/**
   * @fileoverview Rule to flag assignment of the exception parameter
   * @author Stephen Murray <spmurrayzzz>
   */
  
  "use strict";
  
  const astUtils = require("../ast-utils");
  
  //------------------------------------------------------------------------------
  // Rule Definition
  //------------------------------------------------------------------------------
  
  module.exports = {
      meta: {
          docs: {
              description: "disallow reassigning exceptions in `catch` clauses",
              category: "Possible Errors",
              recommended: true
          },
  
          schema: []
      },
  
      create(context) {
  
          /**
           * Finds and reports references that are non initializer and writable.
           * @param {Variable} variable - A variable to check.
           * @returns {void}
           */
          function checkVariable(variable) {
              astUtils.getModifyingReferences(variable.references).forEach(reference => {
                  context.report({ node: reference.identifier, message: "Do not assign to the exception parameter." });
              });
          }
  
          return {
              CatchClause(node) {
                  context.getDeclaredVariables(node).forEach(checkVariable);
              }
          };
  
      }
  };