Hands-On Serverless Applications with Kotlin

Creating a simple cloud function

Let's create a simple cloud function that accepts a string value and returns it.

Create a Main.kt file with the following code inside:

external fun require(module: String): dynamicexternal val exports: dynamicfun main(args: Array<String>) {    val functions = require("firebase-functions")    val admin = require("firebase-admin")    admin.initializeApp(functions.config().firebase)    exports.echoString = functions.https.onRequest { req, res ->        val text = req.query.text        res.status(200).send("Echo : $text")    }}

The dynamic keyword has a meaning. Kotlin is statically-typed, but because of interoperability features, it still has to deal with untyped or loosely-typed languages and environments. This allows you to call any property ...