.config/coc/extensions/node_modules/coc-prettier/node_modules/eslint/lib/rules/func-style.js

   1 /**
   2  * @fileoverview Rule to enforce a particular function style
   3  * @author Nicholas C. Zakas
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Rule Definition
   9 //------------------------------------------------------------------------------
  10
  11 module.exports = {
  12     meta: {
  13         type: "suggestion",
  14
  15         docs: {
  16             description: "enforce the consistent use of either `function` declarations or expressions",
  17             category: "Stylistic Issues",
  18             recommended: false,
  19             url: "https://eslint.org/docs/rules/func-style"
  20         },
  21
  22         schema: [
  23             {
  24                 enum: ["declaration", "expression"]
  25             },
  26             {
  27                 type: "object",
  28                 properties: {
  29                     allowArrowFunctions: {
  30                         type: "boolean",
  31                         default: false
  32                     }
  33                 },
  34                 additionalProperties: false
  35             }
  36         ],
  37
  38         messages: {
  39             expression: "Expected a function expression.",
  40             declaration: "Expected a function declaration."
  41         }
  42     },
  43
  44     create(context) {
  45
  46         const style = context.options[0],
  47             allowArrowFunctions = context.options[1] && context.options[1].allowArrowFunctions,
  48             enforceDeclarations = (style === "declaration"),
  49             stack = [];
  50
  51         const nodesToCheck = {
  52             FunctionDeclaration(node) {
  53                 stack.push(false);
  54
  55                 if (!enforceDeclarations && node.parent.type !== "ExportDefaultDeclaration") {
  56                     context.report({ node, messageId: "expression" });
  57                 }
  58             },
  59             "FunctionDeclaration:exit"() {
  60                 stack.pop();
  61             },
  62
  63             FunctionExpression(node) {
  64                 stack.push(false);
  65
  66                 if (enforceDeclarations && node.parent.type === "VariableDeclarator") {
  67                     context.report({ node: node.parent, messageId: "declaration" });
  68                 }
  69             },
  70             "FunctionExpression:exit"() {
  71                 stack.pop();
  72             },
  73
  74             ThisExpression() {
  75                 if (stack.length > 0) {
  76                     stack[stack.length - 1] = true;
  77                 }
  78             }
  79         };
  80
  81         if (!allowArrowFunctions) {
  82             nodesToCheck.ArrowFunctionExpression = function() {
  83                 stack.push(false);
  84             };
  85
  86             nodesToCheck["ArrowFunctionExpression:exit"] = function(node) {
  87                 const hasThisExpr = stack.pop();
  88
  89                 if (enforceDeclarations && !hasThisExpr && node.parent.type === "VariableDeclarator") {
  90                     context.report({ node: node.parent, messageId: "declaration" });
  91                 }
  92             };
  93         }
  94
  95         return nodesToCheck;
  96
  97     }
  98 };