quiz resetc

internal/service/quiz_service.go

@@ -269,6 +269,16 @@ func (s *QuizService) ParticipantResult(ctx context.Context, quizID, userID stri
 	return s.quizzes.Result(ctx, quizID, userID, true)
 }
 
+// ResetParticipant wipes one participant's attempt; the quiz becomes pending
+// for them. Works on unpublished quizzes too — staff may tidy results up
+// while a quiz is offline.
+func (s *QuizService) ResetParticipant(ctx context.Context, quizID, userID string) error {
+	if _, err := s.quizzes.Get(ctx, quizID, false); err != nil {
+		return err
+	}
+	return s.quizzes.ResetAttempt(ctx, quizID, userID)
+}
+
 // ── Taking ────────────────────────────────────────────────────────────────
 
 // published loads a quiz that users may see.

internal/service/quiz_service_test.go

@@ -278,6 +278,24 @@ func TestQuiz_TakingFlow(t *testing.T) {
 		t.Errorf("responses = %+v, %v", stats, err)
 	}
 
+	// Staff can reset one participant: their attempt and answers go, the quiz
+	// is pending for them again, and they can retake it from the start.
+	if err := svc.ResetParticipant(ctx, quiz.ID, other); !errors.Is(err, repository.ErrQuizNotStarted) {
+		t.Errorf("resetting someone with no attempt: %v, want ErrQuizNotStarted", err)
+	}
+	if err := svc.ResetParticipant(ctx, quiz.ID, user); err != nil {
+		t.Fatal(err)
+	}
+	if card, _ := svc.Card(ctx, user, quiz.ID); card.My.State != model.QuizNotStarted {
+		t.Errorf("state after reset = %s, want not_started", card.My.State)
+	}
+	if parts, _ := svc.Participants(ctx, quiz.ID); len(parts) != 0 {
+		t.Errorf("participants after reset = %d, want 0", len(parts))
+	}
+	if again, err := svc.Start(ctx, user, quiz.ID); err != nil || again.Answered != 0 || again.Question == nil {
+		t.Errorf("retaking after reset: %+v, %v", again, err)
+	}
+
 	// Taken, so questions are frozen — but the title can still change.
 	if _, err := svc.Update(ctx, quiz.ID, QuizDraft{Title: "x", Questions: []repository.QuestionInput{q("p", 0, "a", "b")}}); !errors.Is(err, ErrQuizLocked) {
 		t.Errorf("editing questions after attempts: %v, want ErrQuizLocked", err)