Catch connection errors

[rauchg]

Right now errors from mongoskin/native emitters are not being catched.
They should be re-emitted so that they can be captured by manager.on('error')

[matthewmueller]

+1, trying to get some kind of feedback that the connection hasn't been established.

[rauchg]

Yep basically we need to re-emit as error. Also, if an error occurs before open was emitted, we can fire it as connection_error as well.

[rauchg]

I also wonder whether we have open and close haha

[matthewmueller]

haha, i was actually getting open events even when i didn't have mongod running. That seemed a bit off, but I wasn't sure.

Here's what i had:

monk = require('monk')(url);

monk.on('open', function() {
  // prob shouldn't be firing when mongod not running...
});

[carloscarcamo]

+1

[carloscarcamo]

Maybe the bug is on manager.js in:

 this.driver.open(this.onOpen.bind(this));

What if we just pass a callback and emit events?, something like:

var _this = this;
this.driver.open(function (error) {
  if (error) {
    _this.emit('error', error);
  } else {
    _this.emit('open')
  }
});

...

if (fn) {
  this.once('open', fn);
  this.once('error', fn);
}

Then we can pass a callback to check for errors, something like:

var db = monk(uri, function(err) {
  if (err) console.error(err);
});

or

var db = monk(uri, opts, function(err) {
  if (err) console.error(err);
});

or

var db = monk(uri);
db.on('error', function (err) { console.error(err); })
db.on('open', function () { console.log('open'); });

Mongoskin will return an error if the connection fails:

[ERROR] [Error: failed to connect to [127.0.0.1:27017]]