text: require('dotenv').config({ path: './variables.env' });
  const mongoose = require('mongoose');
  mongoose.Promise = global.Promise;
  let isConnected;
  
  module.exports = connectToDatabase = () => {
    if (isConnected) {
      console.log('=> using existing database connection');
      return Promise.resolve();
    }
  
    console.log('=> using new database connection');
    return mongoose.connect(process.env.DB)
      .then(db => { 
        isConnected = db.connections[0].readyState;
      });
  };