sjs-nodejs

npm helper to bootstrap sbt and link Scala.js (Scala 3) projects to JavaScript. Scala.js compiles through sbt; this package downloads sbt into node_modules and exposes npm scripts for common link and run tasks.

Published on npm: sjs-nodejs

Requirements: Node.js 18+

Recommended versions (v2.x)

Tool	Version
sbt	1.10.7
Scala	3.5.2
Scala.js	1.21.0

Install

In your Scala.js project:

npm install sjs-nodejs

Use locally

To try changes in this repo from another Scala.js project without publishing to npm.

Option 1: npm link

In this repository:

cd /path/to/sjs-nodejs
npm install
npm link

In your Scala.js app:

cd /path/to/your-scalajs-app
npm link sjs-nodejs

Your app’s node_modules/sjs-nodejs now points at your local clone. Re-run npm link sjs-nodejs after pulling changes if behavior looks stale.

To unlink later:

cd /path/to/your-scalajs-app
npm unlink sjs-nodejs
npm install sjs-nodejs   # restore the published package, if needed

Option 2: install from a path

In your Scala.js app:

npm install /path/to/sjs-nodejs
# or, relative path:
npm install ../sjs-nodejs

package.json will record a file: dependency (for example "sjs-nodejs": "file:../sjs-nodejs").

Scripts in the consuming project

Whichever option you use, add the same scripts to your app’s package.json so npm can find sbt and this package:

{
  "scripts": {
    "sbtInit": "node node_modules/sjs-nodejs/index.js",
    "sjsBuild": "npm run sbtInit && node_modules/sbt/bin/sbt fastLinkJS",
    "sjsBuildFull": "npm run sbtInit && node_modules/sbt/bin/sbt fullLinkJS",
    "sjs": "node_modules/sbt/bin/sbt run"
  }
}

Then from your app directory:

npm run sjsBuild

npm scripts

Add these to your project's package.json (or rely on the same script names if you copy them from this package):

Script	Command	Description
sbtInit	downloads & unpacks sbt	Run once (also run by build scripts)
sjsBuild	fastLinkJS	Fast development link
sjsBuildFull	fullLinkJS	Full optimizations for production
sjs	run	Run the Scala.js app via sbt

Example:

npm run sjsBuild      # fast link
npm run sjsBuildFull  # optimized link
npm run sjs           # run

sbt setup (Scala 3)

project/plugins.sbt

addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.21.0")

build.sbt

lazy val root = project
  .in(file("."))
  .enablePlugins(ScalaJSPlugin)
  .settings(
    scalaVersion := "3.5.2",
    scalaJSUseMainModuleInitializer := true,
  )

project/build.properties

sbt.version=1.10.7

Breaking changes in v2.0.0

• Targets Scala 3 and Scala.js 1.x (not Scala 2.12 / Scala.js 0.6).
• Build tasks renamed: fastOptJS → fastLinkJS, fullOptJS → fullLinkJS.
• Bundled sbt upgraded from 1.0.1 to 1.10.7.

Example project

https://github.com/devasthali-os/introv.scalajs

Publishing

Maintainers: see docs/publishing.md for logging in to npm, pre-publish checks, npm publish, and verification on npmjs.com.

Repository

https://github.com/devasthali-os/sjs-nodejs