/**
   * @fileoverview Rule to flag variable leak in CatchClauses in IE 8 and earlier
   * @author Ian Christian Myers
   */
  
  "use strict";
  
  //------------------------------------------------------------------------------
  // Requirements
  //------------------------------------------------------------------------------
  
  var astUtils = require("../ast-utils");
  
  //------------------------------------------------------------------------------
  // Rule Definition
  //------------------------------------------------------------------------------
  
  module.exports = function(context) {
  
      //--------------------------------------------------------------------------
      // Helpers
      //--------------------------------------------------------------------------
  
      /**
       * Check if the parameters are been shadowed
       * @param {object} scope current scope
       * @param {string} name parameter name
       * @returns {boolean} True is its been shadowed
       */
      function paramIsShadowing(scope, name) {
          return astUtils.getVariableByName(scope, name) !== null;
      }
  
      //--------------------------------------------------------------------------
      // Public API
      //--------------------------------------------------------------------------
  
      return {
  
          "CatchClause": function(node) {
              var scope = context.getScope();
  
              // When blockBindings is enabled, CatchClause creates its own scope
              // so start from one upper scope to exclude the current node
              if (scope.block === node) {
                  scope = scope.upper;
              }
  
              if (paramIsShadowing(scope, node.param.name)) {
                  context.report(node, "Value of '{{name}}' may be overwritten in IE 8 and earlier.",
                          { name: node.param.name });
              }
          }
      };
  
  };
  
  module.exports.schema = [];