• Can you go over the significance of why we do export { LocalStore }; or export { DataStore };

    Sure. This is our module interface. The module gets to decide what name(s) are exported (and can be imported). Something that isn't exported is completely private. (Unlike, say, Python, where importing a module gets you access to all the names.)

    In the main-module, there's a matching import statement. Let's look at that. main-module.js

    It's also possible to rename while importing, so a module can 

    
export { someVeryLongDescriptiveName }

    and the importing module can: 

    
import { short } from ./module.js
  • I would like to discuss more about the adjustments that were made in Main.

    Sure. Let's talk about them again. The highlights:

  • Does this mean values from other projects uploaded to Heroku might be accidentally accessed because the projects share the origin? Wouldn't this be an exploitable vulnerability?

    Yes! I remember seeing "coffee orders" that had been saved from other users.

    I also remember long ago having an app that allowed students to insert "comments" and I later discovered it being used as a chat channel by some non-Wellesley people!

  • Could you explain the difference between .get and .getItem?

    Glad to. .get is the name chosen by the CoffeeRun designers for a method that gets data from a data store. The LocalStore has the same method, but it gets the data from the browser's local storage feature.

    .getItem is a method for the browser-based feature.

    There are layers here. I'll draw a picture.

  • Could you also explain this function in detail? I don't quite understand why we only need to access the keys and not t he values: 
        
    function showDictionary(dic) {
        let keys = Object.keys(dic);
        keys.map(k => console.log(k, '=>', dic[k]));
    }

    It does access the values! That's what dic[k] does. The console.log prints both the key and the value. You could do the following instead: 

    
    function showDictionary(dic) {
        let keys = Object.keys(dic);
        keys.forEach( key => {
            const val = dic[key]; 
            console.log(key, '=>', val); 
        });
    }

    The original function really should use forEach and not map. That's an error.