maint(tests): Use global instead of window in node based tools like Jest for registering global variables.

Author: thet

src/setupTests.js

@@ -9,7 +9,8 @@ import "core-js/stable";
 import "regenerator-runtime/runtime";
 
 import jquery from "jquery";
-window.jQuery = jquery;
+global["$"] = global["jQuery"] = jquery;
+
 jquery.expr.pseudos.visible = function () {
     // Fix jQuery ":visible" selector always returns false in JSDOM.
     // https://github.com/jsdom/jsdom/issues/1048#issuecomment-401599392
@@ -26,10 +27,10 @@ document.fullscreenerror = jest.fn();
 
 // pat-subform
 // See https://github.com/jsdom/jsdom/issues/1937#issuecomment-461810980
-window.HTMLFormElement.prototype.submit = () => {};
+global["HTMLFormElement"].prototype.submit = () => {};
 
 // resize-observer
-window.ResizeObserver = function () {
+global["ResizeObserver"] = function () {
     // Just do nothing for now...
     return { observe: () => {} };
 };