Firefox browser extension that can disable the persisted queries GraphQL feature on Twitch.tv

background.js

// Note: This only works in Firefox!
//
// Load the extension in about:debugging
// If it doesn't seem to be working then click the Inspect button and see if there's any information in the Console tab
// One issue with old Firefox versions is that the host permission isn't automatically granted. Double check this in the Add-ons Manager.
//
// https://assets.twitch.tv/config/settings.0fa0027ddfc373022638f7943c4dd40d.js

function listener(details) {
  console.log(details.url);

  const filter = browser.webRequest.filterResponseData(details.requestId);

  filter.onerror = (event) => {
    console.error(`Error: ${filter.error}`);
  };

  filter.ondata = (event) => {
    const decoder = new TextDecoder("utf-8");
    const encoder = new TextEncoder();
    let str = decoder.decode(event.data, { stream: true });
    console.log(str);
    str = str.replace(/"persisted_queries_enabled":\s*true/, '"persisted_queries_enabled":false');
    if (str.includes('"persisted_queries_enabled":false')) {
      console.log(`Successfully set "persisted_queries_enabled":false`);
    }
    filter.write(encoder.encode(str));
    filter.disconnect();
  };

  filter.onstop = (event) => {
    filter.close();
  };

  return {};
}

browser.webRequest.onBeforeRequest.addListener(
  listener,
  {
    urls: ["https://assets.twitch.tv/config/settings.*.js"],
    types: ["script"],
  },
  ["blocking"]
);

manifest.json

{
  "manifest_version": 3,
  "name": "Twitch Disable Persisted GraphQL Queries",
  "description": "Only works in Firefox!",
  "version": "0.0.1",
  "background": {
    "scripts": ["background.js"]
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "webRequestFilterResponse"
  ],
  "host_permissions": [
    "https://www.twitch.tv/*",
    "https://assets.twitch.tv/config/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "127.0"
    }
  }
}