36 lines
724 B
JavaScript
36 lines
724 B
JavaScript
/*global self*/
|
|
import Promise from './promise';
|
|
|
|
export default function polyfill() {
|
|
let local;
|
|
|
|
if (typeof global !== 'undefined') {
|
|
local = global;
|
|
} else if (typeof self !== 'undefined') {
|
|
local = self;
|
|
} else {
|
|
try {
|
|
local = Function('return this')();
|
|
} catch (e) {
|
|
throw new Error('polyfill failed because global object is unavailable in this environment');
|
|
}
|
|
}
|
|
|
|
let P = local.Promise;
|
|
|
|
if (P) {
|
|
var promiseToString = null;
|
|
try {
|
|
promiseToString = Object.prototype.toString.call(P.resolve());
|
|
} catch(e) {
|
|
// silently ignored
|
|
}
|
|
|
|
if (promiseToString === '[object Promise]' && !P.cast){
|
|
return;
|
|
}
|
|
}
|
|
|
|
local.Promise = Promise;
|
|
}
|