Apply interface name resolution to other code paths

lib/absinthe/federation/schema/entity_union.ex

@@ -67,14 +67,24 @@ end
 defimpl Absinthe.Federation.Schema.EntityUnion.Resolver, for: Any do
   alias Absinthe.Adapter.LanguageConventions
 
-  def resolve_type(%struct_name{}, resolution) do
-    struct_name
-    |> Module.split()
-    |> List.last()
-    |> to_internal_name(resolution.adapter)
+  def resolve_type(%struct_name{} = data, resolution) do
+    typename =
+      struct_name
+      |> Module.split()
+      |> List.last()
+
+    inner_resolve_type(data, typename, resolution)
   end
 
   def resolve_type(%{__typename: typename} = data, resolution) do
+    inner_resolve_type(data, typename, resolution)
+  end
+
+  def resolve_type(%{"__typename" => typename} = data, resolution) do
+    inner_resolve_type(data, typename, resolution)
+  end
+
+  defp inner_resolve_type(data, typename, resolution) do
     type = Absinthe.Schema.lookup_type(resolution.schema, typename)
 
     if is_nil(type) do
@@ -94,10 +104,6 @@ defimpl Absinthe.Federation.Schema.EntityUnion.Resolver, for: Any do
     end
   end
 
-  def resolve_type(%{"__typename" => typename}, resolution) do
-    to_internal_name(typename, resolution.adapter)
-  end
-
   defp to_internal_name(name, adapter) when is_nil(adapter) do
     name
     |> LanguageConventions.to_internal_name(:type)

test/absinthe/federation/schema/entity_union_test.exs

@@ -218,6 +218,16 @@ defmodule Absinthe.Federation.Schema.EntityUnionTest do
         key_fields("id")
         field :id, non_null(:id)
 
+        field :_resolve_reference, :shape do
+          resolve(fn _, %{id: id} = args, _ ->
+            case id do
+              "123" -> {:ok, args}
+              "321" -> {:ok, args}
+              _ -> {:error, "ID doesn't exist #{id}"}
+            end
+          end)
+        end
+
         resolve_type fn
           data, _ ->
             case data do
@@ -235,13 +245,31 @@ defmodule Absinthe.Federation.Schema.EntityUnionTest do
         field :id, non_null(:id)
 
         interface :shape
+
+        field :_resolve_reference, :circle do
+          resolve(fn _, %{id: id} = args, _ ->
+            case id do
+              "123" -> {:ok, args}
+              _ -> {:error, "ID doesn't exist #{id}"}
+            end
+          end)
+        end
       end
 
       object :rectangle do
         key_fields("id")
         field :id, non_null(:id)
 
         interface :shape
+
+        field :_resolve_reference, :rectangle do
+          resolve(fn _, %{id: id} = args, _ ->
+            case id do
+              "321" -> {:ok, args}
+              _ -> {:error, "ID doesn't exist #{id}"}
+            end
+          end)
+        end
       end
     end
 

test/support/entity_interface/circle.ex

@@ -4,8 +4,4 @@ defmodule Example.EntityInterface.Circle do
         }
 
   defstruct id: ""
-
-  defimpl Absinthe.Federation.Schema.EntityUnion.Resolver do
-    def resolve_type(_, _), do: :circle
-  end
 end

test/support/entity_interface/rectangle.ex

@@ -4,8 +4,4 @@ defmodule Example.EntityInterface.Rectangle do
         }
 
   defstruct id: ""
-
-  defimpl Absinthe.Federation.Schema.EntityUnion.Resolver do
-    def resolve_type(_, _), do: :rectangle
-  end
 end