feat: Support field presence for query parameters in REST clients (#866)

Also fix witespace issues in rest transport ands tests.
Also update bazel-specific dependencies.

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

@@ -89,7 +89,7 @@ class {{ service.name }}RestTransport({{ service.name }}Transport):
             client_info=client_info,
         )
         self._session = AuthorizedSession(self._credentials, default_host=self.DEFAULT_HOST)
-        {%- if service.has_lro %}
+        {% if service.has_lro %}
         self._operations_client = None
         {% endif %}
         if client_cert_source_for_mtls:
@@ -133,10 +133,10 @@ class {{ service.name }}RestTransport({{ service.name }}Transport):
             request: {{ method.input.ident }}, *,
             metadata: Sequence[Tuple[str, str]] = (),
             ) -> {{ method.output.ident }}:
-        r"""Call the {{ ' ' }}
+        r"""Call the {{- ' ' -}}
         {{ (method.name|snake_case).replace('_',' ')|wrap(
                 width=70, offset=45, indent=8) }}
-        {{ ' ' }} method over HTTP.
+        {{- ' ' -}} method over HTTP.
 
         Args:
             request (~.{{ method.input.ident }}):
@@ -189,21 +189,26 @@ class {{ service.name }}RestTransport({{ service.name }}Transport):
         #}
         # TODO(yon-mg): handle nested fields corerctly rather than using only top level fields
         #               not required for GCE
-        query_params = {
-            {% for field in method.query_params | sort%}
-            '{{ field|camel_case }}': request.{{ field }},
-            {% endfor %}
-        }
+        query_params = {}
+        {% for field in method.query_params | sort%}
+        {% if method.input.fields[field].proto3_optional %}
+        if {{ method.input.ident }}.{{ field }} in request:
+            query_params['{{ field|camel_case }}'] = request.{{ field }}
+        {% else %}
+        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() if v]
         url += '?{}'.format('&'.join(query_params)).replace(' ', '+')
 
         # Send the request
-        {% if not method.void %}response = {% endif %}self._session.{{ method.http_opt['verb'] }}(
-            url
-            {% if 'body' in method.http_opt %},
+        response = self._session.{{ method.http_opt['verb'] }}(
+            url,
+            {% if 'body' in method.http_opt %}
             data=body,
             {% endif %}
         )

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

@@ -1189,7 +1189,11 @@ def test_{{ method.name|snake_case }}_rest_flattened():
         {% endfor %}
         client.{{ method.name|snake_case }}(
             {% for field in method.flattened_fields.values() %}
-            {% if field.field_pb is msg_field_pb %}{{ field.name }}={{ field.name }},{% else %}{{ field.name }}={{ field.mock_value }},{% endif %}
+            {% if field.field_pb is msg_field_pb %}
+            {{ field.name }}={{ field.name }},
+            {% else %}
+            {{ field.name }}={{ field.mock_value }},
+            {% endif %}
             {% endfor %}
         )
 
@@ -1198,16 +1202,17 @@ 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')
-        {% for key, field in method.flattened_fields.items() %}{% if not field.oneof or field.proto3_optional %}
+        {% for key, field in method.flattened_fields.items() %}
+        {% if not field.oneof or field.proto3_optional %}
         {% if field.ident|string() == 'timestamp.Timestamp' %}
         assert TimestampRule().to_proto(http_call[0].{{ key }}) == {{ field.mock_value }}
         {% elif field.ident|string() == 'duration.Duration' %}
         assert DurationRule().to_proto(http_call[0].{{ key }}) == {{ field.mock_value }}
         {% else %}
         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)
+               {%- elif field.field_pb is str_field_pb %}{{ field.mock_value }}
+               {%- else %}str({{ field.mock_value }})
+               {%- endif %} in http_call[1] + str(body)
         {% endif %}
         {% endif %}{% endfor %}
 

repositories.bzl

@@ -15,7 +15,7 @@ def gapic_generator_python():
         requirements = "@gapic_generator_python//:requirements.txt",
     )
 
-    _protobuf_version = "3.14.0"
+    _protobuf_version = "3.15.8"
     _protobuf_version_in_link = "v%s" % _protobuf_version
     _maybe(
         http_archive,
@@ -34,8 +34,8 @@ def gapic_generator_python():
     _maybe(
         http_archive,
         name = "com_github_grpc_grpc",
-        strip_prefix = "grpc-8347f4753568b5b66e49111c60ae2841278d3f33",  # this is 1.25.0 with fixes
-        urls = ["https://github.com/grpc/grpc/archive/8347f4753568b5b66e49111c60ae2841278d3f33.zip"],
+        strip_prefix = "grpc-1.36.4",
+        urls = ["https://github.com/grpc/grpc/archive/v1.36.4.zip"],
     )
 
     _maybe(