/**
   * @fileoverview Rule to flag references to the undefined variable.
   * @author Michael Ficarra
   */
  "use strict";
  
  //------------------------------------------------------------------------------
  // Rule Definition
  //------------------------------------------------------------------------------
  
  module.exports = function(context) {
  
      return {
  
          "Identifier": function(node) {
              if (node.name === "undefined") {
                  var parent = context.getAncestors().pop();
                  if (!parent || parent.type !== "MemberExpression" || node !== parent.property || parent.computed) {
                      context.report(node, "Unexpected use of undefined.");
                  }
              }
          }
      };
  
  };
  
  module.exports.schema = [];