Uncaught exception TypeError, Object.keys called on non-object

[joeltello]

I am trying to set up this module in my project using the nano-adapter. I am trying to save a document in this way:

Schema = require('jugglingdb').Schema
schema = new Schema 'nano', { ###config goes here### }
# creating model
User = schema.define 'User',
  prop: String
# saving instance
user = User()
user.prop = "testing"
user.save (err, result) ->
    console.log "Err", err
    console.log "Res", result  

it does save the document in the DB correctly but throws this exception:

error: Uncaught exception: __chain__=false, __wrapped__=[__chain__=false, name=TypeError, message=Object.keys called on non-object, stack=TypeError: Object.keys called on non-object
    at Function.keys (native)
    at Function.AbstractClass._fromDB (/myproject/node_modules/jugglingdb/lib/model.js:202:28)
    at /myproject/node_modules/jugglingdb/lib/model.js:317:37
    at /myproject/node_modules/jugglingdb-nano/lib/nano.js:105:16
    at Request._callback (/myproject/node_modules/jugglingdb-nano/node_modules/nano/nano.js:288:11)
    at Request.self.callback (/myproject/node_modules/jugglingdb-nano/node_modules/nano/node_modules/request/request.js:129:22)
    at Request.EventEmitter.emit (events.js:98:17)
    at Request.<anonymous> (/myproject/node_modules/jugglingdb-nano/node_modules/nano/node_modules/request/request.js:873:14)
    at Request.EventEmitter.emit (events.js:117:20)
    at IncomingMessage.<anonymous> (/myproject/node_modules/jugglingdb-nano/node_modules/nano/node_modules/request/request.js:824:12)]

I see that inside model.js(317) you have this:

if (rev) {
  rev = Model._fromDB(rev);
  obj._rev = rev
}

Model._fromDB implementation

AbstractClass._fromDB = function (data) {
    if (!data) return;
    var definition = this.schema.definitions[this.modelName].properties;
    var propNames = Object.keys(data);
...

Obviously data in this case is the revision number which is a string not an object.

Am I missing something? Is this bug related to the nano-adapter?