fix recalled message

[wxul]

最近使用发现撤回消息不会被触发, 在分析源码和进行调试后发现有以下几个问题并提交此PR修复:
MessageType.Recalled will not be triggered. After analyzing the source code and debugging, I found the following problems and submitted this PR to fix:

1. 撤回消息的xml中多了一些<br/>导致 xml2json 解析失败 (The <br/> tag in message text causing xml2json parsing to fail.)

src/wechaty-bro.js

      var content = utilFactory.htmlDecode(m.MMActualContent)
      content = utilFactory.encodeEmoji(content)
      // remove <br/> here
      content = content.replace(/<br.*?\/>/g, '')
      var revokemsg = utilFactory.xml2json(content).revokemsg

2. 撤回消息会被当成 MessageType.Text 类型 (WebMessageType.RECALLED message will be converted to MessageType.Text)

src/pure-function-helpers/web-message-type.ts

    // add recall type
    case WebMessageType.RECALLED:
      return MessageType.Recalled

3. 撤回消息之后, 触发的message事件中收到的消息是MessageType.Recalled类型的源消息实例, 无法判断其原有类型 (When message triggered, the received message is revoked message and it's type was overridden by MessageType.Recalled.)

根据我的设想, MessageType.Recalled消息应该保存被撤销消息的id, 然后由用户去获取被撤销的消息实例
According to my assumption, user should get message ID from MessageType.Recalled message, then find the revoked message.

src/wechaty-bro.js
old

      if (revokemsg.msgid) {
        var chatMsgs = chatFactory.getChatMessage(m.MMPeerUserName)
        var i = chatFactory._findMessageByMsgId(chatMsgs, revokemsg.msgid)
        if (i > -1) {
          m = chatMsgs[i]
          m.MsgType = confFactory.MSGTYPE_RECALLED
        } else {
          m.MsgId = revokemsg.msgid
          m.MMActualContent = m.Content = revokemsg.replacemsg.replace(/"/g, '')
        }
        WechatyBro.emit('message', m)
      }

new

      if (revokemsg.msgid) {
        // add recalled message
        m.MsgType = confFactory.MSGTYPE_RECALLED
        m.MMActualContent = JSON.stringify(revokemsg)
        chatFactory.addChatMessage(m)
      }

usage

bot.on('message', async function(message) {
  switch (message.type()) {
    case Message.Type.Recalled:
      console.log('Recalled', message.text()); // {"session":"7056706088@chatroom","oldmsgid":"1627228679","msgid":"176813759318050095","replacemsg":"\\"XXXXX\\" 撤回了一条消息"}
      try {
        let revokemsg = JSON.parse(message.text());
        let msgId = revokemsg.msgid;
        let msg = bot.Message.load(msgId);
        await msg.ready();

        console.log('Revoked message', msg.toString());
      } catch (error) {}
      break;
  }
});

END

PS: 我看源码的时间并不多, 对wechaty以及puppet的理解也仅限于业务接触到的地方, 如果有不合理的设计, 还望指正.

PS(from Google translate): I don't have much time to look at the source code. The understanding of wechaty and puppet is limited to the places where the business comes into contact. If there is an unreasonable design, I still want to correct me.

[huan]

@wxul Thanks, you did a great job!

The analysis looks good and the code basically should work.

This issue is related to wechaty/wechaty#1728, so please go to there and have a look, and also I'd like to invite @windmemory to review this PR for you.

@windmemory Would you like to review this PR so that we can make sure it will compatible with your PR at wechaty/wechaty#1735?

Thank you very much.

[kis87988]

This PR makes sense to me.

[windmemory]

From the design in wechaty/wechaty#1735, the content should be the recalled message id, so looks like here should be:

m.MMActualContent = revokemsg.msgid

Then using the toRecalled method on Message instance, the recalled message can be retrieved back.

[huan]

Yes, I think so.

Please go to review interface and add your suggestions as a required change for this PR, thanks!

[windmemory]

Please revise the code according to the comments in the code.