how to include mongoose

I am trying to include mongoose, but when it goes to api folder, with es6 promise, it won't work.
How should I write the promise version callback?

I am using like this:
`import mongoose from 'mongoose';
mongoose.Promise = Promise;
var User = require('../../models/User.js');

export default function loadArticle(params) {
return new Promise((resolve, reject) => {
User.find({}, function(){
resolve({raw:1});
})

})
}`

the same code works fine in src/server.js like
`User.find('庞龙', function(err, results){
console.log(results);
if (err) return console.error(err);
});`