File upload only displays the string "string($binary)" instead of upload button

[w-biggs]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

After following the official documentation, instead of a file upload button showing in Swagger, just the string "string($binary)" is printed.

Minimum reproduction code

https://github.com/w-biggs/repro-nest-swagger-file-upload-bug

Steps to reproduce

1. npm install
2. npm run start:dev
3. Navigate to http://localhost:3001/api

Expected behavior

There is a file upload button.

Package version

7.3.1

NestJS version

9.4.3

Node.js version

21.5.0

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

No response