need fromJson with Type

[phamconganh]

e.g. I have a nullable list ['text', null] and write a safe conversion

@JsonKey(fromJson: safeList<String>)
List<String> property;

List<T> safeList<T extends Object>(dynamic value, {List<T> defaultValue = const []}) =>
    safeNullableList<T>(value) ?? defaultValue;

List<T>? safeNullableList<T extends Object>(dynamic value) {
  if (value is List<T>) return value;
  if (value is List<Object?>) return value.whereType<T>().toList();
  return null;
}