focus-search.js

const exceptions = ["www.example.com"];

if (!exceptions.includes(new URL(window.location).hostname)) {
  console.log("Adding slash keybinding");

  document.addEventListener("keydown", function (event) {
    const searchInput =
      // https://caniuse.com/css-case-insensitive
      document.querySelector('input[type="search" i]') ??
      document.querySelector('form[role="search" i] text[type="text"]') ??
      document.querySelector('input[aria-label="search" i]') ??
      document.querySelector('input[name="search" i]') ??
      document.querySelector('input[placeholder*="search" i]') ??
      document.querySelector('input[class*="search" i]') ??
      document.querySelector('input[title*="search" i]') ??
      document.querySelector('form[action*="/search" i] input[type="text"]');
    if (isFocusable(document.activeElement) || !searchInput) return;
    if (event.key === "/") {
      event.preventDefault();
      searchInput.focus();
    }
  });
}

function isFocusable(element) {
  return (
    [
      "a",
      "button",
      "details",
      "input",
      "select",
      "textarea",
      "area",
      "audio",
      "iframe",
      "img",
      "link",
      "object",
      "summary",
      "video",
    ].includes(element.tagName?.toLowerCase()) ||
    element.isContentEditable ||
    element.hasAttribute("tabindex")
  );
}