FLUTTER WEB - Error: FormatException: Unexpected extension byte (at offset 0)

[NikGrmek]

Hey Everyone! I've been struggling with this error for past few days, and I can't seem to find any useful answers online, so any help would be much appreciated!

I'm working with Flutter Web, and I am using universal_io package due to dart:io not being supported on the web. With help of an Image package I am converting selected image from Jpg to Png and am trying to convert recieved Unit8List of an converted image to an File variable. However converting Unit8List to File doesn't seem to work.

I KEEP GETTING THIS ERROR:
Error: FormatException: Unexpected extension byte (at offset 0)

Full Error:

WHAT I'M DOING:
I am trying to convert an Unit8List to an File Variable with this line: File convertedFile = File.fromRawPath(png); with png being an Unit8List.

FULL CODE:

convertFiles() async {   
    //1. Requesting file from the internet [✓ works]   
    http.Response response = await http.get(
        Uri.parse(folderFiles[openFileIndex.value]["link"]),   
    );    

    //2. Decoding WEBP image with "Image" package [✓ works]   
    var image = img.decodeWebP(response.bodyBytes);    

    //3. Encoding decoded WEBP file as an PNG [✓ works]   
    Uint8List png = img.encodePng(image!) as Uint8List;    

    //4. Trying to convert file bytes(Unit8List) to a File Variable [✗ error]   
    File convertedFile = File.fromRawPath(png); 
}

VSCode screenshot:

WHAT I TRIED:
I've tried everything I've seen on the internet including moving to Master channel and Upgrading Flutter, but none of those things solved the problem.

FLUTTER DOCTOR:

Doctor summary (to see all details, run flutter doctor -v): 

[✓] Flutter (Channel master, 3.5.0-4.0.pre.23, on macOS 12.6 21G115 darwin-arm64, locale en-SI) 
[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.0) 
[✓] Xcode - develop for iOS and macOS (Xcode 14.0.1) 
[✓] Chrome - develop for the web 
[✓] Android Studio (version 2021.3) 
[✓] VS Code (version 1.71.2) 
[✓] Connected device (2 available) 
[✓] HTTP Host Availability  

• No issues found!

[exaby73]

Hello @NikGrmek. Thank you for filing this issue. Can you please provide the following information?

• A complete and minimal, reproducible example. Please exclude any 3rd party libraries in the sample code.
• The output of flutter doctor -v
• The output of flutter run-v

Please provide the information in the form of text. See how to make collapsible sections with Markdown here.

[github-actions]

Without additional information, we are unfortunately not sure how to resolve this issue. We are therefore reluctantly going to close this bug for now.
If you find this problem please file a new issue with the same description, what happens, logs and the output of 'flutter doctor -v'. All system setups can be slightly different so it's always better to open new issues and reference the related ones.
Thanks for your contribution.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.