blob: 411539b0818c20d3f4d41852082b3f1a263dbcd8 [file] [log] [blame]
'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;
};