fix(gapic-common): ignore inherited Service constants in normalize_service

gapic-common/lib/gapic/logging_concerns.rb

@@ -200,12 +200,14 @@ def normalize_service input
           input
         when Class
           mod = input.name.split("::")[..-2].inject(Object) { |m, n| m.const_get n }
-          if mod.const_defined? "Service"
-            mod.const_get("Service").service_name
+          # inherit: false so a top-level ::Service is not mistaken for the
+          # generated gRPC Service sibling that REST stubs do not define.
+          if mod.const_defined? "Service", false
+            mod.const_get("Service", false).service_name
           else
             name_segments = input.name.split("::")[..-3]
             mod = name_segments.inject(Object) { |m, n| m.const_get n }
-            name_segments.join "." if mod.const_defined? "Rest"
+            name_segments.join "." if mod.const_defined? "Rest", false
           end
         end
       end

gapic-common/test/gapic/logging_concerns_test.rb

@@ -15,8 +15,101 @@
 require "test_helper"
 
 require "gapic/logging_concerns"
+require "gapic/rest"
+
+module NormalizeServiceFixtures
+  module V1
+    module ExampleService
+      class Stub; end
+
+      module Service
+        def self.service_name
+          "example.v1.ExampleService"
+        end
+      end
+
+      module Rest
+        class ServiceStub; end
+      end
+    end
+  end
+
+  module Plain
+    class Stub; end
+  end
+end
 
 describe Gapic::LoggingConcerns do
+  describe ".normalize_service" do
+    def with_toplevel_constant name, klass
+      name = name.to_sym
+      existed = Object.const_defined? name, false
+      original = Object.const_get name, false if existed
+      Object.send :remove_const, name if existed
+      Object.const_set name, klass
+      yield
+    ensure
+      Object.send :remove_const, name if Object.const_defined? name, false
+      Object.const_set name, original if existed
+    end
+
+    it "returns a string unchanged" do
+      input = "google.example.v1.Foo"
+      assert_equal input, Gapic::LoggingConcerns.normalize_service(input)
+    end
+
+    it "returns nil for an unrecognized input" do
+      assert_nil Gapic::LoggingConcerns.normalize_service(nil)
+      assert_nil Gapic::LoggingConcerns.normalize_service(:symbol)
+    end
+
+    it "uses a sibling Service.service_name for gRPC stubs" do
+      result = Gapic::LoggingConcerns.normalize_service NormalizeServiceFixtures::V1::ExampleService::Stub
+      assert_equal "example.v1.ExampleService", result
+    end
+
+    it "falls back to a dotted name for REST stubs" do
+      result = Gapic::LoggingConcerns.normalize_service(
+        NormalizeServiceFixtures::V1::ExampleService::Rest::ServiceStub
+      )
+      assert_equal "NormalizeServiceFixtures.V1.ExampleService", result
+    end
+
+    it "ignores an unrelated top-level Service when resolving REST stubs" do
+      with_toplevel_constant :Service, Class.new do
+        result = Gapic::LoggingConcerns.normalize_service(
+          NormalizeServiceFixtures::V1::ExampleService::Rest::ServiceStub
+        )
+        assert_equal "NormalizeServiceFixtures.V1.ExampleService", result
+      end
+    end
+
+    it "still uses a sibling Service when an unrelated top-level Service exists" do
+      with_toplevel_constant :Service, Class.new do
+        result = Gapic::LoggingConcerns.normalize_service NormalizeServiceFixtures::V1::ExampleService::Stub
+        assert_equal "example.v1.ExampleService", result
+      end
+    end
+
+    it "does not treat a top-level Rest as a REST namespace" do
+      with_toplevel_constant :Rest, Class.new do
+        result = Gapic::LoggingConcerns.normalize_service NormalizeServiceFixtures::Plain::Stub
+        assert_nil result
+      end
+    end
+
+    it "does not raise when constructing a REST client stub if a top-level Service exists" do
+      rest_stub = NormalizeServiceFixtures::V1::ExampleService::Rest::ServiceStub
+      with_toplevel_constant :Service, Class.new do
+        stub = Gapic::Rest::ClientStub.new endpoint: "google.example.com",
+                                           credentials: :dummy_credentials,
+                                           service_name: rest_stub,
+                                           logger: nil
+        assert_nil stub.logger
+      end
+    end
+  end
+
   describe "random_uuid4" do
     it "outputs the correct format" do
       output = Gapic::LoggingConcerns.random_uuid4