fix: disambiguate method names that are reserved in transport classes

In addition to the method specific stubs they provide, the generated
transports expose other methods to e.g. create a gRPC channel.
This presents the opportunity for a naming collision if an API has a
CreateChannel method.

This PR disambiguates colliding method names at the transport
level. Client level method names are unchanged for ergonomic reasons.

gapic/ads-templates/%namespace/%name/%version/%sub/services/%service/client.py.j2

@@ -443,7 +443,7 @@ class {{ service.client_name }}(metaclass={{ service.client_name }}Meta):
 
         # Wrap the RPC method; this adds retry and timeout information,
         # and friendly error handling.
-        rpc = self._transport._wrapped_methods[self._transport.{{ method.name|snake_case}}]
+        rpc = self._transport._wrapped_methods[self._transport.{{ method.transport_safe_name|snake_case}}]
         {% if method.field_headers %}
 
         # Certain fields should be provided within the metadata header;

gapic/ads-templates/%namespace/%name/%version/%sub/services/%service/transports/base.py.j2

@@ -120,8 +120,8 @@ class {{ service.name }}Transport(abc.ABC):
         # Precompute the wrapped methods.
         self._wrapped_methods = {
             {% for method in service.methods.values() %}
-            self.{{ method.name|snake_case }}: gapic_v1.method.wrap_method(
-                self.{{ method.name|snake_case }},
+            self.{{ method.transport_safe_name|snake_case }}: gapic_v1.method.wrap_method(
+                self.{{ method.transport_safe_name|snake_case }},
                 {% if method.retry %}
                 default_retry=retries.Retry(
                     {% if method.retry.initial_backoff %}initial={{ method.retry.initial_backoff }},{% endif %}
@@ -160,7 +160,7 @@ class {{ service.name }}Transport(abc.ABC):
     {% for method in service.methods.values() %}
 
     @property
-    def {{ method.name|snake_case }}(self) -> Callable[
+    def {{ method.transport_safe_name|snake_case }}(self) -> Callable[
             [{{ method.input.ident }}],
             Union[
                 {{ method.output.ident }},

gapic/ads-templates/%namespace/%name/%version/%sub/services/%service/transports/grpc.py.j2

@@ -249,7 +249,7 @@ class {{ service.name }}GrpcTransport({{ service.name }}Transport):
     {% for method in service.methods.values() %}
 
     @property
-    def {{ method.name|snake_case }}(self) -> Callable[
+    def {{ method.transport_safe_name|snake_case }}(self) -> Callable[
             [{{ method.input.ident }}],
             {{ method.output.ident }}]:
         r"""Return a callable for the{{ ' ' }}
@@ -269,13 +269,13 @@ class {{ service.name }}GrpcTransport({{ service.name }}Transport):
         # the request.
         # gRPC handles serialization and deserialization, so we just need
         # to pass in the functions for each.
-        if '{{ method.name|snake_case }}' not in self._stubs:
-            self._stubs['{{ method.name|snake_case }}'] = self.grpc_channel.{{ method.grpc_stub_type }}(
+        if '{{ method.transport_safe_name|snake_case }}' not in self._stubs:
+            self._stubs['{{ method.transport_safe_name|snake_case }}'] = self.grpc_channel.{{ method.grpc_stub_type }}(
                 '/{{ '.'.join(method.meta.address.package) }}.{{ service.name }}/{{ method.name }}',
                 request_serializer={{ method.input.ident }}.{% if method.input.ident.python_import.module.endswith('_pb2') %}SerializeToString{% else %}serialize{% endif %},
                 response_deserializer={{ method.output.ident }}.{% if method.output.ident.python_import.module.endswith('_pb2') %}FromString{% else %}deserialize{% endif %},
             )
-        return self._stubs['{{ method.name|snake_case }}']
+        return self._stubs['{{ method.transport_safe_name|snake_case }}']
     {% endfor %}
 
     {% if opts.add_iam_methods %}

gapic/ads-templates/%namespace/%name/%version/%sub/services/%service/transports/rest.py.j2

@@ -396,12 +396,12 @@ class {{service.name}}RestTransport({{service.name}}Transport):
     {% for method in service.methods.values()|sort(attribute="name") %}
 
     @property
-    def {{method.name | snake_case}}(self) -> Callable[
+    def {{method.transport_safe_name | snake_case}}(self) -> Callable[
             [{{method.input.ident}}],
             {{method.output.ident}}]:
-        stub = self._STUBS.get("{{method.name | snake_case}}")
+        stub = self._STUBS.get("{{method.transport_safe_name | snake_case}}")
         if not stub:
-            stub = self._STUBS["{{method.name | snake_case}}"] = self._{{method.name}}(self._session, self._host, self._interceptor)
+            stub = self._STUBS["{{method.transport_safe_name | snake_case}}"] = self._{{method.name}}(self._session, self._host, self._interceptor)
 
