reddit: sabotage event tracker

Blocks the reddit event collector

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name         reddit: sabotage event tracker
// @namespace    mz1js5x0yt0zxq1kf22z1wdn6zq2ij2g
// @version      1.3.1
// @description  Blocks the reddit event collector
// @license      MIT
// @match        https://*.reddit.com/*
// @grant        none
// @run-at       document-start
// @inject-into  content
// ==/UserScript==

(function() {
	"use strict";

	const blockEventCollector = function (context = window, exporter = (f)=>f, wrapper = (x)=>x) {
		const markedXHRs = new WeakSet();

		const handlerSRH = new window.Object();
		const handlerSend = new window.Object();
		const handlerFetch = new window.Object();


		// Check for X-Signature header being set.
		// Remember this XHR and don't allow it to be sent
		handlerSRH.apply = exporter((setRequestHeader, that, args) => {
			if (args.length && !markedXHRs.has(that)) {
				const header = String(args[0]).toLowerCase();
				const config = wrapper(context.r?.config);

				if (header.startsWith("x-signature") || (config && (
					(config.signature_header && String(config.signature_header).toLowerCase() === header) ||
					(config.signature_header_v2 && String(config.signature_header_v2).toLowerCase() === header)
				))) {
					markedXHRs.add(that);
				}
			}

			return setRequestHeader.apply(that, args);
		});


		handlerSend.apply = exporter((send, that, args) => {
			if (markedXHRs.has(that)) {
				// Nope
				console.log("Canceling tracking request (XHR)");
				that.abort?.();
			} else {
				return send.apply(that, args);
			}
		});


		handlerFetch.apply = exporter((fetch, that, args) => {
			// Check Request object
			if (args[0] instanceof window.Request) {
				const headers = args[0].headers.keys();

				// Iterate with a classic for loop because
				// a for-of loop throws a DOMException.
				// Seems to be a Firefox bug
				for (let header = headers.next(); !header.done; header = headers.next()) {
					if (header.value.toLowerCase?.().startsWith("x-signature")) {
						console.log("Canceling tracking request (fetch-RQ)");
						return new window.Promise(() => {});
					}
				}
			}

			// Check additional request params
			if (typeof args[1]?.headers === "object") {
				const headers = Object.keys(args[1].headers);

				for (const header of headers) {
					if (header.toLowerCase?.().startsWith("x-signature")) {
						console.log("Canceling tracking request (fetch)");
						return new window.Promise(() => {});
					}
				}

			}

			return fetch.apply(that, args);
		});


		context.XMLHttpRequest.prototype.setRequestHeader = new window.Proxy(context.XMLHttpRequest.prototype.setRequestHeader, handlerSRH);
		context.XMLHttpRequest.prototype.send             = new window.Proxy(context.XMLHttpRequest.prototype.send,             handlerSend);
		context.fetch                                     = new window.Proxy(context.fetch,                                     handlerFetch);
	};



	// Firefox sandbox, execute directly
	if ("wrappedJSObject" in window) {
		const context = window.wrappedJSObject;
		blockEventCollector(context, (f) => exportFunction(f, window), XPCNativeWrapper);
	} else {
		// Chrome sandbox, inject as script tag
		const script = document.createElement("script");
		script.text = `"use strict";(${blockEventCollector})();"`;

		(document.head || document.documentElement).prepend(script);
		script.remove();
	}
})();