Screwfix Web Master

Bypass Screwfix

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         Screwfix Web Master
// @description  Bypass Screwfix
// @match        http://*/*
// @match        https://*/*
// @run-at       document-start
// @version 0.0.1.20260611193143
// @namespace https://greasyfork.org/users/1611219
// ==/UserScript==

(() => {
  "use strict";

  const code = `
    (() => {
      "use strict";

      const DEBUG = true;

      const HEADERS_TO_SET = {
        "x-screwfix-client": "consumer-app",
        "x-screwfix-platform": "ios"
      };

      const TARGET_METHODS = ["*"];

      const TARGET_URL_PATTERN = /.*/;

      function log(...args) {
        if (DEBUG) {
          console.log("[Screwfix headers]", ...args);
        }
      }

      function normaliseUrl(url) {
        try {
          return new URL(String(url), location.href).href;
        } catch {
          return String(url);
        }
      }

      function shouldModify(url, method) {
        const fullUrl = normaliseUrl(url);
        const upperMethod = String(method || "GET").toUpperCase();

        const methodMatches =
          TARGET_METHODS.includes("*") ||
          TARGET_METHODS.map(m => m.toUpperCase()).includes(upperMethod);

        return methodMatches && TARGET_URL_PATTERN.test(fullUrl);
      }

      function editHeaders(headersLike) {
        const headers = new Headers(headersLike || {});

        for (const [name, value] of Object.entries(HEADERS_TO_SET)) {
          headers.set(name, value);
        }

        return headers;
      }

      function isManagedHeader(name) {
        const lowerName = String(name).toLowerCase();

        return Object.keys(HEADERS_TO_SET).some(
          headerName => headerName.toLowerCase() === lowerName
        );
      }

      /*
        Patch fetch()
      */
      const originalFetch = window.fetch;

      window.fetch = function patchedFetch(input, init = {}) {
        let url;
        let method;
        let originalHeaders;

        if (input instanceof Request) {
          url = input.url;
          method = init.method || input.method || "GET";
          originalHeaders = init.headers || input.headers;
        } else {
          url = input;
          method = init.method || "GET";
          originalHeaders = init.headers;
        }

        if (!shouldModify(url, method)) {
          return originalFetch.call(this, input, init);
        }

        log("patching fetch", method, normaliseUrl(url), HEADERS_TO_SET);

        const newInit = {
          ...init,
          method,
          headers: editHeaders(originalHeaders)
        };

        if (input instanceof Request) {
          return originalFetch.call(this, new Request(input, newInit));
        }

        return originalFetch.call(this, input, newInit);
      };

      /*
        Patch XMLHttpRequest
      */
      const originalOpen = XMLHttpRequest.prototype.open;
      const originalSend = XMLHttpRequest.prototype.send;
      const originalSetRequestHeader = XMLHttpRequest.prototype.setRequestHeader;

      XMLHttpRequest.prototype.open = function patchedOpen(method, url, ...rest) {
        this.__screwfixHeaderUrl = url;
        this.__screwfixHeaderMethod = method;
        this.__screwfixHeaderShouldModify = shouldModify(url, method);

        return originalOpen.call(this, method, url, ...rest);
      };

      XMLHttpRequest.prototype.setRequestHeader = function patchedSetRequestHeader(name, value) {
        if (this.__screwfixHeaderShouldModify && isManagedHeader(name)) {
          return;
        }

        return originalSetRequestHeader.call(this, name, value);
      };

      XMLHttpRequest.prototype.send = function patchedSend(body) {
        if (this.__screwfixHeaderShouldModify) {
          log("patching xhr", this.__screwfixHeaderMethod, normaliseUrl(this.__screwfixHeaderUrl), HEADERS_TO_SET);

          for (const [name, value] of Object.entries(HEADERS_TO_SET)) {
            originalSetRequestHeader.call(this, name, value);
          }
        }

        return originalSend.call(this, body);
      };

      log("installed");
    })();
  `;

  const script = document.createElement("script");
  script.textContent = code;

  const target = document.documentElement || document.head || document.body;

  if (target) {
    target.appendChild(script);
    script.remove();
  } else {
    document.addEventListener("DOMContentLoaded", () => {
      document.documentElement.appendChild(script);
      script.remove();
    }, { once: true });
  }
})();