Everyauth OAuth 1.0a authorization callback sequence

oauthCallbackSequence.js

everyModule.submodule('oauth')
// .
// .
// .
.get('callbackPath',
       'the callback path that the 3rd party OAuth provider redirects to after an OAuth authorization result - e.g., "/auth/twitter/callback"')
    .step('extractTokenAndVerifier')
      .description('extracts the request token and verifier from the url query')
      .accepts('req res next')
      .promises('requestToken verifier')
      .canBreakTo('handleDuplicateCallbackRequest')
      .canBreakTo('authCallbackErrorSteps')
    .step('getSession')
      .accepts('req')
      .promises('session')
    .step('rememberTokenSecret')
      .description('retrieves the request token secret from the session')
      .accepts('session')
      .promises('requestTokenSecret')
    .step('getAccessToken')
      .description('requests an access token from the OAuth provider')
      .accepts('requestToken requestTokenSecret verifier')
      .promises('accessToken accessTokenSecret params')
    .step('fetchOAuthUser')
      .accepts('accessToken accessTokenSecret params')
      .promises('oauthUser')
    .step('findOrCreateUser')
      .accepts('session accessToken accessTokenSecret oauthUser')
      .promises('user')
    .step('compileAuth')
      .accepts('accessToken accessTokenSecret oauthUser user')
      .promises('auth')
    .step('addToSession')
      .accepts('session auth')
      .promises(null)
    .step('sendResponse')
      .accepts('res')
      .promises(null)

/*
MIT License

Copyright (c) 2011 by Brian Noguchi

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/