         # The return type is fine, but mypy isn't sophisticated enough to determine what's going on here.
         # In C++ this would require a dynamic_cast

gapic/ads-templates/setup.py.j2

@@ -19,7 +19,7 @@ setuptools.setup(
     install_requires=(
         {# TODO(dovs): remove when 1.x deprecation is complete #}
         {% if 'rest' in opts.transport %}
-        'google-api-core[grpc] >= 2.1.0, < 3.0.0dev',
+        'google-api-core[grpc] >= 2.4.0, < 3.0.0dev',
         {% else %}
         'google-api-core[grpc] >= 1.28.0, < 3.0.0dev',
         {% endif %}

gapic/ads-templates/tests/unit/gapic/%name_%version/%sub/test_%service.py.j2

@@ -494,7 +494,7 @@ def test_{{ method_name }}(request_type, transport: str = 'grpc'):
 
     # Mock the actual call within the gRPC stub, and fake the request.
     with mock.patch.object(
-            type(client.transport.{{ method.name|snake_case }}),
+            type(client.transport.{{ method.transport_safe_name|snake_case }}),
             '__call__') as call:
         # Designate an appropriate return value for the call.
         {% if method.void %}
@@ -571,7 +571,7 @@ def test_{{ method_name }}_empty_call():
 
     # Mock the actual call within the gRPC stub, and fake the request.
     with mock.patch.object(
-            type(client.transport.{{ method.name|snake_case }}),
+            type(client.transport.{{ method.transport_safe_name|snake_case }}),
             '__call__') as call:
         client.{{ method_name }}()
         call.assert_called()
@@ -600,7 +600,7 @@ def test_{{ method_name }}_field_headers():
 
     # Mock the actual call within the gRPC stub, and fake the request.
     with mock.patch.object(
-            type(client.transport.{{ method.name|snake_case }}),
+            type(client.transport.{{ method.transport_safe_name|snake_case }}),
             '__call__') as call:
         {% if method.void %}
         call.return_value = None
@@ -638,7 +638,7 @@ def test_{{ method_name }}_from_dict_foreign():
     )
     # Mock the actual call within the gRPC stub, and fake the request.
     with mock.patch.object(
-            type(client.transport.{{ method.name|snake_case }}),
+            type(client.transport.{{ method.transport_safe_name|snake_case }}),
             '__call__') as call:
         # Designate an appropriate return value for the call.
         {% if method.void %}
@@ -668,7 +668,7 @@ def test_{{ method_name }}_flattened():
 
     # Mock the actual call within the gRPC stub, and fake the request.
     with mock.patch.object(
-            type(client.transport.{{ method.name|snake_case }}),
+            type(client.transport.{{ method.transport_safe_name|snake_case }}),
             '__call__') as call:
         # Designate an appropriate return value for the call.
         {% if method.void %}
@@ -746,7 +746,7 @@ def test_{{ method_name }}_pager(transport_name: str = "grpc"):
 
     # Mock the actual call within the gRPC stub, and fake the request.
     with mock.patch.object(
-            type(client.transport.{{ method.name|snake_case }}),
+            type(client.transport.{{ method.transport_safe_name|snake_case }}),
             '__call__') as call:
         # Set the response to a series of pages.
         call.side_effect = (
@@ -808,7 +808,7 @@ def test_{{ method_name }}_pages(transport_name: str = "grpc"):
 
     # Mock the actual call within the gRPC stub, and fake the request.
     with mock.patch.object(
-         type(client.transport.{{ method.name|snake_case }}),
+         type(client.transport.{{ method.transport_safe_name|snake_case }}),
         '__call__') as call:
         # Set the response to a series of pages.
         {% if method.paged_result_field.map%}
@@ -1184,7 +1184,7 @@ def test_{{ method_name }}_rest_required_fields(request_type={{ method.input.ide
 def test_{{ method_name }}_rest_unset_required_fields():
     transport = transports.{{ service.rest_transport_name }}(credentials=ga_credentials.AnonymousCredentials)
 
-    unset_fields = transport.{{ method.name|snake_case }}._get_unset_required_fields({})
+    unset_fields = transport.{{ method.transport_safe_name|snake_case }}._get_unset_required_fields({})
     assert set(unset_fields) == (set(({% for param in method.query_params|sort %}"{{ param|camel_case }}", {% endfor %})) & set(({% for param in method.input.required_fields %}"{{param.name|camel_case}}", {% endfor %})))
 
