AutoMapper.Collection | AutoMapper support for updating existing collections | Code Editor library

I'm working on a project and I need to map collections. I came across Automapper.Collection and am trying to user the class but its all not working. Please I need help. Here is my code.

In my startup class

Is there any way to get AutoMapper.Collection to skip the mapping of a collection if the source collection property is null?

In my case, the client may want to signal to the API that there is no need to update a given collection. A logical way do this would be to set the collection property to null in the dto sent from the client.

Basically:

• If the source collection property is null: Do not touch the destination collection at all but leave it as-is. Do not clear it
• If the source collection is not null: Do the collection mapping. If the source collection is empty this means clearing the destination collection

Is there any way to achieve this in AutoMapper.Collection? What I am looking for is this:

I keep getting this error when I try to Add Razor Pages with Entity Framework Core (CRUD):

How do I go about resolving something like this?

Here is my .csproj file

I try to use AutoMapper to map models to dtos. The first try uses EF-Core but I was able to eliminate EF-Core and reproduce that without it.

I reproduced the behaviour in this DEMO. (Old DEMO using EF-Core is here.)

TL;DR

It seams that this will not work:

A few days a ago I tried AutMapper with Entity Framework Core, now I want to see how the InsertOrUpdate from AutoMapper.Collection.EntityFrameworkCore (v1.0.1) works. But I can't bring it to up to work, here are my Test-classes / settings:

DataContext (DbContext)