Using mongoose and Q.spread gives array callback parameters
The save callback signature is function(err, result, numberAffected) which doesn't conform to node callback convention. nfcall expects a node callback signature, which is function(err, result). To avoid loss of information, the promise returned by nfcall resolves to [result, numberAffected].
Using .bind and Q.nfcall at call sites is very ugly anyway, so you can create a method that does all this:
mongoose.Model.prototype.saveForResult = function() { return Q.nbind(this.save, this)().spread(function(result, numberAffected) { return result; });};Then:
Q.spread([ employee.saveForResult(), dept.saveForResult()],function(emp,dept){ console.log(JSON.stringify(emp)); console.log(JSON.stringify(dept)); mongoose.disconnect();})