update workflow

.github/workflows/tests.yaml

@@ -55,8 +55,9 @@ jobs:
     strategy:
       # Run showcase tests on the lowest and highest supported runtimes
       matrix:
+        # TODO(https://github.com/googleapis/gapic-generator-python/issues/2121) Remove `showcase_w_rest_async` target when async rest is GA.
         python: ["3.7", "3.12"]
-        target: [showcase, showcase_alternative_templates]
+        target: [showcase, showcase_w_rest_async]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4

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

@@ -1,9 +1,11 @@
+{# TODO(https://github.com/googleapis/gapic-generator-python/issues/2121): Remove the following variable (and the condition later in this file) for async rest transport once support for it is GA. #}
+{% set rest_async_io_enabled = api.all_library_settings[api.naming.proto_package].python_settings.experimental_features.rest_async_io_enabled %}
 {% extends '_base.py.j2' %}
 
 {% block content %}
 
 from collections import OrderedDict
-from typing import Dict, Type
+from typing import Dict, Type{% if rest_async_io_enabled %}, Tuple{% endif +%}
 
 from .base import {{ service.name }}Transport
 {% if 'grpc' in opts.transport %}
@@ -13,6 +15,16 @@ from .grpc_asyncio import {{ service.name }}GrpcAsyncIOTransport
 {% if 'rest' in opts.transport %}
 from .rest import {{ service.name }}RestTransport
 from .rest import {{ service.name }}RestInterceptor
+{% if rest_async_io_enabled %}
+ASYNC_REST_CLASSES: Tuple[str, ...]
+try:
+    from .rest_asyncio import Async{{ service.name }}RestTransport
+    ASYNC_REST_CLASSES = ('Async{{ service.name }}RestTransport',)
+    HAS_REST_ASYNC = True
+except ImportError:  # pragma: NO COVER
+    ASYNC_REST_CLASSES = ()
+    HAS_REST_ASYNC = False
+{% endif %}{# if rest_async_io_enabled #}
 {% endif %}
 
 
@@ -25,6 +37,10 @@ _transport_registry['grpc_asyncio'] = {{ service.name }}GrpcAsyncIOTransport
 {% endif %}
 {% if 'rest' in opts.transport %}
 _transport_registry['rest'] = {{ service.name }}RestTransport
+{% if rest_async_io_enabled %}
+if HAS_REST_ASYNC:  # pragma: NO COVER
+    _transport_registry['rest_asyncio'] = Async{{ service.name }}RestTransport
+{% endif %}{# if rest_async_io_enabled #}
 {% endif %}
 
 __all__ = (
@@ -37,5 +53,5 @@ __all__ = (
     '{{ service.name }}RestTransport',
     '{{ service.name }}RestInterceptor',
     {% endif %}
-)
+){% if 'rest' in opts.transport and rest_async_io_enabled%} + ASYNC_REST_CLASSES{%endif%}
 {% endblock %}

tests/integration/goldens/redis/google/cloud/redis_v1/services/cloud_redis/transports/__init__.py

@@ -14,25 +14,35 @@
 # limitations under the License.
 #
 from collections import OrderedDict
-from typing import Dict, Type
+from typing import Dict, Type, Tuple
 
 from .base import CloudRedisTransport
 from .grpc import CloudRedisGrpcTransport
 from .grpc_asyncio import CloudRedisGrpcAsyncIOTransport
 from .rest import CloudRedisRestTransport
 from .rest import CloudRedisRestInterceptor
+ASYNC_REST_CLASSES: Tuple[str, ...]
+try:
+    from .rest_asyncio import AsyncCloudRedisRestTransport
+    ASYNC_REST_CLASSES = ('AsyncCloudRedisRestTransport',)
+    HAS_REST_ASYNC = True
+except ImportError:  # pragma: NO COVER
+    ASYNC_REST_CLASSES = ()
+    HAS_REST_ASYNC = False
 
 
 # Compile a registry of transports.
 _transport_registry = OrderedDict()  # type: Dict[str, Type[CloudRedisTransport]]
 _transport_registry['grpc'] = CloudRedisGrpcTransport
 _transport_registry['grpc_asyncio'] = CloudRedisGrpcAsyncIOTransport
 _transport_registry['rest'] = CloudRedisRestTransport
+if HAS_REST_ASYNC:  # pragma: NO COVER
+    _transport_registry['rest_asyncio'] = AsyncCloudRedisRestTransport
 
 __all__ = (
     'CloudRedisTransport',
     'CloudRedisGrpcTransport',
     'CloudRedisGrpcAsyncIOTransport',
     'CloudRedisRestTransport',
     'CloudRedisRestInterceptor',
-)
+) + ASYNC_REST_CLASSES

tests/system/conftest.py

@@ -38,10 +38,15 @@
     from google.showcase import EchoAsyncClient
     from google.showcase import IdentityAsyncClient
     try:
-        import google.showcase.transports.rest_asyncio
-        SHOWCASE_ASYNC_TRANSPORTS = ["grpc_asyncio", "rest_asyncio"]
+        from google.showcase_v1beta1.services.echo.transports import AsyncEchoRestTransport
+        HAS_ASYNC_REST_ECHO_TRANSPORT = True
     except:
-        SHOWCASE_ASYNC_TRANSPORTS = ["grpc_asyncio"]
+        HAS_ASYNC_REST_ECHO_TRANSPORT = False
+    try:
+        from google.showcase_v1beta1.services.identity.transports import AsyncIdentityRestTransport
+        HAS_ASYNC_REST_IDENTITY_TRANSPORT = True
+    except:
+        HAS_ASYNC_REST_IDENTITY_TRANSPORT = False
 
     # TODO: use async auth anon credentials by default once the minimum version of google-auth is upgraded.
     # See related issue: https://github.com/googleapis/gapic-generator-python/issues/2107.
@@ -62,22 +67,28 @@ def async_anonymous_credentials():
     def event_loop():
         return asyncio.get_event_loop()
 
-    @pytest.fixture(params=SHOWCASE_ASYNC_TRANSPORTS)
+    @pytest.fixture(params=["grpc_asyncio", "rest_asyncio"])
     def async_echo(use_mtls, request, event_loop):
+        transport = request.param
+        if transport == "rest_asyncio" and not HAS_ASYNC_REST_ECHO_TRANSPORT:
+            pytest.skip("Skipping test with async rest.")
         return construct_client(
             EchoAsyncClient,
             use_mtls,
-            transport_name=request.param,
+            transport_name=transport,
             channel_creator=aio.insecure_channel if request.param == "grpc_asyncio" else None,
             credentials=async_anonymous_credentials(),
         )
 
-    @pytest.fixture(params=SHOWCASE_ASYNC_TRANSPORTS)
+    @pytest.fixture(params=["grpc_asyncio", "rest_asyncio"])
     def async_identity(use_mtls, request, event_loop):
+        transport = request.param
+        if transport == "rest_asyncio" and not HAS_ASYNC_REST_IDENTITY_TRANSPORT:
+            pytest.skip("Skipping test with async rest.")
         return construct_client(
             IdentityAsyncClient,
             use_mtls,
-            transport_name=request.param,
+            transport_name=transport,
             channel_creator=aio.insecure_channel if request.param == "grpc_asyncio" else None,
             credentials=async_anonymous_credentials(),
         )