Gemfile

source 'https://rubygems.org'

gem 'grpc', '~> 1.0.0'

# prerelease protobuf magic
git 'git@github.com:google/protobuf.git', tag: 'v3.0.0' do
  gem 'google-protobuf'
end

group :development, :test do
  gem 'rake', '~> 10.5.0'

  gem 'grpc-tools', '~> 1.0.0'
end

group :test do
  gem 'minitest', '~> 5.9.0'
  gem 'simplecov', '~> 0.12.0'
end

hash_test.rb

require 'test_helper'
require 'protobuf_bug'

class HashTest < MiniTest::Test

  def setup
    @names = %w{There are many words and I will use some of them}
    @single_values = @names.each_with_index.map do |name, id|
      ProtobufBug::SingleValues.new(name: name, id: id)
    end
  end


  def test_single_values_hash
    @single_values.each do |pb|
      assert_kind_of Fixnum, pb.hash, format('<%d>%s must hash properly', pb.id, pb.name)
    end
  end

  def test_repeated_values_hash
    @names.each do |name|
      (2...@single_values.size).each do |n|
        @single_values.combination(n).each_with_index do |values, m|
          pb = ProtobufBug::RepeatedValues.new(
            name: format('%s<%d/%d>', name, n, m),
            values: values
          )
          assert_kind_of Fixnum, pb.hash, format('%s must hash properly', pb.name)
        end
      end
    end
  end

end

protobuf_bug.proto

syntax = "proto3";

package ProtobufBug;

message SingleValues {
  uint32 id = 1;
  string name = 2;
}

message RepeatedValues {
  string name = 1;
  repeated SingleValues values = 2;
};

protobuf_bug.rb

# Generated by the protocol buffer compiler.  DO NOT EDIT!
# source: protobuf_bug.proto

require 'google/protobuf'

Google::Protobuf::DescriptorPool.generated_pool.build do
  add_message "ProtobufBug.SingleValues" do
    optional :id, :uint32, 1
    optional :name, :string, 2
  end
  add_message "ProtobufBug.RepeatedValues" do
    optional :name, :string, 1
    repeated :values, :message, 2, "ProtobufBug.SingleValues"
  end
end

module ProtobufBug
  SingleValues = Google::Protobuf::DescriptorPool.generated_pool.lookup("ProtobufBug.SingleValues").msgclass
  RepeatedValues = Google::Protobuf::DescriptorPool.generated_pool.lookup("ProtobufBug.RepeatedValues").msgclass
end

test_helper.rb

require 'minitest/autorun'