/**
   * @fileoverview Validate strings passed to the RegExp constructor
   * @author Michael Ficarra
   * @copyright 2014 Michael Ficarra. All rights reserved.
   */
  "use strict";
  
  //------------------------------------------------------------------------------
  // Requirements
  //------------------------------------------------------------------------------
  
  var espree = require("espree");
  
  //------------------------------------------------------------------------------
  // Rule Definition
  //------------------------------------------------------------------------------
  
  module.exports = function(context) {
  
      /**
       * Check if node is a string
       * @param {ASTNode} node node to evaluate
       * @returns {boolean} True if its a string
       * @private
       */
      function isString(node) {
          return node && node.type === "Literal" && typeof node.value === "string";
      }
  
      /**
       * Validate strings passed to the RegExp constructor
       * @param {ASTNode} node node to evaluate
       * @returns {void}
       * @private
       */
      function check(node) {
          if (node.callee.type === "Identifier" && node.callee.name === "RegExp" && isString(node.arguments[0])) {
              var flags = isString(node.arguments[1]) ? node.arguments[1].value : "";
  
              try {
                  void new RegExp(node.arguments[0].value);
              } catch (e) {
                  context.report(node, e.message);
              }
  
              if (flags) {
  
                  try {
                      espree.parse("/./" + flags, { ecmaFeatures: context.ecmaFeatures });
                  } catch (ex) {
                      context.report(node, "Invalid flags supplied to RegExp constructor '" + flags + "'");
                  }
              }
  
          }
      }
  
      return {
          "CallExpression": check,
          "NewExpression": check
      };
  
  };
  
  module.exports.schema = [];