use absolute package name, add test cases

src/compiler/ruby_generator_string-inl.h

@@ -124,7 +124,7 @@ inline grpc::string RubyTypeOf(const grpc::protobuf::Descriptor* descriptor) {
     ReplacePrefix(&proto_type, ".", "");  // remove the leading . (no package)
     proto_type = RubyPackage(descriptor->file()) + "." + proto_type;
   }
-  grpc::string res(proto_type);
+  grpc::string res("." + proto_type);
   if (res.find('.') == grpc::string::npos) {
     return res;
   } else {

src/ruby/spec/pb/codegen/grpc/testing/same_package_service_name.proto

@@ -0,0 +1,27 @@
+// Copyright 2020 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package same_name;
+
+service SameName {
+  rpc Health(Request) returns (Status);
+}
+
+message Status {
+  string msg = 1;
+}
+
+message Request {}

src/ruby/spec/pb/codegen/grpc/testing/same_ruby_package_service_name.proto

@@ -0,0 +1,29 @@
+// Copyright 2020 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package other_name;
+
+option ruby_package = "SameName2";
+
+service SameName2 {
+  rpc Health(Request) returns (Status);
+}
+
+message Status {
+  string msg = 1;
+}
+
+message Request {}

src/ruby/spec/pb/codegen/package_option_spec.rb

@@ -48,6 +48,26 @@ describe 'Code Generation Options' do
       expect(services[:NestedMessageTest].output).to eq(RPC::Test::New::Package::Options::Bar::Baz)
     end
   end
+
+  it 'should generate when package and service has same name' do
+    with_protos(['grpc/testing/same_package_service_name.proto']) do
+      expect { SameName::SameName::Service }.to raise_error(NameError)
+      expect(require('grpc/testing/same_package_service_name_services_pb')).to be_truthy
+      expect { SameName::SameName::Service }.to_not raise_error
+      expect { SameName::Request }.to_not raise_error
+      expect { SameName::Status }.to_not raise_error
+    end
+  end
+
+  it 'should generate when ruby_package and service has same name' do
+    with_protos(['grpc/testing/same_ruby_package_service_name.proto']) do
+      expect { SameName2::SameName2::Service }.to raise_error(NameError)
+      expect(require('grpc/testing/same_ruby_package_service_name_services_pb')).to be_truthy
+      expect { SameName2::SameName2::Service }.to_not raise_error
+      expect { SameName2::Request }.to_not raise_error
+      expect { SameName2::Status }.to_not raise_error
+    end
+  end
 end
 
 def with_protos(file_paths)