database.js

const { MongoMemoryServer } = require('mongodb-memory-server');
(async () => {
    const mongod = await MongoMemoryServer.create({
        instance: {
            port: 27017,
            ip: '127.0.0.1',
            dbName: 'properties'
        }
    });
    const uri = mongod.getUri();
    const port = mongod.instanceInfo.port;
    const dbPath = mongod.instanceInfo.dbPath;
    const dbName = mongod.instanceInfo.dbName;

    console.log(`Database uri: ${uri}`);
    console.log(`Database running on port: ${port}`);
    console.log(`Database Name: ${dbName}`);
    console.log(`Local DB Storage path ${dbPath}`);

    const MongoClient = require('mongodb').MongoClient;
    MongoClient.connect(uri, function(err, client) {
        const db = client.db(dbName);
        seedUsers(db, function(err, result) {
            if(err) throw new Error("Error seeding");
            console.log(`Seeded ${result.insertedCount} users into users collection.`)
            client.close();
        });
    });
})();

const seedUsers = function(db, callback) {
    const userCollection = db.collection('users');
    userCollection.insertMany([{
        "email": "user1@sideinc.com",
        "token": "676cfd34-e706-4cce-87ca-97f947c43bd4",
    }, {
        "email": "user2@sideinc.com",
        "token": "2f403433-ba0b-4ce9-be02-d1cf4ad6f453",
    }], function(err, result) {
        callback(err, result);
    });
}