MediaWiki:Gadget-TreeDescs.js

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mw.loader.load("ext.gadget.TreeDescs-pagestyles");

$(".mw-heading").filter(function() {
	return $(this).children().first().text() === "Descendants"
}).each(function() {
	let $selected = $(this).nextUntil(".mw-heading");
	$selected.find("ul + ul").each(function () {
		$(this).prev("ul").append($(this).children());
		$(this).remove();
	});
	$selected.filter("ul").addClass("treeview");
	$selected.filter(":not(ul)").find("ul").addClass("treeview");
});