Better

学习代码示例

import axios from axios;

const MAX_RETRY = 3; // 重试次数
const RETRY_INTERVAL = 500; // 重试时间间隔
const TIMEOUT = 15 * 1000; // 超时时间

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

async function request(url, method, params, retry = MAX_RETRY, hookResult = null) {
    let res;
    let requireRetry;
    try {
        let config = {
            url: url,
            method: method,
            timeout: TIMEOUT
        }
        if (Object.is(method, 'get')) {
            config['params'] = params;
        } else if (Object.is(method, 'post')) {
            config['data'] = params;
        }
        res = await axios.request(config);
        // 发生服务器错误，重试
        if (res && res.status >= 500) requireRetry = true;
        // 使用调用者逻辑判断，如果未达到预期，重试
        if (hookResult && !hookResult(res)) requireRetry = true;
    } catch(err) {
        console.log(err);
        // 发生网络错误，重试
        requireRetry = true;
        if (requireRetry && retry > 0) {
            await sleep(TIMEOUT)
            console.log('重试', retry)
            res = await request(url, method, params, --retry)
        }
    }
    return res
}

function get(url, params = {}, retry = MAX_RETRY, hookResult = null) {
    return request(url, 'get', params, retry, hookResult)
}
function post(url, data = {}, retry = MAX_RETRY, hookResult = null) {
    return request(url, 'post', data, retry, hookResult)
}

export default {
    request,
    get,
    post
}

这里用到一个之前没用过的 Object.is 函数，它和 === 有什么区别呢。查阅 MDN 文档，直接看 Polyfill 实现，相信你就明白啦

if (!Object.is) {
  Object.is = function(x, y) {
    // SameValue algorithm
    if (x === y) { // Steps 1-5, 7-10
      // Steps 6.b-6.e: +0 != -0
      return x !== 0 || 1 / x === 1 / y;
    } else {
      // Step 6.a: NaN == NaN
      return x !== x && y !== y;
    }
  };
}

本质使用的还是严格比较运算符，看注释也了解到，不同之处只有两个

1. +0不等于-0
2. NaN等于自身