promises.js

async function foo() {
  console.log('foo');
  return 'foo';
}

function bar() {
  return new Promise(resolve => {
    console.log('bar');
    resolve('bar');
  });
}

const a = foo();
const b = bar();

node promises.js
foo
bar

https://www.javascriptjanuary.com/blog/the-promise-of-a-better-future#eagerness

Promises are eager. This means that when a new Promise is constructed, it immediately starts executing, attempting to resolve the asynchronous value