Download any File/Blob via JS

download.js

/**
 * `url` can be a data URI like data: or a blob URI like blob: or an existing, public resource like http:
 * `filename` is the (default) name the file will be downloaded as
 */
function download( url, filename ) {
	var link = document.createElement('a');
	link.setAttribute('href',url);
	link.setAttribute('download',filename);
	var event = document.createEvent('MouseEvents');
	event.initMouseEvent('click', true, true, window, 1, 0, 0, 0, 0, false, false, false, false, 0, null);
	link.dispatchEvent(event);
}

This doesn't work for anything that has a lot of text, you will need to actually download it as a blob otherwise.

	var event = document.createEvent('MouseEvents');

	event.initMouseEvent('click', true, true, window, 1, 0, 0, 0, 0, false, false, false, false, 0, null);

	link.dispatchEvent(event);

You can write just!:

link.click()

For the people working with Blobs, you probably need this:
const blobUrl = URL.createObjectURL(blob)

@yousayed link.click() doesn't work for Firefox 52.5.3

doen't work for outube