fix: close expired test attempts at the attempt limit

classes/service.go

@@ -286,6 +286,9 @@ func (s *Service) Start(ctx context.Context, userID uint, slug, category string)
 
 func (s *Service) startTest(ctx context.Context, userID uint, quiz *models.Quiz) (*Started, error) {
 	var st *Started
+	// limited refuses the start after the commit, so the expired attempts
+	// closed on the way stay closed (an error would roll the closes back).
+	var limited bool
 	err := lagoon.Transaction(ctx, s.DB, func(ctx context.Context, tx *gorm.DB) error {
 		tx = tx.WithContext(ctx)
 		if err := tx.Exec(`SELECT pg_advisory_xact_lock(hashtext(?))`, AttemptLockKey(quiz.ID, userID)).Error; err != nil {
@@ -327,7 +330,8 @@ func (s *Service) startTest(ctx context.Context, userID uint, quiz *models.Quiz)
 			return nil
 		}
 		if left := AttemptsLeft(quiz, int(used)); left != nil && *left == 0 {
-			return ErrAttemptLimit
+			limited = true
+			return nil
 		}
 		attempt := &models.Attempt{QuizID: quiz.ID, UserID: userID, StartedAt: now.UTC()}
 		maxPoints, err := s.maxPoints(ctx, tx, attempt)
@@ -344,6 +348,9 @@ func (s *Service) startTest(ctx context.Context, userID uint, quiz *models.Quiz)
 	if err != nil {
 		return nil, err
 	}
+	if limited {
+		return nil, ErrAttemptLimit
+	}
 	return st, nil
 }