Feat/prevent forecast resubmission setting

front_end/src/types/projects.ts

@@ -98,6 +98,7 @@ export type Tournament = TournamentPreview & {
   timeline: TournamentTimeline;
   forecasts_flow_enabled: boolean;
   index_data?: IndexData | null;
+  allow_forecast_resubmission: boolean;
 };
 
 export type ProjectIndexWeights = {

front_end/src/utils/questions/predictions.ts

@@ -18,6 +18,7 @@ type CanPredictParams = Pick<
   | "question"
   | "group_of_questions"
   | "conditional"
+  | "projects"
 >;
 
 export function canPredictQuestion({
@@ -26,6 +27,7 @@ export function canPredictQuestion({
   question,
   group_of_questions,
   conditional,
+  projects,
 }: CanPredictParams) {
   // post level checks
   if (
@@ -34,6 +36,11 @@ export function canPredictQuestion({
   ) {
     return false;
   }
+  if (!projects.default_project.allow_forecast_resubmission) {
+    if (!!question?.my_forecasts?.latest) {
+      return false;
+    }
+  }
 
   // question-specific checks
   if (question) {

projects/migrations/0022_project_allow_forecast_resubmission.py

@@ -0,0 +1,21 @@
+# Generated by Django 5.1.11 on 2025-09-17 20:37
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("projects", "0021_projectindex_project_index_projectindexpost"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="project",
+            name="allow_forecast_resubmission",
+            field=models.BooleanField(
+                default=True,
+                help_text="Turning this off prevents users from submitting multiple forecasts on any question where this is it's default_project. Forecasts submitted on those questions will always have infinite duration, ignoring auto-withdrawal.",
+            ),
+        ),
+    ]

projects/models.py

@@ -280,6 +280,14 @@ class BotLeaderboardStatus(models.TextChoices):
     sign_up_fields = models.JSONField(
         default=list, blank=True, help_text="Used during tournament onboarding."
     )
+    allow_forecast_resubmission = models.BooleanField(
+        default=True,
+        help_text=(
+            "Turning this off prevents users from submitting multiple forecasts on any "
+            "question where this is it's default_project. Forecasts submitted on those "
+            "questions will always have infinite duration, ignoring auto-withdrawal."
+        ),
+    )
 
     # SEO
     html_metadata_json = models.JSONField(

projects/serializers/common.py

@@ -38,6 +38,7 @@ class Meta:
             "show_on_homepage",
             "show_on_services_page",
             "forecasts_flow_enabled",
+            "allow_forecast_resubmission",
         )
         read_only_fields = (
             "created_at",
@@ -96,6 +97,7 @@ class Meta:
             "visibility",
             "is_current_content_translated",
             "bot_leaderboard_status",
+            "allow_forecast_resubmission",
         )
 
     def get_score_type(self, project: Project) -> str | None:

questions/views.py

@@ -113,14 +113,25 @@ def bulk_create_forecasts_api_view(request):
         if not question:
             raise ValidationError(f"Wrong question id {forecast["question"]}")
 
-        forecast["question"] = question  # used in create_foreacst_bulk
+        forecast["question"] = question  # used in create_forecast_bulk
 
         # Check permissions
-        permission = get_post_permission_for_user(
-            question.get_post(), user=request.user
-        )
+        post = question.get_post()
+        permission = get_post_permission_for_user(post, user=request.user)
         ObjectPermission.can_forecast(permission, raise_exception=True)
 
