yet-another-abortcontroller-polyfill/index.js

An AbortController Polyfill

const root =
  (typeof globalThis !== "undefined" && globalThis) ||
  (typeof self !== "undefined" && self) ||
  (typeof global !== "undefined" && global);

if (typeof root.AbortController === "undefined") {
  const SECRET = {};

  root.AbortSignal = (function () {
    function AbortSignal(secret) {
      if (secret !== SECRET) {
        throw new TypeError("Illegal constructor.");
      }
      EventTarget.call(this);
      this._aborted = false;
    }

    AbortSignal.prototype = Object.create(EventTarget.prototype);
    AbortSignal.prototype.constructor = AbortSignal;

    Object.defineProperty(AbortSignal.prototype, "onabort", {
      get: function () {
        return this._onabort;
      },
      set: function (callback) {
        const existing = this._onabort;
        if (existing) {
          this.removeEventListener("abort", existing);
        }
        this._onabort = callback;
        this.addEventListener("abort", callback);
      },
    });

    Object.defineProperty(AbortSignal.prototype, "aborted", {
      get: function () {
        return this._aborted;
      },
    });

    return AbortSignal;
  })();

  root.AbortController = (function () {
    function AbortController() {
      this._signal = new AbortSignal(SECRET);
    }

    AbortController.prototype = Object.create(Object.prototype);

    Object.defineProperty(AbortController.prototype, "signal", {
      get: function () {
        return this._signal;
      },
    });

    AbortController.prototype.abort = function () {
      const signal = this.signal;
      if (!signal.aborted) {
        signal._aborted = true;
        signal.dispatchEvent(new Event("abort"));
      }
    };

    return AbortController;
  })();
}