fix: add missing description field to fake attrs for generic actions returning union types (#419)

Author: jtsmills

lib/ash_graphql.ex

@@ -518,6 +518,7 @@ defmodule AshGraphql do
               type: action.returns,
               constraints: action.constraints,
               name: action.name,
+              description: nil,
               from_generic_action?: true
             }
           end)

test/generic_actions_test.exs

@@ -200,6 +200,24 @@ defmodule AshGraphql.GenericActionsTest do
     end
   end
 
+  test "generic action returning an array of union NewType generates valid schema" do
+    resp =
+      """
+      query {
+        searchUnions {
+          ... on GenericActionUnionStringResult {
+            value
+          }
+        }
+      }
+      """
+      |> Absinthe.run(AshGraphql.Test.Schema)
+
+    assert {:ok, result} = resp
+    refute Map.has_key?(result, :errors)
+    assert %{data: %{"searchUnions" => []}} = result
+  end
+
   describe "generic action with require_actor? domain" do
     test "succeeds when actor is provided via GraphQL context" do
       resp =

test/support/resources/resource_with_union.ex

@@ -53,6 +53,30 @@ defmodule AshGraphql.Test.ResourceWithUnion do
     def graphql_input_type(_), do: :uniontype_input
   end
 
+  defmodule GenericActionUnion do
+    @moduledoc false
+
+    use Ash.Type.NewType,
+      subtype_of: :union,
+      constraints: [
+        types: [
+          string_result: [
+            type: :string,
+            tag: :type,
+            tag_value: "string_result"
+          ],
+          integer_result: [
+            type: :integer,
+            tag: :type,
+            tag_value: "integer_result"
+          ]
+        ]
+      ]
+
+    def graphql_type(_), do: :generic_action_union
+    def graphql_input_type(_), do: :generic_action_union_input
+  end
+
   use Ash.Resource,
     domain: AshGraphql.Test.Domain,
     data_layer: Ash.DataLayer.Ets,
@@ -62,6 +86,7 @@ defmodule AshGraphql.Test.ResourceWithUnion do
     type(:resource_with_union)
 
     queries do
+      action(:search_unions, :search_unions)
     end
 
     mutations do
@@ -72,6 +97,12 @@ defmodule AshGraphql.Test.ResourceWithUnion do
   actions do
     default_accept(:*)
 
+    action :search_unions, {:array, GenericActionUnion} do
+      run(fn _input, _ctx ->
+        {:ok, []}
+      end)
+    end
+
     action :action_with_union_arg, :boolean do
       argument(:union_arg, Union, allow_nil?: false)