eventemitter2.js

/*!
 * EventEmitter2
 * https://github.com/hij1nx/EventEmitter2
 *
 * Copyright (c) 2013 hij1nx
 * Licensed under the MIT license.
 */
;!function(undefined) {
  var hasOwnProperty= Object.hasOwnProperty;
  var isArray = Array.isArray ? Array.isArray : function _isArray(obj) {
    return Object.prototype.toString.call(obj) === "[object Array]";
  };
  var defaultMaxListeners = 10;

  function init() {
    this._events = {};
    if (this._conf) {
      configure.call(this, this._conf);
    }
  }

  function configure(conf) {
    if (conf) {
      this._conf = conf;

      conf.delimiter && (this.delimiter = conf.delimiter);

      if(conf.maxListeners!==undefined){
          this._maxListeners= conf.maxListeners;
      }

      conf.wildcard && (this.wildcard = conf.wildcard);
      conf.newListener && (this._newListener = conf.newListener);
      conf.removeListener && (this._removeListener = conf.removeListener);
      conf.verboseMemoryLeak && (this.verboseMemoryLeak = conf.verboseMemoryLeak);
      conf.ignoreErrors && (this.ignoreErrors = conf.ignoreErrors);

      if (this.wildcard) {
        this.listenerTree = {};
      }
    }
  }

  function logPossibleMemoryLeak(count, eventName) {
    var errorMsg = '(node) warning: possible EventEmitter memory ' +
        'leak detected. ' + count + ' listeners added. ' +
        'Use emitter.setMaxListeners() to increase limit.';

    if(this.verboseMemoryLeak){
      errorMsg += ' Event name: ' + eventName + '.';
    }

    if(typeof process !== 'undefined' && process.emitWarning){
      var e = new Error(errorMsg);
      e.name = 'MaxListenersExceededWarning';
      e.emitter = this;
      e.count = count;
      process.emitWarning(e);
    } else {
      console.error(errorMsg);

      if (console.trace){
        console.trace();
      }
    }
  }

  var toArray = function (a, b, c) {
    var n = arguments.length;
    switch (n) {
      case 0:
        return [];
      case 1:
        return [a];
      case 2:
        return [a, b];
      case 3:
        return [a, b, c];
      default:
        var arr = new Array(n);
        while (n--) {
          arr[n] = arguments[n];
        }
        return arr;
    }
  };

  function resolveOptions(options, schema, reducers, allowUnknown) {
    var computedOptions = Object.assign({}, schema);

    if(!options) return computedOptions;

    if (typeof options !== 'object') {
      throw TypeError('options must be an object')
    }

    var keys = Object.keys(options);
    var length = keys.length;
    var option, value;
    var reducer;

    function reject(reason){
      throw Error('Invalid "' + option + '" option value' + (reason? '. Reason: '+ reason : ''))
    }
    for (var i = 0; i < length; i++) {
      option = keys[i];
      if (!allowUnknown && !hasOwnProperty.call(schema, option)) {
        throw Error('Unknown "' + option + '" option');
      }
      value = options[option];
      if (value !== undefined) {
        reducer = reducers[option];
        computedOptions[option] = reducer ? reducer(value, reject) : value;
      }
    }
    return computedOptions;
  }

  function constructorReducer(value, reject) {
    if (typeof value !== 'function' || !value.hasOwnProperty('prototype')) {
      reject('Promise option must be a constructor');
    }
    return value;
  }

  function functionReducer(value, reject) {
    if (typeof value !== 'function') {
      reject('Promise option must be a function');
    }
    return value;
  }

  function makeCancelablePromise(Promise, executor, options) {
    var isCancelable;
    var callbacks;
    var timer= 0;
    var subscribeClosed;

    var promise = new Promise(function (resolve, reject, onCancel) {
      options= resolveOptions(options, {
        timeout: 0,
        overload: false
      }, {
        timeout: function(value, reject){
          value*= 1;
          if (typeof value !== 'number' || value < 0 || !Number.isFinite(value)) {
            reject('timeout must be a positive number');
          }
          return value;
        }
      });

