index.js

"use strict"

const readline = require("readline-sync");

const list = require('./modules/shopping');

do 
	{
	var input = String(readline.question("enter command: ")).trim() 
	if (input.indexOf('add ') == 0)  {
			let space = input.indexOf(' ');
		let item = input.substring(space).trim();
		/* Let's echo the item details back to the user before adding it. Notice the use of Template Literals (https://goo.gl/Yjxa5o), a part of ECMA6. This allows you to include placeholders for variables without the need for concatenation. The string must be enclosed by backticks (`) */
	console.log(`adding "${item}"`) 
        list.add(item)
	}
	if (input.indexOf("list") == 0) {
		const items = list.getAll()
        let i = 1
		for (var value of items) {
            /* process.stdout.write prints to the terminal without adding a newline character at the end. the \t character inserts a tab and the \n character inserts a newline */
	    	process.stdout.write(`${i}. ${value.title}`)
			process.stdout.write(`\t${value.qty}\n`) 
			i++ 
	    }
	}
}  while (input !== "exit");