Rework the alerts panel to be compatible with serialization.

The alerts panel may eventually have other types of alerts that
don't depend on the response. Such as Django's check system.

Author: tim-schilling

debug_toolbar/panels/alerts.py

@@ -139,11 +139,9 @@ def check_invalid_file_form_configuration(self, html_content):
         return self.alerts
 
     def generate_stats(self, request, response):
-        if not is_processable_html_response(response):
-            return
-
-        html_content = response.content.decode(response.charset)
-        self.check_invalid_file_form_configuration(html_content)
+        if is_processable_html_response(response):
+            html_content = response.content.decode(response.charset)
+            self.check_invalid_file_form_configuration(html_content)
 
         # Further alert checks can go here
 

tests/panels/test_alerts.py

@@ -109,4 +109,4 @@ def _render():
         response = StreamingHttpResponse(_render())
 
         self.panel.generate_stats(self.request, response)
-        self.assertEqual(self.panel.get_stats(), {})
+        self.assertEqual(self.panel.get_stats(), {"alerts": []})