test: added regression test for aggregate with action with modify query

test/aggregate_test.exs

@@ -1667,4 +1667,15 @@
     Ash.Query.filter_input(AshPostgres.Test.StandupClub, filter)
     |> Ash.read!(load: [:punchline_count])
   end
+
+  @tag :regression
+  test "aggregates with modify_query works" do
+    assert_raise Ash.Error.Unknown, ~r/^modifying query!$/, fn ->
+      Post
+      |> Ash.Query.load([
+        :count_comments_with_modify_query
+      ])
+      |> Ash.read_one!()
+    end
+  end
 end

test/support/resources/comment.ex

@@ -33,6 +33,10 @@ defmodule AshPostgres.Test.Comment do
 
       change(manage_relationship(:rating, :ratings, on_missing: :ignore, on_match: :create))
     end
+
+    read :with_modify_query do
+      modify_query({AshPostgres.Test.Comment.ModifyQuery, :modify, []})
+    end
   end
 
   attributes do
@@ -104,3 +108,14 @@ defmodule AshPostgres.Test.Comment do
     )
   end
 end
+
+defmodule AshPostgres.Test.Comment.ModifyQuery do
+  @moduledoc """
+  Raises when modifying query so we can assert
+  this code path is called.
+  """
+
+  def modify(_ash_query, _ecto_query) do
+    raise "modifying query!"
+  end
+end

test/support/resources/post.ex

@@ -1164,6 +1164,10 @@ defmodule AshPostgres.Test.Post do
     end
 
     first(:author_profile_description, :author, :description)
+
+    count :count_comments_with_modify_query, :comments do
+      read_action(:with_modify_query)
+    end
   end
 end