impl(generator): refactor generated rest stub to use EndpointOption (#10273)

Author: scotthart

generator/integration_tests/golden/internal/golden_kitchen_sink_rest_stub.cc

@@ -17,6 +17,7 @@
 // source: generator/integration_tests/test.proto
 
 #include "generator/integration_tests/golden/internal/golden_kitchen_sink_rest_stub.h"
+#include "google/cloud/common_options.h"
 #include "google/cloud/internal/absl_str_cat_quiet.h"
 #include "google/cloud/internal/rest_stub_helpers.h"
 #include "google/cloud/status_or.h"
@@ -30,7 +31,7 @@ GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 
 DefaultGoldenKitchenSinkRestStub::DefaultGoldenKitchenSinkRestStub(Options options)
     : rest_client_(rest_internal::MakePooledRestClient(
-          "https://goldenkitchensink.googleapis.com", options)),
+          options.get<EndpointOption>(), options)),
       options_(std::move(options)) {}
 
 DefaultGoldenKitchenSinkRestStub::DefaultGoldenKitchenSinkRestStub(

generator/integration_tests/golden/internal/golden_thing_admin_rest_stub.cc

@@ -17,6 +17,7 @@
 // source: generator/integration_tests/test.proto
 
 #include "generator/integration_tests/golden/internal/golden_thing_admin_rest_stub.h"
+#include "google/cloud/common_options.h"
 #include "google/cloud/internal/absl_str_cat_quiet.h"
 #include "google/cloud/internal/rest_stub_helpers.h"
 #include "google/cloud/status_or.h"
@@ -31,7 +32,7 @@ GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 
 DefaultGoldenThingAdminRestStub::DefaultGoldenThingAdminRestStub(Options options)
     : rest_client_(rest_internal::MakePooledRestClient(
-          "https://test.googleapis.com", options)),
+          options.get<EndpointOption>(), options)),
       options_(std::move(options)) {}
 
 DefaultGoldenThingAdminRestStub::DefaultGoldenThingAdminRestStub(

generator/internal/stub_rest_generator.cc

@@ -141,6 +141,7 @@ Status StubRestGenerator::GenerateCc() {
 
   CcPrint("\n");
   CcLocalIncludes({vars("stub_rest_header_path"),
+                   "google/cloud/common_options.h",
                    "google/cloud/internal/absl_str_cat_quiet.h",
                    "google/cloud/internal/rest_stub_helpers.h",
                    "google/cloud/status_or.h"});
@@ -152,11 +153,10 @@ Status StubRestGenerator::GenerateCc() {
   auto result = CcOpenNamespaces(NamespaceType::kInternal);
   if (!result.ok()) return result;
 
-  // TODO(#10214): Emit code to check options for a potential endpoint override.
   CcPrint(R"""(
 Default$stub_rest_class_name$::Default$stub_rest_class_name$(Options options)
     : rest_client_(rest_internal::MakePooledRestClient(
-          "https://$service_endpoint$", options)),
+          options.get<EndpointOption>(), options)),
       options_(std::move(options)) {}
 
 Default$stub_rest_class_name$::Default$stub_rest_class_name$(