Nodejs中，使用nock做http请求的mock

nock 可以拦截nodejs向外发送的HTTP请求，并模拟HTTP服务器响应，返回特定的结果，这对于接口测试非常方便。

// 例子更改自: 
// https://github.com/node-nock/nock#use
// 和
// https://github.com/node-nock/nock#repeat-response-n-times

var nock = require('nock');
var http = require('http');

var couchdb = nock('http://myapp.iriscouch.com')// 拦截所有发送到这个host(支持字符串和正则表达式)的http请求
                .get('/users/1')// 对发送到这个path(支持字符串和正则表达式)的http请求作出响应; 对其他path的http请求报错
                .times(2)
                .reply(200, {
                  _id: '123ABC',
                  _rev: '946B7D1C',
                  username: 'pgte',
                  email: '[e-mail]'
                 });

function _o(msg){console.log(msg);}

function doGet(path){
  http.get({hostname: 'myapp.iriscouch.com', path: path}, (res)=>{
    res.setEncoding('utf8');
if(res.statusCode == 200){
var newData = '';
      res.on('data', (chunk)=>{ newData += chunk; });
      res.on('end',  ()     =>{
        _o(newData);
      });
    } else{
      _o('res.statusCode = ' + res.statusCode);
    }
  }).
  on('error', (err)=>{
    _o('error: ' + err);
  });
}

doGet('/users/1');     // {"_id":"123ABC","_rev":"946B7D1C","username":"pgte","email":"[e-mail]"}
doGet('/users/10');    // error: Error: Nock: No match for request GET http://myapp.iriscouch.com/users/10
doGet('/users/1?x=b'); // error: Error: Nock: No match for request GET http://myapp.iriscouch.com/users/1?x=b
doGet('/users/1');     // {"_id":"123ABC","_rev":"946B7D1C","username":"pgte","email":"[e-mail]"}
doGet('/users/1');     // error: Error: Nock: No match for request GET http://myapp.iriscouch.com/users/1