refactor: apply review comments

test/mv_web/live/group_live/index_test.exs

@@ -114,17 +114,36 @@ defmodule MvWeb.GroupLive.IndexTest do
     end
   end
 
-  @moduletag :slow
   describe "performance" do
+    @describetag :slow
     test "page loads efficiently with many groups", %{conn: conn} do
       # Create multiple groups
       Enum.each(1..10, fn _ -> Fixtures.group_fixture() end)
 
+      # Count queries using Telemetry
+      query_count_agent = Agent.start_link(fn -> 0 end) |> elem(1)
+
+      handler = fn _event, _measurements, _metadata, _config ->
+        Agent.update(query_count_agent, &(&1 + 1))
+      end
+
+      handler_id = "test-query-counter-#{System.unique_integer([:positive])}"
+      :telemetry.attach(handler_id, [:ash, :query, :start], handler, nil)
+
       # Should load without N+1 queries
       {:ok, _view, html} = live(conn, "/groups")
 
+      final_count = Agent.get(query_count_agent, & &1)
+      :telemetry.detach(handler_id)
+
       # Verify all groups are displayed
       assert html =~ gettext("Groups")
+
+      # Verify query count is reasonable (should avoid N+1 queries)
+      # Expected: 1 query for groups list + possible count queries
+      # Allow some overhead for LiveView setup queries
+      assert final_count <= 5,
+             "Expected max 5 queries (groups list + possible counts + LiveView setup), got #{final_count}. This suggests N+1 query problem."
     end
 
     test "member count is loaded efficiently via calculation", %{conn: conn} do
@@ -143,10 +162,29 @@ defmodule MvWeb.GroupLive.IndexTest do
         actor: system_actor
       )
 
+      # Count queries using Telemetry
+      query_count_agent = Agent.start_link(fn -> 0 end) |> elem(1)
+
+      handler = fn _event, _measurements, _metadata, _config ->
+        Agent.update(query_count_agent, &(&1 + 1))
+      end
+
+      handler_id = "test-query-counter-#{System.unique_integer([:positive])}"
+      :telemetry.attach(handler_id, [:ash, :query, :start], handler, nil)
+
       {:ok, _view, html} = live(conn, "/groups")
 
+      final_count = Agent.get(query_count_agent, & &1)
+      :telemetry.detach(handler_id)
+
       # Member count should be displayed (should be 2)
       assert html =~ "2" or html =~ gettext("Members") or html =~ "Mitglieder"
+
+      # Verify query count is reasonable (member count should be calculated efficiently)
+      # Expected: 1 query for groups + 1 query for member counts (aggregated)
+      # Allow some overhead for LiveView setup queries
+      assert final_count <= 5,
+             "Expected max 5 queries (groups + member counts + LiveView setup), got #{final_count}. This suggests inefficient member count calculation."
     end
   end
 end