      isCancelable = !options.overload && typeof Promise.prototype.cancel === 'function' && typeof onCancel === 'function';

      function cleanup() {
        if (callbacks) {
          callbacks = null;
        }
        if (timer) {
          clearTimeout(timer);
          timer = 0;
        }
      }

      var _resolve= function(value){
        cleanup();
        resolve(value);
      };

      var _reject= function(err){
        cleanup();
        reject(err);
      };

      if (isCancelable) {
        executor(_resolve, _reject, onCancel);
      } else {
        callbacks = [function(reason){
          _reject(reason || Error('canceled'));
        }];
        executor(_resolve, _reject, function (cb) {
          if (subscribeClosed) {
            throw Error('Unable to subscribe on cancel event asynchronously')
          }
          if (typeof cb !== 'function') {
            throw TypeError('onCancel callback must be a function');
          }
          callbacks.push(cb);
        });
        subscribeClosed= true;
      }

      if (options.timeout > 0) {
        timer= setTimeout(function(){
          var reason= Error('timeout');
          timer= 0;
          promise.cancel(reason);
          reject(reason);
        }, options.timeout);
      }
    });

    if (!isCancelable) {
      promise.cancel = function (reason) {
        if (!callbacks) {
          return;
        }
        var length = callbacks.length;
        for (var i = 1; i < length; i++) {
          callbacks[i](reason);
        }
        // internal callback to reject the promise
        callbacks[0](reason);
        callbacks = null;
      };
    }

    return promise;
  }

  function EventEmitter(conf) {
    this._events = {};
    this._newListener = false;
    this._removeListener = false;
    this.verboseMemoryLeak = false;
    configure.call(this, conf);
  }
  EventEmitter.EventEmitter2 = EventEmitter; // backwards compatibility for exporting EventEmitter property

  //
  // Attention, function return type now is array, always !
  // It has zero elements if no any matches found and one or more
  // elements (leafs) if there are matches
  //
  function searchListenerTree(handlers, type, tree, i) {
    if (!tree) {
      return [];
    }
    var listeners=[], leaf, len, branch, xTree, xxTree, isolatedBranch, endReached,
        typeLength = type.length, currentType = type[i], nextType = type[i+1];
    if (i === typeLength && tree._listeners) {
      //
      // If at the end of the event(s) list and the tree has listeners
      // invoke those listeners.
      //
      if (typeof tree._listeners === 'function') {
        handlers && handlers.push(tree._listeners);
        return [tree];
      } else {
        for (leaf = 0, len = tree._listeners.length; leaf < len; leaf++) {
          handlers && handlers.push(tree._listeners[leaf]);
        }
        return [tree];
      }
    }

    if ((currentType === '*' || currentType === '**') || tree[currentType]) {
      //
      // If the event emitted is '*' at this part
      // or there is a concrete match at this patch
      //
      if (currentType === '*') {
        for (branch in tree) {
          if (branch !== '_listeners' && tree.hasOwnProperty(branch)) {
            listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], i+1));
          }
        }
        return listeners;
      } else if(currentType === '**') {
        endReached = (i+1 === typeLength || (i+2 === typeLength && nextType === '*'));
        if(endReached && tree._listeners) {
          // The next element has a _listeners, add it to the handlers.
          listeners = listeners.concat(searchListenerTree(handlers, type, tree, typeLength));
        }

        for (branch in tree) {
          if (branch !== '_listeners' && tree.hasOwnProperty(branch)) {
            if(branch === '*' || branch === '**') {
              if(tree[branch]._listeners && !endReached) {
                listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], typeLength));
              }
              listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], i));
            } else if(branch === nextType) {
              listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], i+2));
            } else {
              // No match on this one, shift into the tree but not in the type array.
              listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], i));
            }
          }
        }
        return listeners;
      }

      listeners = listeners.concat(searchListenerTree(handlers, type, tree[currentType], i+1));
    }

    xTree = tree['*'];
    if (xTree) {
      //
      // If the listener tree will allow any match for this part,
      // then recursively explore all branches of the tree
      //
      searchListenerTree(handlers, type, xTree, i+1);
    }

    xxTree = tree['**'];
    if(xxTree) {
      if(i < typeLength) {
        if(xxTree._listeners) {
          // If we have a listener on a '**', it will catch all, so add its handler.
          searchListenerTree(handlers, type, xxTree, typeLength);
        }

