You can also use nodejs to have your project compile for Node.js, a standalone JavaScript runtime environment commonly used to build web servers.

Perform a Gradle sync after making these changes.

Once again, your project will no longer compile, because ...