100% test coverage for async pager

Author: lidizheng

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

@@ -89,7 +89,6 @@ class {{ service.name }}GrpcAsyncIOTransport({{ service.name }}Transport):
             host,
             credentials=credentials,
             scopes=cls.AUTH_SCOPES,
-            enable_asyncio=True,
             **kwargs
         )
 

gapic/templates/noxfile.py.j2

@@ -10,7 +10,7 @@ import nox  # type: ignore
 def unit(session):
     """Run the unit test suite."""
 
-    session.install('coverage', 'pytest', 'pytest-cov')
+    session.install('coverage', 'pytest', 'pytest-cov', 'asyncmock', 'pytest-asyncio')
     session.install('-e', '.')
 
     session.run(

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

@@ -1,7 +1,7 @@
 {% extends "_base.py.j2" %}
 
 {% block content %}
-from unittest import mock
+import mock
 
 import grpc
 import math
@@ -13,6 +13,7 @@ from google import auth
 from google.auth import credentials
 from google.oauth2 import service_account
 from {{ (api.naming.module_namespace + (api.naming.versioned_module_name,) + service.meta.address.subpackage)|join(".") }}.services.{{ service.name|snake_case }} import {{ service.client_name }}
+from {{ (api.naming.module_namespace + (api.naming.versioned_module_name,) + service.meta.address.subpackage)|join(".") }}.services.{{ service.name|snake_case }} import {{ service.async_client_name }}
 from {{ (api.naming.module_namespace + (api.naming.versioned_module_name,) + service.meta.address.subpackage)|join(".") }}.services.{{ service.name|snake_case }} import transports
 from google.api_core import client_options
 from google.api_core import grpc_helpers
@@ -411,6 +412,98 @@ def test_{{ method.name|snake_case }}_pages():
         pages = list(client.{{ method.name|snake_case }}(request={}).pages)
         for page, token in zip(pages, ['abc','def','ghi', '']):
             assert page.raw_page.next_page_token == token
+
+@pytest.mark.asyncio
+async def test_{{ method.name|snake_case }}_async_pager():
+    client = {{ service.async_client_name }}(
+        credentials=credentials.AnonymousCredentials,
+    )
+
+    # Mock the actual call within the gRPC stub, and fake the request.
+    with mock.patch.object(
+            type(client._transport.{{ method.name|snake_case }}),
+            '__call__', new_callable=mock.AsyncMock) as call:
+        # Set the response to a series of pages.
+        call.side_effect = (
+            {{ method.output.ident }}(
+                {{ method.paged_result_field.name }}=[
+                    {{ method.paged_result_field.message.ident }}(),
+                    {{ method.paged_result_field.message.ident }}(),
+                    {{ method.paged_result_field.message.ident }}(),
+                ],
+                next_page_token='abc',
+            ),
+            {{ method.output.ident }}(
+                {{ method.paged_result_field.name }}=[],
+                next_page_token='def',
+            ),
+            {{ method.output.ident }}(
+                {{ method.paged_result_field.name }}=[
+                    {{ method.paged_result_field.message.ident }}(),
+                ],
+                next_page_token='ghi',
+            ),
+            {{ method.output.ident }}(
+                {{ method.paged_result_field.name }}=[
+                    {{ method.paged_result_field.message.ident }}(),
+                    {{ method.paged_result_field.message.ident }}(),
+                ],
+            ),
+            RuntimeError,
+        )
+        async_pager = await client.{{ method.name|snake_case }}(request={},)
+        assert async_pager.next_page_token == 'abc'
+        responses = []
+        async for response in async_pager:
+            responses.append(response)
+
+        assert len(responses) == 6
+        assert all(isinstance(i, {{ method.paged_result_field.message.ident }})
+                   for i in responses)
+
+@pytest.mark.asyncio
+async def test_{{ method.name|snake_case }}_async_pages():
+    client = {{ service.async_client_name }}(
+        credentials=credentials.AnonymousCredentials,
+    )
+
+    # Mock the actual call within the gRPC stub, and fake the request.
+    with mock.patch.object(
+            type(client._transport.{{ method.name|snake_case }}),
+            '__call__', new_callable=mock.AsyncMock) as call:
+        # Set the response to a series of pages.
+        call.side_effect = (
+            {{ method.output.ident }}(
+                {{ method.paged_result_field.name }}=[
+                    {{ method.paged_result_field.message.ident }}(),
+                    {{ method.paged_result_field.message.ident }}(),
+                    {{ method.paged_result_field.message.ident }}(),
+                ],
+                next_page_token='abc',
+            ),
+            {{ method.output.ident }}(
+                {{ method.paged_result_field.name }}=[],
+                next_page_token='def',
+            ),
+            {{ method.output.ident }}(
+                {{ method.paged_result_field.name }}=[
+                    {{ method.paged_result_field.message.ident }}(),
+                ],
+                next_page_token='ghi',
+            ),
+            {{ method.output.ident }}(
+                {{ method.paged_result_field.name }}=[
+                    {{ method.paged_result_field.message.ident }}(),
+                    {{ method.paged_result_field.message.ident }}(),
+                ],
+            ),
+            RuntimeError,
+        )
+        pages = []
+        async for page in (await client.{{ method.name|snake_case }}(request={})).pages:
+            pages.append(page)
+        for page, token in zip(pages, ['abc','def','ghi', '']):
+            assert page.raw_page.next_page_token == token
 {% elif method.lro and "next_page_token" in method.lro.response_type.fields.keys() %}
 def test_{{ method.name|snake_case }}_raw_page_lro():
     response = {{ method.lro.response_type.ident }}()

noxfile.py

@@ -136,7 +136,7 @@ def showcase_unit(
     #     "git+https://github.com/googleapis/python-api-core.git@ca6c41cf460e505e6b228263170927270626222a#egg=google-api-core",
     # )
     session.install(
-        'coverage', 'pytest', 'pytest-cov', 'pytest-xdist',
+        'coverage', 'pytest', 'pytest-cov', 'pytest-xdist', 'asyncmock',
         'git+https://github.com/pytest-dev/pytest-asyncio.git')
     session.install('.')
 
@@ -148,6 +148,7 @@ def showcase_unit(
 
     # Install a client library for Showcase.
     with tempfile.TemporaryDirectory() as tmp_dir:
+        tmp_dir = '/Users/lidiz/playground/gapic-showcase/dest'
 
         # Download the Showcase descriptor.
         session.run(