zhangnaisong
2023-08-05 24d66c8d82b628a06e93dbb1abfea2049b3d45ab
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'use strict';
 
var GetIntrinsic = require('get-intrinsic');
 
var $SyntaxError = GetIntrinsic('%SyntaxError%');
var $TypeError = GetIntrinsic('%TypeError%');
var $Promise = GetIntrinsic('%Promise%', true);
 
var Call = require('./Call');
var CompletionRecord = require('./CompletionRecord');
var GetMethod = require('./GetMethod');
var Type = require('./Type');
 
var assertRecord = require('../helpers/assertRecord');
 
var callBound = require('call-bind/callBound');
 
var $then = callBound('Promise.prototype.then', true);
 
// https://262.ecma-international.org/12.0/#sec-asynciteratorclose
 
module.exports = function AsyncIteratorClose(iteratorRecord, completion) {
    assertRecord(Type, 'Iterator Record', 'iteratorRecord', iteratorRecord); // step 1
 
    if (!(completion instanceof CompletionRecord)) {
        throw new $TypeError('Assertion failed: completion is not a Completion Record instance'); // step 2
    }
 
    if (!$then) {
        throw new $SyntaxError('This environment does not support Promises.');
    }
 
    var iterator = iteratorRecord['[[Iterator]]']; // step 3
 
    return $then(
        $then(
            $then(
                new $Promise(function (resolve) {
                    resolve(GetMethod(iterator, 'return')); // step 4
                    // resolve(Call(ret, iterator, [])); // step 6
                }),
                function (returnV) { // step 5.a
                    if (typeof returnV === 'undefined') {
                        return completion; // step 5.b
                    }
                    return Call(returnV, iterator); // step 5.c, 5.d.
                }
            ),
            null,
            function (e) {
                if (completion.type() === 'throw') {
                    completion['?'](); // step 6
                } else {
                    throw e; // step 7
                }
            }
        ),
        function (innerResult) { // step 8
            if (completion.type() === 'throw') {
                completion['?'](); // step 6
            }
            if (Type(innerResult) !== 'Object') {
                throw new $TypeError('`innerResult` must be an Object'); // step 10
            }
            return completion;
        }
    );
};