preact watch doesn't kill the process when the stdin pipe is closed

[Ch4s3]

Npm Version: 5.3.0
Node version: 8.0.0
OS: macOS Sierra 10.12.16

Do you want to request a feature or report a bug?
Bug
What is the current behavior?
I run preact watch by running npm run dev, which runs preact watch. But I'm doing this from a process run by another app that serves as the backend. This a app correctly spins up preact watch, but when it shuts down and closes the stdin pipe, the preact process keeps running, which I believe is not the correct behavior.

If the current behavior is a bug, please provide the steps to reproduce.
You should be able to reproduce this by running a bash script like the following:

#!/bin/bash
PORT=8080 npm run watch

Then exit with ctrl-c and run ps -ax | grep 'preact watch', you will likely see something like:

 4845 ??         0:03.29 node /Users/your_user_name/your_project/node_modules/.bin/preact watch

What is the expected behavior?
I would expect preact watch to follow the unix standard and it should either fork and persist, or it should kill itself when stdin closes. Preferably it would kill itself.

[Ch4s3]

Here is how Brunch handles the behavior I expect.

[Ch4s3]

My hot fix for anyone landing here from google is to run this script to start preact watch

#!/bin/bash
PORT=8080 npm run watch &
IPID=$!
cat # This waits until stdin closes
kill $IPID
sleep 1
kill -9 $IPID

[Ch4s3]

I'm guessing a pr would need to target run-webpack.js but I'm not familiar enough with preact or node's syscall handling to feel confident putting it together.