rails/actioncable/CHANGELOG.md

• The Action Cable server is now mounted with anchor: true.

  This means that routes that also start with /cable will no longer clash with Action Cable.

  Alex Ghiculescu

• ActionCable.server.remote_connections.where(...).disconnect now sends disconnect message before closing the connection with the reconnection strategy specified (defaults to true).

  Vladimir Dementyev

• Added command callbacks to ActionCable::Base::Connection.

  Now you can define before_command, after_command, and around_command to be invoked before, after or around any command received by a client respectively.

  Vladimir Dementyev

Please check 7-0-stable for previous changes.