依次(串行)执行多项异步任务

sequence.js

// method 1:
function sequence(tasks, fn) {
  return tasks.reduce(
    (promise, task) => promise.then(() => fn(task)),
    Promise.resolve()
  )
}

// method 2:
async function taskReducer(promise, action){
  let res = await promise;
  return action(res);
}

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

async function asyncTask(i){
  await sleep(500);
  console.log(`task ${i} done`);
  return ++i;
}


[asyncTask, asyncTask, asyncTask].reduce(taskReducer, 0);

method1:
nuxt/lib/common/utils.js

method2:
https://www.h5jun.com/post/three-black-tech-in-modern-js.html?hmsr=toutiao.io&utm_medium=toutiao.io&utm_source=toutiao.io