no-prototype-builtins.js

   1 /**
   2  * @fileoverview Rule to disallow use of Object.prototype builtins on objects
   3  * @author Andrew Levine
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Rule Definition
   9 //------------------------------------------------------------------------------
  10
  11 module.exports = {
  12     meta: {
  13         type: "problem",
  14
  15         docs: {
  16             description: "disallow calling some `Object.prototype` methods directly on objects",
  17             category: "Possible Errors",
  18             recommended: true,
  19             url: "https://eslint.org/docs/rules/no-prototype-builtins"
  20         },
  21
  22         schema: []
  23     },
  24
  25     create(context) {
  26         const DISALLOWED_PROPS = [
  27             "hasOwnProperty",
  28             "isPrototypeOf",
  29             "propertyIsEnumerable"
  30         ];
  31
  32         /**
  33          * Reports if a disallowed property is used in a CallExpression
  34          * @param {ASTNode} node The CallExpression node.
  35          * @returns {void}
  36          */
  37         function disallowBuiltIns(node) {
  38             if (node.callee.type !== "MemberExpression" || node.callee.computed) {
  39                 return;
  40             }
  41             const propName = node.callee.property.name;
  42
  43             if (DISALLOWED_PROPS.indexOf(propName) > -1) {
  44                 context.report({
  45                     message: "Do not access Object.prototype method '{{prop}}' from target object.",
  46                     loc: node.callee.property.loc.start,
  47                     data: { prop: propName },
  48                     node
  49                 });
  50             }
  51         }
  52
  53         return {
  54             CallExpression: disallowBuiltIns
  55         };
  56     }
  57 };