[bug] TS: error 400 (cant support image/pdf) when test using pdf in an array

[averrows]

Product

BAML

Describe the bug

Model (gemini) return 400 when the param of test is an array of file

Unspecified error code: 400 Request failed with status code: 400 Bad Request,
{
"error": {
"code": 400,
"message": "Unsupported MIME type: image/pdf",
"status": "INVALID_ARGUMENT"
}
}

Reproduction Steps

Make a test like this

test ExtractContractStructureTest {
functions [ExtractContractStructure]
args {
contract_files [
{
file "../files/test.pdf"
}
]
}
}

on which contract files have type: (pdf | image)[]

And then it will return

Unspecified error code: 400 Request failed with status code: 400 Bad Request,
{
"error": {
"code": 400,
"message": "Unsupported MIME type: image/pdf",
"status": "INVALID_ARGUMENT"
}
}

BAML Version

0.214.0

Language/Framework

Node.js

LLM Provider

Google

LLM Model

gemini-2.5-flash-lite

Operating System

macOS

Browser

Safari

Code Editor

VS Code

[linear]

BAML-544