Node automatic rest routes

Crud.js

var _ = require('lodash');

function Crud(Model) {
    this.Model = Model;
}

Crud.prototype.find = function(req, res) {
    var criteria = {},
        findMethod = 'find';

    if (req.params.id) {
        criteria._id = req.params.id;
        findMethod = 'findOne';
    }

    if (!_.isEmpty(req.query)) {
        criteria = _.extend(criteria, req.query);
    }

    return this.Model[findMethod](criteria, function(err, documents) {
        if (err) {
            return res.status(501).json(err);
        }

        return res.json(documents);
    });
};

Crud.prototype.create = function(req, res) {
    var document;

    if (req.body) {
        document = new this.Model(req.body);

        document.save(function(err) {
            if (err) {
                return res.status(501).json(err);
            }

            return res.json(document);
        });
    } else {
        return res.status(400).json({
            success: false
        });
    }
};

Crud.prototype.update = function(req, res) {
    if (req.params.id) {
        this.Model.findOne({
            _id: req.params.id
        }, function(err, document) {
            if (err) {
                return res.status(501).json(err);
            }

            document = _.extend(document, req.body);

            document.save(function(err) {
                if (err) {
                    return res.status(501).json(err);
                }

                return res.json(document);
            });
        });
    }
};

Crud.prototype.delete = function(req, res) {
    if (req.params.id) {
        this.Model.findOneAndRemove({
            _id: req.params.id
        }, function(err, document) {
            if (err) {
                return res.status(501).json(err);
            }

            return res.json(document);
        });
    } else {
        return res.status(400).json({
            success: false
        });
    }
};

module.exports = Crud;

Restify.js

module.exports = function(route, controller) {
    var path = '/' + route,
        pathWithId = path + '/:id';

    app.get(path, function(req, res) {
        controller.find(req, res);
    });

    app.get(pathWithId, function(req, res) {
        controller.find(req, res);
    });

    app.post(path, function(req, res) {
        controller.create(req, res);
    });

    app.put(pathWithId, function(req, res) {
        controller.update(req, res);
    });

    app.delete(pathWithId, function(req, res) {
        controller.delete(req, res);
    });
};