Fix rival uniqueness check for food_court_frenzy

In the alpha test, competitors found they couldn’t submit
for an answer that a rival had already submitted.

Author: backspace

registrations/lib/registrations/waydowntown.ex

@@ -391,7 +391,7 @@ defmodule Registrations.Waydowntown do
         check_for_duplicate_normalised_submission(current_user_id, run, submission_text)
 
       concept when concept in ["food_court_frenzy", "fill_in_the_blank", "count_the_items"] ->
-        check_for_paired_answer(run, answer_id)
+        check_for_paired_answer(current_user_id, run, answer_id)
 
       concept when concept in ["orientation_memory", "cardinal_memory"] ->
         check_for_ordered_answer(current_user_id, run, answer_id)
@@ -414,7 +414,7 @@ defmodule Registrations.Waydowntown do
     end
   end
 
-  defp check_for_paired_answer(run, answer_id) do
+  defp check_for_paired_answer(current_user_id, run, answer_id) do
     answer_with_submitted_id = Enum.find(run.specification.answers, fn a -> a.id == answer_id end)
 
     cond do
@@ -424,7 +424,7 @@ defmodule Registrations.Waydowntown do
       is_nil(answer_with_submitted_id) ->
         {:error, "Unknown answer: #{answer_id}"}
 
-      Enum.any?(run.submissions, fn s -> s.correct && s.answer_id == answer_id end) ->
+      Enum.any?(run.submissions, fn s -> s.correct && s.answer_id == answer_id && s.creator_id == current_user_id end) ->
         {:error, "Submission already exists for label: #{answer_with_submitted_id.label}"}
 
       true ->

registrations/test/registrations_web/controllers/submission_controller_test.exs

@@ -1187,6 +1187,45 @@ defmodule RegistrationsWeb.SubmissionControllerTest do
 
       assert json_response(conn, 201)
     end
+
+    test "accepts a submission that duplicates that of another participant", %{
+      conn: conn,
+      run: run,
+      burger: burger
+    } do
+      other_user = insert(:user)
+
+      Repo.insert!(%Submission{
+        submission: "5.99",
+        run_id: run.id,
+        answer_id: burger.id,
+        correct: true,
+        creator: other_user
+      })
+
+      conn =
+        conn
+        |> setup_conn()
+        |> post(
+          Routes.submission_path(conn, :create),
+          %{
+            "data" => %{
+              "type" => "submissions",
+              "attributes" => %{"submission" => "5.99"},
+              "relationships" => %{
+                "run" => %{
+                  "data" => %{"type" => "runs", "id" => run.id}
+                },
+                "answer" => %{
+                  "data" => %{"type" => "answers", "id" => burger.id}
+                }
+              }
+            }
+          }
+        )
+
+      assert json_response(conn, 201)
+    end
   end
 
   describe "create submissions for run with multiple participants" do