Scrape Facebook emojis

fb-emoji-scraper.js

let content_security_policy = "script-src 'self'; object-src 'self' https://www.facebook.com/"; // for running in Chrome's JS console
/* Let’s see which Unicode 10.0 emojis Facebook already supports.
<https://github.com/Crissov/unicode-proposals/issues/254#issuecomment-284831620> */
let myEmojis = new Map([
			['1f6f7', 'U+1F6F7 🛷 SLED'],
			['1f6f8', 'U+1F6F8 🛸 FLYING SAUCER'],
			['1f91f', 'U+1F91F 🤟 I LOVE YOU HAND SIGN'],
			['1f928', 'U+1F928 🤨 FACE WITH ONE EYEBROW RAISED'],
			['1f929', 'U+1F929 🤩 GRINNING FACE WITH STAR EYES'],
			['1f92a', 'U+1F92A 🤪 GRINNING FACE WITH CRAZY EYES'],
			['1f92b', 'U+1F92B 🤫 FACE WITH FINGER COVERING CLOSED LIPS'],
			['1f92c', 'U+1F92C 🤬 SERIOUS FACE WITH SYMBOLS COVERING MOUTH'],
			['1f92d', 'U+1F92D 🤭 SMILING FACE WITH SMILING EYES AND HAND COVERING MOUTH'],
			['1f92e', 'U+1F92E 🤮 FACE WITH OPEN MOUTH VOMITING'],
			['1f92f', 'U+1F92F 🤯 SHOCKED FACE WITH EXPLODING HEAD'],
			['1f931', 'U+1F931 🤱 BREAST-FEEDING'],
			['1f932', 'U+1F932 🤲 PALMS UP TOGETHER'],
			['1f94c', 'U+1F94C 🥌 CURLING STONE'],
			['1f95f', 'U+1F95F 🥟 DUMPLING'],
			['1f960', 'U+1F960 🥠 FORTUNE COOKIE'],
			['1f961', 'U+1F961 🥡 TAKEOUT BOX'],
			['1f962', 'U+1F962 🥢 CHOPSTICKS'],
			['1f963', 'U+1F963 🥣 BOWL WITH SPOON'],
			['1f964', 'U+1F964 🥤 CUP WITH STRAW'],
			['1f965', 'U+1F965 🥥 COCONUT'],
			['1f966', 'U+1F966 🥦 BROCCOLI'],
			['1f967', 'U+1F967 🥧 PIE'],
			['1f968', 'U+1F968 🥨 PRETZEL'],
			['1f969', 'U+1F969 🥩 CUT OF MEAT'],
			['1f96a', 'U+1F96A 🥪 SANDWICH'],
			['1f96b', 'U+1F96B 🥫 CANNED FOOD'],
			['1f992', 'U+1F992 🦒 GIRAFFE FACE'],
			['1f993', 'U+1F993 🦓 ZEBRA FACE'],
			['1f994', 'U+1F994 🦔 HEDGEHOG'],
			['1f995', 'U+1F995 🦕 SAUROPOD'],
			['1f996', 'U+1F996 🦖 T-REX'],
			['1f997', 'U+1F997 🦗 CRICKET'],
			['1f9d0', 'U+1F9D0 🧐 FACE WITH MONOCLE'],
			['1f9d1', 'U+1F9D1 🧑 ADULT'],
			['1f9d2', 'U+1F9D2 🧒 CHILD'],
			['1f9d3', 'U+1F9D3 🧓 OLDER ADULT'],
			['1f9d4', 'U+1F9D4 🧔 BEARDED PERSON'],
			['1f9d5', 'U+1F9D5 🧕 PERSON WITH HEADSCARF'],
			['1f9d6', 'U+1F9D6 🧖 PERSON IN STEAMY ROOM'],
			['1f9d7', 'U+1F9D7 🧗 PERSON CLIMBING'],
			['1f9d8', 'U+1F9D8 🧘 PERSON IN LOTUS POSITION'],
			['1f9d9', 'U+1F9D9 🧙 MAGE'],
			['1f9da', 'U+1F9DA 🧚 FAIRY'],
			['1f9db', 'U+1F9DB 🧛 VAMPIRE'],
			['1f9dc', 'U+1F9DC 🧜 MERPERSON'],
			['1f9dd', 'U+1F9DD 🧝 ELF'],
			['1f9de', 'U+1F9DE 🧞 GENIE'],
			['1f9df', 'U+1F9DF 🧟 ZOMBIE'],
			['1f9e0', 'U+1F9E0 🧠 BRAIN'],
			['1f9e1', 'U+1F9E1 🧡 ORANGE HEART'],
			['1f9e2', 'U+1F9E2 🧢 BILLED CAP'],
			['1f9e3', 'U+1F9E3 🧣 SCARF'],
			['1f9e4', 'U+1F9E4 🧤 GLOVES'],
			['1f9e5', 'U+1F9E5 🧥 COAT'],
			['1f9e6', 'U+1F9E6 🧦 SOCKS']
		]);
/** EmojiStaticConfig, EmojiConfig */
var defaultSize = 32;// 64 does not work, 128 only works for emojis from Unicode 10
var pixelRatio = 3;// values of 1, 1.5, 2 and 3 are working, possibly others as well, but not 2.5
var schemaAuth = "https:\/\/www\.facebook\.com\/images\/emoji\.php\/v8"; // the digit at the end does not seem to matter much, FB uses `7` or `8`
var fileExt = ".png";
var checksumBase = 317426846;
var supportedSizes = {
	"16": "DP16",
	"18": "DP18",
	"20": "DP20",
	"24": "DP24",
	"28": "DP28",
	"30": "DP30",
	"32": "DP32",
	"64": "DP64",
	"128": "DP128"
};
var types = {
	FBEMOJI: "f",
	FB_EMOJI_EXTENDED: "e",
	MESSENGER: "z",
	UNICODE: "u"
}
var FBEMOJI = "f";
var FB_EMOJI_EXTENDED = "e";
var MESSENGER = "z";
var UNICODE = "u";

