Run results for: Check if is thennable, check if is instanceof Promise, or just await

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/116.0

Browser: Firefox 116

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Check await	45157.5 Ops/sec
Instanceof await	39775.2 Ops/sec
Just await	44990.8 Ops/sec

Script Preparation code:

async function checkAwait(value) {
  const result = (typeof value.then === 'function') ? await value : value;
  console.log(result);
}

async function checkAwaitTest() {
  checkAwait(1);
  checkAwait(Promise.resolve(1));
  checkAwait(1);
  checkAwait(Promise.resolve(1));
  checkAwait(1);
  checkAwait(Promise.resolve(1));
  checkAwait(1);
  checkAwait(Promise.resolve(1));
  checkAwait(1);
  checkAwait(Promise.resolve(1));
}

async function instanceofAwait(value) {
  const result = value instanceof Promise ? await value : value;
  console.log(result);
}

async function instanceofAwaitTest() {
  instanceofAwait(1);
  instanceofAwait(Promise.resolve(1));
  instanceofAwait(1);
  instanceofAwait(Promise.resolve(1));
  instanceofAwait(1);
  instanceofAwait(Promise.resolve(1));
  instanceofAwait(1);
  instanceofAwait(Promise.resolve(1));
  instanceofAwait(1);
  instanceofAwait(Promise.resolve(1));
}

async function justAwait(value) {
  const result = await value;
  console.log(result);
}

async function justAwaitTest() {
  justAwait(1);
  justAwait(Promise.resolve(1));
  justAwait(1);
  justAwait(Promise.resolve(1));
  justAwait(1);
  justAwait(Promise.resolve(1));
  justAwait(1);
  justAwait(Promise.resolve(1));
  justAwait(1);
  justAwait(Promise.resolve(1));
}

Tests:

Check await
checkAwaitTest();
Instanceof await
instanceofAwaitTest();
Just await
justAwaitTest();

Run results for: Check if is thennable, check if is instanceof Promise, or just await

Check await

Instanceof await

Just await