test(gameplay): align guess error contract assertions

lobby/tests.py

@@ -599,7 +599,8 @@ class GuessSubmissionTests(TestCase):
         )
 
         self.assertEqual(response.status_code, 400)
-        self.assertEqual(response.json()["error"], "Selected answer is not part of this round")
+        self.assertEqual(response.json()["error_code"], "selected_answer_invalid")
+        self.assertEqual(response.json()["error"], "Selected answer is not part of this round.")
 
     def test_submit_guess_rejects_duplicate_submission(self):
         Guess.objects.create(round_question=self.round_question, player=self.player, selected_text="Mars", is_correct=True)
@@ -614,7 +615,8 @@ class GuessSubmissionTests(TestCase):
         )
 
         self.assertEqual(response.status_code, 409)
-        self.assertEqual(response.json()["error"], "Guess already submitted for this player")
+        self.assertEqual(response.json()["error_code"], "guess_already_submitted")
+        self.assertEqual(response.json()["error"], "Guess has already been submitted for this player.")
 
     def test_submit_guess_rejects_after_deadline(self):
         self.round_question.shown_at = timezone.now() - timedelta(seconds=76)
@@ -630,7 +632,8 @@ class GuessSubmissionTests(TestCase):
         )
 
         self.assertEqual(response.status_code, 400)
-        self.assertEqual(response.json()["error"], "Guess submission window has closed")
+        self.assertEqual(response.json()["error_code"], "guess_submission_window_closed")
+        self.assertEqual(response.json()["error"], "Guess submission window has closed.")
 
 
 
@@ -658,7 +661,8 @@ class GuessSubmissionTests(TestCase):
         )
 
         self.assertEqual(response.status_code, 403)
-        self.assertEqual(response.json()["error"], "Invalid player session token")
+        self.assertEqual(response.json()["error_code"], "invalid_player_session_token")
+        self.assertEqual(response.json()["error"], "Player session token is invalid.")
 
 
 class ScoreCalculationTests(TestCase):