class MessageToValidator
  def initialize(message)
    @message = message
  end

  def validate
    result = {message: @message}

    valid = if @message[:to]
      true
    else
      false
    end

    result.merge(valid: valid, validator: self.class.name, message: @message)
  end
end

class MessageFromValidator
  def initialize(message)
    @message = message
  end

  def validate
    result = {message: @message}

    valid = if @message[:from]
      true
    else
      false
    end

    result.merge(valid: valid, validator: self.class.name, message: @message)
  end
end

class MessageProcessor
  VALIDATORS = [MessageToValidator, MessageFromValidator]
  def initialize(message)
    @message = message
  end

  def process
    validation_results = VALIDATORS.map {|v| v.new(@message).validate}

    if validation_results.all? { |r| r[:valid] }
      puts "Proceed with further message processing"
    else
      failures = validation_results.select {|r| !r[:valid] }
      puts "Handle these known issues: #{failures}"
    end

  rescue => exception
    # Handle unexpected
    puts "Something unexpected happened"
  end
end

# OUTPUT
# $ ruby example.rb
#
#
# message {:id=>1, :to=>"x", :from=>"y"}
# Proceed with further message processing
# ---
# message {:id=>2, :to=>"x"}
# Handle these known issues: [{:message=>{:id=>2, :to=>"x"}, :valid=>false, :validator=>"MessageFromValidator"}]
# ---
# message {:id=>3, :from=>"y"}
# Handle these known issues: [{:message=>{:id=>3, :from=>"y"}, :valid=>false, :validator=>"MessageToValidator"}]
# ---
# message {}
# Handle these known issues: [{:message=>{}, :valid=>false, :validator=>"MessageToValidator"}, {:message=>{}, :valid=>false, :validator=>"MessageFromValidator"}]
# ---
# message #<Object:0x007f84a200d4c0>
# Something unexpected happened
# ---