leaked double reproduction

tangle_spec.rb

class SomeClass
  def self.client
    true
  end
end

class UsesClient
  def self.call
    client.nil?
  end

  def self.client
    @client ||= SomeClass.client
  end
end


RSpec.describe 'tangled web we weave' do

  let(:client) { double(:client) }

  before do
    allow(SomeClass).to receive(:client).and_return(client)
  end

  it 'does one thing' do
    expect(client).to receive(:nil?)

    UsesClient.call
  end

  it 'does another thing' do
    expect(client).to receive(:nil?)

    UsesClient.call
  end
end

the memoized UsesClient.client value gets captured in UsesClient (the class object) and the double supplied to the first example pollutes the environment of the second example