.config/coc/extensions/node_modules/coc-prettier/node_modules/eslint/lib/rules/no-case-declarations.js

   1 /**
   2  * @fileoverview Rule to flag use of an lexical declarations inside a case clause
   3  * @author Erik Arvidsson
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Rule Definition
   9 //------------------------------------------------------------------------------
  10
  11 module.exports = {
  12     meta: {
  13         type: "suggestion",
  14
  15         docs: {
  16             description: "disallow lexical declarations in case clauses",
  17             category: "Best Practices",
  18             recommended: true,
  19             url: "https://eslint.org/docs/rules/no-case-declarations"
  20         },
  21
  22         schema: [],
  23
  24         messages: {
  25             unexpected: "Unexpected lexical declaration in case block."
  26         }
  27     },
  28
  29     create(context) {
  30
  31         /**
  32          * Checks whether or not a node is a lexical declaration.
  33          * @param {ASTNode} node A direct child statement of a switch case.
  34          * @returns {boolean} Whether or not the node is a lexical declaration.
  35          */
  36         function isLexicalDeclaration(node) {
  37             switch (node.type) {
  38                 case "FunctionDeclaration":
  39                 case "ClassDeclaration":
  40                     return true;
  41                 case "VariableDeclaration":
  42                     return node.kind !== "var";
  43                 default:
  44                     return false;
  45             }
  46         }
  47
  48         return {
  49             SwitchCase(node) {
  50                 for (let i = 0; i < node.consequent.length; i++) {
  51                     const statement = node.consequent[i];
  52
  53                     if (isLexicalDeclaration(statement)) {
  54                         context.report({
  55                             node: statement,
  56                             messageId: "unexpected"
  57                         });
  58                     }
  59                 }
  60             }
  61         };
  62
  63     }
  64 };