Node.js mongodb driver async/await queries

Thanks. Working great with ES6:

const middleWare = require('middleWare');
const MONGO = require('mongodb').MongoClient;

router.get('/', middleWare(async (req, res, next) => {
    const db = await MONGO.connect(url);
    const MyCollection = db.collection('MyCollection');
    const result = await MyCollection.find(query).toArray();
    res.send(result);
}))

Edit: 'mongodb' v3.x

according to mongoDB ES6 future you can use this way;

let MongoClient = require('mongodb').MongoClient;
const connectionString = 'mongodb://localhost:27017';

    (async () => {
        let client = await MongoClient.connect(connectionString,
            { useNewUrlParser: true });

        let db = client.db('dbName');
        try {
           const res = await db.collection("collectionName").updateOne({ 
               "someKey": someValue
           }, { $set: someObj }, { upsert: true });

           console.log(`res => ${JSON.stringify(res)}`);
        }
        finally {
            client.close();
        }
    })()
        .catch(err => console.error(err));

Since all answers are missing some bits (catch blocks, checking that client is not null) I came with my own solution. Tested with Mongo server v4.0.7 and Node JS driver 3.2.2.

Note that the example is a console program, where we close the connection to the server in the finally block. In a web application, the connections are reused. See Node Mongo docs. Also, the errors are logged with libraries such as Winston or Morgan and not console logged.

const MongoClient = require('mongodb').MongoClient;

const url = 'mongodb://localhost:27017';

async function findOne() {

    const client = await MongoClient.connect(url, { useNewUrlParser: true })
        .catch(err => { console.log(err); });

    if (!client) {
        return;
    }

    try {

        const db = client.db("testdb");

        let collection = db.collection('cars');

        let query = { name: 'Volkswagen' }

        let res = await collection.findOne(query);

        console.log(res);

    } catch (err) {

        console.log(err);
    } finally {

        client.close();
    }
}

await findOne();