Start script not listening to stdin

[razwanizmi]

Describe the bug

I use Create React App as part of an asset pipeline in a web framework (in my case Phoenix). As part of the development pipeline, I've set up a watcher to run react-scripts start whenever my web server starts.

This works fine, but whenever I terminate my web server, Webpack dev server remains running in the background. I want Webpack dev server to listen on stdin for SIGINT and SIGTERM so it can terminate itself.

I noticed in start.js that there is an event listener set up for SIGINT and SIGTERM, but this didn't work for me.

Referring to this documentation, I can fix the issue on my machine by adding this line;

process.stdin.resume()

before any of the process event handlers are added. I think process will exit prematurely and not listen to stdin without that.

If this works for everyone, I'd be happy to put in a PR.

Did you try recovering your dependencies?

Yes.

Which terms did you search for in User Guide?

Start, listen, stdin, sigint, and sigterm.

Environment

  System:
    OS: macOS 10.15.7
    CPU: (4) x64 Intel(R) Core(TM) i5-5250U CPU @ 1.60GHz
  Binaries:
    Node: 15.8.0 - ~/.asdf/installs/nodejs/15.8.0/bin/node
    Yarn: 1.22.4 - /usr/local/bin/yarn
    npm: 7.5.4 - ~/.asdf/installs/nodejs/15.8.0/.npm/bin/npm
  Browsers:
    Chrome: 92.0.4515.107
    Edge: Not Found
    Firefox: 83.0
    Safari: 14.1.1
  npmPackages:
    react: ^17.0.2 => 17.0.2
    react-dom: ^17.0.2 => 17.0.2
    react-scripts: 4.0.3 => 4.0.3
  npmGlobalPackages:
    create-react-app: Not Found

Steps to reproduce

Described above.

Expected behavior

react-scripts start should listen to stdin for SIGINT and SIGTERM and terminate itself.

Actual behavior

Webpack dev server keeps running in the background after its spawning process gets terminated.

[stale[bot]]

This issue has been automatically marked as stale because it has not had any recent activity. It will be closed in 5 days if no further activity occurs.

[jonatanklosko]

Hey, the original fix from #7203 did work, however process.stdin.resume() has been reverted in #8700, and consequently broke it again.

The simplest way to reproduce the issue is to create a new CRA app and run:

node_modules/react-scripts/bin/react-scripts.js start <&-

Note: <&- immediately closes stdin of the script.

[jonatanklosko]

A similar story happened in rollup. It watched stdin, then process.stdin.resume() was removed in https://github.com/rollup/rollup/pull/2410, but then added back in https://github.com/rollup/rollup/pull/3493.

See the commit description in https://github.com/rollup/rollup/commit/57bb54ea26bef7eab062925364158a4c478062f3 for more details.

I think we should bring process.stdin.resume() back.