/** * @fileoverview Disallow shadowing of NaN, undefined, and Infinity (ES5 section 15.1.1) * @author Michael Ficarra */ "use strict"; //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ module.exports = { meta: { docs: { description: "disallow identifiers from shadowing restricted names", category: "Variables", recommended: false }, schema: [] }, create(context) { const RESTRICTED = ["undefined", "NaN", "Infinity", "arguments", "eval"]; /** * Check if the node name is present inside the restricted list * @param {ASTNode} id id to evaluate * @returns {void} * @private */ function checkForViolation(id) { if (RESTRICTED.indexOf(id.name) > -1) { context.report({ node: id, message: "Shadowing of global property '{{idName}}'.", data: { idName: id.name } }); } } return { VariableDeclarator(node) { checkForViolation(node.id); }, ArrowFunctionExpression(node) { [].map.call(node.params, checkForViolation); }, FunctionExpression(node) { if (node.id) { checkForViolation(node.id); } [].map.call(node.params, checkForViolation); }, FunctionDeclaration(node) { if (node.id) { checkForViolation(node.id); [].map.call(node.params, checkForViolation); } }, CatchClause(node) { checkForViolation(node.param); } }; } };