api-stub.js

////// EXAMPLE
module.exports = function (server) {

  // Create an API namespace, so that the root does not 
  // have to be repeated for each end point.
  server.namespace('/api', function () {

    // Return fixture data for '/api/posts/:id'
    server.get('/posts/:id', function (req, res) {
      var post = {
        "post": {
          "id": 1,
          "title": "Rails is omakase",
          "comments": ["1", "2"],
          "user": "dhh"
        },

        "comments": [{
          "id": "1",
          "body": "Rails is unagi"
        }, {
          "id": "2",
          "body": "Omakase O_o"
        }]
      };

      res.send(post);
    });

  });
};


////////    MY FIRST IMPLEMENTATION
var path = require('path');
var fs = require('fs');
// going two peer directory of lightfixtures repo
var fixtureDir = path.resolve(__dirname, '../..', 'lightfixtures')

module.exports = function (server) {

    // Create an API namespace, so that the root does not
    // have to be repeated for each end point.
    server.namespace('/api', function () {

      var locationsProtocol = JSON.parse(fs.readFileSync(fixtureDir + '/locations.json'));
      var roomsProtocol = JSON.parse(fs.readFileSync(fixtureDir + '/rooms.json'));

      // stub location list request
      server.get(locationsProtocol[0].request.url, function (req, res) {
        res.send(locationsProtocol[0].response.data);
      });

      // stub individual location request
      server.get(locationsProtocol[1].request.url, function (req, res) {
        res.send(locationsProtocol[1].response.data);
      });

      // stub room list request
      server.get(roomsProtocol[0].request.url, function (req, res) {
        res.send(roomsProtocol[0].response.data);
      });

      // stub individual room request
      server.get(roomsProtocol[1].request.url, function (req, res) {
        res.send(roomsProtocol[1].response.data);
      });
    });
  };

///////////////    Something I'd like to do instead
var path = require('path');
var fs = require('fs');
// going two peer directory of lightfixtures repo
var fixtureDir = path.resolve(__dirname, '../..', 'lightfixtures')

module.exports = function (server) {

    // Create an API namespace, so that the root does not
    // have to be repeated for each end point.
    server.namespace('/api', function () {

      var locationsProtocol = JSON.parse(fs.readFileSync(fixtureDir + '/locations.json'));
      var roomsProtocol = JSON.parse(fs.readFileSync(fixtureDir + '/rooms.json'));

      function respondToEach(json) {
        for (var i = 0; i < json.length; i++) {
          server.get(json[i].request.url, function (req, res) {
            res.send(json[i].response.data);
          });
        }
      }

      respondToEach(locationsProtocol);
      respondToEach(roomsProtocol);

    });
  };

It turned out to be a scoping issue. Stackoverflow FTW!