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-import-in-document'] const tests = { valid: [ { code: `import Document, { Html, Head, Main, NextScript } from 'next/document' class MyDocument extends Document { static async getInitialProps(ctx) { //... } render() { return ( ) } } export default MyDocument `, filename: 'pages/_document.tsx', }, { code: `import Head from "next/head"; export default function IndexPage() { return ( My page title ); } `, filename: 'pages/index.tsx', }, ], invalid: [ { code: ` import Document, { Html, Main, NextScript } from 'next/document' import Head from 'next/head' class MyDocument extends Document { render() { return (
) } } export default MyDocument `, filename: 'pages/_document.js', errors: [ { message: '`next/head` should not be imported in `pages/_document.js`. Use `` from `next/document` instead. See: https://nextjs.org/docs/messages/no-head-import-in-document', type: 'ImportDeclaration', }, ], }, { code: ` import Document, { Html, Main, NextScript } from 'next/document' import Head from 'next/head' class MyDocument extends Document { render() { return (
) } } export default MyDocument `, filename: 'pages/_document.page.tsx', errors: [ { message: '`next/head` should not be imported in `pages/_document.page.tsx`. Use `` from `next/document` instead. See: https://nextjs.org/docs/messages/no-head-import-in-document', type: 'ImportDeclaration', }, ], }, { code: ` import Document, { Html, Main, NextScript } from 'next/document' import Head from 'next/head' class MyDocument extends Document { render() { return (
) } } export default MyDocument `, filename: 'pages/_document/index.js', errors: [ { message: '`next/head` should not be imported in `pages/_document/index.js`. Use `` from `next/document` instead. See: https://nextjs.org/docs/messages/no-head-import-in-document', type: 'ImportDeclaration', }, ], }, { code: ` import Document, { Html, Main, NextScript } from 'next/document' import Head from 'next/head' class MyDocument extends Document { render() { return (
) } } export default MyDocument `, filename: 'pages/_document/index.tsx', errors: [ { message: '`next/head` should not be imported in `pages/_document/index.tsx`. Use `` from `next/document` instead. See: https://nextjs.org/docs/messages/no-head-import-in-document', type: 'ImportDeclaration', }, ], }, ], } describe('no-head-import-in-document', () => { 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) })