flatiron/prompt — pull request #56 by Southern (2012-09-22 01:10:16+00:00)
Title: Fix undefined callback errors.

This fixes instances where a callback may not be defined. Rather than throwing a general undefined error, let's let the person know that they forgot to define a callback.

For instance:
```js
prompt.start();
prompt.get('test');
```

This would normally throw an error:
```
/home/sly/dev/Node/flatiron/prompt/lib/prompt.js:317
return err ? done(err) : done(null, result);
^
TypeError: undefined is not a function
at prompt.get (/home/sly/dev/Node/flatiron/prompt/lib/prompt.js:317:20)
at async.forEachSeries.iterate (/home/sly/dev/Node/flatiron/prompt/node_modules/utile/node_modules/async/lib/async.js:110:21)
at assembler (/home/sly/dev/Node/flatiron/prompt/lib/prompt.js:283:18)
at prompt.get (/home/sly/dev/Node/flatiron/prompt/lib/prompt.js:324:20)
at prompt.getInput (/home/sly/dev/Node/flatiron/prompt/lib/prompt.js:486:14)
at onError (/home/sly/dev/Node/flatiron/prompt/node_modules/read/lib/read.js:93:12)
at Interface. (/home/sly/dev/Node/flatiron/prompt/node_modules/read/lib/read.js:65:5)
at Interface.EventEmitter.emit (events.js:85:17)
at Interface._ttyWrite (readline.js:608:16)
at ReadStream.onkeypress (readline.js:98:10)
```

So, instead of throwing an error.. this proposal would turn it into...

SIGINT:
```
$ node test/test
prompt: test: User cancelled input.
```

No callback:
```
$ node test/test
prompt: test: test
User input successful, but no callback defined.
These arguments were returned:
[ { test: 'test' } ]
```

Feedback and suggestions are most definitely welcome.