Only run pay-leave-for-parents tests when required

These tests are in place ready for the conversion of this Smart Answer from
Smartdown to Ruby. We don't need them to run as part of the main regression test
suite until the Smart Answer has been converted.

This isn't the best implementation but I think it's probably OK given that I'll
revert it as soon as this Smart Answer has been converted to Ruby.

lib/smart_answer_test_helper.rb

@@ -124,7 +124,7 @@ def source_files_have_changed?
     changed_files.any?
   end
 
-  def explicitly_run_this_regression_test?
+  public def explicitly_run_this_regression_test?
     ENV['RUN_REGRESSION_TESTS'] == @flow_name
   end
 

test/regression/smart_answers_regression_test.rb

@@ -56,6 +56,16 @@ def teardown_hooks_installed?
 
     next unless smart_answer_helper.run_regression_tests?
 
+    if flow_name == 'pay-leave-for-parents'
+      if smart_answer_helper.explicitly_run_this_regression_test?
+        puts 'Preloading flows to speed up testing of pay-leave-for-parents Smartdown answer'
+        FLOW_REGISTRY_OPTIONS[:preload_flows] = true
+      else
+        # Skip this Smartdown flow if we're running all regression tests or they're being run because checksums are out of date
+        next
+      end
+    end
+
     smart_answer_helper.delete_saved_output_files
     responses_and_expected_results = smart_answer_helper.read_responses_and_expected_results