Roles

roles.rb

class TransferringMoney
  include Context
  ...
  
  def transfer amount
    ...
  end

  module SourceAccount
    include ContextAccssor

    def transfer_out amount
      raise "Insufficient funds" if balance < amount
      decrease_balance amount
      context.destination_account.transfer_in amount
      update_log "Transferred out", amount
    end
  end

  module DestinationAccount
    include ContextAccssor

    def transfer_in amount
      increase_balance amount
      update_log "Transferred in", amount
    end
  end
end

Not sure if I'm a fan of the roles accessing the context. It feels like a bit of a boundary issue to me and it's unnecessary. Why is context.destination_account.transfer_in better than:

source_account.transfer_to(destination_account, amount)
...
def transfer_to destination, amount
  ...
  destination.receive_from(self, amount)
  ...
end

The other odd thing is both roles have the ContextAccssor mixin, but only one even uses it.