git clone https://github.com/remcohaszing/next-issue-broad-patterns.git
cd next-issue-broad-patterns
npm install

---

node script.ts

---

$ npx next build
▲ Next.js 16.2.2 (Turbopack)

  Creating an optimized production build ...
Turbopack build encountered 1 warnings:
./app/page.tsx:14:39
The file pattern ('posts/' <dynamic> '/' <dynamic> '/' <dynamic> '/' <dynamic> | 'posts' <dynamic> '/' <dynamic> '/' <dynamic> '/' <dynamic> | 'posts/' <dynamic> '/' <dynamic> '/' <dynamic> | 'posts' <dynamic> '/' <dynamic> '/' <dynamic> | 'posts/' <dynamic> '/' <dynamic> '/' <dynamic> | 'posts' <dynamic> '/' <dynamic> '/' <dynamic> | 'posts/' <dynamic> '/' <dynamic> | 'posts' <dynamic> '/' <dynamic> | 'posts/' <dynamic> '/' <dynamic> '/' <dynamic> | 'posts' <dynamic> '/' <dynamic> '/' <dynamic> | 'posts/' <dynamic> '/' <dynamic> | 'posts' <dynamic> '/' <dynamic> | 'posts/' <dynamic> '/' <dynamic> | 'posts' <dynamic> '/' <dynamic> | 'posts/' <dynamic> | 'posts' <dynamic>) matches 16000 files in [project]/
  12 |         for(const d of await readdir(cDir)) {
  13 |           // results.push(await readFile(`posts/${a}/${b}/${c}/${d}`, 'utf8'))
> 14 |           results.push(await readFile(join('posts', a, b, c, d), 'utf8'))
     |                                       ^^^^^^^^^^^^^^^^^^^^^^^^^
  15 |         }
  16 |       }
  17 |     }

Overly broad patterns can lead to build performance issues and over bundling.


✓ Compiled successfully in 3.2s
✓ Finished TypeScript in 1576ms
✓ Collecting page data using 4 workers in 335ms
✓ Generating static pages using 4 workers (3/3) in 471ms
✓ Finalizing page optimization in 9ms

Route (app)
┌ ○ /
└ ○ /_not-found


○  (Static)  prerendered as static content

---

Operating System:
  Platform: linux
  Arch: x64
  Version: #202601231045~1769703228~24.04~cb87b5b SMP PREEMPT_DYNAMIC Thu J
  Available memory (MB): 31804
  Available CPU cores: 12
Binaries:
  Node: 24.14.1
  npm: 11.11.0
  Yarn: 1.22.22
  pnpm: 9.14.4
Relevant Packages:
  next: 16.2.2 // Latest available version is detected (16.2.2).
  eslint-config-next: N/A
  react: 19.2.4
  react-dom: 19.2.4
  typescript: 6.0.2
Next.js Config:
  output: N/A