type ConditionalString = string | undefined; let scriptsToBlock: ConditionalString[] = [ "head > script:nth-child(34)", "head > script:nth-child(43)" ]; let count = 0; const observer = new MutationObserver(mutations => { for (let i = 0; i < scriptsToBlock.length; i++) { if (scriptsToBlock[i]) { const script = document.querySelector(scriptsToBlock[i]!) as HTMLScriptElement; if (script) { script.src = ""; count++; scriptsToBlock[i] = undefined; if (count >= scriptsToBlock.length) { observer.disconnect(); break; } } } } }); observer.observe(document, {childList: true, subtree: true});