import { RuleTester as ESLintTesterV8 } from 'eslint-v8' import { RuleTester as ESLintTesterV9 } from 'eslint' import { rules } from '@next/eslint-plugin-next' const NextESLintRule = rules['no-head-element'] const message = 'Do not use `` element. Use `` from `next/head` instead. See: https://nextjs.org/docs/messages/no-head-element' const tests = { valid: [ { code: `import Head from 'next/head'; export class MyComponent { render() { return (
My page title
); } } `, filename: 'pages/index.js', }, { code: `import Head from 'next/head'; export class MyComponent { render() { return (
My page title
); } } `, filename: 'pages/index.tsx', }, { code: ` export default function Layout({ children }) { return ( layout {children} ); } `, filename: './app/layout.js', }, ], invalid: [ { code: ` export class MyComponent { render() { return (
My page title
); } }`, filename: './pages/index.js', errors: [ { message, type: 'JSXOpeningElement', }, ], }, { code: `import Head from 'next/head'; export class MyComponent { render() { return (
My page title My page title
); } }`, filename: 'pages/index.ts', errors: [ { message, type: 'JSXOpeningElement', }, ], }, ], } describe('no-head-element', () => { new ESLintTesterV8({ parserOptions: { ecmaVersion: 2018, sourceType: 'module', ecmaFeatures: { modules: true, jsx: true, }, }, }).run('eslint-v8', NextESLintRule, tests) new ESLintTesterV9({ languageOptions: { ecmaVersion: 2018, sourceType: 'module', parserOptions: { ecmaFeatures: { modules: true, jsx: true, }, }, }, }).run('eslint-v9', NextESLintRule, tests) })