Yalc-watch

Why

Yalc is an awesome tool for developing and testing your packages / libraries locally without publishing to npm.

The only thing yalc is currently missing is a way of watching the build output of a library and then automatically pushing that build into the projects you want to test it with.

This can be really helpful when building something like a design system or component library where you want instant feedback in a consuming app.

What

This very simple package will allow you to monitor an output folder (using nodemon under the hood) and will automatically call yalc push when a change is detected.

The yalc push command will automaticaly update all projects where you have previously installed your package locally using the yalc add your-package-name command.

For projects such as next.js or create-react-app this will automatically trigger a live reload of your project.

How

In your library / package install yalc-watch as a dev dependency:

npm i yalc-watch --save-dev

Add the following confic JSON to your package.json and tweak to your liking:

...
"yalcWatch": {
  "watchFolder": "dist",
  "buildWatchCommand": "tsc --watch",
  "extensions": "js,png,svg,gif,jpeg,css",
}
...

Still in your package.json add the following to the scripts section:

"scripts": {
  ...
  "yalc-watch": "yalc-watch",
  ...
}

Now simply run the command:

npm run yalc-watch

yalc-watch will start running the configured buildWatchCommand and look for changes in your configured watchFolder. When a change is detected the yalc push command will be executed updating all projects that added your package using yalc add your-package-name.

If you haven't already done so. You need to install your package in the consuming app using the yalc add your-package-name for yalc push to have any effect.

Enjoy!