CLJS Shrinkwrap

Tool to package ClojureScript nbb scripts into standalone Node.js executables.

# install cljs-shrinkwrap
npm i chr15m/cljs-shrinkwrap
# turn myscript.cljs into an executable 'myscript.mjs' that only depends on Node
npx shrinkwrap myscript.cljs myscript.mjs

Shrinkwrap bundles your .cljs file and nbb and node_modules deps into a single standalone executable file which only relies on Node.js.

This allows you to distribute your ClojureScript command-line tools as single executable files that only require Node.js to run, without needing nbb or other ClojureScript tooling installed on the user's system.

The resulting executable can be run with any version of Node.js going back to v16.

Usage

You can run shrinkwrap using npx if it's listed in your project's package.json dependencies, or directly if you've installed globally.

Using npx (if installed as a dependency):

npx shrinkwrap your-script.cljs your-executable-name[.mjs]

This will create an executable file named your-executable-name[.mjs] in the current directory.

Command-Line Arguments and Options:

The script expects two main arguments:

1. INPUT_FILE: The input ClojureScript file (e.g., your-script.cljs).
2. OUTPUT_FILE: The desired name for the output executable (e.g., your-executable-name).

Available option:

• -h, --help: Displays help information.

How It Works

The shrinkwrap tool performs the following steps:

1. Compile CLJS to JS: It uses nbb bundle to compile your input ClojureScript file into an intermediate JavaScript module (.mjs).
2. Bundle with NCC: It then uses @vercel/ncc programmatically to bundle this intermediate JavaScript file and all its node_modules dependencies into a single, minified JavaScript file.
3. Create Executable: Finally, it prepends a Node.js shebang (#!/usr/bin/env -S node --experimental-default-type=module) to the bundled JavaScript content and saves it as the specified output file, making it executable.

GitHub Release Action

You can use the GitHub action release-action-example.yml to automatically release your single-file executable on GitHub.

Customize the actions file and put it in e.g. .github/workflows/release.yml.

You can then link people to the executable with instructions like this (replacing SCRIPTNAME with the actual name of your script):

wget https://github.com/USER/REPO/releases/latest/download/SCRIPTNAME
chmod 755 SCRIPTNAME
./SCRIPTNAME

Technology

• nbb: Scripting with ClojureScript on Node.js.
• @vercel/ncc: Compiles a Node.js module into a single file, together with all its dependencies, GCC-style.
• clojure.tools.cli: For command-line argument parsing in Clojure.

License

MIT