async function f() {
  const result = typeof fn === "function" ? await fn() : null;
}

(async function () {
  console.log(await (true ? Promise.resolve("A") : Promise.resolve("B")));
})();

async function f2() {
  await (spellcheck && spellcheck.setChecking(false));
  (await spellcheck) && spellcheck.setChecking(false);
}