Better npm error messages

[eddiemonge]

Running this without a connection throws a not-user friendly error.

yo
-------------------------------------------------------------------------------------------------------------------
? 'Allo Eddie! What would you like to do? Install a generator
? Search npm for generators: angular

     _-----_
    |       |    .----------------------.
    |--(o)--|    |     Bye from us!     |
   `---------´   |      Chat soon.      |
    ( _´U`_ )    |                      |
    /___A___\    |      Yeoman team     |
     |  ~  |     |   http://yeoman.io   |
   __'.___.'__   '----------------------'
 ´   `  |° ´ Y `


NpmError: Failed to fetch npm registry (see http://status.npmjs.org for status)
Error: getaddrinfo ENOTFOUND
undefined
Error: getaddrinfo ENOTFOUND
undefined
    at new NewError (/Users/eddie/Sites/OSS/yeoman/yo/node_modules/custom-error/index.js:14:13)
    at npmError (/Users/eddie/Sites/OSS/yeoman/yo/lib/routes/install.js:35:10)
    at Request._callback (/Users/eddie/Sites/OSS/yeoman/yo/lib/routes/install.js:53:15)
    at self.callback (/Users/eddie/Sites/OSS/yeoman/yo/node_modules/request/request.js:373:22)
    at Request.emit (events.js:95:17)
    at Request.onRequestError (/Users/eddie/Sites/OSS/yeoman/yo/node_modules/request/request.js:971:8)
    at ClientRequest.emit (events.js:95:17)
    at CleartextStream.socketErrorListener (http.js:1552:9)
    at CleartextStream.emit (events.js:95:17)
    at Socket.onerror (tls.js:1456:17)

Maybe something like:

yo
-------------------------------------------------------------------------------------------------------------------
? 'Allo Eddie! What would you like to do? Install a generator
? Search npm for generators: angular

     _-----_
    |       |    .----------------------.
    |--(o)--|    |     Bye from us!     |
   `---------´   |      Chat soon.      |
    ( _´U`_ )    |                      |
    /___A___\    |      Yeoman team     |
     |  ~  |     |   http://yeoman.io   |
   __'.___.'__   '----------------------'
 ´   `  |° ´ Y `

Sorry, but there was an error with your last action.
See the yo-error.log for more details

yo-error.log

NpmError: Failed to fetch npm registry (see http://status.npmjs.org for status)
Error: getaddrinfo ENOTFOUND
undefined
Error: getaddrinfo ENOTFOUND
undefined
    at new NewError (/Users/eddie/Sites/OSS/yeoman/yo/node_modules/custom-error/index.js:14:13)
    at npmError (/Users/eddie/Sites/OSS/yeoman/yo/lib/routes/install.js:35:10)
    at Request._callback (/Users/eddie/Sites/OSS/yeoman/yo/lib/routes/install.js:53:15)
    at self.callback (/Users/eddie/Sites/OSS/yeoman/yo/node_modules/request/request.js:373:22)
    at Request.emit (events.js:95:17)
    at Request.onRequestError (/Users/eddie/Sites/OSS/yeoman/yo/node_modules/request/request.js:971:8)
    at ClientRequest.emit (events.js:95:17)
    at CleartextStream.socketErrorListener (http.js:1552:9)
    at CleartextStream.emit (events.js:95:17)
    at Socket.onerror (tls.js:1456:17)

[SBoudrias]

If we can tell what's been wrong and provide useful error message, I'm all for it.

But simply hiding away the error log is not useful IMO

[eddiemonge]

yeah i was debating having some of the detail but moving the stacktrace and more detailed information to a log.

[gaboesquivel]

if by default yo would only display the error msg, an option/flag to get the full stacktrace in console would be nice/ required.

[sindresorhus]

Yeah, we can just show the stacktrace when --verbose is passed.

[SBoudrias]

Thing is... It's already hard to get a stacktrace when someone open an issue on our repos. If we hide the stack away, it'll be close to impossible to have details.

[kevva]

+1, having to tell everyone to include the --verbose flag after opening an issue is going to be miserable.

[eddiemonge]

isnt that kind of a convention in other things though?'

side conversation, should we really be throwing an error on network issues? Shouldn't it just say, 'network problems, want to try something else?'

[sindresorhus]

Hmm, yeah, that's true...

At least we can handle it for Error: getaddrinfo ENOTFOUND and show a message instead as it means we can't connect. No need for stacktrace in that case.