title: Why my Supertest test that should be failing is passing?
body: <p>I'm starting my project based on this repo:
  <a href="https://github.com/madhums/node-express-mongoose" rel="nofollow">https://github.com/madhums/node-express-mongoose</a></p>
  
  <p>The first thing I decided to do was write tests, so I went to the test file, and it looks something like this:</p>
  
  <pre><code>var mongoose = require('mongoose');
  var should = require('should');
  var request = require('supertest');
  var app = require('../server');
  var context = describe;
  // other stuff you want to include for tests
  
  before(function (done) {
    // clear db and other stuff
    done();
  });
  
  describe('Users', function () {
    describe('POST /users', function () {
      it('should create a user', function (done) {
  
        request(app)
        .post('/users')
        .field('name', 'foo')
        .field('email', 'foo')
        .field('password', 'foo')
        .expect('Content-Type', /json/)
        .expect(200)
        .end(function(err, res){
          console.log(err);
          if(err){
            console.log("error");
          }
          // console.log(res);
        });
  
  
        done();
      });
    });
  });
  
  after(function (done) {
    // do some stuff
    done();
  });
  </code></pre>
  
  <p>I haven't actually created the route, so the test should be failing, and I even do get an error on .end, so any idea why is the test not failing?</p>
  
  <p>My console shows me this when I run npm test</p>
  
  <pre><code>Express app started on port 3000
  
  
    Users
      POST /users
        ✓ should create a user
  [Error: expected "Content-Type" matching /json/, got "text/html; charset=utf-8"]
  error
  
  
    1 passing (653ms)
  </code></pre>