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 = [
  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     /* istanbul ignore else: correctly returns null */
  32     if (references.length === 1) {
  33         return references[0];
  34     }
  35     return null;
  36
  37 }
  38
  39 /**
  40  * Checks if the given identifier node is shadowed in the given scope.
  41  * @param {Object} scope The current scope.
  42  * @param {ASTNode} node The identifier node to check.
  43  * @returns {boolean} Whether or not the name is shadowed.
  44  */
  45 function isShadowed(scope, node) {
  46     const reference = findReference(scope, node);
  47
  48     return reference && reference.resolved && reference.resolved.defs.length > 0;
  49 }
  50
  51 /** @type {import('../shared/types').Rule} */
  52 module.exports = {
  53     meta: {
  54         deprecated: true,
  55
  56         replacedBy: [],
  57
  58         type: "suggestion",
  59
  60         docs: {
  61             description: "require `require()` calls to be placed at top-level module scope",
  62             recommended: false,
  63             url: "https://eslint.org/docs/rules/global-require"
  64         },
  65
  66         schema: [],
  67         messages: {
  68             unexpected: "Unexpected require()."
  69         }
  70     },
  71
  72     create(context) {
  73         return {
  74             CallExpression(node) {
  75                 const currentScope = context.getScope();
  76
  77                 if (node.callee.name === "require" && !isShadowed(currentScope, node.callee)) {
  78                     const isGoodRequire = context.getAncestors().every(parent => ACCEPTABLE_PARENTS.indexOf(parent.type) > -1);
  79
  80                     if (!isGoodRequire) {
  81                         context.report({ node, messageId: "unexpected" });
  82                     }
  83                 }
  84             }
  85         };
  86     }
  87 };