        // Build arrays of matching next branches and others.
        for(branch in xxTree) {
          if(branch !== '_listeners' && xxTree.hasOwnProperty(branch)) {
            if(branch === nextType) {
              // We know the next element will match, so jump twice.
              searchListenerTree(handlers, type, xxTree[branch], i+2);
            } else if(branch === currentType) {
              // Current node matches, move into the tree.
              searchListenerTree(handlers, type, xxTree[branch], i+1);
            } else {
              isolatedBranch = {};
              isolatedBranch[branch] = xxTree[branch];
              searchListenerTree(handlers, type, { '**': isolatedBranch }, i+1);
            }
          }
        }
      } else if(xxTree._listeners) {
        // We have reached the end and still on a '**'
        searchListenerTree(handlers, type, xxTree, typeLength);
      } else if(xxTree['*'] && xxTree['*']._listeners) {
        searchListenerTree(handlers, type, xxTree['*'], typeLength);
      }
    }

    return listeners;
  }

  function growListenerTree(type, listener) {

    type = typeof type === 'string' ? type.split(this.delimiter) : type.slice();

    //
    // Looks for two consecutive '**', if so, don't add the event at all.
    //
    for(var i = 0, len = type.length; i+1 < len; i++) {
      if(type[i] === '**' && type[i+1] === '**') {
        return;
      }
    }

    var tree = this.listenerTree;
    var name = type.shift();

    while (name !== undefined) {

      if (!tree[name]) {
        tree[name] = {};
      }

      tree = tree[name];

      if (type.length === 0) {

        if (!tree._listeners) {
          tree._listeners = listener;
        }
        else {
          if (typeof tree._listeners === 'function') {
            tree._listeners = [tree._listeners];
          }

          tree._listeners.push(listener);

          if (
            !tree._listeners.warned &&
            this._maxListeners > 0 &&
            tree._listeners.length > this._maxListeners
          ) {
            tree._listeners.warned = true;
            logPossibleMemoryLeak.call(this, tree._listeners.length, name);
          }
        }
        return true;
      }
      name = type.shift();
    }
    return true;
  }

  // By default EventEmitters will print a warning if more than
  // 10 listeners are added to it. This is a useful default which
  // helps finding memory leaks.
  //
  // Obviously not all Emitters should be limited to 10. This function allows
  // that to be increased. Set to zero for unlimited.

  EventEmitter.prototype.delimiter = '.';

  EventEmitter.prototype.setMaxListeners = function(n) {
    if (n !== undefined) {
      this._maxListeners = n;
      if (!this._conf) this._conf = {};
      this._conf.maxListeners = n;
    }
  };

  EventEmitter.prototype.getMaxListeners = function() {
    return this._maxListeners;
  };

  EventEmitter.prototype.event = '';

  EventEmitter.prototype.once = function(event, fn) {
    return this._once(event, fn, false);
  };

  EventEmitter.prototype.prependOnceListener = function(event, fn) {
    return this._once(event, fn, true);
  };

  EventEmitter.prototype._once = function(event, fn, prepend) {
    this._many(event, 1, fn, prepend);
    return this;
  };

  EventEmitter.prototype.many = function(event, ttl, fn) {
    return this._many(event, ttl, fn, false);
  };

  EventEmitter.prototype.prependMany = function(event, ttl, fn) {
    return this._many(event, ttl, fn, true);
  };

