fix: Avoid reverse in apps.ready() since it is not async safe

Author: fsbraun

djangocms_form_builder/apps.py

@@ -2,7 +2,7 @@
 
 from django.apps import AppConfig
 from django.conf import settings
-from django.urls import NoReverseMatch, clear_url_caches, include, path, reverse
+from django.urls import clear_url_caches, include, path
 from django.utils.translation import gettext_lazy as _
 
 
@@ -13,18 +13,29 @@ class FormsConfig(AppConfig):
 
     def ready(self):
         """Install the URLs"""
-        try:
-            reverse("form_builder:ajaxview", args=(1,))
-        except NoReverseMatch:  # Not installed yet
-            urlconf_module = import_module(settings.ROOT_URLCONF)
-            urlconf_module.urlpatterns = [
-                path(
-                    "@form-builder/",
-                    include(
-                        "djangocms_form_builder.urls",
-                        namespace="form_builder",
-                    ),
-                )
-            ] + urlconf_module.urlpatterns
-            clear_url_caches()
-            reverse("form_builder:ajaxview", args=(1,))
+        urlconf_module = import_module(settings.ROOT_URLCONF)
+
+        # Idempotency guard
+        for pattern in urlconf_module.urlpatterns:
+            if hasattr(pattern, "urlconf_name"):
+                # Check if this pattern includes the form builder urls
+                urlconf_name = pattern.urlconf_name
+                if urlconf_name == "djangocms_form_builder.urls" or (
+                    hasattr(pattern, "urlconf_module")
+                    and getattr(pattern.urlconf_module, "__name__", None)
+                    == "djangocms_form_builder.urls"
+                ):
+                    return
+
+        urlconf_module.urlpatterns = [
+            path(
+                "@form-builder/",
+                include(
+                    "djangocms_form_builder.urls",
+                    namespace="form_builder",
+                ),
+            ),
+            *urlconf_module.urlpatterns,
+        ]
+
+        clear_url_caches()

tests/test_apps.py

@@ -0,0 +1,90 @@
+from unittest.mock import MagicMock, patch
+
+from django.test import TestCase
+
+
+class AppsIdempotencyGuardTests(TestCase):
+    """Test that the FormsConfig.ready() method properly handles idempotency."""
+
+    @patch("djangocms_form_builder.apps.clear_url_caches")
+    @patch("djangocms_form_builder.apps.settings")
+    @patch("djangocms_form_builder.apps.import_module")
+    def test_urls_not_registered_twice_with_same_module(
+        self, mock_import, mock_settings, mock_clear_cache
+    ):
+        """Test that URLs are not registered twice when the same module is already included."""
+        # Create a mock urlconf module
+        mock_urlconf = MagicMock()
+
+        # Create a mock pattern that already has the form builder urls
+        mock_pattern = MagicMock()
+        mock_pattern.urlconf_name = "djangocms_form_builder.urls"
+        mock_pattern.urlconf_module = None  # Ensure this doesn't match the second check
+
+        mock_urlconf.urlpatterns = [mock_pattern]
+        mock_import.return_value = mock_urlconf
+        mock_settings.ROOT_URLCONF = "test_urlconf"
+
+        from djangocms_form_builder.apps import FormsConfig
+
+        config = FormsConfig.__new__(FormsConfig)
+        config.ready()
+
+        # Verify that urlpatterns was not modified
+        self.assertEqual(len(mock_urlconf.urlpatterns), 1)
+
+    @patch("djangocms_form_builder.apps.clear_url_caches")
+    @patch("djangocms_form_builder.apps.settings")
+    @patch("djangocms_form_builder.apps.import_module")
+    def test_urls_not_registered_twice_with_module_attribute(
+        self, mock_import, mock_settings, mock_clear_cache
+    ):
+        """Test that URLs are not registered twice when urlconf_module is already set."""
+        # Create a mock urlconf module
+        mock_urlconf = MagicMock()
+
+        # Create a mock pattern with urlconf_module attribute
+        mock_pattern = MagicMock()
+        mock_pattern.urlconf_name = "some.other.path"
+        mock_pattern.urlconf_module = MagicMock()
+        mock_pattern.urlconf_module.__name__ = "djangocms_form_builder.urls"
+
+        mock_urlconf.urlpatterns = [mock_pattern]
+        original_patterns = mock_urlconf.urlpatterns.copy()
+        mock_import.return_value = mock_urlconf
+        mock_settings.ROOT_URLCONF = "test_urlconf"
+
+        from djangocms_form_builder.apps import FormsConfig
+
+        config = FormsConfig.__new__(FormsConfig)
+        config.ready()
+
+        # Verify that urlpatterns was not modified
+        self.assertEqual(len(mock_urlconf.urlpatterns), 1)
+        self.assertEqual(mock_urlconf.urlpatterns, original_patterns)
+
+    @patch("djangocms_form_builder.apps.clear_url_caches")
+    @patch("djangocms_form_builder.apps.settings")
+    @patch("djangocms_form_builder.apps.import_module")
+    def test_urls_registered_when_not_already_present(
+        self, mock_import, mock_settings, mock_clear_cache
+    ):
+        """Test that URLs are registered when not already present."""
+        # Create a mock urlconf module
+        mock_urlconf = MagicMock()
+
+        # Create a mock pattern that doesn't have form builder urls
+        mock_pattern = MagicMock()
+        mock_pattern.urlconf_name = "some.other.urls"
+
+        mock_urlconf.urlpatterns = [mock_pattern]
+        mock_import.return_value = mock_urlconf
+        mock_settings.ROOT_URLCONF = "test_urlconf"
+
+        from djangocms_form_builder.apps import FormsConfig
+
+        config = FormsConfig.__new__(FormsConfig)
+        config.ready()
+
+        # Verify that urlpatterns was modified (new pattern prepended)
+        self.assertEqual(len(mock_urlconf.urlpatterns), 2)