Check when the DOM has loaded like `DOMContentLoaded`
Get the current readyState of the environment we're loaded in.
Get / Check the document readyState by Promise, when the DOM and Window is loaded
React Effect Hook based on document.readyState
Await the return of this function in order to guarantee that everything that goes after will be running after the loading of the document DOM.
XMLHttpRequest ready state map for Node.js and the browser.
jQuery ajaxreadystate plugin