Universal Scala.js executable

This repository shows how you can create Scala.js actually portable executables using cosmopolitan and the QuickJS Javascript Engine. αcτµαlly pδrταblε εxεcµταblε is a binary can run natively in many operative systems.

For the impatient

Just run these commands to enjoy a portable Scala.js binary:

scala-cli package -f --js-mode release main.scala
zip qjs.com main.js .args
./qjs.com

Getting Started

You need the quickjs universal binary qjs.com. I included it in the repo but you can build it yourself with:

git clone https://github.com/jart/cosmopolitan
cd cosmopolitan
make -j8 o//third_party/quickjs/qjs.com
cp o//third_party/quickjs/qjs.com ..

Now you can build your Javascript file with your favorite Scala.js toolchain. For example with scala-cli:

scala-cli package --js-mode release main.scala

Now you need to add the Scala.js produced main.js to the qjs.com binary. APE binaries are also zip archives and can access the files contained in theirselves.

You also need to add a .args file to set some command line arguments to pass to quickjs. In our case we will pass the file name in the /zip directory, which is a special path containing the files in the zip archive.

zip qjs.com main.js .args

Now you created your universal Scala.js binary, you can run in every major operating system with no dependencies.

Fast compile run loop

You don't need to zip a Javascript file to run it with quickjs. You can just use qjs.com as a standalone Javascript runtime.

scala-cli package -f -w main.scala && ./qjs.com main.js