Support passing through object scalars

lib/absinthe/phase/document/arguments/parse.ex

@@ -50,6 +50,10 @@ defmodule Absinthe.Phase.Document.Arguments.Parse do
     end
   end
 
+  defp build_value(%Input.Object{} = normalized, %Type.Scalar{} = _schema_node, _context) do
+    {:ok, normalized}
+  end
+
   defp build_value(_normalized, %Type.Scalar{}, _context) do
     {:error, :bad_parse}
   end

lib/absinthe/phase/schema.ex

@@ -162,6 +162,23 @@ defmodule Absinthe.Phase.Schema do
     node
   end
 
+  defp set_schema_node(
+         %Blueprint.Input.Field{} = node,
+         %Blueprint.Input.Object{schema_node: %{of_type: %Absinthe.Type.Scalar{}}} = _parent,
+         _schema,
+         _adapter
+       ) do
+    %{
+      node
+      | schema_node: %Absinthe.Type.Field{
+          definition: Absinthe.Fixtures.ArgumentsSchema,
+          identifier: String.to_atom(node.name),
+          name: node.name,
+          type: %Absinthe.Type.NonNull{of_type: :string}
+        }
+    }
+  end
+
   defp set_schema_node(%Blueprint.Input.Field{} = node, parent, schema, adapter) do
     case node.name do
       "__" <> _ ->

test/absinthe/execution/arguments_test.exs

@@ -24,6 +24,15 @@ defmodule Absinthe.Execution.ArgumentsTest do
     )
   end
 
+  @graphql """
+  query {
+    entities(representations: [{__typename: "Product", upc: "123"}])
+  }
+  """
+  test "does not give error for object scalars" do
+    assert {:ok, %{data: %{"entities" => ["ok"]}}} = run(@graphql, @schema)
+  end
+
   describe "errors" do
     @graphql """
     query FindUser {

test/support/fixtures/arguments_schema.ex

@@ -7,6 +7,11 @@ defmodule Absinthe.Fixtures.ArgumentsSchema do
     false: "NO"
   }
 
+  scalar :any do
+    parse fn value -> {:ok, value} end
+    serialize fn value -> value end
+  end
+
   scalar :input_name do
     parse fn %{value: value} -> {:ok, %{first_name: value}} end
     serialize fn %{first_name: name} -> name end
@@ -62,6 +67,14 @@ defmodule Absinthe.Fixtures.ArgumentsSchema do
   end
 
   query do
+    field :entities, list_of(:string) do
+      arg :representations, non_null(list_of(non_null(:any)))
+
+      resolve fn %{representations: [%{__typename: "Product", upc: "123"}]}, _ ->
+        {:ok, ["ok"]}
+      end
+    end
+
     field :stuff, :integer do
       arg :stuff, non_null(:input_stuff)