/**
   * @fileoverview Rule to flag comparison where left part is the same as the right
   * part.
   * @author Ilya Volodin
   */
  
  "use strict";
  
  //------------------------------------------------------------------------------
  // Rule Definition
  //------------------------------------------------------------------------------
  
  module.exports = {
      meta: {
          docs: {
              description: "disallow comparisons where both sides are exactly the same",
              category: "Best Practices",
              recommended: false
          },
  
          schema: []
      },
  
      create(context) {
  
          return {
  
              BinaryExpression(node) {
                  const operators = ["===", "==", "!==", "!=", ">", "<", ">=", "<="];
  
                  if (operators.indexOf(node.operator) > -1 &&
                      (node.left.type === "Identifier" && node.right.type === "Identifier" && node.left.name === node.right.name ||
                      node.left.type === "Literal" && node.right.type === "Literal" && node.left.value === node.right.value)) {
                      context.report({ node, message: "Comparing to itself is potentially pointless." });
                  }
              }
          };
  
      }
  };