esnext.promise.try.js

'use strict';
var $ = require('../internals/export');
var globalThis = require('../internals/global-this');
var apply = require('../internals/function-apply');
var slice = require('../internals/array-slice');
var newPromiseCapabilityModule = require('../internals/new-promise-capability');
var aCallable = require('../internals/a-callable');
var perform = require('../internals/perform');

var Promise = globalThis.Promise;

var ACCEPT_ARGUMENTS = false;
// Avoiding the use of polyfills of the previous iteration of this proposal
// that does not accept arguments of the callback
var FORCED = !Promise || !Promise['try'] || perform(function () {
  Promise['try'](function (argument) {
    ACCEPT_ARGUMENTS = argument === 8;
  }, 8);
}).error || !ACCEPT_ARGUMENTS;

// `Promise.try` method
// https://github.com/tc39/proposal-promise-try
$({ target: 'Promise', stat: true, forced: FORCED }, {
  'try': function (callbackfn /* , ...args */) {
    var args = arguments.length > 1 ? slice(arguments, 1) : [];
    var promiseCapability = newPromiseCapabilityModule.f(this);
    var result = perform(function () {
      return apply(aCallable(callbackfn), undefined, args);
    });
    (result.error ? promiseCapability.reject : promiseCapability.resolve)(result.value);
    return promiseCapability.promise;
  }
});