一、说明：

本翻译器是基于有道智云翻译api实现的翻译器：https://ai.youdao.com
因此，需要先上有道智云注册一个开发者应用appKey

二、翻译器代码如下：

translator.js

const request = require('request-promise')
var crypto = require('crypto');

/**
 * 翻译器
 */
function Translator() {
  this.config = {
    from: '',
    to: '',
    appKey: '',
    secretKey: '',
  }
}

/**
 * md5加密
 */
Translator.prototype.md5 = function md5(str) {
  var crypto_md5 = crypto.createHash("md5");
  crypto_md5.update(str);
  return crypto_md5.digest('hex');
}

/**
* 生成[0,n]区间的随机整数
* 比如生成[0,100]的闭区间随机整数，getRandomN(100)
*/
Translator.prototype.getRandomN = function getRandomN(roundTo) {
  return Math.round(Math.random() * roundTo);
}

/**
 * {a:'111',b:'222'} => a=111&b=222
 */
Translator.prototype.generateUrlParams = function generateUrlParams(_params) {
  const paramsData = [];
  for (const key in _params) {
    if (_params.hasOwnProperty(key)) {
      paramsData.push(key + '=' + _params[key]);
    }
  }
  const result = paramsData.join('&');
  return result;
}

/**
 * 进行翻译
 */
Translator.prototype.translate = async function (word) {
  let youdaoHost = 'http://openapi.youdao.com/api';
  // 在get请求中，中文需要进行uri编码
  let encodeURIWord = encodeURI(word);
  let salt = this.getRandomN(1000);
  let sign = this.md5(this.config.appKey + word + salt + this.config.secretKey);
  let paramsJson = {
    q: encodeURIWord,
    from: this.config.from,
    to: this.config.to,
    appKey: this.config.appKey,
    salt: salt,
    sign: sign
  }
  // let url = `http://openapi.youdao.com/api?q=${encodeURI(q)}&from=${from}&to=${to}&appKey=${appKey}&salt=${salt}&sign=${sign}`;
  let url = youdaoHost + '?' + this.generateUrlParams(paramsJson);
  let result = await request.get({ url: url });
  return result;
}

module.exports = Translator;

三、使用方法

const Translator = require('./src/translator');
let translator = new Translator();

// config the translator
translator.config = {
  from: 'zh_CHS', // zh-CHS(中文) || ja(日语) || EN(英文) || fr(法语) ...
  to: 'EN',
  appKey: 'xxxxxxxxxxxxx', // https://ai.youdao.com 在有道云上进行注册
  secretKey: 'xxxxxxxxxxxxxxxx'
}

async function translateString(str) {
  let resultStr = await translator.translate(str)
  console.log(resultStr);
}

translateString('你好');