es.promise.all-settled.js

'use strict';
var $ = require('../internals/export');
var aFunction = require('../internals/a-function');
var newPromiseCapabilityModule = require('../internals/new-promise-capability');
var perform = require('../internals/perform');
var iterate = require('../internals/iterate');

// `Promise.allSettled` method
// https://github.com/tc39/proposal-promise-allSettled
$({ target: 'Promise', stat: true }, {
  allSettled: function allSettled(iterable) {
    var C = this;
    var capability = newPromiseCapabilityModule.f(C);
    var resolve = capability.resolve;
    var reject = capability.reject;
    var result = perform(function () {
      var promiseResolve = aFunction(C.resolve);
      var values = [];
      var counter = 0;
      var remaining = 1;
      iterate(iterable, function (promise) {
        var index = counter++;
        var alreadyCalled = false;
        values.push(undefined);
        remaining++;
        promiseResolve.call(C, promise).then(function (value) {
          if (alreadyCalled) return;
          alreadyCalled = true;
          values[index] = { status: 'fulfilled', value: value };
          --remaining || resolve(values);
        }, function (e) {
          if (alreadyCalled) return;
          alreadyCalled = true;
          values[index] = { status: 'rejected', reason: e };
          --remaining || resolve(values);
        });
      });
      --remaining || resolve(values);
    });
    if (result.error) reject(result.value);
    return capability.promise;
  }
});