feat: add 'from_service_account_info' factory to clients (#706)

Closes #705

Author: tseaver

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

@@ -97,6 +97,22 @@ class {{ service.client_name }}(metaclass={{ service.client_name }}Meta):
         DEFAULT_ENDPOINT
     )
 
+    @classmethod
+    def from_service_account_info(cls, info: dict, *args, **kwargs):
+        """Creates an instance of this client using the provided credentials info.
+
+        Args:
+            info (dict): The service account private key info.
+            args: Additional arguments to pass to the constructor.
+            kwargs: Additional arguments to pass to the constructor.
+
+        Returns:
+            {@api.name}: The constructed client.
+        """
+        credentials = service_account.Credentials.from_service_account_info(info)
+        kwargs["credentials"] = credentials
+        return cls(*args, **kwargs)
+
     @classmethod
     def from_service_account_file(cls, filename: str, *args, **kwargs):
         """Creates an instance of this client using the provided credentials

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

@@ -61,6 +61,17 @@ def test__get_default_mtls_endpoint():
     assert {{ service.client_name }}._get_default_mtls_endpoint(non_googleapi) == non_googleapi
 
 
+def test_{{ service.client_name|snake_case }}_from_service_account_info():
+    creds = credentials.AnonymousCredentials()
+    with mock.patch.object(service_account.Credentials, 'from_service_account_info') as factory:
+        factory.return_value = creds
+        info = {"valid": True}
+        client = {{ service.client_name }}.from_service_account_info(info)
+        assert client.transport._credentials == creds
+
+        {% if service.host %}assert client.transport._host == '{{ service.host }}{% if ":" not in service.host %}:443{% endif %}'{% endif %}
+
+
 def test_{{ service.client_name|snake_case }}_from_service_account_file():
     creds = credentials.AnonymousCredentials()
     with mock.patch.object(service_account.Credentials, 'from_service_account_file') as factory:

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

@@ -48,6 +48,7 @@ class {{ service.async_client_name }}:
     parse_common_{{ resource_msg.message_type.resource_type|snake_case }}_path = staticmethod({{ service.client_name }}.parse_common_{{ resource_msg.message_type.resource_type|snake_case }}_path)
     {% endfor %}
 
+    from_service_account_info = {{ service.client_name }}.from_service_account_info
     from_service_account_file = {{ service.client_name }}.from_service_account_file
     from_service_account_json = from_service_account_file
 

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

@@ -113,6 +113,22 @@ class {{ service.client_name }}(metaclass={{ service.client_name }}Meta):
         DEFAULT_ENDPOINT
     )
 
+    @classmethod
+    def from_service_account_info(cls, info: dict, *args, **kwargs):
+        """Creates an instance of this client using the provided credentials info.
+
+        Args:
+            info (dict): The service account private key info.
+            args: Additional arguments to pass to the constructor.
+            kwargs: Additional arguments to pass to the constructor.
+
+        Returns:
+            {@api.name}: The constructed client.
+        """
+        credentials = service_account.Credentials.from_service_account_info(info)
+        kwargs["credentials"] = credentials
+        return cls(*args, **kwargs)
+
     @classmethod
     def from_service_account_file(cls, filename: str, *args, **kwargs):
         """Creates an instance of this client using the provided credentials

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

@@ -70,6 +70,17 @@ def test__get_default_mtls_endpoint():
     assert {{ service.client_name }}._get_default_mtls_endpoint(non_googleapi) == non_googleapi
 
 
+def test_{{ service.client_name|snake_case }}_from_service_account_info():
+    creds = credentials.AnonymousCredentials()
+    with mock.patch.object(service_account.Credentials, 'from_service_account_info') as factory:
+        factory.return_value = creds
+        info = {"valid": True}
+        client = {{ service.client_name }}.from_service_account_info(info)
+        assert client.transport._credentials == creds
+
+        {% if service.host %}assert client.transport._host == '{{ service.host }}{% if ":" not in service.host %}:443{% endif %}'{% endif %}
+
+
 @pytest.mark.parametrize("client_class", [{{ service.client_name }}, {{ service.async_client_name }}])
 def test_{{ service.client_name|snake_case }}_from_service_account_file(client_class):
     creds = credentials.AnonymousCredentials()