Some thoughts on OOP principles

policy_telldontask.rb

class Ctrl
    def close
        user = User.new # load from somewhere
        CloseAccountPolicy.new(user).apply!
        puts user.inspect
    end
end

# Nearly an AnemicDomainModel because some of it's behavor is externalized
class User
    def initialize
        @open = true
    end

    def open?
        @open
    end

    def close!
        @open = false
    end
end

class CloseAccountPolicy
    def initialize(user)
        @user = user
    end

    def apply!
        if @user.open? # Violate Tell don't ask
            @user.close!
            send_notification!
        end
    end

    def send_notification!
        puts "Notification sent!"
    end
end

puts Ctrl.new.close

policy_trigger.rb

class Ctrl
    def close
        user = User.new # load from somewhere
        CloseAccountPolicy.new(user).apply!
        puts user.inspect
    end
end

# SRP : OK | Non-Anemic | All behavior at the same place
class User
    def initialize
        @open = true
    end

    def close!(&block)
        @open = false
        block.call if block # Trigger system/Observer DP
    end
end

class CloseAccountPolicy
    def initialize(user)
        @user = user
    end

    def apply!
        @user.close! do # Tell don't ask : OK!
            send_notification!
        end
    end

    def send_notification!
        puts "Notification sent!"
    end
end

puts Ctrl.new.close

single_srp.rb

class Ctrl
    def close
        user = User.new # load from somewhere
        user.close!
        puts user.inspect
    end
end

# SRP : All the behavior is here but it coupled too all the system parts
class User
    def initialize
        @open = true
    end

    def close!
        if @open
            @open = false
            send_notification!
        end
    end

    def send_notification!
        puts "Notification sent!"
    end
end

puts Ctrl.new.close