VSCode Extension in Scala.js

This Project is a port of the helloworld-minimal-sample to ScalaJS. It's an update of vscode-scalajs-hello.

Please check the VSCode documentation for more general information.

Your first Extension

A step-by-step tutorial for Scala.js using this example project.

Here is the original: visualstudio.com/api/get-started

Setup

• Install the extensions to develop: Metals, Scala syntax

• Clone this project

• Open the project in VSCode, run the import build task with Metals (it should display a popup automatically).

• Open the terminal, run

sbt

You're now in the SBT console. Great! Let's compile to see if everything works:

compile

The first time it may take a few minutes, because Scala will use "ScalablyTyped" to analyze the types of the VSCode extension API. Thanks to this, it can typecheck your code and catch mistakes before you run the extension!

• In the SBT console, transpile the extension to Javascript and open a new VSCode window with the extension loaded:

open

This will run fastOptJS and then open the Extension Host of VSCode.

• Run the Hello World command from the Command Palette (⇧⌘P) in the new VSCode window.
• Type hello and select Hello World.
  • You should see a Notification Hello World!.

Project structure

The project uses the following:

• SBT build tool for building the project
• [Scala.js] for general coding
• Scalably Typed for JavaScript facades
• scalajs-bundler for bundling the JavaScript dependencies

SBT is configured with the build.sbt file. Scala.js, ScalablyTyped and the bundler are SBT plugins. With these, SBT manages your JavaScript npm dependencies. You should never have to run npm directly, simply edit the npmDependencies settings in build.sbt.

How do I code in Scala.js?

In general, javascript functions and classes can be used in the same way as in JS/TS! If the typechecker disagrees, you can insert casts with .asInstanceOf[Type].

The JS types (like js.Array) are available with

import scala.scalajs.js

The VSCode classes and functions are available with

import typings.vscode.mod as vscode
// to use:
vscode.function(arg)

Some additional types are available in the anon subpackage, for example:

import typings.vscode.anon.Dispose
vscode.commands.registerCommand(name, fun).asInstanceOf[Dispose]

You can find more information and tutorials on the Scala.js website.