First Check

• I added a very descriptive title to this issue.
• I used the GitHub search to find a similar issue and didn't find it.
• I searched the FastAPI documentation, with the integrated search.
• I already searched in Google "How to X in FastAPI" and didn't find any information.
• I already read and followed all the tutorial in the docs and didn't find an answer.
• I already checked if it is not related to FastAPI but to Pydantic.
• I already checked if it is not related to FastAPI but to Swagger UI.
• I already checked if it is not related to FastAPI but to ReDoc.

Commit to Help

• I commit to help with one of those options 👆

Example Code

@router.post('/add',status_code=200)
async def add(values: List[float] = Form(...), file: UploadFile = File(...)):
    ...

Description

Given a post route with a file and array of floats when using the swagger interface '/docs' and posting a file and an array with a SINGLE item everything works. Posting an file and an array with MORE then one value fastAPI returns 422 Unprocessable Entity.

Working CURL request:

curl -X 'POST' \
  'http://localhost:8000/add' \
  -H 'accept: application/json' \
  -H 'Content-Type: multipart/form-data' \
  -F 'file=@image.jpg;type=image/jpeg' \
  -F 'value=1'  // <-------------------

Failing CURL request:

curl -X 'POST' \
  'http://localhost:8000/add' \
  -H 'accept: application/json' \
  -H 'Content-Type: multipart/form-data' \
  -F 'file=@image.jpg;type=image/jpeg' \
  -F 'value=1,2' // <-------------------

Operating System

Linux

Operating System Details

No response

FastAPI Version

0.74.1

Python Version

3.9.10

Additional Context

No response