improvement: old json -> json_string

improvement: new json does not stringify outpu

lib/resource/resource.ex

@@ -2297,7 +2297,7 @@ defmodule AshGraphql.Resource do
         else
           case type(type) do
             nil ->
-              :json
+              Application.get_env(:ash_graphql, :json_type) || :json_string
 
             type ->
               type
@@ -2348,7 +2348,10 @@ defmodule AshGraphql.Resource do
   defp do_field_type(Ash.Type.Date, _, _), do: :date
   defp do_field_type(Ash.Type.Decimal, _, _), do: :decimal
   defp do_field_type(Ash.Type.Integer, _, _), do: :integer
-  defp do_field_type(Ash.Type.Map, _, _), do: :json
+
+  defp do_field_type(Ash.Type.Map, _, _),
+    do: Application.get_env(:ash_graphql, :json_type) || :json_string
+
   defp do_field_type(Ash.Type.String, _, _), do: :string
   defp do_field_type(Ash.Type.Term, _, _), do: :string
   defp do_field_type(Ash.Type.UtcDatetime, _, _), do: :naive_datetime

lib/types/json.ex

@@ -32,6 +32,5 @@ defmodule AshGraphql.Types.JSON do
     :error
   end
 
-  def encode(nil), do: nil
-  def encode(value), do: Jason.encode!(value)
+  def encode(value), do: value
 end

lib/types/json_string.ex

@@ -0,0 +1,37 @@
+defmodule AshGraphql.Types.JSONString do
+  @moduledoc """
+  The Json scalar type allows arbitrary JSON values to be passed in and out.
+  """
+  use Absinthe.Schema.Notation
+
+  scalar :json_string, name: "JsonString" do
+    description("""
+    The `Json` scalar type represents arbitrary json string data, represented as UTF-8
+    character sequences. The Json type is most often used to represent a free-form
+    human-readable json string.
+    """)
+
+    serialize(&encode/1)
+    parse(&decode/1)
+  end
+
+  @spec decode(Absinthe.Blueprint.Input.String.t()) :: {:ok, term()} | :error
+  @spec decode(Absinthe.Blueprint.Input.Null.t()) :: {:ok, nil}
+  def decode(%Absinthe.Blueprint.Input.String{value: value}) do
+    case Jason.decode(value) do
+      {:ok, result} -> {:ok, result}
+      _ -> :error
+    end
+  end
+
+  def decode(%Absinthe.Blueprint.Input.Null{}) do
+    {:ok, nil}
+  end
+
+  def decode(_) do
+    :error
+  end
+
+  def encode(nil), do: nil
+  def encode(value), do: Jason.encode!(value)
+end