Bug: Node 22 - "Could not find exported `rules` object in ESLint plugin." error

[marcalexiei]

I have updated Node to v22.x and I started to get Could not find exported rules object in ESLint plugin. error.

Note

I'm able to reproduce the issue only using Node 22.13.0.
On Node 20.17.0 the issue is not present.

This PR contains a successful run and a failed run to show the issue
You can check node version inside "Install dependencies" step

• ❌ - Error with Node 22
• ✅ - No error with Node 20

Steps to reproduce the issue

1. Download / clone the example repository
2. Use Node 20
3. Run pnpm install
4. Run pnpm run lint:docs, no error should be present
5. Switch to Node 22 (I use nvm)
6. Run pnpm run lint:docs, the error should be present

---

Initial investigation

From my initial investigation the problem seems originated from loadPlugin function:

eslint-doc-generator/lib/package-json.ts

Line 35 in a88f8cb

export async function loadPlugin(path: string): Promise<Plugin> {

Inside the require() try for CommonJS

eslint-doc-generator/lib/package-json.ts

Lines 37 to 41 in a88f8cb

	try {
	// Try require first which should work for CJS plugins.
	return require(pluginRoot) as Plugin; // eslint-disable-line import/no-dynamic-require
	} catch (error) {
	// Otherwise, for ESM plugins, we'll have to try to resolve the exact plugin entry point and import it.

On Node 20 the require throws an error and the code inside the catch is executed.

On the contrary, on Node 22 the require doesn't throw an error, and the plugin module is resolved.
However the module itself is an ESModule, so instead of the plugin object the loadPlugin function
returns a { __esModule: true, default: { /** plugin */ } }

I attached a screenshot of the debugger in this scenario

[marcalexiei]

I removed the main field from package.json and the issue is no longer present in Node 22,
and, same as previously, no issue is present on Node 20.

Maybe this change is related to Support require()ing synchronous ESM graphs of Node 22...
but this should be enabled only when using the experimental flag which isn't the case here