index.js

require('dotenv').config();
const prompt = require('prompt');
const https = require('https');
const colors = require('colors/safe');

var questionCount = 0;
var score = 0;

let showAnswers = false;
let question_pool;

let options = {
	host: process.env.SPREADSHEET_HOST,
	path: process.env.SPREADSHEET_URL,
	method: 'GET'
};

process.argv.forEach((val, index) => {
  if(index === 2) {
  	showAnswers = val;
  }
});

var hreq = https.request(options, function(res){
	var body = '';
	res.on('data', function(chunk){
		body += chunk;
	});

	res.on('end', function(){
		question_pool = utilArrayShuffle(JSON.parse(body));
		getQuestion();
	});

});

hreq.end();

function getQuestion() {
	var acronym = question_pool[questionCount].tla;		

	prompt.get([acronym], function(err, result){
		if(err) {
			return;
		}

		var input = result[acronym];
		var answer = question_pool[questionCount].expanded;
		if(input.toLowerCase() === answer.toLowerCase()) {
			console.warn(colors.green('CORRECT'));
			++score;
		} else {
			if(showAnswers) console.warn(colors.red('INCORRECT ' + answer));
			else console.warn(colors.red('INCORRECT'));
		}

		++questionCount;
		console.log('Your score is ' + score + '/' + questionCount + '\n');
		
		if(questionCount < question_pool.length) getQuestion();
		else {
			console.log('You finished with '+ (score*100/questionCount)+'% success\n');
		}
	});
}

function utilArrayShuffle(array) {
  var currentIndex = array.length, temporaryValue, randomIndex;

  while (0 !== currentIndex) {
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;
    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }

  return array;
}