| /** |
| * @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" }); |
| } |
| } |
| } |
| }; |
| } |
| }; |