/**
   * @fileoverview Rule to flag octal escape sequences in string literals.
   * @author Ian Christian Myers
   */
  
  "use strict";
  
  //------------------------------------------------------------------------------
  // Rule Definition
  //------------------------------------------------------------------------------
  
  module.exports = {
      meta: {
          docs: {
              description: "disallow octal escape sequences in string literals",
              category: "Best Practices",
              recommended: false
          },
  
          schema: []
      },
  
      create(context) {
  
          return {
  
              Literal(node) {
                  if (typeof node.value !== "string") {
                      return;
                  }
  
                  const match = node.raw.match(/^([^\\]|\\[^0-7])*\\([0-3][0-7]{1,2}|[4-7][0-7]|[0-7])/);
  
                  if (match) {
                      const octalDigit = match[2];
  
                      // \0 is actually not considered an octal
                      if (match[2] !== "0" || typeof match[3] !== "undefined") {
                          context.report({ node, message: "Don't use octal: '\\{{octalDigit}}'. Use '\\u....' instead.", data: { octalDigit } });
                      }
                  }
              }
  
          };
  
      }
  };