hexo/node_modules/es-abstract/2019/IsPromise.js

25 lines
504 B
JavaScript

'use strict';
var callBound = require('call-bind/callBound');
var $PromiseThen = callBound('Promise.prototype.then', true);
var Type = require('./Type');
// https://262.ecma-international.org/6.0/#sec-ispromise
module.exports = function IsPromise(x) {
if (Type(x) !== 'Object') {
return false;
}
if (!$PromiseThen) { // Promises are not supported
return false;
}
try {
$PromiseThen(x); // throws if not a promise
} catch (e) {
return false;
}
return true;
};