Handle stdin closing

[wmonk]

Description

When running react-script from something like Phoenix, when you stop the phoenix process, the react-script process hangs around in the background. Brunch and webpack have both implemented this.

Expected behavior

The process is stopped when stdin is closed.

Actual behavior

The process does not stop.

[gaearon]

Do you want to send a PR?

[SpaceK33z]

Not sure if it helps anyone, but we recently fixed the same issue in webpack-dev-server. See here. I imagine the fix in CRA would look a lot like this.

[gaearon]

Hopefully this is fixed by #2246.
Let me know if you see this again with react-scripts >= 1.0.1.

[gaearon]

react-scripts@1.0.1 should be out with a fix.
Can you please verify it helps?

[notnarb]

I'm not OP but as far as I can tell #2246 does not solve this issue. This issue is about adding an option to create-react-app to terminate when stdin closes, not gracefully handling SIGINT and SIGTERM. For better or worse, listening for stdin closing is how Phoenix signals to its watcher processes that they should terminate

---

The relevant code for webpack is here:

https://github.com/webpack/webpack/blob/2bbbf508439728a84c33880bfb6ac547f0aa2a15/bin/webpack.js#L374-L378

if(watchOptions.stdin) {
	process.stdin.on("end", function() {
		process.exit(); // eslint-disable-line
	});
	process.stdin.resume();
}

---

webpack/webpack-dev-server has an example for specifically this functionality:

https://github.com/webpack/webpack-dev-server/tree/master/examples/cli-stdin

node ../../bin/webpack-dev-server.js --stdin
When stdin ends, we want to close the webpack-dev-server.

---

I see two solutions:

1. Modify create-react-app to pass the --stdin flag to webpack (or any flag? does that feature already exist?)
2. Copy the code from webpack and incorporate it into create-react-app

Happy to make a PR if desired

[1player]

Manually fixed in an ejected app by editing scripts/start.js and changing the end of the main block so that it reads:

   // [snip]
    ["SIGINT", "SIGTERM"].forEach(function(sig) {
      process.on(sig, function() {
        devServer.close();
        process.exit();
      });
    });

   // ADDED BY ME
    process.stdin.on("end", function() {
      devServer.close();
      process.exit();
    });
    process.stdin.resume();

@gaearon Can we please reopen this? It's not fixed at this time.

[Timer]

Could you please send a pull request?

[jakehasler]

@1player @Timer I just submitted a PR with the proposed (and working) change here.

#3430

[connorjacobsen]

This is still broken. The above PR is still open.