How many cups of coffee a day?

coffee.js

module.exports = function (ctx, done) {
  var MongoClient = require('mongodb').MongoClient;
  var assert = require('assert');
  var ObjectId = require('mongodb').ObjectID;
  var url = ctx.data.MONGO_URL;

  var insertValue = function(db) {
    db.collection('cups').insertOne({
      'date': new Date(),
      'coffee': 1
    }, function(err, result) {
      assert.equal(err, null);
      done(null, "New coffee added!");
    });
  };
  
  MongoClient.connect(url, function(err, db) {
    assert.equal(null, err);
    insertValue(db, function() {
      db.close();
    });
  });

};