eslint/lib/rules/no-native-reassign.js

   1 /**
   2  * @fileoverview Rule to disallow assignments to native objects or read-only global variables
   3  * @author Ilya Volodin
   4  * @deprecated in ESLint v3.3.0
   5  */
   6
   7 "use strict";
   8
   9 //------------------------------------------------------------------------------
  10 // Rule Definition
  11 //------------------------------------------------------------------------------
  12
  13 /** @type {import('../shared/types').Rule} */
  14 module.exports = {
  15     meta: {
  16         type: "suggestion",
  17
  18         docs: {
  19             description: "Disallow assignments to native objects or read-only global variables",
  20             recommended: false,
  21             url: "https://eslint.org/docs/latest/rules/no-native-reassign"
  22         },
  23
  24         deprecated: true,
  25
  26         replacedBy: ["no-global-assign"],
  27
  28         schema: [
  29             {
  30                 type: "object",
  31                 properties: {
  32                     exceptions: {
  33                         type: "array",
  34                         items: { type: "string" },
  35                         uniqueItems: true
  36                     }
  37                 },
  38                 additionalProperties: false
  39             }
  40         ],
  41
  42         messages: {
  43             nativeReassign: "Read-only global '{{name}}' should not be modified."
  44         }
  45     },
  46
  47     create(context) {
  48         const config = context.options[0];
  49         const exceptions = (config && config.exceptions) || [];
  50         const sourceCode = context.sourceCode;
  51
  52         /**
  53          * Reports write references.
  54          * @param {Reference} reference A reference to check.
  55          * @param {int} index The index of the reference in the references.
  56          * @param {Reference[]} references The array that the reference belongs to.
  57          * @returns {void}
  58          */
  59         function checkReference(reference, index, references) {
  60             const identifier = reference.identifier;
  61
  62             if (reference.init === false &&
  63                 reference.isWrite() &&
  64
  65                 /*
  66                  * Destructuring assignments can have multiple default value,
  67                  * so possibly there are multiple writeable references for the same identifier.
  68                  */
  69                 (index === 0 || references[index - 1].identifier !== identifier)
  70             ) {
  71                 context.report({
  72                     node: identifier,
  73                     messageId: "nativeReassign",
  74                     data: identifier
  75                 });
  76             }
  77         }
  78
  79         /**
  80          * Reports write references if a given variable is read-only builtin.
  81          * @param {Variable} variable A variable to check.
  82          * @returns {void}
  83          */
  84         function checkVariable(variable) {
  85             if (variable.writeable === false && !exceptions.includes(variable.name)) {
  86                 variable.references.forEach(checkReference);
  87             }
  88         }
  89
  90         return {
  91             Program(node) {
  92                 const globalScope = sourceCode.getScope(node);
  93
  94                 globalScope.variables.forEach(checkVariable);
  95             }
  96         };
  97     }
  98 };