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musix-oss/node_modules/es6-promisify/dist/promise.js
2019-10-10 16:43:04 +03:00

73 lines
1.9 KiB
JavaScript

"use strict";
/* global self, window, module, global, require */
module.exports = function () {
"use strict";
var globalObject = void 0;
function isFunction(x) {
return typeof x === "function";
}
// Seek the global object
if (global !== undefined) {
globalObject = global;
} else if (window !== undefined && window.document) {
globalObject = window;
} else {
globalObject = self;
}
// Test for any native promise implementation, and if that
// implementation appears to conform to the specificaton.
// This code mostly nicked from the es6-promise module polyfill
// and then fooled with.
var hasPromiseSupport = function () {
// No promise object at all, and it's a non-starter
if (!globalObject.hasOwnProperty("Promise")) {
return false;
}
// There is a Promise object. Does it conform to the spec?
var P = globalObject.Promise;
// Some of these methods are missing from
// Firefox/Chrome experimental implementations
if (!P.hasOwnProperty("resolve") || !P.hasOwnProperty("reject")) {
return false;
}
if (!P.hasOwnProperty("all") || !P.hasOwnProperty("race")) {
return false;
}
// Older version of the spec had a resolver object
// as the arg rather than a function
return function () {
var resolve = void 0;
var p = new globalObject.Promise(function (r) {
resolve = r;
});
if (p) {
return isFunction(resolve);
}
return false;
}();
}();
// Export the native Promise implementation if it
// looks like it matches the spec
if (hasPromiseSupport) {
return globalObject.Promise;
}
// Otherwise, return the es6-promise polyfill by @jaffathecake.
return require("es6-promise").Promise;
}();