UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1)

var http = require('http'),
fs = require('fs'),
url = require('url');


// var db = require('../db');


var mongo = require( '../db_mongo' );


http.createServer(function(request, response){
var path = url.parse(request.url).pathname;
var url_parts = url.parse(request.url, true);
var query = url_parts.query;
    var url_parts = url.parse(request.url, true);
    var query = url_parts.query;

var setval = {username: query.name, email: query.email, password: query.pass};
//     db.query('INSERT INTO users  SET ?', setval, function (err, res) {
//         if (err)
//             throw err;
//
// });


if (mongo) {console.log("mongo  connected here ss");}

var userCollection =   mongo.collection('users');

userCollection.insert((setval, function(err, result) {
    if(err) { throw err; }
    res.write("<p>Product inserted:</p>");
    res.end("<p>" + result[0].make + " " + result[0].model + "</p>");
}));


    // db.collection('users').insertOne( {
    //     username: query.name, email: query.email, password: query.pass
    // }, function(err, result) {
    //     assert.equal(err, null);
    //     console.log("Inserted a document into users");
    //     callback();
    // });
// };

// insertDocument(db, function() {
// });




}).listen(8001);

var mongodb = require('mongodb');
var MongoClient = mongodb.MongoClient;
var url_db = 'mongodb://localhost:27017/test';

exports.connectdb = function (callback) {

module.exports = MongoClient.connect(url_db, function (err, db) {
    if (err) {
        console.log('Unable to connect to the mongoDB server. Error:', err);
    }
    if (!err) {
        console.log('Connection established to', url_db);
        return db;
    }
});
}
module.exports = exports;