clearImmediate not polyfilled when setImmediate is polyfilled earlier

[waxidiotic]

If another script on a page polyfills only setImmediate and not clearImmediate, when this polyfill runs, it only checks for setImmediate and if that exists, it does not polyfill clearImmediate.

// setimmediate attaches itself to the global object
require("setimmediate");
// On some exotic environments, it's not clear which object `setimmeidate` was
// able to install onto.  Search each possibility in the same order as the
// `setimmediate` library.
exports.setImmediate = (typeof self !== "undefined" && self.setImmediate) ||
                       (typeof global !== "undefined" && global.setImmediate) ||
                       (this && this.setImmediate);
exports.clearImmediate = (typeof self !== "undefined" && self.clearImmediate) ||
                         (typeof global !== "undefined" && global.clearImmediate) ||
(this && this.clearImmediate);

This causes libraries compiled with webpack to not load properly and throw an exception when clearImmediate is undefined.

From jwplayer/jwplayer:

/*!***************************************************!*\
  !*** ./node_modules/setimmediate/setImmediate.js ***!
  \***************************************************/
/*! dynamic exports provided */
/*! all exports used */
/*! ModuleConcatenation bailout: Module is not an ECMAScript module */
/***/ (function(module, exports, __webpack_require__) {

/* WEBPACK VAR INJECTION */(function(global, process) {(function (global, undefined) {
    "use strict";

    if (global.setImmediate) {
        return;
    }

[robwalch]

@waxidiotic we can close this. I've opened a PR in setImmediate that handles this issue: YuzuJS/setImmediate#71

[jryans]

Interesting! My first impression is that a fix in setImmediate is the right place for this, and it appears one has now been filed. For now, I'll close this, but please reopen if the situation changes.

[robwalch]

@jryans yep! Thanks. We filed this as we were still stepping through the issue.