Missing Header in Dio Web

[YukiAttano]

Package

dio

Version

5.7.0

Operating-System

Web

Adapter

Default Dio

Output of flutter doctor -v

[✓] Flutter (Channel stable, 3.27.0, on macOS 15.0.1 24A348 darwin-arm64, locale de-DE)
    • Flutter version 3.27.0 on channel stable at /Users/user/Library/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 8495dee1fd (5 weeks ago), 2024-12-10 14:23:39 -0800
    • Engine revision 83bacfc525
    • Dart version 3.6.0
    • DevTools version 2.40.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

Dart Version

3.6.0

Steps to Reproduce

Downloading a file on a native device returns all expected header.
Downloading a file in web lacks some header, see differences in 'Expected Result' and 'Actual Result'

Specifically, i am missing the 'content-disposition: attachment; filename=Filename.txt;' Header in web, which is received but not accessible in Dio on web platforms.

Call a link to download a file.

Options options = Options(responseType: ResponseType.stream);

Response<ResponseBody> r = await dio.request("https://file.example.com/Files/some_file", options: options);

print(r.headers);

Expected Result

Actual Result

Logged with Dio Tralker

┌─────────────────────────────────────────────────────────────────
│ [http-response] [GET] https://file.example.com/Files/some_file
│ Status: 200
│ Message: 
│ Headers: {
│   "cache-control": [
│     "no-cache, no-store"
│   ],
│   "content-length": [
│     "235800"
│   ],
│   "content-type": [
│     "application/octet-stream"
│   ],
│   "pragma": [
│     "no-cache"
│   ]
│ }
└─────────────────────────────────────────────────────────────────