Ruby Date & DateTime class extension

My recent user story demanded me to extend Date and  DateTime classes to support few more methods.

Following is the code and this is done using Ruby's Dynamic Proxy Technique.

	=begin
	Author: Vigram K
	Date: 27th August 2014
	Title: Extension for Date & DateTime classes
	Adds following methods for date object,
	first_monday_of_month, first_tuesday_of_month .. first_sunday_of_month
	last_monday_of_month, last_tuesday_of_month .. last_sunday_of_month
	monday_of_week, tuesday_of_week .. sunday_of_week
	Usages:
	date = Date.today #=> Wed, 27 Aug 2014
	date.first_monday_of_month #=> Mon, 04 Aug 2014
	date.last_friday_of_month #=> Fri, 29 Aug 2014
	date.tuesday_of_week #=> Tue, 26 Aug 2014
	=end
	module InstanceMethods
	def self.included(base)
	base.class_eval do
	def last_date_of_month
	@last_date_of_month ||= self.class.new(year, month, -1)
	end
	def first_date_of_month
	@first_date_of_month ||= self.class.new(year, month, 1)
	end
	# Dynamic Proxy
	def method_missing(method, *args, &block)
	case
	when method.match(/^(first|last)_(.+)_of_month$/)
	if $1 == "last"
	send("#{$1}_date_of_month").downto(0).find {|day| day.send("#{$2}?") }
	else
	send("#{$1}_date_of_month").upto(10000000).find {|day| day.send("#{$2}?") }
	end
	when method.match(/^(monday|tuesday|wednesday|thursday|friday)_of_week$/)
	(beginning_of_week .. end_of_week).find{|day| day.send("#{$1}?")}
	else
	super
	end
	end
	end
	end
	end
	class Date
	include InstanceMethods
	end
	class DateTime
	include InstanceMethods
	end

view raw date.rb hosted with ❤ by GitHub

Copy above date.rb file and keep it under initializer directory of your Rails application.