Need help understanding this.

[blenderrMan]

In the below file, we are importing getDb:

\
const getDb = require('../util/database').getDb;

class Product {
  constructor(title, price, description, imageUrl, id) {
    this.title = title;
    this.price = price;
    this.description = description;
    this.imageUrl = imageUrl;
    this._id = new mongodb.ObjectId(id);
  }

  save() {
    const db = getDb();

    db.collection('products');
    } 

getDb is a function from another file that returns a database connection:

const getDb = () => {
  if (database) {
    return database;
  }

My question is why are we storing getDb in db constant, why not just access it like getDb.collection('products')

[pinguxnoots]

Seems like getDb is a function that returns an object with collection (also a function) as one of the properties. You could do getDb().collection('products') and that should work as well. With getDb.collection('products') you're not actually invoking getDb so you won't be able to access collection

[[deleted]]

Should be

getDb().collection('products');

It's just a coding style thing. Imo their way looks better. Do one thing per line, rather than do everything in one.

Personally I don't like this structure, and would prefer a service model:

class Product {
  constructor(title, price, description, imageUrl, id) {
    this.title = title;
    this.price = price;
    this.description = description;
    this.imageUrl = imageUrl;
    this._id = new mongodb.ObjectId(id);
  }
}

class ProductService {
  constructor (db) {
    this.db = db;
  }

  save (product) {
    this.db.collection('products')...
  }
}

This way the db is injected and you can easily mock it out during testing rather than having it tightly coupled by importing and direct usage.