Question

I am working on a testing framework for the software that my company writes. Our product is web based and After I run a RESTful request I want to process the results. I want to be able to have activerecord type validations in each command class so that after it is run the results are automatically tested against all the ‘validations’. However, I am not sure how to do this. My code looks like this (simplified to show the important parts).

class CodesecureCommand   def execute     result = RestClient.post('http://#{codesecure.host_name_port}#{path}', post_data)      return parse(result) #parse simple returns a Hpricot document   end end  class RunScan < CodesecureCommand    #What I have now   #I have to override the execute function so that it calls the local success method   #to see if it failed or not.   def execute()     result = super()      if success(result)       return true     else     end    end    def success(result)     result.search('div.transaction-message') do |message|       if message.innerHTML.scan(/Configure abuse setting for domain users successfully\./).length == 1         return true       end     end   end      #What I would like is to be able to call execute (without having to override it).   #then after it runs it calls back to this class to check    #if the regex matches the command was successful and returns true   test_success /regex/    #if test_success fails then these are called   #the idea being that I can use the regex to identify errors that happened then   #report them to the user   identify_error /regex/, 'message'   identify_error /regex/, 'message'   end end 

What I want is that after the execute method is called the test_success and identify_error are automatically called like the validations in activerecord. Can anybody tell me how to do this? Thanks

Answer 1

Without having looked much at your code, here’s my take on implementing validation class methods:

module Validations   def self.included(base)     base.extend ClassMethods   end    def validate     errors.clear     self.class.validations.each {|validation| validation.call(self) }   end    def valid?     validate     errors.blank?   end    def errors     @errors ||= {}   end    module ClassMethods     def validations       @validations ||= []     end      def validates_presence_of(*attributes)       validates_attributes(*attributes) do |instance, attribute, value, options|         instance.errors[attribute] = 'cant't be blank' if value.blank?       end     end      def validates_format_of(*attributes)       validates_attributes(*attributes) do |instance, attribute, value, options|         instance.errors[attribute] = 'is invalid' unless value =~ options[:with]       end     end      def validates_attributes(*attributes, &proc)       options = attributes.extract_options!        validations << Proc.new { |instance|         attributes.each {|attribute|           proc.call(instance, attribute, instance.__send__(attribute), options)         }       }     end   end end 

It assumes that ActiveSupport is around, which it is in a Rails environment. You might want to extend it to allow multiple errors per attribute, with instance.errors[attribute] << 'the message', but I left out obscurities like that in order to keep this short sample as simple as possible.

Here’s a short usage example:

class MyClass   include Validations    attr_accessor :foo   validates_presence_of :foo   validates_format_of :foo, :with => /^[a-z]+$/ end  a = MyClass.new puts a.valid? # => false  a.foo = 'letters' puts a.valid? # => true  a.foo = 'Oh crap$(!)*#' puts a.valid? # => false