Added UnsupportedTarget error code (#224)

Author: Brianwithay21

src/cloudformation_cli_python_lib/exceptions.py

@@ -96,6 +96,14 @@ def __init__(self, type_name: str, message: str):
         )
 
 
+class UnsupportedTarget(_HandlerError):
+    def __init__(self, hook_type_name: str, target_type_name: str):
+        super().__init__(
+            f"Hook of type '{hook_type_name}' received request"
+            f" for unsupported target '{target_type_name}'"
+        )
+
+
 class Unknown(_HandlerError):
     pass
 

src/cloudformation_cli_python_lib/interface.py

@@ -73,6 +73,7 @@ class HandlerErrorCode(str, _AutoName):
     InvalidTypeConfiguration = auto()
     HandlerInternalFailure = auto()
     NonCompliant = auto()
+    UnsupportedTarget = auto()
     Unknown = auto()