Show system notifications for errors

[goshacmd]

Uses webpack-notifier under the hood. No setup necessary.
Supports Notification Center on OS X, Toaster on Windows 8 and later.
Falls back to Growl if present.

(https://github.com/mikaelbr/node-notifier/blob/master/DECISION_FLOW.md)

Ref #89.

Notifications look like this:

for this error:

Error in ./src/App.js
Syntax error: /Users/goshakkk/Projects/oss/create-react-app/demo/src/App.js: Unexpected token (11:38)
   9 |         <div className="App-header">
  10 |           <img src={logo} className="App-logo" alt="logo" />
> 11 |           <h2>Welcome to React z</h2><<div
     |                                       ^
  12 |         </div>
  13 |         <p className="App-intro">
  14 |           To get started, edit <code>src/App.js</code> and save to reload.
 @ ./src/index.js 11:11-27

• Possible to supply a custom image to webpack-notifier, could be React logo. Considerations: eject will have to copy the logo as well. Might be okay though.

• Custom title is supported by webpack-notifier. "React" might be a bit too broad, "React Scripts" or "Create React App" or "React CLI" might be better.

• Custom error formatter is not supported, plus terminal coloring artifacts are present ([4m). Not currently possible to supply a custom formatter to webpack-notifier. Ideally the message should have been

  Error: ./App.js
  Unexpected token (11:38)

  Full path & parts of stack trace seem irrelevant for the notification. Error message is much more informative.

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[lacker]

Why do you want a system notification for every error? - they are already displayed from the npm start process. To me this seems like a customization that some but not most developers will want, and so the right thing to do if you would like system notifications for each error is to eject and then customize webpack accordingly, rather than turn it on for everyone by default.

[gaearon]

I’m not sure we’ll want to go with this but I’d like to try it out this week and see what it feels like.
If notifications can be muted on system level, maybe we could include this by default.
But I haven’t tried it so can’t say whether it’s annoying or useful to me.

[vjeux]

By default notifications are turned off from 8pm to 8am on mac, which is very confusing when it stops working for no apparent reason :(

Unrelated but this little script is awesome: http://frantic.im/notify-on-completion

[gaearon]

Thanks for the PR. I think we won’t go ahead with this as it seems a little too intrusive.