onemon

Run a npm script as a deamon, once

Usage no npm install needed!

<script type="module">
  import onemon from 'https://cdn.skypack.dev/onemon';
</script>

README

Welcome to onemon 👋

Version License: MIT

A CLI to help you share a deamon between your scripts

onemon has been created to fill a gap in the complex tooling world of javascript. When you have a monorepo, you may want to share a watcher between all your processes.

Of course you can do this by creating a vscode task like one that will launch tsc --watch in the background but maybe you want something more generic: a task that will launch both an instance of the watcher and your process in the same process.

The problem is if you launch two tasks, you don't want two watchers, so here onemon will help you, it will launch only one deamon and share it between your processes by using sockets to output its stdout.

Install

yarn global add onemon

Usage

onemon [deamon-script] <script>

How it works?

The only deamon

  • onemon starts your deamon-script .js as a deamon, if it's not already started.
  • onemon attach to a socket opened by the deamon, so you can watch your deamon output.
  • onemon starts your script if you provided one.
  • when no script using onemon deamon-script ... is running, onemon kills your one deamon.

What can be scripts?

  • For the deamon, you can only use a .js file path.
  • For the script, you can either use a .js file path, or a script entry from the nearest package.json

Flags

name shortcut description
silent -s Don't attach to the deamon output.
wait -w Wait for the deamon to call notifyReady() before launching the script.

Using it programmatically

  • The main function is exported so instead of using the CLI you can use onemon in your own code programmatically and we encourage you to do this.
  • A notifyReady function is exported that you can use on your deamon so it notifies onemon that an event happened, like a succeed built.

Can I test it?

  • clone the repository
  • execute yarn install, yarn build and yarn link or install onemon globally from the npm registry.
  • execute onemon examples/deamon.js on one terminal
  • execute onemon examples/deamon.js script on another terminal
  • play with the flags and use more terminals

Author

👤 Paul Le Couteur