fix: fix rest transport unit test and required query prams handling (#951)

Author: vam-google

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

@@ -52,6 +52,7 @@ class {{ service.name }}RestTransport({{ service.name }}Transport):
             client_cert_source_for_mtls: Callable[[], Tuple[bytes, bytes]] = None,
             quota_project_id: Optional[str] = None,
             client_info: gapic_v1.client_info.ClientInfo = DEFAULT_CLIENT_INFO,
+            always_use_jwt_access: Optional[bool] = False,
             ) -> None:
         """Instantiate the transport.
 
@@ -88,6 +89,7 @@ class {{ service.name }}RestTransport({{ service.name }}Transport):
             host=host,
             credentials=credentials,
             client_info=client_info,
+            always_use_jwt_access=always_use_jwt_access,
         )
         self._session = AuthorizedSession(self._credentials, default_host=self.DEFAULT_HOST)
         {% if service.has_lro %}
@@ -196,23 +198,17 @@ class {{ service.name }}RestTransport({{ service.name }}Transport):
         if {{ method.input.ident }}.{{ field }} in request:
             query_params['{{ field|camel_case }}'] = request.{{ field }}
         {% else %}
-        if request.{{ field }}:
-            query_params['{{ field|camel_case }}'] = request.{{ field }}
+        query_params['{{ field|camel_case }}'] = request.{{ field }}
         {% endif %}
         {% endfor %}
 
-        # TODO(yon-mg): further discussion needed whether 'python truthiness' is appropriate here
-        #               discards default values
-        # TODO(yon-mg): add test for proper url encoded strings
-        query_params = ['{k}={v}'.format(k=k, v=v) for k, v in query_params.items()]
-        url += '?{}'.format('&'.join(query_params)).replace(' ', '+')
-
         # Send the request
         headers = dict(metadata)
         headers['Content-Type'] = 'application/json'
         response = self._session.{{ method.http_opt['verb'] }}(
             url,
             headers=headers,
+            params=query_params,
             {% if 'body' in method.http_opt %}
             data=body,
             {% endif %}

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

@@ -1220,6 +1220,7 @@ def test_{{ method.name|snake_case }}_rest_flattened():
         assert len(req.mock_calls) == 1
         _, http_call, http_params = req.mock_calls[0]
         body = http_params.get('data')
+        params = http_params.get('params')
         {% for key, field in method.flattened_fields.items() %}
         {% if not field.oneof or field.proto3_optional %}
         {% if field.ident|string() == 'timestamp_pb2.Timestamp' %}
@@ -1230,7 +1231,7 @@ def test_{{ method.name|snake_case }}_rest_flattened():
         assert {% if field.field_pb is msg_field_pb %}{{ field.ident }}.to_json({{ field.name }}, including_default_value_fields=False, use_integers_for_enums=False)
                {%- elif field.field_pb is str_field_pb %}{{ field.mock_value }}
                {%- else %}str({{ field.mock_value }})
-               {%- endif %} in http_call[1] + str(body)
+               {%- endif %} in http_call[1] + str(body) + str(params)
         {% endif %}
         {% endif %}{% endfor %}