@lhr0909 I have updated more files, please feel free to comment if you have any suggestions.

Thank you very much!

Most of it looks good. The main issue I see right now is the use of aggregate root. Aggregate roots are mainly for maintaining a retrievable state from the event stream (think xstate context). So we generally don’t fire any external logic in the aggregate roots. The better place to do so is via the Event Handlers.

Now I'm working on the latest two domain projects:

1. Update https://chatie.statuspage.io/ with CommunityDevelopersCount, MessagesReceivedCount, and MessagesSentCount. This should be a domain and it's a great practice for building this domain model
2. Cross-post the messages between WeChat, QQ, WhatsApp, and Gitter channels. This should be a domain too, and by designing this model, it can help the Wechaty design to start thinking in a CQRS way.

Please stay tuned.

@lhr0909 This PR has been almost finished with lots of refactoring since your last review.

It will be greatly appreciated if you can take a look at the latest version of the code, and any comments/suggestions are welcome!

CC @windmemory @atorber