rspec with allow in multithread

rsec-allow.rb

# frozen_string_literal: true
# ruby 3.2.2
#     rspec (3.11.0)
#       rspec-core (~> 3.11.0)
#       rspec-expectations (~> 3.11.0)
#       rspec-mocks (~> 3.11.0)
#     rspec-core (3.11.0)
#       rspec-support (~> 3.11.0)
#     rspec-expectations (3.11.0)
#       diff-lcs (>= 1.2.0, < 2.0)
#       rspec-support (~> 3.11.0)
#     rspec-mocks (3.11.0)
#       diff-lcs (>= 1.2.0, < 2.0)
#       rspec-support (~> 3.11.0)
#     rspec-support (3.11.0)

class UseCase
  def self.call
    "x"
  end
end

RSpec.describe RShade, focus: true do
  context do
    # In that case rspec smart and raise RSpec::Mocks::OutsideOfExampleError
    # before do
    #   allow(UseCase).to receive(:call).and_return('z')
    # end
    context 'thread 1' do
      it do
        Thread.new do
          allow(UseCase).to receive(:call).and_return('y')
        end
      end
    end

    context 'thread 2' do
      it do
        sleep 3
        # expect to have x but will return y
        expect(UseCase.call).to eq('x')
      end
    end
  end
end