  EventEmitter.prototype._many = function(event, ttl, fn, prepend) {
    var self = this;

    if (typeof fn !== 'function') {
      throw new Error('many only accepts instances of Function');
    }

    function listener() {
      if (--ttl === 0) {
        self.off(event, listener);
      }
      return fn.apply(this, arguments);
    }

    listener._origin = fn;

    this._on(event, listener, prepend);

    return self;
  };

  EventEmitter.prototype.emit = function() {
    if (!this._events && !this._all) {
      return false;
    }

    this._events || init.call(this);

    var type = arguments[0];

    if (type === 'newListener' && !this._newListener) {
      if (!this._events.newListener) {
        return false;
      }
    }

    var al = arguments.length;
    var args,l,i,j;
    var handler;

    if (this._all && this._all.length) {
      handler = this._all.slice();
      if (al > 3) {
        args = new Array(al);
        for (j = 0; j < al; j++) args[j] = arguments[j];
      }

      for (i = 0, l = handler.length; i < l; i++) {
        this.event = type;
        switch (al) {
        case 1:
          handler[i].call(this, type);
          break;
        case 2:
          handler[i].call(this, type, arguments[1]);
          break;
        case 3:
          handler[i].call(this, type, arguments[1], arguments[2]);
          break;
        default:
          handler[i].apply(this, args);
        }
      }
    }

    if (this.wildcard) {
      handler = [];
      var ns = typeof type === 'string' ? type.split(this.delimiter) : type.slice();
      searchListenerTree.call(this, handler, ns, this.listenerTree, 0);
    } else {
      handler = this._events[type];
      if (typeof handler === 'function') {
        this.event = type;
        switch (al) {
        case 1:
          handler.call(this);
          break;
        case 2:
          handler.call(this, arguments[1]);
          break;
        case 3:
          handler.call(this, arguments[1], arguments[2]);
          break;
        default:
          args = new Array(al - 1);
          for (j = 1; j < al; j++) args[j - 1] = arguments[j];
          handler.apply(this, args);
        }
        return true;
      } else if (handler) {
        // need to make copy of handlers because list can change in the middle
        // of emit call
        handler = handler.slice();
      }
    }

    if (handler && handler.length) {
      if (al > 3) {
        args = new Array(al - 1);
        for (j = 1; j < al; j++) args[j - 1] = arguments[j];
      }
      for (i = 0, l = handler.length; i < l; i++) {
        this.event = type;
        switch (al) {
        case 1:
          handler[i].call(this);
          break;
        case 2:
          handler[i].call(this, arguments[1]);
          break;
        case 3:
          handler[i].call(this, arguments[1], arguments[2]);
          break;
        default:
          handler[i].apply(this, args);
        }
      }
      return true;
    } else if (!this.ignoreErrors && !this._all && type === 'error') {
      if (arguments[1] instanceof Error) {
        throw arguments[1]; // Unhandled 'error' event
      } else {
        throw new Error("Uncaught, unspecified 'error' event.");
      }
    }

    return !!this._all;
  };

  EventEmitter.prototype.emitAsync = function() {
    if (!this._events && !this._all) {
      return false;
    }

    this._events || init.call(this);

    var type = arguments[0];

    if (type === 'newListener' && !this._newListener) {
        if (!this._events.newListener) { return Promise.resolve([false]); }
    }

    var promises= [];

    var al = arguments.length;
    var args,l,i,j;
    var handler;

    if (this._all) {
      if (al > 3) {
        args = new Array(al);
        for (j = 1; j < al; j++) args[j] = arguments[j];
      }
      for (i = 0, l = this._all.length; i < l; i++) {
        this.event = type;
        switch (al) {
        case 1:
          promises.push(this._all[i].call(this, type));
          break;
        case 2:
          promises.push(this._all[i].call(this, type, arguments[1]));
          break;
        case 3:
          promises.push(this._all[i].call(this, type, arguments[1], arguments[2]));
          break;
        default:
          promises.push(this._all[i].apply(this, args));
        }
      }
    }

