https://www.linuxfm.org/website/static/src/js/content/cookie_watcher.js

1// This script is to be called directly in the <head>. It should not import any
2// other file or library, as it cannot be transformed into a module (because a
3// module is deferred): the function should be the very first thing launched on
4// the page to be able to bypass other IIFE of 3rd-party services that inject
5// new scripts client-side.
6
7// eslint-disable-next-line no-unused-vars
8function watch3rdPartyScripts(thirdPartyDomainsBlockList) {
9    const removeWWW = (domain) => (domain.startsWith("www.") ? domain.slice(4) : domain);
10    const blockList = thirdPartyDomainsBlockList.map(removeWWW);
11    const cookieRegex = /(^|(; ))website_cookies_bar=(?<value>[^;]+)/;
12    const scriptSrcDesc = Object.getOwnPropertyDescriptor(HTMLScriptElement.prototype, "src");
13    Object.defineProperty(HTMLScriptElement.prototype, "_src", scriptSrcDesc);
14    Object.defineProperty(HTMLScriptElement.prototype, "src", {
15        enumerable: true,
16        configurable: true,
17        get() {
18            return this._src;
19        },
20        set(val) {
21            const cookiesBarCookie = document.cookie.match(cookieRegex)?.groups.value;
22            const host = removeWWW(new URL(val, window.location.origin).host.toLowerCase());
23            if (
24                (!cookiesBarCookie || !JSON.parse(cookiesBarCookie).optional) &&
25                blockList.some((domain) => host === domain || host.endsWith(`.${domain}`))
26            ) {
27                this.dataset.nocookieSrc = val;
28                this.dataset.needCookiesApproval = "true";
29                this._src = "about:blank";
30            } else {
31                this._src = val;
32            }
33        },
34    });
35    document.addEventListener(
36        "optionalCookiesAccepted",
37        () => {
38            for (const scriptEl of document.querySelectorAll(
39                "script[data-need-cookies-approval]"
40            )) {
41                // We have to completely recreate the scripts for them to fire, we
42                // cannot just switch the src.
43                const newScript = document.createElement("script");
44                newScript._src = scriptEl.dataset.nocookieSrc;
45                scriptEl.insertAdjacentElement("beforebegin", newScript);
46                scriptEl.remove();
47            }
48        },
49        { once: true }
50    );
51}