RFC: Exporting start script to facilitate custom start scripts in a CRA app without ejecting

[benglass]

The use-case we had in mind was customizing the start script without ejecting (for example to add a listener for API calls to proxy them to a separate API server so the web app can talk to it without needing to use CORS). The thought was that if react-scripts start script exported a function to create the dev server then our code could simply require the start script and then add our own custom logic.

The code in this PR is for illustration/discussion purposes only, I havent run it. I wanted to see what your thoughts on this approach were or if there is another way to achieve our use case.

[facebook-github-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign up at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need the corporate CLA signed.

If you have received this in error or have any questions, please contact us at [email protected]. Thanks!

[benglass]

If you require'd this module, you could call start() yourself and then off it to get the devServer/host/port/launchBrowser methods and launch the server yourself.

// my-code/scripts/start.js
const start = require('react-scripts/start');
start
  .then(
    ({ devServer, host, post, openBrowser }) => {
      // boot devServer however you want, maybe as middleware on express server?
   }

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Facebook open source project. Thanks!

[gaearon]

Why not just modify start script to do two different things?
Something like

    "start": "concurrently \"npm run start:proxy\" \"npm run start:client\"",
    "start:client": "react-scripts start",
    "start:proxy: "..."

[benglass]

Good question, primary reason being I was hoping to run the proxy on the same port to avoid the need for CORS which I think would require we have a single server.

[gaearon]

Please describe your use case in #3366 and we can address it as a part of fixing that issue. Thanks!

[benglass]

Thanks for pointing me in the direction of the proxy feature, I'll post in #3366 if I find I can't use that feature for my use case.