API calls mocking & validation

example_test.rb

      api_exchange << {
        request_validator: method(:request_validator).curry[an_option_for_request_validator: true],
        response: response_for_valid
      }
      rv = initiate_authorization
      assert_trx_result rv, three_ds_1: TestCaseFaker.test_case

# .....

    def request_validator options, request
      exp_request = ....
      assert_equal_hashes exp_request, act_request, "request doesn't meet expectations"
    end

    def response_for_valid
<<XML
<?xml version="1.0" encoding="windows-1251"?>
...
XML
    end

faker_for_tests.rb

      class FakerForTests
        extend ClassFunctional
    
        def self.call request
          api_exchange = $faked_api_exchange.shift || {}
          raise "undefined response for '#{request}'" unless api_exchange[:response]
    
          request_validator = api_exchange[:request_validator]
          response = api_exchange[:response]
    
          request_validator&.call(request)
    
          response
    
        rescue Minitest::Assertion => e
          puts "#{e.class}: #{e.message}"
          puts e.backtrace.join("\n")
    
          raise(e)
        end
    
      end