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

   1 /**
   2  * @fileoverview Disallow Labeled Statements
   3  * @author Nicholas C. Zakas
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Requirements
   9 //------------------------------------------------------------------------------
  10
  11 const astUtils = require("./utils/ast-utils");
  12
  13 //------------------------------------------------------------------------------
  14 // Rule Definition
  15 //------------------------------------------------------------------------------
  16
  17 module.exports = {
  18     meta: {
  19         type: "suggestion",
  20
  21         docs: {
  22             description: "disallow labeled statements",
  23             category: "Best Practices",
  24             recommended: false,
  25             url: "https://eslint.org/docs/rules/no-labels"
  26         },
  27
  28         schema: [
  29             {
  30                 type: "object",
  31                 properties: {
  32                     allowLoop: {
  33                         type: "boolean",
  34                         default: false
  35                     },
  36                     allowSwitch: {
  37                         type: "boolean",
  38                         default: false
  39                     }
  40                 },
  41                 additionalProperties: false
  42             }
  43         ]
  44     },
  45
  46     create(context) {
  47         const options = context.options[0];
  48         const allowLoop = options && options.allowLoop;
  49         const allowSwitch = options && options.allowSwitch;
  50         let scopeInfo = null;
  51
  52         /**
  53          * Gets the kind of a given node.
  54          * @param {ASTNode} node A node to get.
  55          * @returns {string} The kind of the node.
  56          */
  57         function getBodyKind(node) {
  58             if (astUtils.isLoop(node)) {
  59                 return "loop";
  60             }
  61             if (node.type === "SwitchStatement") {
  62                 return "switch";
  63             }
  64             return "other";
  65         }
  66
  67         /**
  68          * Checks whether the label of a given kind is allowed or not.
  69          * @param {string} kind A kind to check.
  70          * @returns {boolean} `true` if the kind is allowed.
  71          */
  72         function isAllowed(kind) {
  73             switch (kind) {
  74                 case "loop": return allowLoop;
  75                 case "switch": return allowSwitch;
  76                 default: return false;
  77             }
  78         }
  79
  80         /**
  81          * Checks whether a given name is a label of a loop or not.
  82          * @param {string} label A name of a label to check.
  83          * @returns {boolean} `true` if the name is a label of a loop.
  84          */
  85         function getKind(label) {
  86             let info = scopeInfo;
  87
  88             while (info) {
  89                 if (info.label === label) {
  90                     return info.kind;
  91                 }
  92                 info = info.upper;
  93             }
  94
  95             /* istanbul ignore next: syntax error */
  96             return "other";
  97         }
  98
  99         //--------------------------------------------------------------------------
 100         // Public
 101         //--------------------------------------------------------------------------
 102
 103         return {
 104             LabeledStatement(node) {
 105                 scopeInfo = {
 106                     label: node.label.name,
 107                     kind: getBodyKind(node.body),
 108                     upper: scopeInfo
 109                 };
 110             },
 111
 112             "LabeledStatement:exit"(node) {
 113                 if (!isAllowed(scopeInfo.kind)) {
 114                     context.report({
 115                         node,
 116                         message: "Unexpected labeled statement."
 117                     });
 118                 }
 119
 120                 scopeInfo = scopeInfo.upper;
 121             },
 122
 123             BreakStatement(node) {
 124                 if (node.label && !isAllowed(getKind(node.label.name))) {
 125                     context.report({
 126                         node,
 127                         message: "Unexpected label in break statement."
 128                     });
 129                 }
 130             },
 131
 132             ContinueStatement(node) {
 133                 if (node.label && !isAllowed(getKind(node.label.name))) {
 134                     context.report({
 135                         node,
 136                         message: "Unexpected label in continue statement."
 137                     });
 138                 }
 139             }
 140         };
 141
 142     }
 143 };