如何在 vanilla JS 中编写 async/await

Question

In the MDN Doc , it says

async function foo() { 
    await 1
}

is equivalent to:

function foo() {
    return Promise.resolve(1).then(() => undefined)
}

so what is the eqivalent of

async function foo() {
    await genPromise();
}

assuming that genPromise() returns another Promise.

Would it be

function foo() {
    return Promise.resolve(new Promise((resolve, reject) => {})).then(() => undefined)
}

Answer 1

so what is the eqivalent of

async function foo() { await genPromise(); }

That code will wait for the promise returned by genPromise to resolve, and then will resolve its own promise to undefined . So the equivalent is:

function foo() {
  return genPromise().then(() => undefined);
}