Vue SFC generates duplicate files with numeric suffixes during library build

[lhz960904]

Describe the bug

When building a Vue library with npm run build, a single button.vue component generates two files with the same base name, resulting in button.js and button2.js. The button2.js file contains only a simple re-export that imports from button.js, expect only generate button.js

Reproduction

https://stackblitz.com/edit/vitejs-vite-g1wlnnnn?file=dist%2Fes%2Fbutton%2Fbutton2.js

Steps to reproduce

1. Run pnpm run build
2. Check the output in dist/es/button/ directory
3. Observe that both button.js and button2.js are generated

System Info

System:
    OS: macOS 14.1
    CPU: (10) arm64 Apple M2 Pro
    Memory: 85.28 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.17.1 - ~/.nvm/versions/node/v22.17.1/bin/node
    Yarn: 1.22.22 - ~/.nvm/versions/node/v20.10.0/bin/yarn
    npm: 10.9.2 - ~/.nvm/versions/node/v22.17.1/bin/npm
    pnpm: 10.13.1 - ~/.nvm/versions/node/v20.10.0/bin/pnpm
    bun: 1.1.8 - ~/.bun/bin/bun
  Browsers:
    Chrome: 138.0.7204.158
    Safari: 17.1
  npmPackages:
    @vitejs/plugin-vue: ^6.0.0 => 6.0.0 
    @vitejs/plugin-vue-jsx: ^5.0.1 => 5.0.1 
    vite: ^7.0.4 => 7.0.4

Used Package Manager

npm

Logs

No response

Validations

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• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
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• The provided reproduction is a minimal reproducible example of the bug.

[github-actions]

Hello @lhz960904. Please provide a minimal reproduction using a GitHub repository or StackBlitz. Issues marked with need reproduction will be closed if they have no activity within 3 days.