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(function (root) {
// Store setTimeout reference so promise-polyfill will be unaffected by
// other code modifying setTimeout (like sinon.useFakeTimers())
var setTimeoutFunc = setTimeout;
function noop() {}
// Polyfill for Function.prototype.bind
function bind(fn, thisArg) {
return function () {
fn.apply(thisArg, arguments);
};
}
function Promise(fn) {
if (typeof this !== 'object') throw new TypeError('Promises must be constructed via new');
if (typeof fn !== 'function') throw new TypeError('not a function');
this._state = 0;
this._handled = false;
this._value = undefined;
this._deferreds = [];
doResolve(fn, this);
}
function handle(self, deferred) {
while (self._state === 3) {
self = self._value;
}
if (self._state === 0) {
self._deferreds.push(deferred);
return;
}
self._handled = true;
Promise._immediateFn(function () {
var cb = self._state === 1 ? deferred.onFulfilled : deferred.onRejected;
if (cb === null) {
(self._state === 1 ? resolve : reject)(deferred.promise, self._value);
return;
}
var ret;
try {
ret = cb(self._value);
} catch (e) {
reject(deferred.promise, e);
return;
}
resolve(deferred.promise, ret);
});
}
function resolve(self, newValue) {
try {
// Promise Resolution Procedure: https://github.com/promises-aplus/promises-spec#the-promise-resolution-procedure
if (newValue === self) throw new TypeError('A promise cannot be resolved with itself.');
if (newValue && (typeof newValue === 'object' || typeof newValue === 'function')) {
var then = newValue.then;
if (newValue instanceof Promise) {
self._state = 3;
self._value = newValue;
finale(self);
return;
} else if (typeof then === 'function') {
doResolve(bind(then, newValue), self);
return;
}
}
self._state = 1;
self._value = newValue;
finale(self);
} catch (e) {
reject(self, e);
}
}
function reject(self, newValue) {
self._state = 2;
self._value = newValue;
finale(self);
}
function finale(self) {
if (self._state === 2 && self._deferreds.length === 0) {
Promise._immediateFn(function() {
if (!self._handled) {
Promise._unhandledRejectionFn(self._value);
}
});
}
for (var i = 0, len = self._deferreds.length; i < len; i++) {
handle(self, self._deferreds[i]);
}
self._deferreds = null;
}
function Handler(onFulfilled, onRejected, promise) {
this.onFulfilled = typeof onFulfilled === 'function' ? onFulfilled : null;
this.onRejected = typeof onRejected === 'function' ? onRejected : null;
this.promise = promise;
}
/**
* Take a potentially misbehaving resolver function and make sure
* onFulfilled and onRejected are only called once.
*
* Makes no guarantees about asynchrony.
*/
function doResolve(fn, self) {
var done = false;
try {
fn(function (value) {
if (done) return;
done = true;
resolve(self, value);
}, function (reason) {
if (done) return;
done = true;
reject(self, reason);
});
} catch (ex) {
if (done) return;
done = true;
reject(self, ex);
}
}
Promise.prototype['catch'] = function (onRejected) {
return this.then(null, onRejected);
};
Promise.prototype.then = function (onFulfilled, onRejected) {
var prom = new (this.constructor)(noop);
handle(this, new Handler(onFulfilled, onRejected, prom));
return prom;
};
Promise.all = function (arr) {
var args = Array.prototype.slice.call(arr);
return new Promise(function (resolve, reject) {
if (args.length === 0) return resolve([]);
var remaining = args.length;
function res(i, val) {
try {
if (val && (typeof val === 'object' || typeof val === 'function')) {
var then = val.then;
if (typeof then === 'function') {
then.call(val, function (val) {
res(i, val);
}, reject);
return;
}
}
args[i] = val;
if (--remaining === 0) {
resolve(args);
}
} catch (ex) {
reject(ex);
}
}
for (var i = 0; i < args.length; i++) {
res(i, args[i]);
}
});
};
Promise.resolve = function (value) {
if (value && typeof value === 'object' && value.constructor === Promise) {
return value;
}
return new Promise(function (resolve) {
resolve(value);
});
};
Promise.reject = function (value) {
return new Promise(function (resolve, reject) {
reject(value);
});
};
Promise.race = function (values) {
return new Promise(function (resolve, reject) {
for (var i = 0, len = values.length; i < len; i++) {
values[i].then(resolve, reject);
}
});
};
// Use polyfill for setImmediate for performance gains
Promise._immediateFn = (typeof setImmediate === 'function' && function (fn) { setImmediate(fn); }) ||
function (fn) {
setTimeoutFunc(fn, 0);
};
Promise._unhandledRejectionFn = function _unhandledRejectionFn(err) {
if (typeof console !== 'undefined' && console) {
console.warn('Possible Unhandled Promise Rejection:', err); // eslint-disable-line no-console
}
};
/**
* Set the immediate function to execute callbacks
* @param fn {function} Function to execute
* @deprecated
*/
Promise._setImmediateFn = function _setImmediateFn(fn) {
Promise._immediateFn = fn;
};
/**
* Change the function to execute on unhandled rejection
* @param {function} fn Function to execute on unhandled rejection
* @deprecated
*/
Promise._setUnhandledRejectionFn = function _setUnhandledRejectionFn(fn) {
Promise._unhandledRejectionFn = fn;
};
if (typeof module !== 'undefined' && module.exports) {
module.exports = Promise;
} else if (!root.Promise) {
root.Promise = Promise;
}
})(this);
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