 
@@ -1645,7 +1645,7 @@ def test_{{ service.name|snake_case }}_base_transport():
     # raise NotImplementedError.
     methods = (
         {% for method in service.methods.values() %}
-        '{{ method.name|snake_case }}',
+        '{{ method.transport_safe_name|snake_case }}',
         {% endfor %}
         {% if opts.add_iam_methods %}
         'set_iam_policy',

gapic/schema/wrappers.py

@@ -945,9 +945,22 @@ class Method:
         default_factory=metadata.Metadata,
     )
 
+    # These names conflict with other methods in the transport.
+    # We don't want to disambiguate the names at the client level
+    # because the disambiguated name is less convenient and user friendly.
+    TRANSPORT_UNSAFE_NAMES: ClassVar[FrozenSet] = frozenset({
+        "CreateChannel",
+        "GrpcChannel",
+        "OperationsClient",
+    })
+
     def __getattr__(self, name):
         return getattr(self.method_pb, name)
 
+    @property
+    def transport_safe_name(self) -> str:
+        return f"{self.name}_" if self.name in self.TRANSPORT_UNSAFE_NAMES else self.name
+
     @property
     def is_operation_polling_method(self):
         return self.output.is_extended_operation and self.options.Extensions[ex_ops_pb2.operation_polling_method]

gapic/templates/%namespace/%name_%version/%sub/services/%service/async_client.py.j2

@@ -92,15 +92,15 @@ class {{ service.async_client_name }}:
 
     @classmethod
     def get_mtls_endpoint_and_cert_source(cls, client_options: Optional[ClientOptions] = None):
-        """Return the API endpoint and client cert source for mutual TLS. 
+        """Return the API endpoint and client cert source for mutual TLS.
 
         The client cert source is determined in the following order:
         (1) if `GOOGLE_API_USE_CLIENT_CERTIFICATE` environment variable is not "true", the
         client cert source is None.
         (2) if `client_options.client_cert_source` is provided, use the provided one; if the
         default client cert source exists, use the default one; otherwise the client cert
         source is None.
- 
+
         The API endpoint is determined in the following order:
         (1) if `client_options.api_endpoint` if provided, use the provided one.
         (2) if `GOOGLE_API_USE_CLIENT_CERTIFICATE` environment variable is "always", use the
@@ -118,7 +118,7 @@ class {{ service.async_client_name }}:
         Returns:
             Tuple[str, Callable[[], Tuple[bytes, bytes]]]: returns the API endpoint and the
                 client cert source to use.
-        
+
         Raises:
             google.auth.exceptions.MutualTLSChannelError: If any errors happen.
         """
@@ -302,7 +302,7 @@ class {{ service.async_client_name }}:
         # Wrap the RPC method; this adds retry and timeout information,
         # and friendly error handling.
         rpc = gapic_v1.method_async.wrap_method(
-            self._client._transport.{{ method.name|snake_case }},
+            self._client._transport.{{ method.transport_safe_name|snake_case }},
             {% if method.retry %}
             default_retry=retries.Retry(
                 {% if method.retry.initial_backoff %}initial={{ method.retry.initial_backoff }},{% endif %}

gapic/templates/%namespace/%name_%version/%sub/services/%service/client.py.j2

@@ -477,7 +477,7 @@ class {{ service.client_name }}(metaclass={{ service.client_name }}Meta):
 
         # Wrap the RPC method; this adds retry and timeout information,
         # and friendly error handling.
-        rpc = self._transport._wrapped_methods[self._transport.{{ method.name|snake_case}}]
+        rpc = self._transport._wrapped_methods[self._transport.{{ method.transport_safe_name|snake_case}}]
 
         {% if method.explicit_routing %}
         header_params = {}

gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/base.py.j2

@@ -120,8 +120,8 @@ class {{ service.name }}Transport(abc.ABC):
         # Precompute the wrapped methods.
         self._wrapped_methods = {
             {% for method in service.methods.values() %}
-            self.{{ method.name|snake_case }}: gapic_v1.method.wrap_method(
-                self.{{ method.name|snake_case }},
+            self.{{ method.transport_safe_name|snake_case }}: gapic_v1.method.wrap_method(
+                self.{{ method.transport_safe_name|snake_case }},
                 {% if method.retry %}
                 default_retry=retries.Retry(
                     {% if method.retry.initial_backoff %}initial={{ method.retry.initial_backoff }},{% endif %}
@@ -160,7 +160,7 @@ class {{ service.name }}Transport(abc.ABC):
     {% for method in service.methods.values() %}
 
