NodeJS Timers

test-timers.js

async function testImmediate() {
  console.log('A');
  setImmediate(() => {
    console.log('B')
  });
  await new Promise((resolve) => {
    console.log('C');
    setTimeout(() => {
      console.log('D');
      resolve();
    }, 0);
    console.log('E');
  });
  console.log('F');
}

async function testImmediate2() {
  console.log('A');
  await new Promise((resolve) => {
    console.log('C');
    setTimeout(() => {
      console.log('D');
      resolve();
    }, 0);
    console.log('E');
  });
  setImmediate(() => {
    console.log('B')
  });
  console.log('F');
}

testImmediate1().then(() => console.log('G')).catch(err => console.error(err));

// => A C E B D F G

testImmediate2().then(() => console.log('G')).catch(err => console.error(err));

// => A C E D F G B