GOG Don't Giveaway Consent - Revoke consent for sharing data with third-parties when claiming a giveaway

gog-consent.user.js

// ==UserScript==
// @name        GOG Don't Giveaway Consent
// @namespace   https://github.com/TheDcoder
// @license     GPLv3
// @match       *://www.gog.com/*
// @run-at      document-start
// @grant       GM_notification
// @grant       GM_openInTab
// @version     1.3.1
// @author      [email protected]
// @description Revoke consent for sharing data with third-parties when claiming a giveaway
// ==/UserScript==

main();

function main() {
	// Check if it is the front-page
	if(!['', 'en', 'de', 'fr', 'pl', 'ru', 'zh'].some(x => x == window.location.pathname.replaceAll('/', ''))) {
		// Check if it is the "Thank You" page
		if (window.location.pathname.startsWith('/giveaway/thank-you')) {
			revoke();
		}
		return;
	}

	// Inform the user if a giveaway is present
	window.addEventListener('load', inform_user);

	// Monkey-patch to intercept the claim request
	const RealXMLHttpRequest = {open: unsafeWindow.XMLHttpRequest.prototype.open};
	unsafeWindow.XMLHttpRequest.prototype.open = function monkey(method, url, ...args) {
		// Hook onto the result if's for a claim
		var path = new URL(url, window.location.href).pathname.slice(1).split('/');
		if (path.every((x, i) => x == ['giveaway', 'claim'][i])) {
			this.addEventListener("load", revoke);
			// Remove the monkey as we don't need it anymore
			unsafeWindow.XMLHttpRequest.prototype.open = RealXMLHttpRequest.open;
		}

		// Perform the real call
		return RealXMLHttpRequest.open.call(this, method, url, ...args);
	}

	function revoke() {
		revoke_consent().then(x => {
			GM_notification({
				title: "GOG Giveaway Consent",
				text: "A request to revoke your consent to sharing data has been sent! Click to check settings.",
				onclick: () => GM_openInTab('https://www.gog.com/account/settings/subscriptions', false),
			});
		}).catch(e => {
			GM_notification({
				title: "GOG Giveaway Consent",
				text: "Failed to revoke consent, please revoke it manually in your subscription settings! Error: " + e,
			});
		});
	}
}

function inform_user() {
	var button = document.querySelector('.giveaway-banner__button, .giveaway__button');
	if (!button) return;
	GM_notification({
		title: "GOG Giveaway Consent",
		text: "Giveaway detected! GOG wants your consent to share data if you claim the game, but this script will revoke it almost immediately.",
	});
}

async function revoke_consent() {
	var result = await fetch(
		"/account/save_newsletter_subscription/5353f0f4-3c06-11ee-b0fc-fa163ec9fc5f/0", {
		"credentials": "include",
		"referrer": "https://www.gog.com/en/account/settings/subscriptions",
		"method": "POST",
		"mode": "cors",
	});
	result = await result.json();
	if (result.status === true) {
		return true;
	} else {
		throw result;
	}
}

Install Instructions:

1. Install an user script manager for your browser, I recommend Violentmonkey.
2. Click this link to open a dialogue from your manager extension. (NOTE: Do not use the "Raw" button link as it's permanently linked to the specific version that's being displayed, you won't get updates if you use that link.)
3. Install and enjoy!

This script seems to not work after GOG's homepage layout overhaul. giveawayand claim don't match.

@6b6279 It worked for me when I last claimed a giveaway, can you share more info? Do you see the "giveaway detected" notification when you visit the homepage?

Hey, uh, no; it didn't work while claiming Oaken (Black Friday giveaway). No notification.