/** * @fileoverview Rule to flag when a function has too many parameters * @author Ilya Volodin */ "use strict"; //------------------------------------------------------------------------------ // Requirements //------------------------------------------------------------------------------ const lodash = require("lodash"); const astUtils = require("../util/ast-utils"); //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ module.exports = { meta: { docs: { description: "enforce a maximum number of parameters in function definitions", category: "Stylistic Issues", recommended: false, url: "https://eslint.org/docs/rules/max-params" }, schema: [ { oneOf: [ { type: "integer", minimum: 0 }, { type: "object", properties: { maximum: { type: "integer", minimum: 0 }, max: { type: "integer", minimum: 0 } }, additionalProperties: false } ] } ] }, create(context) { const option = context.options[0]; let numParams = 3; if (typeof option === "object" && Object.prototype.hasOwnProperty.call(option, "maximum") && typeof option.maximum === "number") { numParams = option.maximum; } if (typeof option === "object" && Object.prototype.hasOwnProperty.call(option, "max") && typeof option.max === "number") { numParams = option.max; } if (typeof option === "number") { numParams = option; } /** * Checks a function to see if it has too many parameters. * @param {ASTNode} node The node to check. * @returns {void} * @private */ function checkFunction(node) { if (node.params.length > numParams) { context.report({ node, message: "{{name}} has too many parameters ({{count}}). Maximum allowed is {{max}}.", data: { name: lodash.upperFirst(astUtils.getFunctionNameWithKind(node)), count: node.params.length, max: numParams } }); } } return { FunctionDeclaration: checkFunction, ArrowFunctionExpression: checkFunction, FunctionExpression: checkFunction }; } };