eslint 9 + typescritp without type module

Question

I'm trying to upgrade eslint to v9 for next-json

I followed the official Getting started guideline, but in order to make it work I need to set "type": "module" in the package.json file.

Since I'm distributing the package both as CJS and ESM, I'm warried this setting may create issues on the CJS distributed version.

Can I safely distribute the package with this setting as well?

Answer 1

Yes, you can. If you can't set "type": "module" in your package.json, you can still either:

• Force the ESLint config file to execute as a module by naming it eslint.config.mjs instead of *.cjs or .js
• Use CommonJS syntax in the ESLint config file. Instead of imports and export default [ ... ], you'd use requires and module.exports = [ ... ]:

  const eslint = require('eslint');
  const tseslint = require('typescript-eslint');
  
  module.exports = [
    eslint.configs.recommended,
    ...tseslint.configs.recommended,
  ];
  

This question came up in the typescript-eslint docs: see https://github.com/typescript-eslint/typescript-eslint/pull/927 and its linked issues. Naming the ESLint config file eslint.config.mjs is what the typescript-eslint docs now do.