Blind Chat Messages

    const messageData = {
      whisper: ChatMessage.getWhisperRecipients('gm'),
      blind: !game.user.isGM,
      user: game.user.data._id,
      type: CONST.CHAT_MESSAGE_TYPES.WHISPER,
      speaker: { alias: game.i18n.localize(`${this.MODULE_NAME}.MESSAGE_HEADER`) },
      content: html,
    }

    const messageData = {
      whisper: ChatMessage.getWhisperRecipients('gm'),
      blind: !game.user.isGM,
      user: game.user.data._id,
      type: CONST.CHAT_MESSAGE_TYPES.WHISPER,
      speaker: { alias: game.i18n.localize(`${this.MODULE_NAME}.MESSAGE_HEADER`) },
      content: html,
    }

  get visible() {
    // if this has whisper recipients
    if ( this.data.whisper.length ) {
      // if its a roll, always yes (`isContentVisible` has more rules)
      if ( this.data.type === CONST.CHAT_MESSAGE_TYPES.ROLL ) return true;

      // if this chat message's user is the same as the logged in user --> true
      // or if the logged in user matches one of the recipients
      return (this.data.user === game.user.id) || (this.data.whisper.indexOf(game.user.id) !== -1);
    }
    return true;
  }

  get visible() {
    // if this has whisper recipients
    if ( this.data.whisper.length ) {
      // if its a roll, always yes (`isContentVisible` has more rules)
      if ( this.data.type === CONST.CHAT_MESSAGE_TYPES.ROLL ) return true;

      // if this chat message's user is the same as the logged in user --> true
      // or if the logged in user matches one of the recipients
      return (this.data.user === game.user.id) || (this.data.whisper.indexOf(game.user.id) !== -1);
    }
    return true;
  }