eslint/lib/rules/default-case-last.js

   1 /**
   2  * @fileoverview Rule to enforce default clauses in switch statements to be last
   3  * @author Milos Djermanovic
   4  */
   5
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Rule Definition
  10 //------------------------------------------------------------------------------
  11
  12 /** @type {import('../shared/types').Rule} */
  13 module.exports = {
  14     meta: {
  15         type: "suggestion",
  16
  17         docs: {
  18             description: "Enforce default clauses in switch statements to be last",
  19             recommended: false,
  20             url: "https://eslint.org/docs/rules/default-case-last"
  21         },
  22
  23         schema: [],
  24
  25         messages: {
  26             notLast: "Default clause should be the last clause."
  27         }
  28     },
  29
  30     create(context) {
  31         return {
  32             SwitchStatement(node) {
  33                 const cases = node.cases,
  34                     indexOfDefault = cases.findIndex(c => c.test === null);
  35
  36                 if (indexOfDefault !== -1 && indexOfDefault !== cases.length - 1) {
  37                     const defaultClause = cases[indexOfDefault];
  38
  39                     context.report({ node: defaultClause, messageId: "notLast" });
  40                 }
  41             }
  42         };
  43     }
  44 };