gravy.js

'use strict';

const got = require('got');

const user = process.argv[2];
const opts = process.argv[3];
const url = `http://en.gravatar.com/${user}.json`;

if (!user || ! opts) {
	console.log('Gimme what I need');
	process.exit(1);
}

/*
opts can be -
   --id
   --hash
   --requestHash
   --profileUrl
   --preferredUsername
   --thumbnailUrl
   --displayName
   --aboutMe
   --currentLocation
   --emails
   --accounts
   --urls
 */

got(url, {json: true}).then(res => {
	const boi = res.body;
	const data = boi.entry[0].opts;
	// returns undefined because opts is a string 
	console.log(data);
});

// I was thinking to use this as a solution to my problem, but looks like it's not working

Object.prototype.getKeyByValue = function(value) {
	for (const prop in this) {
		if (this.hasOwnProperty(prop)) {
			if (this[prop] === value)
				return prop;
		}
	}
}

const test = {
	id: '--id',
	hash: '--hash'
};

const a = test.getKeyByValue('--id');
console.log(a);