chore(generator): use {% set %} to extract repeated logic in conditionals (#17890)

Updating the use of global variable for auto populated fields, we are
making sure that the Jinja variables are defined at the top of the file
so they can easily reference throughout the template.

Author: hebaalazzeh

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

@@ -1,13 +1,14 @@
 {% extends '_base.py.j2' %}
-
 {% block content %}
+{% set has_auto_populated_fields = api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+
 {% import "%namespace/%name/%version/%sub/services/%service/_shared_macros.j2" as shared_macros %}
 
 from collections import OrderedDict
 import os
 import re
 from typing import Callable, Dict, Mapping, MutableMapping, MutableSequence, Optional, {% if service.any_server_streaming %}Iterable, {% endif %}{% if service.any_client_streaming %}Iterator, {% endif %}Sequence, Tuple, Type, Union, cast
-{% if api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+{% if has_auto_populated_fields %}
 import uuid
 {% endif %}
 {% if service.any_deprecated %}

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

@@ -1,10 +1,12 @@
 {% extends "_base.py.j2" %}
-
 {% block content %}
+{% set has_auto_populated_fields = api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+
+
 {% import "%namespace/%name/%version/%sub/services/%service/_shared_macros.j2" as shared_macros %}
 
 import os
-{% if api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+{% if has_auto_populated_fields %}
 import re
 {% endif %}
 from unittest import mock
@@ -70,7 +72,7 @@ from google.iam.v1 import policy_pb2  # type: ignore
 {% endfilter %}
 {{ shared_macros.add_google_api_core_version_header_import(service.version) }}
 
-{% if api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|list %}
+{% if has_auto_populated_fields %}
 _UUID4_RE = re.compile(r"{{ uuid4_re }}")
 {% endif %}
 

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

@@ -1,14 +1,14 @@
 {% extends "_base.py.j2" %}
-
 {% block content %}
+{% set has_auto_populated_fields = api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
 {% import "%namespace/%name_%version/%sub/services/%service/_client_macros.j2" as macros %}
 {% import "%namespace/%name_%version/%sub/services/%service/_shared_macros.j2" as shared_macros %}
 
 import logging as std_logging
 from collections import OrderedDict
 import re
 from typing import Dict, Callable, Mapping, MutableMapping, MutableSequence, Optional, {% if service.any_server_streaming %}AsyncIterable, Awaitable, {% endif %}{% if service.any_client_streaming %}AsyncIterator, {% endif %}Sequence, Tuple, Type, Union
-{% if api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+{% if has_auto_populated_fields %}
 import uuid
 {% endif %}
 {% if service.any_deprecated %}

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

@@ -1,8 +1,8 @@
-{# 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 %}
+{# 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 %}
+{% set has_auto_populated_fields = api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
 {% import "%namespace/%name_%version/%sub/services/%service/_client_macros.j2" as macros %}
 {% import "%namespace/%name_%version/%sub/services/%service/_shared_macros.j2" as shared_macros %}
 
@@ -16,7 +16,7 @@ import logging as std_logging
 import os
 import re
 from typing import Dict, Callable, Mapping, MutableMapping, MutableSequence, Optional, {% if service.any_server_streaming %}Iterable, {% endif %}{% if service.any_client_streaming %}Iterator, {% endif %}Sequence, Tuple, Type, Union, cast
-{% if api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+{% if has_auto_populated_fields %}
 import uuid
 {% endif %}
 import warnings
@@ -453,7 +453,8 @@ class {{ service.client_name }}(metaclass={{ service.client_name }}Meta):
         # NOTE (b/349488459): universe validation is disabled until further notice.
         return True
 
-    {% if api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+    {% if has_auto_populated_fields %}
+
     @staticmethod
     def _setup_request_id(request, field_name: str, is_proto3_optional: bool):
         """Populate a UUID4 field in the request if it is not already set.

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

@@ -1,14 +1,14 @@
-{# 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 %}
+{# 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 %}
+{% set has_auto_populated_fields = api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
 {% import "tests/unit/gapic/%name_%version/%sub/test_macros.j2" as test_macros %}
 {% import "%namespace/%name_%version/%sub/services/%service/_shared_macros.j2" as shared_macros %}
 
 import os
 import asyncio
-{% if api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+{% if has_auto_populated_fields %}
 import re
 {% endif %}
 from unittest import mock
@@ -107,7 +107,7 @@ CRED_INFO_JSON = {
     "principal": "service-account@example.com",
 }
 CRED_INFO_STRING = json.dumps(CRED_INFO_JSON)
-{% if api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+{% if has_auto_populated_fields %}
 _UUID4_RE = re.compile(r"{{ uuid4_re }}")
 {% endif %}
 
@@ -434,7 +434,7 @@ def test__add_cred_info_for_auth_errors_no_get_cred_info(error_code):
     client._add_cred_info_for_auth_errors(error)
     assert error.details == []
 
-{% if api.all_method_settings.values()|map(attribute="auto_populated_fields", default=[])|select|list %}
+{% if has_auto_populated_fields %}
 def test__setup_request_id():
     class MockRequest:
         def __init__(self, **kwargs):