Fix handling of non-object troubleshooting data

kitsune/questions/forms.py

@@ -186,6 +186,24 @@ def clean_content(self):
             raise forms.ValidationError(_("Question content cannot be empty."))
         return content
 
+    def clean_troubleshooting(self):
+        troubleshooting = self.cleaned_data.get("troubleshooting", "")
+        if not troubleshooting:
+            return troubleshooting
+
+        try:
+            parsed = json.loads(troubleshooting)
+        except ValueError:
+            parsed = None
+
+        if not isinstance(parsed, dict):
+            # L10n: An error shown when troubleshooting information isn't a JSON object.
+            raise forms.ValidationError(
+                _("Troubleshooting information must be a valid JSON object.")
+            )
+
+        return troubleshooting
+
     @property
     def metadata_field_keys(self):
         """Returns the keys of the metadata fields for the current
@@ -214,7 +232,7 @@ def cleaned_metadata(self):
             except ValueError:
                 parsed = None
 
-            if parsed:
+            if isinstance(parsed, dict):
                 # Clean out unwanted garbage preferences.
                 if "modifiedPreferences" in parsed and isinstance(
                     parsed["modifiedPreferences"], dict

kitsune/questions/tests/test_forms.py

@@ -123,6 +123,29 @@ def test_cleaned_metadata(self):
         actual = form.cleaned_metadata
         self.assertDictEqual(actual, expected)
 
+    def test_invalid_troubleshooting_json(self):
+        """Troubleshooting information must be a valid JSON object."""
+        topic = TopicFactory(slug="cookies", products=[self.product], in_aaq=True)
+        base_data = {
+            "title": "Test question",
+            "content": "Test question content",
+            "email": "t@t.com",
+            "category": topic.id,
+        }
+
+        for troubleshooting in ("[1,2,3]", "123", "true", '"hello"', "not json"):
+            with self.subTest(troubleshooting=troubleshooting):
+                form = NewQuestionForm(
+                    product=self.product,
+                    data={**base_data, "troubleshooting": troubleshooting},
+                )
+
+                self.assertFalse(form.is_valid())
+                self.assertEqual(
+                    "Troubleshooting information must be a valid JSON object.",
+                    form.errors["troubleshooting"][0],
+                )
+
     def test_clean_content_with_html_entities(self):
         """Test that content with only HTML entities is rejected."""
         topic = TopicFactory(slug="cookies", products=[self.product], in_aaq=True)