PT-MCP (Paul Test Man Context Protocol)

/** * @fileoverview Rule to flag duplicate arguments * @author Jamund Ferguson */ "use strict"; //------------------------------------------------------------------------------ // Requirements //------------------------------------------------------------------------------ const astUtils = require("./utils/ast-utils"); //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ /** @type {import('../types').Rule.RuleModule} */ module.exports = { meta: { type: "problem", docs: { description: "Disallow duplicate arguments in `function` definitions", recommended: true, url: "https://eslint.org/docs/latest/rules/no-dupe-args", }, schema: [], messages: { unexpected: "Duplicate param '{{name}}'.", }, }, create(context) { const sourceCode = context.sourceCode; //-------------------------------------------------------------------------- // Helpers //-------------------------------------------------------------------------- /** * Checks whether or not a given definition is a parameter's. * @param {eslint-scope.DefEntry} def A definition to check. * @returns {boolean} `true` if the definition is a parameter's. */ function isParameter(def) { return def.type === "Parameter"; } /** * Determines if a given node has duplicate parameters. * @param {ASTNode} node The node to check. * @returns {void} * @private */ function checkParams(node) { const variables = sourceCode.getDeclaredVariables(node); for (let i = 0; i < variables.length; ++i) { const variable = variables[i]; // Checks and reports duplications. const defs = variable.defs.filter(isParameter); const loc = { start: astUtils.getOpeningParenOfParams(node, sourceCode) .loc.start, end: sourceCode.getTokenBefore(node.body).loc.end, }; if (defs.length >= 2) { context.report({ loc, messageId: "unexpected", data: { name: variable.name }, }); } } } //-------------------------------------------------------------------------- // Public API //-------------------------------------------------------------------------- return { FunctionDeclaration: checkParams, FunctionExpression: checkParams, }; }, };