unambiguous

💼 This rule is enabled in the following configs: recommended, typescript.

Rule DetailsCopy Anchor Link

Tools that follow the Unambiguous JavaScript Grammar decide between script and module from the syntax alone. A file with no import or export parses as a script too, so a tool may load your module in the wrong mode. This rule reports a module file with code but no module syntax.

Module syntax is: an import declaration (also type-only and side-effect), any export (also export {} and TS export =), TS import x = require('m') (TypeScript treats the file as a module), and import.meta (a syntax error in a script). A dynamic import() is legal in a script, so it does not disambiguate.

Not reported: an empty file, a file with a 'use strict' directive (its author stated a parse mode), and a file the config parses as a script or CommonJS, or a .cjs / .cts file (CommonJS by its extension). oxlint infers the parse goal from the content, so there a file counts as not-a-module only by a CommonJS sourceType or its extension.

❌ IncorrectCopy Anchor Link

const a = 1;
console.log(a);

const lazy = () => import('./a');

✅ CorrectCopy Anchor Link

import a from './a';
console.log(a);

console.log(import.meta.url);

const b = 1;
export {};

OptionsCopy Anchor Link

[]

No options.

When Not To Use ItCopy Anchor Link

When every consumer of your files is told the parse mode explicitly ("type": "module", .mjs, bundler config).

Use this rule

npm install -D oxlint-plugin-import-next

{  "jsPlugins": ["oxlint-plugin-import-next"],  "rules": {    "import-next/unambiguous": "error"  }}

import { defineConfig } from 'vite-plus';export default defineConfig({  lint: {    jsPlugins: ['oxlint-plugin-import-next'],    rules: {      'import-next/unambiguous': 'error',    },  },});