    if (this.wildcard) {
      handler = [];
      var ns = typeof type === 'string' ? type.split(this.delimiter) : type.slice();
      searchListenerTree.call(this, handler, ns, this.listenerTree, 0);
    } else {
      handler = this._events[type];
    }

    if (typeof handler === 'function') {
      this.event = type;
      switch (al) {
      case 1:
        promises.push(handler.call(this));
        break;
      case 2:
        promises.push(handler.call(this, arguments[1]));
        break;
      case 3:
        promises.push(handler.call(this, arguments[1], arguments[2]));
        break;
      default:
        args = new Array(al - 1);
        for (j = 1; j < al; j++) args[j - 1] = arguments[j];
        promises.push(handler.apply(this, args));
      }
    } else if (handler && handler.length) {
      handler = handler.slice();
      if (al > 3) {
        args = new Array(al - 1);
        for (j = 1; j < al; j++) args[j - 1] = arguments[j];
      }
      for (i = 0, l = handler.length; i < l; i++) {
        this.event = type;
        switch (al) {
        case 1:
          promises.push(handler[i].call(this));
          break;
        case 2:
          promises.push(handler[i].call(this, arguments[1]));
          break;
        case 3:
          promises.push(handler[i].call(this, arguments[1], arguments[2]));
          break;
        default:
          promises.push(handler[i].apply(this, args));
        }
      }
    } else if (!this.ignoreErrors && !this._all && type === 'error') {
      if (arguments[1] instanceof Error) {
        return Promise.reject(arguments[1]); // Unhandled 'error' event
      } else {
        return Promise.reject("Uncaught, unspecified 'error' event.");
      }
    }

    return Promise.all(promises);
  };

  EventEmitter.prototype.on = function(type, listener) {
    return this._on(type, listener, false);
  };

  EventEmitter.prototype.prependListener = function(type, listener) {
    return this._on(type, listener, true);
  };

  EventEmitter.prototype.onAny = function(fn) {
    return this._onAny(fn, false);
  };

  EventEmitter.prototype.prependAny = function(fn) {
    return this._onAny(fn, true);
  };

  EventEmitter.prototype.addListener = EventEmitter.prototype.on;

  EventEmitter.prototype._onAny = function(fn, prepend){
    if (typeof fn !== 'function') {
      throw new Error('onAny only accepts instances of Function');
    }

    if (!this._all) {
      this._all = [];
    }

    // Add the function to the event listener collection.
    if(prepend){
      this._all.unshift(fn);
    }else{
      this._all.push(fn);
    }

    return this;
  };

  EventEmitter.prototype._on = function(type, listener, prepend) {
    if (typeof type === 'function') {
      this._onAny(type, listener);
      return this;
    }

    if (typeof listener !== 'function') {
      throw new Error('on only accepts instances of Function');
    }
    this._events || init.call(this);

    // To avoid recursion in the case that type == "newListeners"! Before
    // adding it to the listeners, first emit "newListeners".
    if (this._newListener)
       this.emit('newListener', type, listener);

    if (this.wildcard) {
      growListenerTree.call(this, type, listener);
      return this;
    }

    if (!this._events[type]) {
      // Optimize the case of one listener. Don't need the extra array object.
      this._events[type] = listener;
    }
    else {
      if (typeof this._events[type] === 'function') {
        // Change to array.
        this._events[type] = [this._events[type]];
      }

      // If we've already got an array, just add
      if(prepend){
        this._events[type].unshift(listener);
      }else{
        this._events[type].push(listener);
      }

      // Check for listener leak
      if (
        !this._events[type].warned &&
        this._maxListeners > 0 &&
        this._events[type].length > this._maxListeners
      ) {
        this._events[type].warned = true;
        logPossibleMemoryLeak.call(this, this._events[type].length, type);
      }
    }

    return this;
  };

