Cache custom field and value model

The models don't change in a running app.

Author: Joel-Luca

app/tests/__init__.py

@@ -4,6 +4,8 @@
 from django.test import TransactionTestCase
 from rest_framework.test import APIClient
 
+from django_features.custom_fields.helpers import clear_custom_field_model_cache
+
 
 User = get_user_model()
 
@@ -18,6 +20,10 @@ def setUp(self) -> None:
         self.login("kathi.barfuss")
         self.session = self.client.session
 
+    def tearDown(self) -> None:
+        super().tearDown()
+        clear_custom_field_model_cache()
+
     def get_or_create_user(self, username: str) -> tuple[Any, bool]:
         user, created = User.objects.get_or_create(username=username)
         if created:

django_features/custom_fields/helpers.py

@@ -1,15 +1,26 @@
-__all__ = ["get_custom_field_model", "get_custom_value_model"]
+__all__ = [
+    "get_custom_field_model",
+    "get_custom_value_model",
+    "clear_custom_field_model_cache",
+]
 
 
+from functools import lru_cache
+
 from django.apps import apps as django_apps
 from django.conf import settings
+from django.contrib.auth import get_user_model
 from django.core.exceptions import ImproperlyConfigured
 
 from django_features.custom_fields.models.field import AbstractBaseCustomField
 from django_features.custom_fields.models.value import AbstractBaseCustomValue
 
 
-def get_custom_field_model() -> AbstractBaseCustomField:
+@lru_cache(maxsize=1)
+def get_custom_field_model() -> type[AbstractBaseCustomField]:
+
+    get_user_model()
+
     """
     Return the CustomField model that is active in this project.
     """
@@ -31,7 +42,8 @@ def get_custom_field_model() -> AbstractBaseCustomField:
         )
 
 
-def get_custom_value_model() -> AbstractBaseCustomValue:
+@lru_cache(maxsize=1)
+def get_custom_value_model() -> type[AbstractBaseCustomValue]:
     """
     Return the CustomValue model that is active in this project.
     """
@@ -53,3 +65,11 @@ def get_custom_value_model() -> AbstractBaseCustomValue:
             "CUSTOM_FIELD_VALUE_MODEL refers to model '%s' that has not been installed"
             % settings.CUSTOM_FIELD_VALUE_MODEL
         )
+
+
+def clear_custom_field_model_cache() -> None:
+    """
+    Clear cached model lookups for custom fields.
+    """
+    get_custom_field_model.cache_clear()
+    get_custom_value_model.cache_clear()