Add fallback for blank string representations in audit log, and add tests for creating/editing invalid draft snippets

wagtail/models/audit_log.py

@@ -97,7 +97,7 @@ class BaseLogEntryManager(models.Manager):
         return LogEntryQuerySet(self.model, using=self._db)
 
     def get_instance_title(self, instance):
-        return str(instance)
+        return str(instance) or f"{instance.__class__.__name__} object ({instance.pk})"
 
     def log_action(self, instance, action, **kwargs):
         """

wagtail/snippets/tests/test_snippets.py

@@ -1325,6 +1325,45 @@ class TestCreateDraftStateSnippet(WagtailTestUtils, TestCase):
         # The revision content should contain the data
         self.assertEqual(snippet.latest_revision.content["text"], "Draft-enabled Foo")
 
+        # A log entry should be created
+        log_entry = ModelLogEntry.objects.for_instance(snippet).get(
+            action="wagtail.create"
+        )
+        self.assertEqual(log_entry.revision, snippet.latest_revision)
+        self.assertEqual(log_entry.label, "Draft-enabled Foo")
+
+    def test_create_skips_validation_when_saving_draft(self):
+        response = self.post(post_data={"text": ""})
+        snippet = DraftStateModel.objects.get(text="")
+
+        self.assertRedirects(
+            response,
+            reverse(
+                "wagtailsnippets_tests_draftstatemodel:edit", args=[quote(snippet.pk)]
+            ),
+        )
+
+        self.assertFalse(snippet.live)
+
+        # A log entry should be created (with a fallback label)
+        log_entry = ModelLogEntry.objects.for_instance(snippet).get(
+            action="wagtail.create"
+        )
+        self.assertEqual(log_entry.revision, snippet.latest_revision)
+        self.assertEqual(log_entry.label, f"DraftStateModel object ({snippet.pk})")
+
+    def test_create_will_not_publish_invalid_snippet(self):
+        response = self.post(
+            post_data={"text": "", "action-publish": "Publish"},
+        )
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(
+            response, "The draft state model could not be created due to errors."
+        )
+
+        snippets = DraftStateModel.objects.filter(text="")
+        self.assertEqual(snippets.count(), 0)
+
     def test_publish(self):
         # Connect a mock signal handler to published signal
         mock_handler = mock.MagicMock()
@@ -2238,6 +2277,84 @@ class TestEditDraftStateSnippet(BaseTestSnippetEditView):
         # The revision content should contain the new data
         self.assertEqual(latest_revision.content["text"], "Draft-enabled Bar")
 
+        # A log entry should be created
+        log_entry = (
+            ModelLogEntry.objects.for_instance(self.test_snippet)
+            .filter(action="wagtail.edit")
+            .order_by("-timestamp")
+            .first()
+        )
+        self.assertEqual(log_entry.revision, self.test_snippet.latest_revision)
+        self.assertEqual(log_entry.label, "Draft-enabled Bar")
+
+    def test_skip_validation_on_save_draft(self):
+        response = self.post(post_data={"text": ""})
+        self.test_snippet.refresh_from_db()
+        revisions = Revision.objects.for_instance(self.test_snippet)
+        latest_revision = self.test_snippet.latest_revision
+
+        self.assertRedirects(response, self.get_edit_url())
+
+        # The instance should be updated, since it is still a draft
+        self.assertEqual(self.test_snippet.text, "")
+
+        # The instance should be a draft
+        self.assertFalse(self.test_snippet.live)
+        self.assertTrue(self.test_snippet.has_unpublished_changes)
+        self.assertIsNone(self.test_snippet.first_published_at)
+        self.assertIsNone(self.test_snippet.last_published_at)
+        self.assertIsNone(self.test_snippet.live_revision)
+
+        # The revision should be created and set as latest_revision
+        self.assertEqual(revisions.count(), 1)
+        self.assertEqual(latest_revision, revisions.first())
+
+        # The revision content should contain the new data
+        self.assertEqual(latest_revision.content["text"], "")
+
+        # A log entry should be created (with a fallback label)
+        log_entry = (
+            ModelLogEntry.objects.for_instance(self.test_snippet)
+            .filter(action="wagtail.edit")
+            .order_by("-timestamp")
+            .first()
+        )
+        self.assertEqual(log_entry.revision, self.test_snippet.latest_revision)
+        self.assertEqual(
+            log_entry.label,
+            f"DraftStateCustomPrimaryKeyModel object ({self.test_snippet.pk})",
+        )
+
+    def test_cannot_publish_invalid(self):
+        # Connect a mock signal handler to published signal
+        mock_handler = mock.MagicMock()
+        published.connect(mock_handler)
+
+        try:
+            response = self.post(
+                post_data={
+                    "text": "",
+                    "action-publish": "action-publish",
+                }
+            )
+
+            self.test_snippet.refresh_from_db()
+
+            self.assertEqual(response.status_code, 200)
+            self.assertContains(
+                response,
+                "The draft state custom primary key model could not be saved due to errors.",
+            )
+
+            # The instance should be unchanged
+            self.assertEqual(self.test_snippet.text, "Draft-enabled Foo")
+            self.assertFalse(self.test_snippet.live)
+
+            # The published signal should not have been fired
+            self.assertEqual(mock_handler.call_count, 0)
+        finally:
+            published.disconnect(mock_handler)
+
     def test_publish(self):
         # Connect a mock signal handler to published signal
         mock_handler = mock.MagicMock()