Automatically running commands with nodemon

Instead of running the same commands over and over again, some of the command-line tools that I use have a watch mode and will automatically re-run when files are changed, however, not all do.

Instead of doing this manually, I can achieve the same thing though using a tool called nodemon - a script monitor for node projects, but it can work with non-node projects too.

Here's an example where I'm automatically re-running my PHPUnit tests using a just test recipe each time a file within my custom modules directory changes:

nodemon \
--watch web/modules/custom \
--ext '*' \
--exec "just test --stop-on-failure --colors=always"

I specify the files or directories I want to watch, which file extensions should trigger a restart (in this case, I've enabled all extensions), and the command to execute.

This watches all files and run all of the tests, but I can filter either if I need to.

As well as PHP tools like PHPUnit and PHPStan, I also use this for other things such as when creating presentation slides with rst2pdf where I can automatically re-generate the PDF whenever I update the rst file.