spec.rb

def recurly_tax_info(request)
  # dump from https://api.recurly.com/js/v1/tax?vat_number=&country=FR&currency=USD&version=3.0.10&key=my_key&callback=__jp1
  country = request.uri.query_values['country']
  currency = request.uri.query_values['currency']
  vat_number = request.uri.query_values['vat_number']

  expect(country).to eq('FR')
  expect(currency).to eq('USD')
  expect(vat_number).to eq('')

  [{
    "type" => "vat",
    "region" => "FR",
    "rate" => "0.2"
  }]
end

stub_request(:get, %r{api.recurly.com:443/js/v1/tax\?}).to_return { |r| jsonp_callback!(r, recurly_tax_info(r)) }

@token_query = nil
stub = stub_request(:get, %r{api.recurly.com:443/js/v1/token\?}).to_return do |r|
  # grab back the values for later comparison
  # trying expectation here will fail silently
  # and I couldn't get :query on stub_request to work either
  @token_query = r.uri.query_values
  jsonp_callback!(r, recurly_json_token)
end

def jsonp_callback!(request, response)
  callback = request.uri.query_values['callback']
  raise "Missing jsonp callback" if callback.blank?
  {body: "#{callback}(#{response.to_json})"}
end