Why doesn't the load event fire on window?

Question

AJAX

Hello Connoisseurs! The question is why the load event in window. An example is here https://jsfiddle.net/Navaho/4krntxwj/1/ , lines 6 and 7 (click/scroll events) work like clockwork, but the load event freezes something! Did the same only on pure XMLHttpRequest all events (click & load & scroll) work like clockwork.

Answer 1

The "load" event doesn't fire because this code is called after the page has loaded.

window.addEventListener('load',  event => f(event))

The page loaded and window.onload fired, and only then do you make a fetch that registers a listener for this event. Naturally, the event will not be caught.
By the way, it is not at all clear why you are trying to listen to it. You can do without it, because it has nothing to do with the end of the download using fetch.

Answer 2

if( (event.type == 'scroll' && document.documentElement.clientHeight + document.documentElement.scrollTop == document.documentElement.offsetHeight)  || (event.type == 'click')  ){

where is something about load?