Stalling Accept.JS Script Loads

stall-acceptjs.js

(() => {
  if (window.__acceptStalled) {
    console.warn("[stall] already installed");
    return;
  }

  const ACCEPT_RE = /authorize\.net\/v1\/Accept\.js/i;
  const origAdd = EventTarget.prototype.addEventListener;
  const stalled = [];

  EventTarget.prototype.addEventListener = function (type, listener, opts) {
    const isAcceptScript =
      this instanceof HTMLScriptElement &&
      typeof this.src === "string" &&
      ACCEPT_RE.test(this.src);

    if (isAcceptScript && (type === "load" || type === "error")) {
      stalled.push({ target: this, type, listener });
      console.warn("[stall] swallowed Accept.js", type, "listener for", this.src);
      return;
    }
    return origAdd.call(this, type, listener, opts);
  };

  window.__acceptStalled = true;
  window.__stalledAccept = stalled;

  window.__releaseAccept = () => {
    EventTarget.prototype.addEventListener = origAdd;
    console.warn("[stall] releasing", stalled.length, "load listeners");
    stalled.forEach(({ listener, type }) => {
      if (type === "load") {
        try { listener(new Event("load")); } catch (e) { console.error(e); }
      }
    });
    stalled.length = 0;
    delete window.__acceptStalled;
    delete window.__releaseAccept;
  };

  console.warn(
    "[stall] Accept.js load is now stalled. Click Purchase to repro. " +
    "Run window.__releaseAccept() when you're done observing."
  );
})();