Based on johot's yalc-watch, but with a few improvements:

• Package is now published with LF line endings instead of CRLF to improve compatibility with Mac + Linux when using yarn.
• Cleaned up + updated dependencies => less vulnerabilities.
• buildWatchCommand property in config is now optional, in case you want to directly publish your source without processing it with something like Babel or TSC.

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.

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.

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

npm i yalc-watch-improved --save-dev

or

yarn add -D yalc-watch-improved

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!