Repository: vercel/next.js
Pull request: Include types in published `eslint-plugin-next`

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[@next/eslint-plugin-next](https://github.com/vercel/next.js/tree/canary/packages/eslint-plugin-next)
### What?
1. Set types export to `dist/index.d.ts` in `package.json`.
2. Added `types` script to generate type declarations similar to that in the [next-env](https://github.com/vercel/next.js/blob/canary/packages/next-env/package.json) package. Types script run after swc build.

### Why?
When using ESLint v9 flat config with `eslint-plugin-next` you get eslint errors when checking config file itself.
```ts
    plugins: {
      "@next/next": nextPlugin,
    },
    rules: {
      ...nextPlugin.configs.recommended.rules,
      ...nextPlugin.configs["core-web-vitals"].rules,
    },
```
examples: [my boilerplate](https://github.com/OreQr/next-clean-boilerplate/blob/main/eslint.config.mjs), [create-t3-turbo](https://github.com/t3-oss/create-t3-turbo/blob/main/tooling/eslint/nextjs.js)

Closes https://github.com/vercel/next.js/discussions/74957

Changed files:
filename: packages/eslint-plugin-next/package.json
patch: @@ -3,6 +3,7 @@
   "version": "15.3.1-canary.8",
   "description": "ESLint plugin for Next.js.",
   "main": "dist/index.js",
+  "types": "dist/index.d.ts",
   "license": "MIT",
   "repository": {
     "url": "vercel/next.js",
@@ -18,7 +19,8 @@
     "eslint": "8.56.0"
   },
   "scripts": {
-    "build": "swc -d dist src",
+    "build": "swc -d dist src && pnpm types",
+    "types": "tsc src/index.ts --skipLibCheck --declaration --emitDeclarationOnly --declarationDir dist",
     "prepublishOnly": "cd ../../ && turbo run build"
   }
 }

filename: packages/eslint-plugin-next/src/index.ts
patch: @@ -66,8 +66,7 @@ const plugin = {
   },
 }
 
-module.exports = plugin
-module.exports.flatConfig = {
+const flatConfig = {
   recommended: {
     name: 'next/recommended',
     plugins: {
@@ -86,3 +85,7 @@ module.exports.flatConfig = {
     },
   },
 }
+
+export default plugin
+export const { rules, configs } = plugin
+export { flatConfig }