dart2js: creating a Uint8List throws: full width integer not supported on this platform

[konsultaner]

For some reason it is impossible for me to work with Uint8List in dart2js converted libs.

I tried this:

js.allowInterop((js.JsArray listOfInt) {
    var convertedList = Uint8List.fromList([for (var i = 0; i < listOfInt.length; i++) listOfInt[i] as int]);
    // throws: Uncaught full width integer not supported on this platform
    // if I don't cast or use int.parse(). I obviously get a type error
});

when [omitting type checks][4] and doing something like this:

js.allowInterop((js.JsArray listOfInt) {
    var convertedList = Uint8List.fromList(listOfInt);
    // throws: Uncaught full width integer not supported on this platform
});

js.allowInterop((js.JsArray listOfInt) {
    print(base64Encode(listOfInt)); // this works
    var convertedList = base64Decode(base64Encode(listOfInt));
    // throws: Uncaught full width integer not supported on this platform
});

This tracker is for issues related to:

• dart2js

Platform

• Dart SDK version: 2.14.4 (stable) (Wed Oct 13 11:11:32 2021 +0200) on "windows_x64"
• Windows
• Chrome

Issue at stack overflow

https://stackoverflow.com/questions/71481645/dartjs-convert-jsarray-from-allowinterop-to-uint8list

[sigmundch]

Thanks @konsultaner for your question an for posting it also in stack overflow.

One thing that caught my eye here is your samples use dart:js, which even though is not deprecated, is one of our less supported JSInterop APIs and likely to be deprecated in the near future. Both dart:js_util for low level interactions, and package:js for more declarative APIs, have better support and are more efficient than dart:js.

Meanwhile, could you share also how is this interop function invoked on the other end? Do you export it as a property? What is provided from the JavaScript side when this is called?

[konsultaner]

since dart:js is pretty much outdated, I will close this one.