blob: 95bd0317088582e7daef935194b4da00b9f1605d [file] [log] [blame] [edit]
'use strict';
var callBound = require('call-bound');
var $PromiseThen = callBound('Promise.prototype.then', true);
var isObject = require('../helpers/isObject');
// https://262.ecma-international.org/6.0/#sec-ispromise
module.exports = function IsPromise(x) {
if (!isObject(x)) {
return false;
}
if (!$PromiseThen) { // Promises are not supported
return false;
}
try {
$PromiseThen(x); // throws if not a promise
} catch (e) {
return false;
}
return true;
};