/** * @fileoverview Enforce no duplicate props * @author Markus Ånöstam */ 'use strict'; const has = require('object.hasown/polyfill')(); const docsUrl = require('../util/docsUrl'); const report = require('../util/report'); // ------------------------------------------------------------------------------ // Rule Definition // ------------------------------------------------------------------------------ const messages = { noDuplicateProps: 'No duplicate props allowed', }; module.exports = { meta: { docs: { description: 'Disallow duplicate properties in JSX', category: 'Possible Errors', recommended: true, url: docsUrl('jsx-no-duplicate-props'), }, messages, schema: [{ type: 'object', properties: { ignoreCase: { type: 'boolean', }, }, additionalProperties: false, }], }, create(context) { const configuration = context.options[0] || {}; const ignoreCase = configuration.ignoreCase || false; return { JSXOpeningElement(node) { const props = {}; node.attributes.forEach((decl) => { if (decl.type === 'JSXSpreadAttribute') { return; } let name = decl.name.name; if (typeof name !== 'string') { return; } if (ignoreCase) { name = name.toLowerCase(); } if (has(props, name)) { report(context, messages.noDuplicateProps, 'noDuplicateProps', { node: decl, }); } else { props[name] = 1; } }); }, }; }, };