Following does not work as expected

[mnbuch]

Class BEntity { ID, Name } Class B { ID, Name }

cfg.CreateMap<BEntity, B>().ReverseMap()
                   .EqualityComparison((be, b) => be.ID == b.ID);
var source= new List<B>()
 {
     new B() { ID = 1, Name = "B Entity 1"},
     new B() { ID = 2, Name = "B Entity 2"}
};

var dest = new List<BEntity>()
{
      new BEntity() { ID = 2, Name = "B Entity 2.1"},
      new BEntity() { ID = 3, Name = "B Entity 3"}
};

var list = mapper.Map(source, dest);

As far I understood list should have following 3 items:

{ID =1 , Name = B Entity 1} {ID =2 , Name = B Entity 2.1} {ID =3 , Name = B Entity3}

But this always has following {ID =2 , Name = B Entity 2} {ID =1 , Name = B Entity 1}

Is my understanding incorrect?

[Tasteful]

No, the target list will only contain the items that you have in the source item. If the item already exists in the target list (as id 2) then the same object will be reused.

[mnbuch]

The following is taken from the README.MD, which is not in sync with what you are saying.

If ID's match will map OrderDTO to Order
If OrderDTO exists and Order doesn't add to collection
If Order exists and OrderDTO doesn't remove from collection

[Tasteful]

It's the readme that not is correct, it think the text was meant as

• If ID's match: map OrderDTO to Order
• If OrderDTO exists and Order doesn't: add to collection
• If Order exists and OrderDTO doesn't: remove from collection

Ping @TylerCarlson1