blob: 4af3a6a4669a7983bb55a0407e9950b56f40afa0 [file] [log] [blame]
/**
* @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" });
}
}
}
};
}
};