+        if not post.default_project.allow_forecast_resubmission:
+            if question.user_forecasts.filter(author=request.user).exists():
+                return Response(
+                    {
+                        "error": f"Question {question.id}'s Project does not allow "
+                        "resubmission of forecasts !"
+                    },
+                    status=status.HTTP_405_METHOD_NOT_ALLOWED,
+                )
+            # If resubmission is not allowed, forecast duration is set to infinite
+            forecast["end_time"] = None
+
         if not question.open_time or question.open_time > now:
             return Response(
                 {"error": f"Question {question.id} is not open for forecasting yet !"},
@@ -162,6 +173,16 @@ def bulk_withdraw_forecasts_api_view(request):
     # Replacing prefetched optimized questions
     for withdrawal in validated_data:
         question = questions_map.get(withdrawal["question"])
+
+        if not question.get_post().default_project.allow_forecast_resubmission:
+            return Response(
+                {
+                    "error": f"Question {question.id}'s Project does not allow "
+                    "withdrawal of forecasts !"
+                },
+                status=status.HTTP_405_METHOD_NOT_ALLOWED,
+            )
+
         withdrawal["question"] = question  # used in withdraw_foreacst_bulk
         withdraw_at = withdrawal.get("withdraw_at", now)
         withdrawal["withdraw_at"] = withdraw_at  # used in withdraw_foreacst_bulk

tests/unit/test_questions/test_views.py

@@ -261,6 +261,76 @@ def test_forecast_numeric_boundary_test(
         )
         assert response.status_code == status_code
 
+    @pytest.mark.parametrize(
+        "allow_foreacst_resubmission, status_code",
+        [
+            (True, 201),
+            (False, 405),
+        ],
+    )
+    def test_allow_forecast_resubmission(
+        self,
+        post_binary_public: Post,
+        user1,
+        user1_client,
+        allow_foreacst_resubmission,
+        status_code,
+    ):
+        # explicitly set field
+        project = post_binary_public.default_project
+        project.allow_forecast_resubmission = allow_foreacst_resubmission
+        project.save()
+
+        # predict once
+        response = user1_client.post(
+            self.url,
+            data=json.dumps(
+                [{"question": post_binary_public.question.id, "probability_yes": 0.5}]
+            ),
+            content_type="application/json",
+        )
+        assert response.status_code == 201
+        # predict again
+        response = user1_client.post(
+            self.url,
+            data=json.dumps(
+                [{"question": post_binary_public.question.id, "probability_yes": 0.5}]
+            ),
+            content_type="application/json",
+        )
+        assert response.status_code == status_code
+
+    def test_allow_forecast_resubmission_enforces_infinite_forecast(
+        self,
+        post_binary_public: Post,
+        user1,
+        user1_client,
+    ):
+        # explicitly set field
+        project = post_binary_public.default_project
+        project.allow_forecast_resubmission = False
+        project.save()
+
+        question = post_binary_public.question
+        response = user1_client.post(
+            self.url,
+            data=json.dumps(
+                [
+                    {
+                        "question": question.id,
+                        "probability_yes": 0.5,
+                        "end_time": question.scheduled_close_time.strftime(
+                            "%Y-%m-%dT%H:%M:%S"
+                        ),
+                    }
+                ]
+            ),
+            content_type="application/json",
+        )
+        assert response.status_code == 201
+        user_forecast = Forecast.objects.filter(question=question, author=user1).first()
+        assert user_forecast.end_time is None
+
 
 class TestQuestionWithdraw:
     url = reverse("create-withdraw")
@@ -285,6 +355,35 @@ def test_cant_withdraw_forecast_if_no_forecast(
         )
         assert response.status_code == 400
 
+    @pytest.mark.parametrize(
+        "allow_foreacst_resubmission, status_code",
+        [
+            (True, 201),
+            (False, 405),
+        ],
+    )
+    def test_allow_forecast_resubmission(
+        self,
+        question_binary_with_forecast_user_1: Question,
+        user1,
+        user1_client,
+        allow_foreacst_resubmission,
+        status_code,
+    ):
+        # explicitly set field
+        post = question_binary_with_forecast_user_1.get_post()
+        project = post.default_project
+        project.allow_forecast_resubmission = allow_foreacst_resubmission
+        project.save()
+
+        # withdraw
+        response = user1_client.post(
+            self.url,
+            data=json.dumps([{"question": question_binary_with_forecast_user_1.id}]),
+            content_type="application/json",
+        )
+        assert response.status_code == status_code
+
 
 class TestQuestionResolve: