core-js/modules/es.promise.all.js

'use strict';
var $ = require('../internals/export');
var call = require('../internals/function-call');
var aCallable = require('../internals/a-callable');
var newPromiseCapabilityModule = require('../internals/new-promise-capability');
var perform = require('../internals/perform');
var iterate = require('../internals/iterate');
var PROMISE_STATICS_INCORRECT_ITERATION = require('../internals/promise-statics-incorrect-iteration');

// `Promise.all` method
// https://tc39.es/ecma262/#sec-promise.all
$({ target: 'Promise', stat: true, forced: PROMISE_STATICS_INCORRECT_ITERATION }, {
  all: function all(iterable) {
    var C = this;
    var capability = newPromiseCapabilityModule.f(C);
    var resolve = capability.resolve;
    var reject = capability.reject;
    var result = perform(function () {
      var $promiseResolve = aCallable(C.resolve);
      var values = [];
      var counter = 0;
      var remaining = 1;
      iterate(iterable, function (promise) {
        var index = counter++;
        var alreadyCalled = false;
        remaining++;
        call($promiseResolve, C, promise).then(function (value) {
          if (alreadyCalled) return;
          alreadyCalled = true;
          values[index] = value;
          --remaining || resolve(values);
        }, reject);
      });
      --remaining || resolve(values);
    });
    if (result.error) reject(result.value);
    return capability.promise;
  }
});