Pact issue with Blueprinter and Oj

oj-pact-reproduction-script.rb

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  # Activate the gem you are reporting the issue against.
  # gem "oj", "3.11.3"  # test ok
  gem "oj", "3.16.0" # test fail

  gem "activesupport"
  gem "pact"
  gem "pact-support"
  gem "rspec"
  gem "httparty"
end

require "active_support"
require "active_support/json"
require "json"
require "pact"
require "oj"

require "pact/consumer/rspec"

Pact.service_consumer "Zoo App" do
  has_pact_with "Animal Service" do
    mock_service :animal_service do
      port 1234
    end
  end
end

require "httparty"

class Alligator
  attr_reader :name

  def initialize name
    @name = name
  end

  def == other
    other.is_a?(Alligator) && other.name == name
  end
end

class AnimalServiceClient
  include HTTParty
  base_uri "http://animal-service.com"

  def get_alligator
    name = JSON.parse(self.class.get("/alligator").body)['name']
    Alligator.new(name)
  end
end

require "rspec/autorun"

RSpec.describe AnimalServiceClient, :pact => true, :order => :defined do
  before do
    # Configure your client to point to the stub service on localhost using the port you have specified
    AnimalServiceClient.base_uri "localhost:1234"
  end

  let(:body) { { name: Pact.like("Betty") } }

  subject { AnimalServiceClient.new }

  describe "get_alligator" do
    it "returns a alligator" do
      animal_service.given("an alligator exists")
        .upon_receiving("a request for an alligator")
        .with(method: :get, path: "/alligator", query: "")
        .will_respond_with(
          status: 200,
          headers: {"Content-Type" => "application/json"},
          body: body
        )

      expect(subject.get_alligator).to eq(Alligator.new("Betty"))
    end

    context "rendering via Oj.generate prior" do
      before do
        Oj.generate({ name: "Boop" })
      end

      it "does not set create_additions by default" do
        expect(Oj.default_options).to include(create_additions: false)
      end

      it "returns a alligator" do
        animal_service
          .given("an alligator exists one")
          .upon_receiving("a request for an alligator")
          .with(method: :get, path: "/alligator", query: "")
          .will_respond_with(
            status: 200,
            headers: {"Content-Type" => "application/json"},
            body: body
          )

        expect(subject.get_alligator).to eq(Alligator.new("Betty"))
      end

      context "and setting create_additions" do
        before do
          Oj.generate({ name: "Boop" })
          Oj.default_options = { create_additions: true }
        end

        it "returns a alligator" do
          animal_service
            .given("an alligator exists one")
            .upon_receiving("a request for an alligator again")
            .with(method: :get, path: "/alligator", query: "")
            .will_respond_with(
              status: 200,
              headers: {"Content-Type" => "application/json"},
              body: body
            )

          expect(subject.get_alligator).to eq(Alligator.new("Betty"))
        end
      end
    end

    context "with Oj" do
      xit "returns a alligator" do
        pending "fails regardless of Oj version"

        Oj.optimize_rails()

        animal_service
          .given("an alligator exists two")
          .upon_receiving("a request for an alligator")
          .with(method: :get, path: "/alligator", query: "")
          .will_respond_with(
            status: 200,
            headers: { "Content-Type" => "application/json" },
            body: body
          )

        expect(subject.get_alligator).to eq(Alligator.new("Betty"))
      end
    end
  end
end

It produces the error:

Failures:

  1) AnimalServiceClient get_alligator rendering a Blueprint JSON before returns a alligator
     Failure/Error: expect(subject.get_alligator).to eq(Alligator.new("Betty"))

       expected: #<Alligator:0x00007f81d7aeeda8 @name="Betty">
            got: #<Alligator:0x00007f81d7aeeec0 @name={"json_class"=>"Pact::SomethingLike", "contents"=>"Betty"}>

       (compared using ==)

       Diff:
       @@ -1,2 +1,3 @@
       -#<Alligator:0x00007f81d7aeeda8 @name="Betty">
       +#<Alligator:0x00007f81d7aeeec0
       + @name={"json_class"=>"Pact::SomethingLike", "contents"=>"Betty"}>

Ok, I have been a professional Ruby developer for 10+ years now, and I did not know you could inline a gemfile declaration! That is going to come in handy.