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+/** @license MIT License (c) copyright 2010-2014 original author or authors */
+/** @author Brian Cavalier */
+/** @author John Hann */
+
+(function(define) { 'use strict';
+define(function() {
+
+ return function flow(Promise) {
+
+ var resolve = Promise.resolve;
+ var reject = Promise.reject;
+ var origCatch = Promise.prototype['catch'];
+
+ /**
+ * Handle the ultimate fulfillment value or rejection reason, and assume
+ * responsibility for all errors. If an error propagates out of result
+ * or handleFatalError, it will be rethrown to the host, resulting in a
+ * loud stack track on most platforms and a crash on some.
+ * @param {function?} onResult
+ * @param {function?} onError
+ * @returns {undefined}
+ */
+ Promise.prototype.done = function(onResult, onError) {
+ this._handler.visit(this._handler.receiver, onResult, onError);
+ };
+
+ /**
+ * Add Error-type and predicate matching to catch. Examples:
+ * promise.catch(TypeError, handleTypeError)
+ * .catch(predicate, handleMatchedErrors)
+ * .catch(handleRemainingErrors)
+ * @param onRejected
+ * @returns {*}
+ */
+ Promise.prototype['catch'] = Promise.prototype.otherwise = function(onRejected) {
+ if (arguments.length < 2) {
+ return origCatch.call(this, onRejected);
+ }
+
+ if(typeof onRejected !== 'function') {
+ return this.ensure(rejectInvalidPredicate);
+ }
+
+ return origCatch.call(this, createCatchFilter(arguments[1], onRejected));
+ };
+
+ /**
+ * Wraps the provided catch handler, so that it will only be called
+ * if the predicate evaluates truthy
+ * @param {?function} handler
+ * @param {function} predicate
+ * @returns {function} conditional catch handler
+ */
+ function createCatchFilter(handler, predicate) {
+ return function(e) {
+ return evaluatePredicate(e, predicate)
+ ? handler.call(this, e)
+ : reject(e);
+ };
+ }
+
+ /**
+ * Ensures that onFulfilledOrRejected will be called regardless of whether
+ * this promise is fulfilled or rejected. onFulfilledOrRejected WILL NOT
+ * receive the promises' value or reason. Any returned value will be disregarded.
+ * onFulfilledOrRejected may throw or return a rejected promise to signal
+ * an additional error.
+ * @param {function} handler handler to be called regardless of
+ * fulfillment or rejection
+ * @returns {Promise}
+ */
+ Promise.prototype['finally'] = Promise.prototype.ensure = function(handler) {
+ if(typeof handler !== 'function') {
+ return this;
+ }
+
+ return this.then(function(x) {
+ return runSideEffect(handler, this, identity, x);
+ }, function(e) {
+ return runSideEffect(handler, this, reject, e);
+ });
+ };
+
+ function runSideEffect (handler, thisArg, propagate, value) {
+ var result = handler.call(thisArg);
+ return maybeThenable(result)
+ ? propagateValue(result, propagate, value)
+ : propagate(value);
+ }
+
+ function propagateValue (result, propagate, x) {
+ return resolve(result).then(function () {
+ return propagate(x);
+ });
+ }
+
+ /**
+ * Recover from a failure by returning a defaultValue. If defaultValue
+ * is a promise, it's fulfillment value will be used. If defaultValue is
+ * a promise that rejects, the returned promise will reject with the
+ * same reason.
+ * @param {*} defaultValue
+ * @returns {Promise} new promise
+ */
+ Promise.prototype['else'] = Promise.prototype.orElse = function(defaultValue) {
+ return this.then(void 0, function() {
+ return defaultValue;
+ });
+ };
+
+ /**
+ * Shortcut for .then(function() { return value; })
+ * @param {*} value
+ * @return {Promise} a promise that:
+ * - is fulfilled if value is not a promise, or
+ * - if value is a promise, will fulfill with its value, or reject
+ * with its reason.
+ */
+ Promise.prototype['yield'] = function(value) {
+ return this.then(function() {
+ return value;
+ });
+ };
+
+ /**
+ * Runs a side effect when this promise fulfills, without changing the
+ * fulfillment value.
+ * @param {function} onFulfilledSideEffect
+ * @returns {Promise}
+ */
+ Promise.prototype.tap = function(onFulfilledSideEffect) {
+ return this.then(onFulfilledSideEffect)['yield'](this);
+ };
+
+ return Promise;
+ };
+
+ function rejectInvalidPredicate() {
+ throw new TypeError('catch predicate must be a function');
+ }
+
+ function evaluatePredicate(e, predicate) {
+ return isError(predicate) ? e instanceof predicate : predicate(e);
+ }
+
+ function isError(predicate) {
+ return predicate === Error
+ || (predicate != null && predicate.prototype instanceof Error);
+ }
+
+ function maybeThenable(x) {
+ return (typeof x === 'object' || typeof x === 'function') && x !== null;
+ }
+
+ function identity(x) {
+ return x;
+ }
+
+});
+}(typeof define === 'function' && define.amd ? define : function(factory) { module.exports = factory(); }));