Populating MongoDB in a loop in Node.js - node.js

Question

I would like to populate a MongoDB database using Node.js (mongoose). I'm trying to do it asynchronously (using async.js) after the DB connection has been made, but it's not working as I hoped. Instead of filling the database with a small number of documents, the database connection is opened and closed before the writes can be made. Sounds like a very typical async problem, but I am at a loss.
My code is currently as follows.
var runStart = '2019-01-01 00:00:00';
var runEnd = '2019-01-17 00:00:00';
var periods = [];
var d = moment(runStart);
while (d < moment(runEnd)) {
periods.push([d.format(), d.add(1, 'day').format()]);
}
mongoose.connect(config.db);
const db = mongoose.connection;
db.on('error', () => {
throw new Error('unable to connect to database');
});
db.on('open', () => {
console.log('DB open');
async.each(
periods,
function(period, next) {
Period({
start: moment(period[0]),
end: moment(period[1]),
type: 'delivery',
notes: ''
}).save((err) => {
if (err) callback(err);
});
next();
},
function(err) {
db.close();
console.log('FINISHED!');
});
});
What am I doing wrong?

Answer 1

function(period, next) {
Period({
start: moment(period[0]),
end: moment(period[1]),
type: 'delivery',
notes: ''
}).save((err) => {
if (err) callback(err); // `callback` is supposed to be `next
});
next(); // `next` is called before the document is saved
},
Change that code to this:
function(period, next) {
Period({
start: moment(period[0]),
end: moment(period[1]),
type: 'delivery',
notes: ''
}).save((err) => {
next(err);
});
},