超时重试

retry.ts

interface ResponseData {
  code: -1 | 0 | 1
  msg: string
  data: any
}


function getData(timeout: number) {
  return Promise.race([
    new Promise<ResponseData>((resolve, reject) => {
      setTimeout(() => {
        const random = Math.random()
        if (random > 0.5) {
          resolve({ code: 0, msg: '', data: 'success' })
        } else if (random > 0.1 && random < 0.4) {
          resolve({ code: 1, msg: '', data: 'success' })
        } else {
          resolve({ code: -1, msg: '', data: '-1' })
        }
      }, Math.random() * 4000)
    }),
    new Promise<ResponseData>((resolve, reject) => setTimeout(reject, timeout, new Error('timeout')))
  ])
}

const EXCEPTION = Symbol('exception')

async function request() {
  let i = 1
  let isRetry = false
  while (i > 0) {
    let res = await getData(3000).catch(e => EXCEPTION)
    if (typeof res === 'symbol') {
      if (isRetry) {
        i--
      } else {
        isRetry = true
        i = 5
      }
    } else {
      if (res.code === -1) throw new Error('获取数据失败,请稍后重试')
      else return res.data
    }
  }
  throw new Error('获取数据失败,请稍后重试')
}