Console log not printing in awaited promise in an async function

Question

  function sleep(cb, ms) {
    return new Promise((cb) => setTimeout(cb, ms));
  }

  async function delayedGreeting() {
    console.log("Hello");
    await sleep(myfun, 1000);
    console.log("World!");
  }

  function myfun() {
    console.log("whatever");
  }

  delayedGreeting();
  console.log("Goodbye!");

Can someone please explain in the context of Eventloop, Callback Queue and Stack as to what is happening here as I don't see the word 'whatever' in the output. Is there a mistake in the code and if so what is it?

Answer 1

There are some minor mistakes in the code. I am pointing them below.

1. You should write resolve in the Promise.

return new Promise((resolve) => resolve (setTimeout(()=>{cb()}, ms)));

2. If you want myfun to run after a timeout of 1000 millisecond, you must call the function in the settimeout first parameter. Like this,

setTimeout(()=>{cb()}, ms);

Here is the updated source code,

      function sleep(cb, ms) {
        return new Promise((resolve) => resolve (setTimeout(()=>{cb()}, ms)));
      }

      async function delayedGreeting() {
        console.log("Hello");
        await sleep(myfun, 1000);
        console.log("World!");
      }

      function myfun() {
        console.log("whatever");
      }

      delayedGreeting();
      console.log("Goodbye!");

And the right output according to the implementation that you are trying the code should be like this,

Hello
Goodbye!
World!
whatever