React Native 中的 Fetch封装

之前做的React Native 项目使用的 Fetch封装，当初踩的坑还蛮多的...

import { Alert, Platform } from 'react-native';
import REQUEST from './HTTPRequest';   // 网络接口文件

let HTTPBase = {};
const REQUEST_URL = REQUEST.MAIN;

/**
 * HTTP REQUEST
 * @param   {string}  $method  : GET||POST||PUT||DELETE||POSTFILE
 * @param   {string}  $url     : 接口
 * @param   {object}  $params  : {}包装 --json
 * @param   {object}  $headers : 头部信息
 * @returns {Promise}
 */
HTTPBase.request = ($method, $url, $params, $headers) => {
  $url = REQUEST_URL + $url;

  $headers = $headers || {};
  $headers["Platform"] = Platform.OS;
  $headers["Version"] = global.appInfo.version_current;
  $headers["X-language"] = global.user.language;
  $headers["Accept"] = "application/json,text/plain,*/*";
  $headers["Authorization"] = "Bearer " + global.user.userToken;  // 用户的token

  let setting = { method: $method, headers: $headers };

  switch ($method) {
    case "GET":
      $headers["Content-Type"] = "application/json";
      if ($params) {
        let paramsArray = [];
        let paramsKeyArray = Object.keys($params);
        paramsKeyArray.forEach(key => paramsArray.push(key + "=" + $params[key]));

        //网址拼接
        if ($url.search(/\?/) === -1) {
          $url += "?" + paramsArray.join("&");
        } else {
          $url += paramsArray.join("&");
        }
      }
      break;
    
    case "POST":
    case "PUT":
    case "DELETE":
      $headers["Content-Type"] = "application/json";
      setting["body"] = JSON.stringify($params);
      break;
    // 上传文件
    case "POSTFILE":
      let formData = new FormData();
      for (let key in $params) {
        let file = {
          uri: $params[key],
          type: "application/octet-stream",
          name: $params[key].split("/")[$params[key].split("/").length - 1]
        };
        formData.append(key, file);
      }
      setting["method"] = "POST";
      setting["body"] = formData;
      break;
  }

  return new Promise((resolve, reject) => fetch($url, setting)
    .then(response => {
      // 提示更新app版本
      if (global.appInfo.flag == 0) {
        const version = response.headers.map.version[0];
        global.appInfo.version_latest = version;
        global.appInfo.flag = 1;  // 设置-已更新版本号
      }
      // 提示身份验证过期
      if (response.status == 401) {
        reject('登录已过期');
      } else {
        resolve(response);
      }
    })
    .catch(error => {
      reject('网络问题');
    })
    .done());
};

export default HTTPBase;