Mapster returning null for Collections instead of empty collection

[hann4n]

I recently migrated to Mapster from Automapper.
We have a huge application and applied mapster and it looks good.
But we are facing an issue that When collections are mapped they are returning as null instead of empty collection when source object property is null.

Is there any workaround or feature so that we can have Empty collection instead of null just like Automapper.

Thanks

[chaowlert]

You can use AddDestinationTransform.

TypeAdapterConfig.GlobalSettings.Default
    .AddDestinationTransform((IReadOnlyList<ChildDto> list) => list ?? new List<ChildDto>());

Problem is you need to list all target types to handle null.

I think Mapster need to support this in future version.

[chaowlert]

Added generic support for AddDestinationTransform.

config.Default.AddDestinationTransform(DestinationTransform.EmptyCollectionIfNull);

[hann4n]

Thank you very much. This is great

[hann4n]

@chaowlert This is working great when Collections are a property of a class however when we map Collections directly its still returning null

var lst3 = mapster.Map<List<CA2>>(lst); returns null

Here I have tried using both config.Default.AddDestinationTransform((List<CA2> list) => list ?? new List<CA2>()); and config.Default.AddDestinationTransform(DestinationTransform.EmptyCollectionIfNull);