Using spys in rspec to mock connections to services

rspec_spy_example.rb

  # Set up the spy object
  let(:chargebee_site) { spy(ChargebeeSite) }

  # Hook it into the work flow
  before do
    allow(ChargebeeSite).to receive(:new).and_return(chargebee_site)
  end
    
  # use `have_received` to test connection 
  it 'creates a chargebee coupon' do
    subject
    expect(chargebee_site).
      to have_received(:create_coupon).
           with(
             id:   customer.coupon,
             name: customer.coupon,
             meta_data: {
               referrer_shopify_customer_id: customer.shopify_id
             }.to_json
           )
  end

See https://relishapp.com/rspec/rspec-mocks/docs/basics/spies