https://www.utsuwayayuuyuu.com/assets/js/recent-artists.js

1(function () {
2  'use strict';
3  var container = document.querySelector('#tab-0 > .select-nav');
4  if (!container || !window.fetch) return;
5  var cards = Array.prototype.filter.call(container.children, function (e) { return e.classList.contains('box'); });
6  var first = Object.create(null);
7  cards.forEach(function (card) {
8    var id = card.getAttribute('data-artist-id');
9    if (id && !first[id]) first[id] = card;
10  });
11  var controller = window.AbortController ? new AbortController() : null;
12  var timer = controller ? setTimeout(function () { controller.abort(); }, 8000) : null;
13  var url = new URL('data/trending.json', document.baseURI);
14  url.searchParams.set('v', String(Math.floor(Date.now() / 1800000)));
15  fetch(url.href, controller ? {signal:controller.signal} : {})
16    .then(function (r) { if (!r.ok) throw new Error('JSON unavailable'); return r.json(); })
17    .then(function (data) {
18      var items = data && data.recentArtists;
19      if (!Array.isArray(items) || items.length > 18) return;
20      var seen = Object.create(null);
21      var valid = items.every(function (item) {
22        if (!item || typeof item.artistId !== 'string' || !/^[a-z0-9]+(?:-[a-z0-9]+)*$/.test(item.artistId)
23          || seen[item.artistId] || !first[item.artistId] || !/^\d{4}\.\d{2}\.\d{2}$/.test(item.date)
24          || !/^(new|restock)$/.test(item.type) || item.label !== (item.type === 'new' ? '新作品' : '再入荷')) return false;
25        var d = new Date(item.date.replace(/\./g, '-') + 'T00:00:00Z');
26        if (!isFinite(d.getTime()) || d.toISOString().slice(0,10).replace(/-/g,'.') !== item.date) return false;
27        seen[item.artistId] = true;
28        return true;
29      });
30      if (!valid) return;
31      // Validate the entire payload before touching existing cards or labels.
32      var promoted = items.map(function (item) { return first[item.artistId]; });
33      cards.forEach(function (card) {
34        Array.prototype.forEach.call(card.querySelectorAll('.box_new'), function (badge) { badge.remove(); });
35      });
36      items.forEach(function (item, i) {
37        var badge = document.createElement('div'); badge.className = 'box_new'; badge.textContent = item.label;
38        promoted[i].insertBefore(badge, promoted[i].firstChild);
39      });
40      var fragment = document.createDocumentFragment();
41      promoted.concat(cards.filter(function (card) { return promoted.indexOf(card) < 0; })).forEach(function (card) { fragment.appendChild(card); });
42      container.appendChild(fragment);
43    })
44    .catch(function () { /* Keep the complete fixed HTML on failure. */ })
45    .then(function () { if (timer) clearTimeout(timer); });
46}());