Dart2js errors out when it encounters `const Map<Type, AnyThing>`

[tejainece]

When Dart2Js encounters const Map<Type, AnyThing>, it throws the following error:

[Error from Dart2JS on web/panel/main.dart]: packages/....dart:14:21: Const-map key type 'TypeImpl' overrides 'operator =='. @ProvideSerializers(const <Type, Type>{ Establishment: EstablishmentSerializer, Speciality: SpecialitySerializer })

Analyzer doesn't have a problem with it. DartVM executes the code pretty fine. source_gen and analyzer package seems to handle them pretty well.

[sigmundch]

Thanks for reporting this bug, we have run into this in the past but apparently we haven't resolved it. I agree they should be allowed. I'll close this entry to mark it as a duplicate of #17207.

Meanwhile, there is something you can try to work around this limitation. I believe you can define a const class like:

const TypeWrapper {
  final Type type;
  const TypeWrapper(this.type);
}

and use that in a key of a const-map.

Cheers!