1 check per line format:
return {
jquery: (typeof jQuery === "undefined") ? true : jQuery.active < 1,
ajax: (typeof Ajax === "undefined") ? true : Ajax.activeRequestCount < 1,
document: document.readyState == "complete",
angular: (typeof angular === "undefined") ? true : angular.element(document).injector().get("$http").pendingRequests.length < 1,
spinner: (document.getElementById("turbolinks-progress") === null) ? true : document.getElementById("turbolinks-progress").style["display"] == "none"
}