How can I structure a mocha unit test that involves promises and third party NPM modules?

The code I am trying to test is:

exports.hasTokenOrApi = (req, res, next) ->
  if not req.headers?.authorization
    return res.status(403).end()

  new Promise (resolve, reject) ->
    if req.headers.authorization.length is 32
      # We are using an API key
      global.db.User.find
        where:
          api_key: req.headers.authorization
      .then (dbUser) ->
        resolve dbUser.apiDisplay()
    else
      # We are using a redis session
      req.redisSession.getAsync
        app: 'sessions'
        token: req.headers.authorization
      .then (response) ->
        resolve response.d
  .then (user) ->
    if not user.id
      return res.status(403).end()
    req.user = user

    next()
  .catch (err) ->
    next err

This is a middleware (I'm using Express) to catch tokens or API keys for various API endpoints.

So far the tests I have are:

describe 'Authentication Middleware', ->
  mock_res = {}
  before (done) ->
    mock_res =
      status: ->
        @
      end: ->
        @

    global.db =
      User:
        find: ->
          @
        then: ->
          id: 1


    done()

  it 'should return a 403 is no authorization is set in the header', ->
    mock_req = {}
    mock_next = null

    status_spy = sinon.spy mock_res, 'status'
    end_spy = sinon.spy mock_res, 'end'

    authentication.hasTokenOrApi mock_req, mock_res, mock_next
    status_spy.calledWith(403).should.equal true
    end_spy.called.should.equal true

  it.only 'should detect a valid API key', ->
    mock_req =
      headers:
        authorization: 'e16b2ab8d12314bf4efbd6203906ea6c'
    mock_next = sinon.spy()

    authentication.hasTokenOrApi mock_req, mock_res, mock_next
    mock_next.called.should.equal true

The first test is fine, works great, solves all of my problems. The second one isn't working properly. I assume it has something to do with the Promises? My test us returning false, when what I'm trying to do is true

Any help would be GREATLY appreciated!