Function safeThumb

static/mobile/app.js:109–111

(url)

// gradient + initial. The URL is constrained to a clean https URL so it can't
// break out of the CSS url().
function safeThumb(url) {
  return typeof url === "string" && /^https:\/\/[^"'()\\\s]+$/.test(url) ? url : "";
}
function artStyle(card) {
  const g = (card && card.gradient) || DEFAULT_GRADIENT;
  const t = card && safeThumb(card.thumb);