`Re-exporting all exports from a page is disallowed` occurs on non-page file when using `pageExtensions`

What version of Next.js are you using?

12.0.7

What version of Node.js are you using?

14.176

What browser are you using?

Chrome

What operating system are you using?

macOS

How are you deploying your application?

Vercel

Describe the Bug

Re-exporting all exports from a page is disallowed

Have been rewritten with Rust but it seems to not care of pageExtensions option in next.config.js.

Expected Behavior

Re-exporting all exports from a page is disallowed Error shouldn’t occur on non-page files under /pages when using pageExtensions option.

To Reproduce

Create a fresh Next project with the pageExtensions set to ['page.tsx', 'page.ts'].

The pages folder looks like:

pages/
  users/
   index.page.tsx // import { UserComments } from './components';
   components/
      index.tsx // <= re-export all: export * from './UserComments';
      UserComments.tsx // contain a named export: export cont UserComments = () => <h1>User comments</h1>
     
package.json

[smitpatel1010]

Hi, I was just checking the code to solve this issue for next-page-disallow-re-export-all-exports plugin. and I found one issue here https://github.com/vercel/next.js/blob/canary/packages/next/build/babel/loader/get-config.ts#L98

actual behaviour : isPageFile is true for components/index.tsx because it is inside pages folder. expected behaviour : isPageFile should be false here for components/index.tsx because of pageExtensions

I was just wondering from where I can get pageExtensions to pass it to getCacheCharacteristics ?

UPDATE: I found it for babel config. I am now exploring code for swc loader

UPDATE: raised PR

[raulfdm]

It’s a pity we didn’t have a response from anyone from the contributors. It was working, them a new feature or something introduced this bug and it’s there forever. I know there’s tons of issues opened, sprints on going but it has been 3 months.

I have to adapt my codebase as workaround for this problem (removing index.ts files even thought they don’t have .page extension).