eslint/lib/rules/global-require.js

   1 /**
   2  * @fileoverview Rule for disallowing require() outside of the top-level module context
   3  * @author Jamund Ferguson
   4  * @deprecated in ESLint v7.0.0
   5  */
   6
   7 "use strict";
   8
   9 const ACCEPTABLE_PARENTS = new Set([
  10     "AssignmentExpression",
  11     "VariableDeclarator",
  12     "MemberExpression",
  13     "ExpressionStatement",
  14     "CallExpression",
  15     "ConditionalExpression",
  16     "Program",
  17     "VariableDeclaration",
  18     "ChainExpression"
  19 ]);
  20
  21 /**
  22  * Finds the eslint-scope reference in the given scope.
  23  * @param {Object} scope The scope to search.
  24  * @param {ASTNode} node The identifier node.
  25  * @returns {Reference|null} Returns the found reference or null if none were found.
  26  */
  27 function findReference(scope, node) {
  28     const references = scope.references.filter(reference => reference.identifier.range[0] === node.range[0] &&
  29             reference.identifier.range[1] === node.range[1]);
  30
  31     if (references.length === 1) {
  32         return references[0];
  33     }
  34
  35     /* c8 ignore next */
  36     return null;
  37
  38 }
  39
  40 /**
  41  * Checks if the given identifier node is shadowed in the given scope.
  42  * @param {Object} scope The current scope.
  43  * @param {ASTNode} node The identifier node to check.
  44  * @returns {boolean} Whether or not the name is shadowed.
  45  */
  46 function isShadowed(scope, node) {
  47     const reference = findReference(scope, node);
  48
  49     return reference && reference.resolved && reference.resolved.defs.length > 0;
  50 }
  51
  52 /** @type {import('../shared/types').Rule} */
  53 module.exports = {
  54     meta: {
  55         deprecated: true,
  56
  57         replacedBy: [],
  58
  59         type: "suggestion",
  60
  61         docs: {
  62             description: "Require `require()` calls to be placed at top-level module scope",
  63             recommended: false,
  64             url: "https://eslint.org/docs/latest/rules/global-require"
  65         },
  66
  67         schema: [],
  68         messages: {
  69             unexpected: "Unexpected require()."
  70         }
  71     },
  72
  73     create(context) {
  74         const sourceCode = context.sourceCode;
  75
  76         return {
  77             CallExpression(node) {
  78                 const currentScope = sourceCode.getScope(node);
  79
  80                 if (node.callee.name === "require" && !isShadowed(currentScope, node.callee)) {
  81                     const isGoodRequire = sourceCode.getAncestors(node).every(parent => ACCEPTABLE_PARENTS.has(parent.type));
  82
  83                     if (!isGoodRequire) {
  84                         context.report({ node, messageId: "unexpected" });
  85                     }
  86                 }
  87             }
  88         };
  89     }
  90 };