esnext.async-iterator.async-dispose.js

'use strict';
// https://github.com/tc39/proposal-async-explicit-resource-management
var call = require('../internals/function-call');
var defineBuiltIn = require('../internals/define-built-in');
var getBuiltIn = require('../internals/get-built-in');
var getMethod = require('../internals/get-method');
var hasOwn = require('../internals/has-own-property');
var wellKnownSymbol = require('../internals/well-known-symbol');
var AsyncIteratorPrototype = require('../internals/async-iterator-prototype');

var ASYNC_DISPOSE = wellKnownSymbol('asyncDispose');
var Promise = getBuiltIn('Promise');

if (!hasOwn(AsyncIteratorPrototype, ASYNC_DISPOSE)) {
  defineBuiltIn(AsyncIteratorPrototype, ASYNC_DISPOSE, function () {
    var O = this;
    return new Promise(function (resolve, reject) {
      var $return = getMethod(O, 'return');
      if ($return) {
        Promise.resolve(call($return, O)).then(function () {
          resolve(undefined);
        }, reject);
      } else resolve(undefined);
    });
  });
}