  EventEmitter.prototype.off = function(type, listener) {
    if (typeof listener !== 'function') {
      throw new Error('removeListener only takes instances of Function');
    }

    var handlers,leafs=[];

    if(this.wildcard) {
      var ns = typeof type === 'string' ? type.split(this.delimiter) : type.slice();
      leafs = searchListenerTree.call(this, null, ns, this.listenerTree, 0);
    }
    else {
      // does not use listeners(), so no side effect of creating _events[type]
      if (!this._events[type]) return this;
      handlers = this._events[type];
      leafs.push({_listeners:handlers});
    }

    for (var iLeaf=0; iLeaf<leafs.length; iLeaf++) {
      var leaf = leafs[iLeaf];
      handlers = leaf._listeners;
      if (isArray(handlers)) {

        var position = -1;

        for (var i = 0, length = handlers.length; i < length; i++) {
          if (handlers[i] === listener ||
            (handlers[i].listener && handlers[i].listener === listener) ||
            (handlers[i]._origin && handlers[i]._origin === listener)) {
            position = i;
            break;
          }
        }

        if (position < 0) {
          continue;
        }

        if(this.wildcard) {
          leaf._listeners.splice(position, 1);
        }
        else {
          this._events[type].splice(position, 1);
        }

        if (handlers.length === 0) {
          if(this.wildcard) {
            delete leaf._listeners;
          }
          else {
            delete this._events[type];
          }
        }
        if (this._removeListener)
          this.emit("removeListener", type, listener);

        return this;
      }
      else if (handlers === listener ||
        (handlers.listener && handlers.listener === listener) ||
        (handlers._origin && handlers._origin === listener)) {
        if(this.wildcard) {
          delete leaf._listeners;
        }
        else {
          delete this._events[type];
        }
        if (this._removeListener)
          this.emit("removeListener", type, listener);
      }
    }

    function recursivelyGarbageCollect(root) {
      if (root === undefined) {
        return;
      }
      var keys = Object.keys(root);
      for (var i in keys) {
        var key = keys[i];
        var obj = root[key];
        if ((obj instanceof Function) || (typeof obj !== "object") || (obj === null))
          continue;
        if (Object.keys(obj).length > 0) {
          recursivelyGarbageCollect(root[key]);
        }
        if (Object.keys(obj).length === 0) {
          delete root[key];
        }
      }
    }
    recursivelyGarbageCollect(this.listenerTree);

    return this;
  };

  EventEmitter.prototype.offAny = function(fn) {
    var i = 0, l = 0, fns;
    if (fn && this._all && this._all.length > 0) {
      fns = this._all;
      for(i = 0, l = fns.length; i < l; i++) {
        if(fn === fns[i]) {
          fns.splice(i, 1);
          if (this._removeListener)
            this.emit("removeListenerAny", fn);
          return this;
        }
      }
    } else {
      fns = this._all;
      if (this._removeListener) {
        for(i = 0, l = fns.length; i < l; i++)
          this.emit("removeListenerAny", fns[i]);
      }
      this._all = [];
    }
    return this;
  };

  EventEmitter.prototype.removeListener = EventEmitter.prototype.off;

  EventEmitter.prototype.removeAllListeners = function(type) {
    if (type === undefined) {
      !this._events || init.call(this);
      return this;
    }

    if (this.wildcard) {
      var ns = typeof type === 'string' ? type.split(this.delimiter) : type.slice();
      var leafs = searchListenerTree.call(this, null, ns, this.listenerTree, 0);

      for (var iLeaf=0; iLeaf<leafs.length; iLeaf++) {
        var leaf = leafs[iLeaf];
        leaf._listeners = null;
      }
    }
    else if (this._events) {
      this._events[type] = null;
    }
    return this;
  };

