From: walter@...
Date: 2004-04-15T23:07:55+09:00
Subject: Hash == not always working? Or am I missing something?

Hi everyone,


I am having difficulty with Hash and sometimes Arrays with ==.  Below 
is an example with Hashes.  I am trying to do some simple cleanup of 
our data and was trying TDD some code but I do not understand why it 
says my 2 Hashes are different.  They appear identical but show up as 
false using ==.

According to ri : 
---------------------------------------------------------------- 
Hash#==
     hsh == anOtherHash -> true or false
----------------------------------------------------------------------
--
     Equality---Two hashes are equal if they each contain the same
     number of keys and if each key-value pair is equal to (according 
to
     Object#==) the corresponding elements in the other hash.
        h1 = { "a" => 1, "c" => 2 }
        h2 = { 7 => 35, "c" => 2, "a" => 1 }
        h3 = { "a" => 1, "c" => 2, 7 => 35 }
        h4 = { "a" => 1, "d" => 2, "f" => 35 }
        h1 == h2   #=> false
        h2 == h3   #=> true
        h3 == h4   #=> false



This should work.  The code is below along with the Test::Unit 
output.


Am I missing something stupid????


<CODE>

module ShipToCleanUp
  def notes
    results = []
    1.upto(6) do |i|
      results << send("note#{i}")
    end
    results.join(" ").strip
  end
  
  def word_counts
    results = Hash.new{|h,k| h[k] = 0}
    notes.split(/\s+/).each{|word| results[word]+=1}
    results
  end
end


if __FILE__ == $0
  require 'test/unit'
  class ShipToCleanUpTester < Test::Unit::TestCase
    class ShipTo
      include ShipToCleanUp
      attr_accessor :note1, :note2, :note3, :note4, :note5, :note6
      def initialize(n1='', n2='', n3='', n4='', n5='', n6='')
        @note1, @note2, @note3, @note4, @note5, @note6 = n1, n2, n3, 
n4, n5, n6
      end
    end
    
    def setup
      @shipTo1 = ShipTo.new('LINE 1 AND SOME MORE ON LINE 1 ', '      
***** LINE 2 *****     ', '', '', 'LINE 5   ', 'AND LINE 6')
    end

    def test_word_counts
      expected = {}
      expected['LINE'] = 5
      expected['1']  = 2
      expected['AND'] = 2
      expected['SOME'] = 1
      expected['MORE'] = 1
      expected['ON'] = 1
      expected['*****'] = 2
      expected['2']  = 1
      expected['5']  = 1
      expected['6']  = 1
            
      assert_equal(expected, @shipTo1.word_counts)
    end
    
    def test_notes_some_empty
      expected = "1     6"
      assert_equal(expected, ShipTo.new("1", '', '', '', '', 
'6').notes)
    end
    
    def test_notes_empty
      expected = ""
      assert_equal(expected, ShipTo.new.notes)
    end
    
    def test_notes
      expected = "LINE 1 AND SOME MORE ON LINE 1        ***** LINE 2 
*****        LINE 5    AND LINE 6"
      assert_equal(expected, @shipTo1.notes)
    end
  end
end

</CODE>


When I run the code I get

Loaded suite C:/DOCUME~1/ADMINI~1/LOCALS~1/Temp/rbC.tmp
Started
...F
Finished in 0.04 seconds.

  1) Failure:
test_word_counts(ShipToCleanUpTester) 
[C:/DOCUME~1/ADMINI~1/LOCALS~1/Temp/rbC.tmp:46]:
<{"6"=>1,
 "AND"=>2,
 "LINE"=>5,
 "*****"=>2,
 "1"=>2,
 "2"=>1,
 "ON"=>1,
 "SOME"=>1,
 "5"=>1,
 "MORE"=>1}> expected but was
<{"6"=>1,
 "AND"=>2,
 "LINE"=>5,
 "*****"=>2,
 "1"=>2,
 "2"=>1,
 "ON"=>1,
 "SOME"=>1,
 "5"=>1,
 "MORE"=>1}>.

4 tests, 4 assertions, 1 failures, 0 errors




Any insight would be greatly appreciated.


Thanks,

Walt
*****************************************************
Walter Szewelanczyk
IS Director
M.W. Sewall & CO.        email : walter@mwsewall.com     
259 Front St.            Phone : (207) 442-7994 x 128
Bath, ME 04530           Fax   : (207) 443-6284
*****************************************************