Fix supernav update on save (#2941)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: JacobCoffee

apps/downloads/models.py

@@ -5,7 +5,7 @@
 from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.db import models
-from django.db.models.signals import post_save
+from django.db.models.signals import post_delete, post_save
 from django.dispatch import receiver
 from django.template.loader import render_to_string
 from django.urls import reverse
@@ -332,6 +332,31 @@ def update_download_supernav_and_boxes(sender, instance, **kwargs):
         update_homepage_download_box()
 
 
+def _update_boxes_for_release_file(instance):
+    """Update supernav and download boxes if the file's release is published."""
+    if instance.release_id and instance.release.is_published:
+        update_supernav()
+        update_download_landing_sources_box()
+        update_homepage_download_box()
+        purge_url("/box/supernav-python-downloads/")
+        purge_url("/box/homepage-downloads/")
+        purge_url("/box/download-sources/")
+
+
+@receiver(post_save, sender="downloads.ReleaseFile")
+def update_boxes_on_release_file_save(sender, instance, **kwargs):
+    """Refresh supernav when a release file is added or changed."""
+    if kwargs.get("raw", False):
+        return
+    _update_boxes_for_release_file(instance)
+
+
+@receiver(post_delete, sender="downloads.ReleaseFile")
+def update_boxes_on_release_file_delete(sender, instance, **kwargs):
+    """Refresh supernav when a release file is deleted."""
+    _update_boxes_for_release_file(instance)
+
+
 class ReleaseFile(ContentManageable, NameSlugModel):
     """Individual files in a release.
 

apps/downloads/tests/test_models.py

@@ -1,4 +1,5 @@
 import datetime as dt
+from unittest.mock import patch
 
 from apps.downloads.models import Release, ReleaseFile
 from apps.downloads.tests.base import BaseDownloadTests
@@ -232,3 +233,59 @@ def test_update_supernav_skips_os_without_files(self):
 
         # Android (no files) should not be present
         self.assertNotIn("android", content.lower())
+
+    @patch("apps.downloads.models.update_supernav")
+    @patch("apps.downloads.models.update_download_landing_sources_box")
+    @patch("apps.downloads.models.update_homepage_download_box")
+    def test_release_file_save_triggers_box_updates(self, mock_home, mock_sources, mock_supernav):
+        """Saving a ReleaseFile on a published release should update boxes."""
+        mock_supernav.reset_mock()
+        mock_sources.reset_mock()
+        mock_home.reset_mock()
+
+        ReleaseFile.objects.create(
+            os=self.windows,
+            release=self.python_3,
+            name="Windows installer",
+            url="/ftp/python/3.10.19/python-3.10.19.exe",
+            download_button=True,
+        )
+
+        mock_supernav.assert_called()
+        mock_sources.assert_called()
+        mock_home.assert_called()
+
+    @patch("apps.downloads.models.update_supernav")
+    @patch("apps.downloads.models.update_download_landing_sources_box")
+    @patch("apps.downloads.models.update_homepage_download_box")
+    def test_release_file_save_skips_unpublished_release(self, mock_home, mock_sources, mock_supernav):
+        """Saving a ReleaseFile on a draft release should not update boxes."""
+        mock_supernav.reset_mock()
+        mock_sources.reset_mock()
+        mock_home.reset_mock()
+
+        ReleaseFile.objects.create(
+            os=self.windows,
+            release=self.draft_release,
+            name="Windows installer draft",
+            url="/ftp/python/9.7.2/python-9.7.2.exe",
+        )
+
+        mock_supernav.assert_not_called()
+        mock_sources.assert_not_called()
+        mock_home.assert_not_called()
+
+    @patch("apps.downloads.models.update_supernav")
+    @patch("apps.downloads.models.update_download_landing_sources_box")
+    @patch("apps.downloads.models.update_homepage_download_box")
+    def test_release_file_delete_triggers_box_updates(self, mock_home, mock_sources, mock_supernav):
+        """Deleting a ReleaseFile on a published release should update boxes."""
+        mock_supernav.reset_mock()
+        mock_sources.reset_mock()
+        mock_home.reset_mock()
+
+        self.release_275_windows_32bit.delete()
+
+        mock_supernav.assert_called()
+        mock_sources.assert_called()
+        mock_home.assert_called()