SOURCE

let saveMsg = [];

const ajax = (url,i) => {
    var p = new Promise((resolve, reject) => {
        var random = Math.round(Math.random() * 9) + 1
        setTimeout(() => {
            if (random > 5) {
                console.log(`第${i}轮循环,${url}请求成功`)
                resolve({ url, code: 0 })
            } else {
                console.log(`第${i}轮循环,${url}请求失败`)
                reject({ url, code: -1 })
            }
        }, random * 100)
    })
    return p
}
const pfn = async (i) => {
    return ajax('req1', i)
        .then(res => ajax('req2', i))
        .then(res => ajax('req3', i))
        .catch(err => {
            console.log(i, err)
            saveMsg.push({index: i, err})
        })
}

async function batchReq () {
  //遍历5次，每次分别请求3个接口,如果第1接口失败，后面2个接口停止执行
  for (let i = 0; i < 5; i++) {
     await pfn(i)     
   }
}

async function main () {
  await batchReq()
  console.log('alert', JSON.stringify(saveMsg, null, 2))
}

main()