abortcontroller-polyfill/dist/polyfill-patch-fetch.js

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (factory());
}(this, (function () { 'use strict';

  var classCallCheck = function (instance, Constructor) {
    if (!(instance instanceof Constructor)) {
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    return function (Constructor, protoProps, staticProps) {
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      if (staticProps) defineProperties(Constructor, staticProps);
      return Constructor;
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  var get = function get(object, property, receiver) {
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    var desc = Object.getOwnPropertyDescriptor(object, property);

    if (desc === undefined) {
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      if (parent === null) {
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      return desc.value;
    } else {
      var getter = desc.get;

      if (getter === undefined) {
        return undefined;
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      return getter.call(receiver);
    }
  };

  var inherits = function (subClass, superClass) {
    if (typeof superClass !== "function" && superClass !== null) {
      throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
    }

    subClass.prototype = Object.create(superClass && superClass.prototype, {
      constructor: {
        value: subClass,
        enumerable: false,
        writable: true,
        configurable: true
      }
    });
    if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass;
  };

  var possibleConstructorReturn = function (self, call) {
    if (!self) {
      throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
    }

    return call && (typeof call === "object" || typeof call === "function") ? call : self;
  };

  var Emitter = function () {
    function Emitter() {
      classCallCheck(this, Emitter);

      this.listeners = {};
    }

    createClass(Emitter, [{
      key: 'addEventListener',
      value: function addEventListener(type, callback) {
        if (!(type in this.listeners)) {
          this.listeners[type] = [];
        }
        this.listeners[type].push(callback);
      }
    }, {
      key: 'removeEventListener',
      value: function removeEventListener(type, callback) {
        if (!(type in this.listeners)) {
          return;
        }
        var stack = this.listeners[type];
        for (var i = 0, l = stack.length; i < l; i++) {
          if (stack[i] === callback) {
            stack.splice(i, 1);
            return;
          }
        }
      }
    }, {
      key: 'dispatchEvent',
      value: function dispatchEvent(event) {
        var _this = this;

        if (!(event.type in this.listeners)) {
          return;
        }
        var debounce = function debounce(callback) {
          setTimeout(function () {
            return callback.call(_this, event);
          });
        };
        var stack = this.listeners[event.type];
        for (var i = 0, l = stack.length; i < l; i++) {
          debounce(stack[i]);
        }
        return !event.defaultPrevented;
      }
    }]);
    return Emitter;
  }();

  var AbortSignal = function (_Emitter) {
    inherits(AbortSignal, _Emitter);

    function AbortSignal() {
      classCallCheck(this, AbortSignal);

      var _this2 = possibleConstructorReturn(this, (AbortSignal.__proto__ || Object.getPrototypeOf(AbortSignal)).call(this));

      _this2.aborted = false;
      _this2.onabort = null;
      return _this2;
    }

    createClass(AbortSignal, [{
      key: 'toString',
      value: function toString() {
        return '[object AbortSignal]';
      }
    }, {
      key: 'dispatchEvent',
      value: function dispatchEvent(event) {
        if (event.type === 'abort') {
          this.aborted = true;
          if (typeof this.onabort === 'function') {
            this.onabort.call(this, event);
          }
        }

        get(AbortSignal.prototype.__proto__ || Object.getPrototypeOf(AbortSignal.prototype), 'dispatchEvent', this).call(this, event);
      }
    }]);
    return AbortSignal;
  }(Emitter);

  var AbortController = function () {
    function AbortController() {
      classCallCheck(this, AbortController);

      this.signal = new AbortSignal();
    }

    createClass(AbortController, [{
      key: 'abort',
      value: function abort() {
        var event = void 0;
        try {
          event = new Event('abort');
        } catch (e) {
          if (typeof document !== 'undefined') {
            if (!document.createEvent) {
              // For Internet Explorer 8:
              event = document.createEventObject();
              event.type = 'abort';
            } else {
              // For Internet Explorer 11:
              event = document.createEvent('Event');
              event.initEvent('abort', false, false);
            }
          } else {
            // Fallback where document isn't available:
            event = {
              type: 'abort',
              bubbles: false,
              cancelable: false
            };
          }
        }
        this.signal.dispatchEvent(event);
      }
    }, {
      key: 'toString',
      value: function toString() {
        return '[object AbortController]';
      }
    }]);
    return AbortController;
  }();

  if (typeof Symbol !== 'undefined' && Symbol.toStringTag) {
    // These are necessary to make sure that we get correct output for:
    // Object.prototype.toString.call(new AbortController())
    AbortController.prototype[Symbol.toStringTag] = 'AbortController';
    AbortSignal.prototype[Symbol.toStringTag] = 'AbortSignal';
  }

  function polyfillNeeded(self) {
    if (self.__FORCE_INSTALL_ABORTCONTROLLER_POLYFILL) {
      console.log('__FORCE_INSTALL_ABORTCONTROLLER_POLYFILL=true is set, will force install polyfill');
      return true;
    }

    // Note that the "unfetch" minimal fetch polyfill defines fetch() without
    // defining window.Request, and this polyfill need to work on top of unfetch
    // so the below feature detection needs the !self.AbortController part.
    // The Request.prototype check is also needed because Safari versions 11.1.2
    // up to and including 12.1.x has a window.AbortController present but still
    // does NOT correctly implement abortable fetch:
    // https://bugs.webkit.org/show_bug.cgi?id=174980#c2
    return typeof self.Request === 'function' && !self.Request.prototype.hasOwnProperty('signal') || !self.AbortController;
  }

