Webpack process is killed whenever some of the integrated scripts finishes with errors, under Windows

[abuseofnotation]

Under windows, scripts which finish with code different than 0 return errors to this callback:

https://github.com/1337programming/webpack-shell-plugin/blob/master/src/webpack-shell-plugin.js#L21

I think this is normal behaviour. From the node docs :

If a callback function is provided, it is called with the arguments (error, stdout, stderr). On success, error will be null. On error, error will be an instance of Error. The error.code property will be the exit code of the child process while error.signal will be set to the signal that terminated the process. Any exit code other than 0 is considered to be an error.

This callback throws all errors it gets.

As a result, the Webpack process is killed whenever some of the integrated scripts finishes with errors.

[abuseofnotation]

Do you want me to submit a PR for this?