resolve undeterministic generation issue

Author: ohmayr

packages/gapic-generator/gapic/schema/api.py

@@ -170,9 +170,12 @@ def resource_messages(self) -> Mapping[str, wrappers.MessageType]:
             if msg.options.Extensions[resource_pb2.resource].type
         )
         return collections.OrderedDict(
-            itertools.chain(
-                file_resource_messages,
-                resource_messages,
+            sorted(
+                itertools.chain(
+                    file_resource_messages,
+                    resource_messages,
+                ),
+                key=lambda item: item[0]
             )
         )
 

packages/gapic-generator/gapic/schema/wrappers.py

@@ -2278,9 +2278,9 @@ def names(self) -> FrozenSet[str]:
         return frozenset(answer)
 
     @utils.cached_property
-    def resource_messages(self) -> FrozenSet[MessageType]:
+    def resource_messages(self) -> Sequence['MessageType']:
         """Returns all the resource message types used in all
-        request and response fields in the service."""
+        request and response fields in the service, deterministically sorted."""
 
         def gen_resources(message):
             if message.resource_path:
@@ -2301,7 +2301,7 @@ def gen_indirect_resources_used(message):
                 if resource:
                     yield resource
 
-        return frozenset(
+        unique_messages = frozenset(
             msg
             for method in self.methods.values()
             for msg in chain(
@@ -2316,6 +2316,13 @@ def gen_indirect_resources_used(message):
             )
         )
 
+        return tuple(
+            sorted(
+                unique_messages,
+                key=lambda m: m.resource_type_full_path or m.name
+            )
+        )
+
     @utils.cached_property
     def resource_messages_dict(self) -> Dict[str, MessageType]:
         """Returns a dict from resource reference to