  /**
   * Note: the "fetch.Request" default value is available for fetch imported from
   * the "node-fetch" package and not in browsers. This is OK since browsers
   * will be importing umd-polyfill.js from that path "self" is passed the
   * decorator so the default value will not be used (because browsers that define
   * fetch also has Request). One quirky setup where self.fetch exists but
   * self.Request does not is when the "unfetch" minimal fetch polyfill is used
   * on top of IE11; for this case the browser will try to use the fetch.Request
   * default value which in turn will be undefined but then then "if (Request)"
   * will ensure that you get a patched fetch but still no Request (as expected).
   * @param {fetch, Request = fetch.Request}
   * @returns {fetch: abortableFetch, Request: AbortableRequest}
   */
  function abortableFetchDecorator(patchTargets) {
    if ('function' === typeof patchTargets) {
      patchTargets = { fetch: patchTargets };
    }

    var _patchTargets = patchTargets,
        fetch = _patchTargets.fetch,
        _patchTargets$Request = _patchTargets.Request,
        NativeRequest = _patchTargets$Request === undefined ? fetch.Request : _patchTargets$Request,
        NativeAbortController = _patchTargets.AbortController,
        _patchTargets$__FORCE = _patchTargets.__FORCE_INSTALL_ABORTCONTROLLER_POLYFILL,
        __FORCE_INSTALL_ABORTCONTROLLER_POLYFILL = _patchTargets$__FORCE === undefined ? false : _patchTargets$__FORCE;

    if (!polyfillNeeded({ fetch: fetch, Request: NativeRequest, AbortController: NativeAbortController, __FORCE_INSTALL_ABORTCONTROLLER_POLYFILL: __FORCE_INSTALL_ABORTCONTROLLER_POLYFILL })) {
      return { fetch: fetch, Request: Request };
    }

    var Request = NativeRequest;
    // Note that the "unfetch" minimal fetch polyfill defines fetch() without
    // defining window.Request, and this polyfill need to work on top of unfetch
    // hence we only patch it if it's available. Also we don't patch it if signal
    // is already available on the Request prototype because in this case support
    // is present and the patching below can cause a crash since it assigns to
    // request.signal which is technically a read-only property. This latter error
    // happens when you run the main5.js node-fetch example in the repo
    // "abortcontroller-polyfill-examples". The exact error is:
    //   request.signal = init.signal;
    //   ^
    // TypeError: Cannot set property signal of #<Request> which has only a getter
    if (Request && !Request.prototype.hasOwnProperty('signal') || __FORCE_INSTALL_ABORTCONTROLLER_POLYFILL) {
      Request = function Request(input, init) {
        var signal = void 0;
        if (init && init.signal) {
          signal = init.signal;
          // Never pass init.signal to the native Request implementation when the polyfill has
          // been installed because if we're running on top of a browser with a
          // working native AbortController (i.e. the polyfill was installed due to
          // __FORCE_INSTALL_ABORTCONTROLLER_POLYFILL being set), then passing our
          // fake AbortSignal to the native fetch will trigger:
          // TypeError: Failed to construct 'Request': member signal is not of type AbortSignal.
          delete init.signal;
        }
        var request = new NativeRequest(input, init);
        if (signal) {
          Object.defineProperty(request, 'signal', {
            writable: false,
            enumerable: false,
            configurable: true,
            value: signal
          });
        }
        return request;
      };
      Request.prototype = NativeRequest.prototype;
    }

    var realFetch = fetch;
    var abortableFetch = function abortableFetch(input, init) {
      var signal = Request && Request.prototype.isPrototypeOf(input) ? input.signal : init ? init.signal : undefined;

      if (signal) {
        var abortError = void 0;
        try {
          abortError = new DOMException('Aborted', 'AbortError');
        } catch (err) {
          // IE 11 does not support calling the DOMException constructor, use a
          // regular error object on it instead.
          abortError = new Error('Aborted');
          abortError.name = 'AbortError';
        }

        // Return early if already aborted, thus avoiding making an HTTP request
        if (signal.aborted) {
          return Promise.reject(abortError);
        }

        // Turn an event into a promise, reject it once `abort` is dispatched
        var cancellation = new Promise(function (_, reject) {
          signal.addEventListener('abort', function () {
            return reject(abortError);
          }, { once: true });
        });

        if (init && init.signal) {
          // Never pass .signal to the native implementation when the polyfill has
          // been installed because if we're running on top of a browser with a
          // working native AbortController (i.e. the polyfill was installed due to
          // __FORCE_INSTALL_ABORTCONTROLLER_POLYFILL being set), then passing our
          // fake AbortSignal to the native fetch will trigger:
          // TypeError: Failed to execute 'fetch' on 'Window': member signal is not of type AbortSignal.
          delete init.signal;
        }
        // Return the fastest promise (don't need to wait for request to finish)
        return Promise.race([cancellation, realFetch(input, init)]);
      }

      return realFetch(input, init);
    };

    return { fetch: abortableFetch, Request: Request };
  }

  (function (self) {

    if (!polyfillNeeded(self)) {
      return;
    }

    if (!self.fetch) {
      console.warn('fetch() is not available, cannot install abortcontroller-polyfill');
      return;
    }

    var _abortableFetch = abortableFetchDecorator(self),
        fetch = _abortableFetch.fetch,
        Request = _abortableFetch.Request;

    self.fetch = fetch;
    self.Request = Request;

    Object.defineProperty(self, 'AbortController', {
      writable: true,
      enumerable: false,
      configurable: true,
      value: AbortController
    });

    Object.defineProperty(self, 'AbortSignal', {
      writable: true,
      enumerable: false,
      configurable: true,
      value: AbortSignal
    });
  })(typeof self !== 'undefined' ? self : global);

})));