index.js

var Response = function() {
  var _context
      , _contentType
      , _defaultContentType = 'application/json'
      , _defaultHttpStatusCode = 200
      , _headers = {}
      , _httpStatusCode;

  this.setContentType = function(type) {
    this.setHeader('Content-Type', type);
    _contentType = type;
  };

  this.setContext = function(context) {
    _context = context;    
  };

  this.setHeader = function(name, value) {
    _headers[name] = value;
  };

  this.setHttpStatusCode = function(code) {
    var headerString
        , reason = '';

    // https://www.w3.org/Protocols/rfc2616/rfc2616-sec6.html
    switch(code) {
      case 200:
        reason = 'OK';
        break;
      case 201:
        reason = 'Created';
        break;
      case 202:
        reason = 'Accepted';
        break;
      case 400:
        reason = 'Bad Request';
        break;
      case 401:
        reason = 'Unauthorized';
        break;
      case 403:
        reason = 'Forbidden';
        break;
      case 404:
        reason = 'Not Found';
        break;
      case 409:
        reason = 'Conflict';
        break;
      default:
        reason = 'Unknown';
        break;
    }

    this.setHeader('Status', code + ' ' + reason);
    _httpStatusCode = code;
  },

  // success codes
  this.send = function(data) {
    result = {};
    if(typeof(_httpStatusCode) === 'undefined') {
      this.setHttpStatusCode(_defaultHttpStatusCode);
    }
    if(typeof(_contentType) === 'undefined') {
      this.setContentType(_defaultContentType);
    }
    result['headers'] = _headers;
    result['data'] = data;
    _context.succeed(result);
  }
};

module.exports = Response;