'a'

mh-two-thousand-and-two

2024-04-12 44d2c92345cd156a59fc327b3060292a282d2893

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'use strict';
 
var $TypeError = require('es-errors/type');
 
var IsCallable = require('./IsCallable');
var IsConstructor = require('./IsConstructor');
 
// https://262.ecma-international.org/6.0/#sec-newpromisecapability
 
module.exports = function NewPromiseCapability(C) {
    if (!IsConstructor(C)) {
        throw new $TypeError('C must be a constructor'); // step 1
    }
 
    var resolvingFunctions = { '[[Resolve]]': void undefined, '[[Reject]]': void undefined }; // step 3
 
    var promise = new C(function (resolve, reject) { // steps 4-5
        if (typeof resolvingFunctions['[[Resolve]]'] !== 'undefined' || typeof resolvingFunctions['[[Reject]]'] !== 'undefined') {
            throw new $TypeError('executor has already been called'); // step 4.a, 4.b
        }
        resolvingFunctions['[[Resolve]]'] = resolve; // step 4.c
        resolvingFunctions['[[Reject]]'] = reject; // step 4.d
    }); // step 4-6
 
    if (!IsCallable(resolvingFunctions['[[Resolve]]']) || !IsCallable(resolvingFunctions['[[Reject]]'])) {
        throw new $TypeError('executor must provide valid resolve and reject functions'); // steps 7-8
    }
 
    return {
        '[[Promise]]': promise,
        '[[Resolve]]': resolvingFunctions['[[Resolve]]'],
        '[[Reject]]': resolvingFunctions['[[Reject]]']
    }; // step 9
};