Make after_commit work reliabliy inside nested transactions

lib/statesman/adapters/active_record.rb

@@ -78,12 +78,20 @@ def create_transition(from, to, metadata)
           transition.save!
           @last_transition = transition
           @observer.execute(:after, from, to, transition)
+          add_after_commit_callback(from, to, transition)
         end
-        @observer.execute(:after_commit, from, to, transition)
 
         transition
       end
 
+      def add_after_commit_callback(from, to, transition)
+        ::ActiveRecord::Base.connection.add_transaction_record(
+          ActiveRecordAfterCommitWrap.new do
+            @observer.execute(:after_commit, from, to, transition)
+          end,
+        )
+      end
+
       def transitions_for_parent
         @parent_model.send(@association_name)
       end
@@ -149,5 +157,31 @@ def with_updated_timestamp(params)
         params.merge(column => timestamp)
       end
     end
+
+    class ActiveRecordAfterCommitWrap
+      def initialize
+        @callback = Proc.new
+        @connection = ::ActiveRecord::Base.connection
+      end
+
+      # rubocop: disable Naming/PredicateName
+      def has_transactional_callbacks?
+        true
+      end
+      # rubocop: enable Naming/PredicateName
+
+      def committed!(*)
+        @callback.call
+      end
+
+      def before_committed!(*); end
+
+      def rolledback!(*); end
+
+      # Required for +transaction(requires_new: true)+
+      def add_to_transaction(*)
+        @connection.add_transaction_record(self)
+      end
+    end
   end
 end