This tiny fetcher library will help you write your code in a more semantic fashion :

Methods :

======================== Constructor ==============================

-> Constructor = function(model) - Specify the model that will be used to query the database

-> Returns false on undefined model
-> Returns false if mongoose is not a project dependency
-> Library instance on valid model

-> Basic usage :
var MongooseModel = require(<mongoose model path>);
// Notice that the constructor is called immediatly
var MongooseModelPromises = require("mongoose.promises.js")(MongooseModel);

======================== Get method ==============================

-> Get = function (filter, numberOf) - Gets one or more documents from a specified model

=> Returns : promise

=> Callback parameters
	=> Success : function(data)
		- data : object, if numberOf not specified or numberOf = 1
				 array, if numberOf present and > 1
	=> Failure : function(message)
		- message : {
			status: "failed",
			message: the error message
		}

-> If filter is not specified, it will return all of the documents
MongooseModelPromises.Get()
.then(function(data) {
    res.status(200).send(data);
}).fail(function(message) {
    res.status(400).send(message);
});

-> Specifying filter only will return one value

var filter = {
	_id: req.params.id
};

MongooseModelPromises.Get(filter)
.then(function(data) {
    res.status(200).send(data);
}).fail(function(message) {
    res.status(400).send(message);
});

-> Specifying filter and limit

var filter = {
	_id: req.params.id
};

var limit = 20;

MongooseModelPromises.Get(filter, limit)
.then(function(data) {
    res.status(200).send(data);
}).fail(function(message) {
    res.status(400).send(message);
});

======================== Update method ==============================

-> Update = function(filter, update) - Updates a document based on "filter" parameter with keys from the "update" parameter

=> Returns : promise

=> Callback parameters
	=> Success : function(message)
		- message : {
			status: "ok",
			old: the document fields before update (all fields)
			new: the document updated fields (the update field provided)
		}
	=> Failure : function(message)
		- message : {
			status: "failed",
			message: the error message
		}

-> If filter or update objects are undefined (unspecified), false or plain objects {}, the promise will be rejected
	(it will fail)
Note : internally uses mongoose#model.findOneAndUpdate method
- Basic usage :
var filter = {
	_id: req.params.id
};

var update = {
	name: "Garfield"
};

MongooseModelPromises.Update(filter, update)
.then(function(message) {
    res.status(200).send(message);
}).fail(function(message) {
    res.status(400).send(message);
});

======================== Save method ==============================

-> Save = function(attrs) - Saves a new document based on its attributes

=> Returns : promise

=> Callback parameters
	=> Success : function(message)
		- message : {
			status: "ok",
			message: "addition successfull",
			data: the new added document's fields
		}
	=> Failure : function(message)
		- message : {
			status: "failed",
			message: the error message
		}

-> If attrs object is undefined (unspecified), false or plain object {}, the promise will be rejected
	(it will fail)
- Basic usage :
var attrs = {
	name: "Dan The Man"
};

MongooseModelPromises.Save(attrs)
.then(function(message) {
    res.status(200).send(message);
}).fail(function(message) {
    res.status(400).send(message);
});

======================== Remove method ==============================

-> Remove = function(filter) - Removes an element from the list

=> Returns : promise

=> Callback parameters
	=> Success : function(message)
		- message : {
			status: "ok",
			removed: the removed document's fields
		}
	=> Failure : function(message)
		- message : {
			status: "failed",
			message: the error message
		}

-> If attrs object is undefined (unspecified), false or plain object {}, the promise will be rejected
	(it will fail)
- Basic usage :

var filter = {
	_id: 123
};

TemplateModelPromises.Remove(filter)
.then(function(message) {
    res.status(200).send(message);
}).fail(function(message) {
    res.status(400).send(message);
});