Add ExplicitNullValue support

Author: lgarber-akamai

linode_api4/objects/linode_interfaces.py

@@ -1,7 +1,7 @@
 from dataclasses import dataclass, field
-from typing import List, Optional
+from typing import List, Optional, Union
 
-from linode_api4.objects.base import Base, Property
+from linode_api4.objects.base import Base, ExplicitNullValue, Property
 from linode_api4.objects.dbase import DerivedBase
 from linode_api4.objects.networking import Firewall
 from linode_api4.objects.serializable import JSONObject
@@ -193,13 +193,10 @@ class LinodeInterfaceOptions(JSONObject):
     NOTE: Linode interfaces may not currently be available to all users.
     """
 
-    always_include = {
-        # If a default firewall_id isn't configured, the API requires that
-        # firewall_id is defined in the LinodeInterface POST body.
-        "firewall_id"
-    }
+    # If a default firewall_id isn't configured, the API requires that
+    # firewall_id is defined in the LinodeInterface POST body.
+    firewall_id: Union[int, ExplicitNullValue, None] = None
 
-    firewall_id: Optional[int] = None
     default_route: Optional[LinodeInterfaceDefaultRouteOptions] = None
     vpc: Optional[LinodeInterfaceVPCOptions] = None
     public: Optional[LinodeInterfacePublicOptions] = None

linode_api4/objects/serializable.py

@@ -186,6 +186,16 @@ def attempt_serialize(value: Any) -> Any:
             if issubclass(type(value), JSONObject):
                 return value._serialize(is_put=is_put)
 
+            # Needed to avoid circular imports without a breaking change
+            from linode_api4.objects.base import (  # pylint: disable=import-outside-toplevel
+                ExplicitNullValue,
+            )
+
+            if value == ExplicitNullValue or isinstance(
+                value, ExplicitNullValue
+            ):
+                return None
+
             return value
 
         def should_include(key: str, value: Any) -> bool:

test/integration/conftest.py

@@ -13,6 +13,7 @@
 from requests.exceptions import ConnectionError, RequestException
 
 from linode_api4 import (
+    ExplicitNullValue,
     InterfaceGeneration,
     LinodeInterfaceDefaultRouteOptions,
     LinodeInterfaceOptions,
@@ -585,6 +586,7 @@ def linode_with_linode_interfaces(
                 public=LinodeInterfacePublicOptions(),
             ),
             LinodeInterfaceOptions(
+                firewall_id=ExplicitNullValue,
                 vpc=LinodeInterfaceVPCOptions(
                     subnet_id=subnet.id,
                 ),