Type 'System.Byte[]' does not have a default constructor (Parameter 'type').

[satheeshgurujan26]

Type 'System.Byte[]' does not have a default constructor (Parameter 'type').

Migrating existing API from EF6 to EF Core.
DetachedMapper.MapAsync function is returning the above issue when Entity Object is passed with RowVersion: byte [].
Could you advise on this?

public class BaseEntity
{
//Audit Fields
public int Id { get; set; }
public int CreatedBy { get; set; }
public DateTime CreatedDate { get; set; }
public int? ModifiedBy { get; set; }
public DateTime? ModifiedDate { get; set; }
public byte[] RowVersion { get; set; }
}

Stack Trace:
at System.Linq.Expressions.Expression.New(Type type)
at Detached.Mappers.TypeMappers.POCO.Collection.CollectionTypeMapperFactory.Create(TypePair typePair, ITypeOptions sourceType, ITypeOptions targetType)
at Detached.Mappers.MapperOptions.<>c__DisplayClass31_0.b__0(TypePair t)
at System.Collections.Concurrent.ConcurrentDictionary2.GetOrAdd(TKey key, Func2 valueFactory)
at Detached.Mappers.MapperOptions.GetTypeMapper(TypePair typePair)
at Detached.Mappers.TypeMappers.LazyTypeMapper2.get_Value() at Detached.Mappers.TypeMappers.Entity.Complex.ComposedEntityTypeMapper3.Create(TSource source, IMapContext context, TKey sourceKey, EntityRef entityRef)
at Detached.Mappers.TypeMappers.Entity.Complex.ComposedEntityTypeMapper3.Map(TSource source, TTarget target, IMapContext context) at Detached.Mappers.TypeMappers.Entity.Collection.EntityCollectionTypeMapper5.Map(TSource source, TTarget target, IMapContext context)
at Detached.Mappers.TypeMappers.Entity.Complex.ComposedEntityTypeMapper3.Create(TSource source, IMapContext context, TKey sourceKey, EntityRef entityRef) at Detached.Mappers.TypeMappers.Entity.Complex.ComposedEntityTypeMapper3.Map(TSource source, TTarget target, IMapContext context)
at Detached.Mappers.TypeMappers.Entity.Collection.EntityCollectionTypeMapper5.Map(TSource source, TTarget target, IMapContext context) at Detached.Mappers.TypeMappers.Entity.Complex.RootEntityTypeMapper3.Map(TSource source, TTarget target, IMapContext context)
at Detached.Mappers.TypeMappers.TypeMapper2.Map(Object source, Object target, IMapContext context) at Detached.Mappers.EntityFramework.MappingDbContextExtensions.Map[TEntity](DbContext dbContext, Object entityOrDTO, MapParameters parameters) at System.Threading.Tasks.Task1.InnerInvoke()
at System.Threading.Tasks.Task.<>c.<.cctor>b__272_0(Object obj)
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()

[leonardoporro]

Hi @satheeshgurujan26
As a workaround, please add byte[] to the primitives list. It is not supposed to be mapped like an object, I'll investigate this.

.UseMapping(cfg =>
{
    cfg.Primitives.Add(typeof(byte[]));
}

here is more info about this
thanks for the feedback!

[leonardoporro]

Fixed in 7.0.1