  EventEmitter.prototype.listeners = function(type) {
    if (this.wildcard) {
      var handlers = [];
      var ns = typeof type === 'string' ? type.split(this.delimiter) : type.slice();
      searchListenerTree.call(this, handlers, ns, this.listenerTree, 0);
      return handlers;
    }

    this._events || init.call(this);

    if (!this._events[type]) this._events[type] = [];
    if (!isArray(this._events[type])) {
      this._events[type] = [this._events[type]];
    }
    return this._events[type];
  };

  EventEmitter.prototype.eventNames = function(){
    return Object.keys(this._events);
  };

  EventEmitter.prototype.listenerCount = function(type) {
    return this.listeners(type).length;
  };

  EventEmitter.prototype.listenersAny = function() {

    if(this._all) {
      return this._all;
    }
    else {
      return [];
    }

  };

  EventEmitter.prototype.waitFor = function (event, options) {
    var self = this;
    var type = typeof options;
    if (type === 'number') {
      options = {timeout: options};
    } else if (type === 'function') {
      options = {filter: options};
    }

    options= resolveOptions(options, {
      timeout: 0,
      filter: undefined,
      handleError: false,
      Promise: Promise,
      overload: false
    }, {
      filter: functionReducer,
      Promise: constructorReducer
    });

    return makeCancelablePromise(options.Promise, function (resolve, reject, onCancel) {
      function listener() {
        var filter= options.filter;
        if (filter && !filter.apply(self, arguments)) {
          return;
        }
        if (options.handleError) {
          var err = arguments[0];
          err ? reject(err) : resolve(toArray.apply(null, arguments).slice(1));
        } else {
          resolve(toArray.apply(null, arguments));
        }
      }

      onCancel(function(){
        self.off(event, listener);
      });

      self._on(event, listener, false);
    }, {
      timeout: options.timeout,
      overload: options.overload
    })
  };

  function once(emitter, name, options) {
    options= resolveOptions(options, {
      Promise: Promise,
      timeout: 0,
      overload: false
    }, {
      Promise: constructorReducer
    });

    var _Promise= options.Promise;

    return makeCancelablePromise(_Promise, function(resolve, reject, onCancel){
      var handler;
      if (typeof emitter.addEventListener === 'function') {
        handler=  function () {
          resolve(toArray.apply(null, arguments));
        };

        onCancel(function(){
          emitter.removeEventListener(name, handler);
        });

        emitter.addEventListener(
            name,
            handler,
            {once: true}
        );
        return;
      }

      var eventListener = function(){
        errorListener && emitter.removeListener('error', errorListener);
        resolve(toArray.apply(null, arguments));
      };

      var errorListener;

      if (name !== 'error') {
        errorListener = function (err){
          emitter.removeListener(name, eventListener);
          reject(err);
        };

        emitter.once('error', errorListener);
      }

      onCancel(function(){
        errorListener && emitter.removeListener('error', errorListener);
        emitter.removeListener(name, eventListener);
      });

      emitter.once(name, eventListener);
    }, {
      timeout: options.timeout,
      overload: options.overload
    });
  }

  var prototype= EventEmitter.prototype;

  Object.defineProperties(EventEmitter, {
    defaultMaxListeners: {
      get: function(){
        return prototype._maxListeners;
      },
      set: function (n) {
        if (typeof n !== 'number' || n < 0 || Number.isNaN(n)) {
          throw TypeError('n must be a non-negative number')
        }
        prototype._maxListeners = n;
      },
      enumerable: true
    },
    once: {
      value: once,
      writable: true,
      configurable: true
    }
  });

  Object.defineProperties(prototype, {
      _maxListeners: {
          value: defaultMaxListeners,
          writable: true,
          configurable: true
      }
  });

  if (typeof define === 'function' && define.amd) {
     // AMD. Register as an anonymous module.
    define(function() {
      return EventEmitter;
    });
  } else if (typeof exports === 'object') {
    // CommonJS
    module.exports = EventEmitter;
  }
  else {
    // global for any kind of environment.
    var _global= new Function('','return this')();
    _global.EventEmitter2 = EventEmitter;
  }
}();