You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
25 lines
485 B
25 lines
485 B
4 years ago
|
'use strict';
|
||
|
|
|
||
|
|
var callBound = require('call-bind/callBound');
|
||
|
|
|
||
|
|
var $PromiseThen = callBound('Promise.prototype.then', true);
|
||
|
|
|
||
|
|
var Type = require('./Type');
|
||
|
|
|
||
|
|
// https://ecma-international.org/ecma-262/6.0/#sec-ispromise
|
||
|
|
|
||
|
|
module.exports = function IsPromise(x) {
|
||
|
|
if (Type(x) !== 'Object') {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
if (!$PromiseThen) { // Promises are not supported
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
try {
|
||
|
|
$PromiseThen(x); // throws if not a promise
|
||
|
|
} catch (e) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
};
|