/** * @fileoverview Rule to disallow an empty pattern * @author Alberto Rodríguez */ "use strict"; const astUtils = require("./utils/ast-utils"); //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ /** @type {import('../types').Rule.RuleModule} */ module.exports = { meta: { type: "problem", defaultOptions: [ { allowObjectPatternsAsParameters: false, }, ], docs: { description: "Disallow empty destructuring patterns", recommended: true, url: "https://eslint.org/docs/latest/rules/no-empty-pattern", }, schema: [ { type: "object", properties: { allowObjectPatternsAsParameters: { type: "boolean", }, }, additionalProperties: false, }, ], messages: { unexpected: "Unexpected empty {{type}} pattern.", }, }, create(context) { const [{ allowObjectPatternsAsParameters }] = context.options; return { ObjectPattern(node) { if (node.properties.length > 0) { return; } // Allow {} and {} = {} empty object patterns as parameters when allowObjectPatternsAsParameters is true if ( allowObjectPatternsAsParameters && (astUtils.isFunction(node.parent) || (node.parent.type === "AssignmentPattern" && astUtils.isFunction(node.parent.parent) && node.parent.right.type === "ObjectExpression" && node.parent.right.properties.length === 0)) ) { return; } context.report({ node, messageId: "unexpected", data: { type: "object" }, }); }, ArrayPattern(node) { if (node.elements.length === 0) { context.report({ node, messageId: "unexpected", data: { type: "array" }, }); } }, }; }, };