fix leaf response building.

Author: gmac

lib/graphql/cardinal/executor.rb

@@ -209,13 +209,7 @@ def resolve_execution_field(exec_field, resolved_sources)
           # build leaf results
           resolved_sources.each_with_index do |val, i|
             # DANGER: HOT PATH!
-            parent_responses[i][field_key] = if val.nil? || val.is_a?(StandardError)
-              build_missing_value(exec_field, field_type, val)
-            elsif return_type.kind.leaf?
-              coerce_leaf_value(exec_field, field_type, val)
-            else
-              val
-            end
+            parent_responses[i][field_key] = coerce_leaf_value(exec_field, field_type, val)
           end
         end
       end

lib/graphql/cardinal/executor/hot_paths.rb

@@ -50,7 +50,9 @@ def build_missing_value(exec_field, current_type, val)
       # DANGER: HOT PATH!
       # Overhead added here scales dramatically...
       def coerce_leaf_value(exec_field, current_type, val)
-        if current_type.list?
+        if val.nil? || val.is_a?(StandardError)
+          build_missing_value(exec_field, current_type, val)
+        elsif current_type.list?
           unless val.is_a?(Array)
             report_exception("#{INCORRECT_LIST_VALUE}#{val.class}", field: exec_field)
             return build_missing_value(exec_field, current_type, nil)