Enhance fileupload UI for multipart/form-data

[imjuni]

Prerequisites

• [X] I have written a descriptive issue title
• [X] I have searched existing issues to ensure the feature has not already been requested

🚀 Feature Proposal

As a first, Great thank you for good tools. I suggest to enhance swagger ui for fileupload. Recently OpenAPI 3.0 support filpupload widget below,

from: https://swagger.io/docs/specification/describing-request-body/file-upload/

But I cannot found documentation that display fileupload widget on @fastify/multipart and @fastify/swagger.

So I test 4 way of usage.

• case01 display fileupload widget but cannot pass validation
• case02 display plaing object ui
  • from: @fastify/multipart
• case03 display string ui
• case04 working

Expectation

I think that display fileupload widget and validate using by sharedSchemaId in @fastify/multipart. Or I want to know best practice for file upload and swagger.

Environment

Package	Version
@fastify/multipart	^7.1.2
@fastify/swagger	^7.5.1
fastify	^4.5.3
fastify-plugin	^4.2.1
ajv	^8.11.0
ajv-formats	^2.1.1
node	16.17.0
npm	8.15.0
os	win32, macOSX

Motivation

Better develop experience provide to co-worker or consumer.

Example

I upload sample project my repo.

1. Checkout feature/fileupload
2. Install package: npm install
3. Run development server: npm run dev
4. open url on browser: http://localhost:17878

Finally you can see like that:

[mcollina]

Thanks for reporting! Would you like to send a Pull Request to address this issue? Remember to add unit tests.