nextTick nodejs

main.js

const getDataService = () => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve('data');
    }, 1000);
  });
};

const getA = async () => {
  process.nextTick(async () => {
    // do something
    console.log('start3 getA');
  });

  const data = await getDataService();
  console.log(data);
  return data;
};

async function start() {

  // await getA();
  process.nextTick(async () => {
    // do something
    console.log('start nextTick');
    console.log('end nextTick');
  });
  await getA();

  console.log(1);
  
  setTimeout(() => {
    console.log(3);
  } , 0);


  Promise.resolve().then(() => {
    console.log(2);
  });




}

start();

// - Trước process.nextTick không có tác vụ dạng async, block I/IO, thứ tự chạy
//     callstack => microtask queue => process.nextTick => macrotask queue

// - Trước process.nextTick có tác vụ dạng async, block I/IO, thứ tự chạy
//     callstack => process.nextTick => microtask queue => macrotask queue

// - nextTick + normal + async

// normal => nextTick => async => microtask queue => macrotask queue

// - nextTick + async + normal

// nextTick => async => normal => microtask queue => macrotask queue