feat: validate token family settings on app startup in TokenFamilyConfig

Author: juanbailon

rest_framework_simplejwt/token_family/apps.py

@@ -1,8 +1,60 @@
 from django.apps import AppConfig
 from django.utils.translation import gettext_lazy as _
+from django.core.exceptions import ImproperlyConfigured
+from django.utils.module_loading import import_string
+from datetime import timedelta
+from rest_framework_simplejwt.settings import api_settings
 
 
 class TokenFamilyConfig(AppConfig):
     name = "rest_framework_simplejwt.token_family"
     verbose_name = _("Token Family")
-    default_auto_field = "django.db.models.BigAutoField"
+    default_auto_field = "django.db.models.BigAutoField"
+
+    def ready(self):
+        """Validate token family settings at startup."""
+        try:
+            self._validate_family_settings()
+        except (ImproperlyConfigured, ImportError) as e:
+            raise ImproperlyConfigured(f"Invalid Token Family settings: {e}") from e
+
+    @staticmethod
+    def _validate_family_settings() -> None:
+        """
+        Ensures that required token family settings are properly configured.
+        This way we prevent undesired behavior.
+        """
+        family_claim = api_settings.TOKEN_FAMILY_CLAIM
+        if not isinstance(family_claim, str) or not family_claim.strip():
+            raise ImproperlyConfigured("TOKEN_FAMILY_CLAIM must be a non-empty string")
+
+        family_exp_claim = api_settings.TOKEN_FAMILY_EXPIRATION_CLAIM
+        if not isinstance(family_exp_claim, str) or not family_exp_claim.strip():
+            raise ImproperlyConfigured("TOKEN_FAMILY_EXPIRATION_CLAIM must be a non-empty string")
+
+        family_lifetime = api_settings.TOKEN_FAMILY_LIFETIME
+        if family_lifetime is not None and not isinstance(family_lifetime, timedelta):
+            raise ImproperlyConfigured("TOKEN_FAMILY_LIFETIME must be of type timedelta or None")
+
+        family_enabled = api_settings.TOKEN_FAMILY_ENABLED
+        if not isinstance(family_enabled, bool):
+            raise ImproperlyConfigured("TOKEN_FAMILY_ENABLED must be of type bool")
+
+        check_on_access = api_settings.TOKEN_FAMILY_CHECK_ON_ACCESS
+        if not isinstance(check_on_access, bool):
+            raise ImproperlyConfigured("TOKEN_FAMILY_CHECK_ON_ACCESS must be of type bool")
+
+        blacklist_on_reuse = api_settings.TOKEN_FAMILY_BLACKLIST_ON_REUSE
+        if not isinstance(blacklist_on_reuse, bool):
+            raise ImproperlyConfigured("TOKEN_FAMILY_BLACKLIST_ON_REUSE must be of type bool")
+        
+
+        # Validate TOKEN_FAMILY_BLACKLIST_SERIALIZER
+        blacklist_serializer_path = api_settings.TOKEN_FAMILY_BLACKLIST_SERIALIZER
+        if not isinstance(blacklist_serializer_path, str) or not blacklist_serializer_path.strip():
+            raise ImproperlyConfigured("TOKEN_FAMILY_BLACKLIST_SERIALIZER must be a non-empty string")
+
+        try:
+            import_string(blacklist_serializer_path)
+        except ImportError as e:
+            raise ImportError(f"Could not import serializer '{blacklist_serializer_path}': {e}") from e