| /** | |
| * @fileoverview Rule for disallowing require() outside of the top-level module context | |
| * @author Jamund Ferguson | |
| */ | |
| "use strict"; | |
| const ACCEPTABLE_PARENTS = [ | |
| "AssignmentExpression", | |
| "VariableDeclarator", | |
| "MemberExpression", | |
| "ExpressionStatement", | |
| "CallExpression", | |
| "ConditionalExpression", | |
| "Program", | |
| "VariableDeclaration" | |
| ]; | |
| /** | |
| * Finds the eslint-scope reference in the given scope. | |
| * @param {Object} scope The scope to search. | |
| * @param {ASTNode} node The identifier node. | |
| * @returns {Reference|null} Returns the found reference or null if none were found. | |
| */ | |
| function findReference(scope, node) { | |
| const references = scope.references.filter(reference => reference.identifier.range[0] === node.range[0] && | |
| reference.identifier.range[1] === node.range[1]); | |
| /* istanbul ignore else: correctly returns null */ | |
| if (references.length === 1) { | |
| return references[0]; | |
| } | |
| return null; | |
| } | |
| /** | |
| * Checks if the given identifier node is shadowed in the given scope. | |
| * @param {Object} scope The current scope. | |
| * @param {ASTNode} node The identifier node to check. | |
| * @returns {boolean} Whether or not the name is shadowed. | |
| */ | |
| function isShadowed(scope, node) { | |
| const reference = findReference(scope, node); | |
| return reference && reference.resolved && reference.resolved.defs.length > 0; | |
| } | |
| module.exports = { | |
| meta: { | |
| type: "suggestion", | |
| docs: { | |
| description: "require `require()` calls to be placed at top-level module scope", | |
| category: "Node.js and CommonJS", | |
| recommended: false, | |
| url: "https://eslint.org/docs/rules/global-require" | |
| }, | |
| schema: [], | |
| messages: { | |
| unexpected: "Unexpected require()." | |
| } | |
| }, | |
| create(context) { | |
| return { | |
| CallExpression(node) { | |
| const currentScope = context.getScope(); | |
| if (node.callee.name === "require" && !isShadowed(currentScope, node.callee)) { | |
| const isGoodRequire = context.getAncestors().every(parent => ACCEPTABLE_PARENTS.indexOf(parent.type) > -1); | |
| if (!isGoodRequire) { | |
| context.report({ node, messageId: "unexpected" }); | |
| } | |
| } | |
| } | |
| }; | |
| } | |
| }; |