BuitlValue: Ignore cast error

As we know, when the backend returns a mismatched type of JSON, it throws DeserializationError as default.

For example:

abstract class User implements Built<User, UserBuilder> {
  User._();
  factory User([void Function(UserBuilder) updates]) = _$User;

  bool? get activated;
  static Serializer<User> get serializer => _$userSerializer;
  static User? fromJson(String jsonString) {
    return serializers.deserializeWith(
      serializer, json.decode(jsonString));
  }
}

When User.fromJson(jsonString) with the following jsonString:

{
  "activated": 0
}

it throws DeserializationError:

Deserializing '0' to 'bool' failed due to: type 'int' is not a subtype of type 'bool' in type cast

Ideally, we want to make it null if it’s nullable type as well instead of throwing a case exception.

Let modify the serializers.dart :

extension SerializersBuilderX on SerializersBuilder {
  void mergeEntireSerializers(Serializers serializers) {
    addPlugins(serializers.serializerPlugins);
    merge(serializers);
    addBuilderFactories(serializers.builderFactories);
  }

  void addBuilderFactories(BuiltMap<FullType, Function> builderFactories) {
    for (final entry in builderFactories.entries) {
      addBuilderFactory(entry.key, entry.value);
    }
  }
  void addPlugins(Iterable<SerializerPlugin> plugins) {
    for (final plugin in plugins) {
      addPlugin(plugin);
    }
  }
}
/// - final Serializers serializers =
/// - (_$serializers.toBuilder()
/// -   ..addPlugin(StandardJsonPlugin()))
/// -     .build();
final Serializers serializers = (SimpleBuiltJsonSerializersBuilder()
  ..mergeEntireSerializers(_$serializers.toBuilder().build())
  ..addPlugin(StandardJsonPlugin())
).build();

And add simple_built_json_serializers.dart

That’s it, it will keep it null instead of throwing a cast exception.