从transporter.sendMail创建可观察对象

Question

我正在尝试从sendMail创建一个可观察对象，目前我的测试是这样的：

/// <reference path="../../typings/index.d.ts" />
import * as chai from "chai";
let assert = chai.assert;
const Rx = require('rxjs');
var nodemailer = require('nodemailer');

describe("emailPlugin", function() {
   it.only('should emit one value from a callback', function () {
       let mailOptions = {
          from: '"Fred Foo ?" <MY@gmail.com>', // sender address
          to: 'YOUR@gmail.com', // list of receivers; comma seperated
          subject: 'Hello ✔', // Subject line
          text: 'Hello world ?', // plaintext body
          html: '<b>Hello world ?</b>' // html body
      };
      let transporter = nodemailer.createTransport('smtps://MY%40gmail.com:MY@smtp.gmail.com');

      let boundCallback = Rx.Observable.bindNodeCallback(transporter.sendMail);
      boundCallback(mailOptions, function(error, info){
          if(error){
              return error;
          }
          return info.response;
      }).subscribe(x => console.log(x), e => console.error(e));
  });   
});

结果是一个错误：

[TypeError: Cannot convert undefined or null to object]

有人能帮帮我吗？

Answer 1

我和你有完全一样的问题，我找到了解决它的方法。而不是：

let boundCallback = Rx.Observable.bindNodeCallback(transporter.sendMail);

这对我来说很有效：

let boundCallback = Rx.Observable.bindNodeCallback((options: any, callback: any) => {
  return transporter.sendMail(options, callback);
});

我不知道为什么，在我看来，原来的形式应该是正确的。看起来TypeScript在处理sendMail函数的类型上有些困难。希望这能有所帮助！