old_contents: var expect = require('chai').expect,
      wechatPlacekitten = require('..');
  
  describe('wechat-placekitten', function() {
    it('should say hello', function(done) {
      expect(wechatPlacekitten()).to.equal('Hello, world');
      done();
    });
  });
  
new_contents: var expect = require('chai').expect,
      wechatPlacekitten = require('..');
  
  describe('wechat-placekitten', function() {
    it('should create a handler', function(done) {
      expect(wechatPlacekitten()).to.be.a('function');
      done();
    });
  });
  
subject: Fix test case