gistfile1.txt

ruby find_same_name_different_size.rb 
find_same_name_different_size.rb:18:in `==': undefined method `key' for #<SharedFile:0x007fd54b091078> (NoMethodError)
	from find_same_name_different_size.rb:23:in `eql?'
	from find_same_name_different_size.rb:39:in `each'
	from find_same_name_different_size.rb:39:in `group_by'
	from find_same_name_different_size.rb:39:in `<main>'

test.rb

require 'find'
require 'pathname'
require 'pp'
require 'digest/md5'

class SharedFile
  attr_reader :file_name
  attr_reader :file_size
  
  def initialize(path, file_size)
    #@path = path
    @key = Digest::MD5.hexdigest(IO.read(path)).to_sym
    @file_name = Pathname.new(path).basename.to_s
    @file_size = file_size
  end
  
  def ==(other)
    self.file_name == other.file_name && self.key != other.key
    # self.file_name == other.file_name && self.file_size != other.file_size
  end
  
  def eql?(other)
    self == other
  end

  def hash
    [file_name].hash
  end
 
end  

files = []

Dir.glob("**/*", File::FNM_DOTMATCH).each do |filename|
  next if File.directory?(filename)
  files << SharedFile.new(filename,File.size(filename))
end

results = files.group_by{|i| i}.map{|k,v| [k, v.count] }


results.each do |result|
  puts "#{result[0]} , #{result[1]}"
end