Fix error on empty balance

lib/teiserver_web/controllers/api/spads_controller.ex

@@ -152,7 +152,7 @@ defmodule TeiserverWeb.API.SpadsController do
             opts
           })
 
-        if balance_result do
+        if is_non_empty_balance_result?(balance_result) do
           # Get some counts for later
           team_count =
             balance_result.team_sizes
@@ -215,6 +215,14 @@ defmodule TeiserverWeb.API.SpadsController do
     end
   end
 
+  def is_non_empty_balance_result?(balance_result) do
+    cond do
+      balance_result == nil -> false
+      balance_result.team_sizes == %{} -> false
+      true -> true
+    end
+  end
+
   @spec get_member_lobby(non_neg_integer()) :: T.lobby() | nil
   defp get_member_lobby(userid) do
     case Account.get_client_by_id(userid) do

test/teiserver_web/controllers/api/spads_controller_test.exs

@@ -6,6 +6,7 @@ defmodule TeiserverWeb.API.SpadsControllerTest do
   alias Teiserver.Coordinator
   alias Teiserver.Account.ClientLib
   alias Teiserver.Client
+  alias TeiserverWeb.API.SpadsController
 
   import Teiserver.TeiserverTestLib,
     only: [
@@ -104,5 +105,25 @@ defmodule TeiserverWeb.API.SpadsControllerTest do
 
       assert data == %{}
     end
+
+    test "can detect empty balance result" do
+      # This is the default balance result when no players
+      # Defined inside balance_lib.ex
+      balance_result = %{
+        logs: [],
+        time_taken: 0,
+        captains: %{},
+        deviation: 0,
+        ratings: %{},
+        team_groups: %{},
+        team_players: %{},
+        team_sizes: %{},
+        means: %{},
+        stdevs: %{},
+        has_parties?: false
+      }
+
+      assert SpadsController.is_non_empty_balance_result?(balance_result) == false
+    end
   end
 end