prefer-reflect.js

   1 /**
   2  * @fileoverview Rule to suggest using "Reflect" api over Function/Object methods
   3  * @author Keith Cirkel <http://keithcirkel.co.uk>
   4  * @deprecated in ESLint v3.9.0
   5  */
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Rule Definition
  10 //------------------------------------------------------------------------------
  11
  12 module.exports = {
  13     meta: {
  14         type: "suggestion",
  15
  16         docs: {
  17             description: "require `Reflect` methods where applicable",
  18             category: "ECMAScript 6",
  19             recommended: false,
  20             url: "https://eslint.org/docs/rules/prefer-reflect"
  21         },
  22
  23         deprecated: true,
  24
  25         replacedBy: [],
  26
  27         schema: [
  28             {
  29                 type: "object",
  30                 properties: {
  31                     exceptions: {
  32                         type: "array",
  33                         items: {
  34                             enum: [
  35                                 "apply",
  36                                 "call",
  37                                 "delete",
  38                                 "defineProperty",
  39                                 "getOwnPropertyDescriptor",
  40                                 "getPrototypeOf",
  41                                 "setPrototypeOf",
  42                                 "isExtensible",
  43                                 "getOwnPropertyNames",
  44                                 "preventExtensions"
  45                             ]
  46                         },
  47                         uniqueItems: true
  48                     }
  49                 },
  50                 additionalProperties: false
  51             }
  52         ]
  53     },
  54
  55     create(context) {
  56         const existingNames = {
  57             apply: "Function.prototype.apply",
  58             call: "Function.prototype.call",
  59             defineProperty: "Object.defineProperty",
  60             getOwnPropertyDescriptor: "Object.getOwnPropertyDescriptor",
  61             getPrototypeOf: "Object.getPrototypeOf",
  62             setPrototypeOf: "Object.setPrototypeOf",
  63             isExtensible: "Object.isExtensible",
  64             getOwnPropertyNames: "Object.getOwnPropertyNames",
  65             preventExtensions: "Object.preventExtensions"
  66         };
  67
  68         const reflectSubsitutes = {
  69             apply: "Reflect.apply",
  70             call: "Reflect.apply",
  71             defineProperty: "Reflect.defineProperty",
  72             getOwnPropertyDescriptor: "Reflect.getOwnPropertyDescriptor",
  73             getPrototypeOf: "Reflect.getPrototypeOf",
  74             setPrototypeOf: "Reflect.setPrototypeOf",
  75             isExtensible: "Reflect.isExtensible",
  76             getOwnPropertyNames: "Reflect.getOwnPropertyNames",
  77             preventExtensions: "Reflect.preventExtensions"
  78         };
  79
  80         const exceptions = (context.options[0] || {}).exceptions || [];
  81
  82         /**
  83          * Reports the Reflect violation based on the `existing` and `substitute`
  84          * @param {Object} node The node that violates the rule.
  85          * @param {string} existing The existing method name that has been used.
  86          * @param {string} substitute The Reflect substitute that should be used.
  87          * @returns {void}
  88          */
  89         function report(node, existing, substitute) {
  90             context.report({
  91                 node,
  92                 message: "Avoid using {{existing}}, instead use {{substitute}}.",
  93                 data: {
  94                     existing,
  95                     substitute
  96                 }
  97             });
  98         }
  99
 100         return {
 101             CallExpression(node) {
 102                 const methodName = (node.callee.property || {}).name;
 103                 const isReflectCall = (node.callee.object || {}).name === "Reflect";
 104                 const hasReflectSubsitute = Object.prototype.hasOwnProperty.call(reflectSubsitutes, methodName);
 105                 const userConfiguredException = exceptions.indexOf(methodName) !== -1;
 106
 107                 if (hasReflectSubsitute && !isReflectCall && !userConfiguredException) {
 108                     report(node, existingNames[methodName], reflectSubsitutes[methodName]);
 109                 }
 110             },
 111             UnaryExpression(node) {
 112                 const isDeleteOperator = node.operator === "delete";
 113                 const targetsIdentifier = node.argument.type === "Identifier";
 114                 const userConfiguredException = exceptions.indexOf("delete") !== -1;
 115
 116                 if (isDeleteOperator && !targetsIdentifier && !userConfiguredException) {
 117                     report(node, "the delete keyword", "Reflect.deleteProperty");
 118                 }
 119             }
 120         };
 121
 122     }
 123 };