Can't build React/Next project - found page without a React Component as default export (context api file)

Question

I'm trying to build my Next.js project but it keeps giving me this error in the terminal:

Error: Build optimization failed: found page without a React Component as default export in 
pages/components/context/Context

That's the React context API file, there isn't supposed to be any default export there. Is this a bug or what?

Answer 1

You should move your components outside the pages folder. pages/ should only be used for page components as Next.js routing is based on its structure.

Next.js has a file-system based router built on the concept of pages.

When a file is added to the pages directory it's automatically available as a route.

By default, Next.js assumes anything under the pages folder is a page component and will try to build each file as a page.

---

Even though the above is the default behaviour, you can configure your Next.js app to include non-page files in the pages directory.

To do so, you can modify the pageExtensions entry in the next.config.js file as shown below. Then rename your page components to have a file extension that includes .page (_document.page.js, _app.page.js, index.page.js, etc).

module.exports = {
    pageExtensions: ['page.tsx', 'page.ts', 'page.jsx', 'page.js']
}

With this configuration, Next.js will ignore any file that doesn't contain .page for the purpose of building pages/API routes and routing.

Answer 2

In my case, I had an empty file index.js in a folder. Using Nextjs Default Router