resolve_generics.dart

DartType resolveGenerics(DartType type) {
  if (type is TypeParameterType) {
    return type.resolveToBound(dynamicType); // T --> dynamic.
  } else if (type is ParameterizedType) {
    // [T, ...] --> [dynamic, ...]
    final resolvedTypeArguments =
        type.typeArguments.map(resolveTypeParameters).toList();
    // Fails on nested unbounded type arguments.
    //  * List<T>.instantiate([dynamic])           --> List<dynamic>
    //  * List<Foo<T>>.instantiate([Foo<dynamic>]) --> List<Foo<T>>
    return type.instantiate(typeArguments);
  }
  return type; // Nothing to resolve.
}