const marker = Symbol("marker");

async function promiseStateAsync(promise) {
  if (!(typeof promise === "object" && typeof promise.then === "function")) {
    throw new TypeError(`Expected a promise, got ${typeof promise}`);
  }

  // Ensure unhandled rejections don't get swallowed.
  await new Promise((resolve) => {
    if (typeof setImmediate === "function") {
      setImmediate(resolve);
    } else {
      setTimeout(resolve);
    }
  });

  try {
    return (await Promise.race([promise, marker])) === marker
      ? "pending"
      : "fulfilled";
  } catch {
    return "rejected";
  }
}

let reject;
let promise = new Promise((_res, rej) => {
  reject = rej;
});

const promiseState = await promiseStateAsync(promise);
console.log(promiseState);

setTimeout(() => {
  reject("dinosaur");
  console.log("the setTimeout triggered");
}, 1000);

window.addEventListener("unhandledrejection", (ev) => {
  console.warn(`UNHANDLED PROMISE REJECTION: ${ev.reason}`);
});

window.addEventListener('error', (ev) => {
  console.warn(`UNHANDLED ERROR: ${ev.reason}`);
});