Make proposal submission limit configurable per conference

- Add max_proposals field to Conference model (default: None for no limit)
- Update API validation to use conference-specific limit instead of hardcoded 3
- Update existing test to set max_proposals=3
- Add new test to verify unlimited submissions when max_proposals is None

Fixes #4523

Co-authored-by: Marco Acierno <[email protected]>

Author: github-actions[bot]

backend/api/submissions/mutations.py

@@ -412,16 +412,18 @@ def send_submission(
         if not conference.is_cfp_open:
             errors.add_error("non_field_errors", "The call for paper is not open!")
 
-        if (
-            SubmissionModel.objects.of_user(request.user)
-            .for_conference(conference)
-            .non_cancelled()
-            .count()
-            >= 3
-        ):
-            errors.add_error(
-                "non_field_errors", "You can only submit up to 3 proposals"
+        if conference.max_proposals is not None:
+            user_submissions_count = (
+                SubmissionModel.objects.of_user(request.user)
+                .for_conference(conference)
+                .non_cancelled()
+                .count()
             )
+            if user_submissions_count >= conference.max_proposals:
+                errors.add_error(
+                    "non_field_errors",
+                    f"You can only submit up to {conference.max_proposals} proposals",
+                )
 
         if errors.has_errors:
             return errors

backend/api/submissions/tests/test_send_submission.py

@@ -1249,6 +1249,7 @@ def test_cannot_submit_more_than_3_proposals(graphql_client, user):
         active_cfp=True,
         durations=("50",),
         audience_levels=("Beginner",),
+        max_proposals=3,
     )
 
     SubmissionFactory(
@@ -1275,6 +1276,39 @@ def test_cannot_submit_more_than_3_proposals(graphql_client, user):
     ]
 
 
+def test_can_submit_unlimited_proposals_when_max_proposals_is_none(graphql_client, user):
+    graphql_client.force_login(user)
+
+    conference = ConferenceFactory(
+        topics=("my-topic",),
+        languages=("en", "it"),
+        submission_types=("talk",),
+        active_cfp=True,
+        durations=("50",),
+        audience_levels=("Beginner",),
+        max_proposals=None,  # No limit
+    )
+
+    EmailTemplateFactory(
+        conference=conference,
+        identifier=EmailTemplateIdentifier.proposal_received_confirmation,
+    )
+
+    # Create 3 existing submissions
+    for _ in range(3):
+        SubmissionFactory(
+            speaker_id=user.id,
+            conference=conference,
+            status=Submission.STATUS.proposed,
+        )
+
+    # Should be able to submit a 4th proposal
+    resp, _ = _submit_talk(graphql_client, conference, title={"en": "My fourth talk"})
+
+    assert resp["data"]["sendSubmission"]["__typename"] == "Submission"
+    assert resp["data"]["sendSubmission"]["title"]["en"] == "My fourth talk"
+
+
 def test_submit_talk_with_do_not_record_true(graphql_client, user):
     graphql_client.force_login(user)
 

backend/conferences/migrations/0056_conference_max_proposals.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.1.4 on 2026-01-07 01:11
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('conferences', '0055_remove_conference_grants_default_accommodation_amount_and_more'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='conference',
+            name='max_proposals',
+            field=models.PositiveIntegerField(blank=True, help_text='Maximum number of proposals a user can submit. Leave empty for no limit.', null=True, verbose_name='max proposals per user'),
+        ),
+    ]

backend/conferences/models/conference.py

@@ -117,6 +117,13 @@ class Conference(GeoLocalizedModel, TimeFramedModel, TimeStampedModel):
         max_length=32224,
     )
 
+    max_proposals = models.PositiveIntegerField(
+        _("max proposals per user"),
+        null=True,
+        blank=True,
+        help_text=_("Maximum number of proposals a user can submit. Leave empty for no limit."),
+    )
+
     def get_slack_oauth_token(self):
         return self.organizer.slack_oauth_bot_token