Allow AWSHelperFn for Tag properties (#2271)

Instead of checking the property name, we check the type of the value.
This means that the Tags class gets checked, but other helper functions are allowed.

tests/test_tags.py

@@ -1,6 +1,6 @@
 import unittest
 
-from troposphere import If, Sub, Tag, Tags
+from troposphere import GetAtt, If, Sub, Tag, Tags
 from troposphere.autoscaling import Tags as ASTags
 
 
@@ -88,6 +88,18 @@ def test_json_tags(self):
             Tags={"foo": "bar"},
         )
 
+        JobDefinition(
+            "myjobdef",
+            Type="container",
+            ContainerProperties=ContainerProperties(
+                Image="image",
+                Vcpus=2,
+                Memory=2000,
+                Command=["echo", "foobar"],
+            ),
+            Tags=GetAtt("resource", "tags"),
+        )
+
         with self.assertRaises(TypeError):
             JobDefinition(
                 "myjobdef",
@@ -114,6 +126,39 @@ def test_json_tags(self):
                 Tags="string",
             )
 
+    def test_object_tags(self):
+        from troposphere.dynamodb import KeySchema, Table
+
+        Table(
+            "mytable",
+            KeySchema=[KeySchema(KeyType="HASH", AttributeName="id")],
+            BillingMode="PAY_PER_REQUEST",
+            Tags=Tags(Name="Example"),
+        )
+
+        Table(
+            "mytable",
+            KeySchema=[KeySchema(KeyType="HASH", AttributeName="id")],
+            BillingMode="PAY_PER_REQUEST",
+            Tags=GetAtt("resource", "tags"),
+        )
+
+        with self.assertRaises(TypeError):
+            Table(
+                "mytable",
+                KeySchema=[KeySchema(KeyType="HASH", AttributeName="id")],
+                BillingMode="PAY_PER_REQUEST",
+                Tags={"Name": "Example"},
+            )
+
+        with self.assertRaises(TypeError):
+            Table(
+                "mytable",
+                KeySchema=[KeySchema(KeyType="HASH", AttributeName="id")],
+                BillingMode="PAY_PER_REQUEST",
+                Tags="string",
+            )
+
 
 if __name__ == "__main__":
     unittest.main()

troposphere/__init__.py

@@ -256,7 +256,7 @@ def __setattr__(self, name: str, value: Any) -> None:
             # to deal with this that we'll come up with eventually
             #
             # Don't do this for Tags since we can validate the assigned type below
-            if isinstance(value, AWSHelperFn) and name != "Tags":
+            if isinstance(value, AWSHelperFn) and not isinstance(value, Tags):
                 return self.properties.__setitem__(name, value)
 
             # If it's a function, call it...