Proposal: `run` and `watch` scripts to use different entry points

As I start to build out real apps I find cases where I want to run a one-off script using the same language features as the rest of my app. If the only way to enter my code is via npm start then there’s no way to do this.

The proposed solution is to add two more scripts, react-scripts run and react-scripts watch that the developer can use to make their own npm script which uses the same babel environment. For example, let’s say you had a script src/populate.js to populate initial data in a remote backend. You could add to your npm scripts:

"scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "eject": "react-scripts eject",
    "populate": "react-scripts run src/populate.js"
  },

and then when you ran npm run populate it would invoke src/populate.js but do all the babel preprocessing to let you use ES6 features. watch would work just like run, but when any file changed it would restart the process. So watch would be used for long-running processes; run would be used for one-off scripts. run here works similarly to rails run if you are familiar with rails.

Without this sort of feature, developers are likely to make these one-off scripts using ES5 or using whatever language subset is node-compatible. This would also be a useful hook for people who wanted to build node server functionality, while not forcing it on anyone.

What do you think?

[tslater]

We’re using a mono-repo and link local dependencies within the same repo for fast development. It’s sometimes helpful to run watch on dependent module and develop on it while running it as a dependency. I think this would be a nice feature to have.

[lacker]

OK I am going to take a stab at creating run, and then depending on how that goes maybe watch will also be useful.