/**
 * Facebook emoji URL checksum
 * @param string codepoints = "{single-digit pixel ratio}/"
 *                          + "{decimal pixel width/height}/"
 *                          + "{lowercase hexadecimal Unicode positions, separated by underscores}.png"
 *                          = `\d/\d{2,3}/[a-f\d_]+\.png` (lax RX)
 *                          = `[12]/(16|18|20|24|28|30|32|64|128)/[a-f\d]{4,5}(_[a-f\d]{4,5})*\.png` (stricter RX)
 * @param int base = 317426846 (default)
 * @returns string of 2 hexadecimal digits
 */
function checksum(path, base) { /* i(k, l) */
	//	path = unescape(encodeURIComponent(path));
	/** `unescape()`: `&amp;` → `&`, `&lt;` → `<`, `&gt;` → `>`, `&quot;` → `"`, `&#x27;` → `'` */
	for (var pos = 0; pos < path.length; pos++) {
		base = (base << 5) - base + path.charCodeAt(pos);
		base &= 4294967295;
	}
	return (base & 255).toString(16);
}

function getURL(codepoints, size, type) { /* j(k, l, m) */
	size in supportedSizes || defaultSize;
	var path = pixelRatio + '/' + size + '/' + codepoints + fileExt;
	var check = checksum(path, checksumBase);
	return schemaAuth + '/' + type + check + '/' + path;
}
function getMessengerURL(codepoints, size) { /* k(l, m) */
	return getURL(codepoints, size, types.MESSENGER);
}
function getFBEmojiURL(codepoints) { /* k(l) */
	var size = arguments.length <= 1 || arguments[1] === undefined ? defaultSize : arguments[1];
	return getURL(codepoints, size, types.FBEMOJI);
}
function getFBEmojiExtendedURL(codepoints) { /* k(l) */
	var size = arguments.length <= 1 || arguments[1] === undefined ? defaultSize : arguments[1];
	return getURL(codepoints, size, types.FB_EMOJI_EXTENDED);
}

/** Output HTML and automatically click on each link */
function FBemoji(codepoints, alt) {
	var address = getFBEmojiURL(codepoints);
	var download = document.createElement("a");
	download.setAttribute("id", codepoints);
	download.setAttribute("download", alt + ".png");
	download.setAttribute("title", alt);
	download.setAttribute("href", address);
	var thumb = document.createElement("img");
	thumb.setAttribute("src", address);
	thumb.setAttribute("alt", alt);
	thumb.setAttribute("title", codepoints);
	download.appendChild(thumb);
	return document.body.appendChild(download);
}
var title = document.getElementsByTagName("title")[0];
title.textContent = "Facebook emoji image scraper";
var body = document.getElementsByTagName("body")[0];
body.textContent = ""; // clear all existing body content
for (let [codepoint, name] of myEmojis) {
	var node = FBemoji(codepoint, name);
	node.click();
}

Apparently for the emoticons PACMAN :v LIKE (y) and FACE_WITH_COLON_THREE :3 the capitalized name should be used as the codepoint and the type set to "e".