feature-change.js

var feature_change = require ('feature-change');
var Q = require(‘q’);

exports.getData = function(request, response, next) {
	var options = {
		expected: function(cb){
			currentImplementation(request, response, next, cb);
		},
		actual: function(cb){
			newImplementation(request, response, next, cb);
		},
		logAction: function(currentResult, newResult){
			//This method will be called if the resuts are different
			var resultstDifferences = getResultsDifferences(currentResult, newResult);
			logFeatureChangeResultDifferences(resultsdifferences);
		}
	}

  feature_change(options, function(err, result){
    response(result);
  });
}