     @property
-    def {{ method.name|snake_case }}(self) -> Callable[
+    def {{ method.transport_safe_name|snake_case }}(self) -> Callable[
             [{{ method.input.ident }}],
             Union[
                 {{ method.output.ident }},

gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/grpc.py.j2

@@ -249,7 +249,7 @@ class {{ service.name }}GrpcTransport({{ service.name }}Transport):
     {% for method in service.methods.values() %}
 
     @property
-    def {{ method.name|snake_case }}(self) -> Callable[
+    def {{ method.transport_safe_name|snake_case }}(self) -> Callable[
             [{{ method.input.ident }}],
             {{ method.output.ident }}]:
         r"""Return a callable for the{{ ' ' }}
@@ -269,13 +269,13 @@ class {{ service.name }}GrpcTransport({{ service.name }}Transport):
         # the request.
         # gRPC handles serialization and deserialization, so we just need
         # to pass in the functions for each.
-        if '{{ method.name|snake_case }}' not in self._stubs:
-            self._stubs['{{ method.name|snake_case }}'] = self.grpc_channel.{{ method.grpc_stub_type }}(
+        if '{{ method.transport_safe_name|snake_case }}' not in self._stubs:
+            self._stubs['{{ method.transport_safe_name|snake_case }}'] = self.grpc_channel.{{ method.grpc_stub_type }}(
                 '/{{ '.'.join(method.meta.address.package) }}.{{ service.name }}/{{ method.name }}',
                 request_serializer={{ method.input.ident }}.{% if method.input.ident.python_import.module.endswith('_pb2') %}SerializeToString{% else %}serialize{% endif %},
                 response_deserializer={{ method.output.ident }}.{% if method.output.ident.python_import.module.endswith('_pb2') %}FromString{% else %}deserialize{% endif %},
             )
-        return self._stubs['{{ method.name|snake_case }}']
+        return self._stubs['{{ method.transport_safe_name|snake_case }}']
     {% endfor %}
 
     {% if opts.add_iam_methods %}

gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/grpc_asyncio.py.j2

@@ -250,7 +250,7 @@ class {{ service.grpc_asyncio_transport_name }}({{ service.name }}Transport):
     {% for method in service.methods.values() %}
 
     @property
-    def {{ method.name|snake_case }}(self) -> Callable[
+    def {{ method.transport_safe_name|snake_case }}(self) -> Callable[
             [{{ method.input.ident }}],
             Awaitable[{{ method.output.ident }}]]:
         r"""Return a callable for the{{ ' ' }}
@@ -270,13 +270,13 @@ class {{ service.grpc_asyncio_transport_name }}({{ service.name }}Transport):
         # the request.
         # gRPC handles serialization and deserialization, so we just need
         # to pass in the functions for each.
-        if '{{ method.name|snake_case }}' not in self._stubs:
-            self._stubs['{{ method.name|snake_case }}'] = self.grpc_channel.{{ method.grpc_stub_type }}(
+        if '{{ method.transport_safe_name|snake_case }}' not in self._stubs:
+            self._stubs['{{ method.transport_safe_name|snake_case }}'] = self.grpc_channel.{{ method.grpc_stub_type }}(
                 '/{{ '.'.join(method.meta.address.package) }}.{{ service.name }}/{{ method.name }}',
                 request_serializer={{ method.input.ident }}.{% if method.input.ident.python_import.module.endswith('_pb2') %}SerializeToString{% else %}serialize{% endif %},
                 response_deserializer={{ method.output.ident }}.{% if method.output.ident.python_import.module.endswith('_pb2') %}FromString{% else %}deserialize{% endif %},
             )
-        return self._stubs['{{ method.name|snake_case }}']
+        return self._stubs['{{ method.transport_safe_name|snake_case }}']
     {% endfor %}
 
     {% if opts.add_iam_methods %}

gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest.py.j2

@@ -396,12 +396,12 @@ class {{service.name}}RestTransport({{service.name}}Transport):
     {% for method in service.methods.values()|sort(attribute="name") %}
 
     @property
-    def {{method.name | snake_case}}(self) -> Callable[
+    def {{method.transport_safe_name|snake_case}}(self) -> Callable[
             [{{method.input.ident}}],
             {{method.output.ident}}]:
-        stub = self._STUBS.get("{{method.name | snake_case}}")
+        stub = self._STUBS.get("{{method.transport_safe_name|snake_case}}")
         if not stub:
-            stub = self._STUBS["{{method.name | snake_case}}"] = self._{{method.name}}(self._session, self._host, self._interceptor)
+            stub = self._STUBS["{{method.transport_safe_name|snake_case}}"] = self._{{method.name}}(self._session, self._host, self._interceptor)
 
         # The return type is fine, but mypy isn't sophisticated enough to determine what's going on here.
         # In C++ this would require a dynamic_cast