From: Louis J Scoras <louis.j.scoras@...>
Date: 2007-02-12T01:27:42+09:00
Subject: Re: [QUIZ] One-Liners (#113)

# Largely just to play around with rspec a bit.
# The random_line solution too long as well.

require 'rubygems'
require 'spec'

def commify(quiz)
 quiz.to_s.reverse.gsub(/(\d{3})(?=\d)(?!\d*\.)/) {"#$1,"}.reverse
end

context "integers to strings" do
 specify "should get commas every three digits from the right" do
   commify(123).should      == '123'
   commify(1234).should     == '1,234'
   commify(123456).should   == '123,456'
   commify(-12345).should   == '-12,345'
   commify(-1001001).should == '-1,001,001'
 end
end

context "floats to strings" do
 specify "should not get commas after decimal" do
   commify(123.456).should     == '123.456'
   commify(123.456789).should  == '123.456789'
   commify(123456.789).should  == '123,456.789'
   commify(-123456.789).should == '-123,456.789'
 end
end

def flatten1(quiz)
  quiz.inject([]){|r,n| n.respond_to?(:each) ? n.each {|i| r<< i} : (r<< n) ; r}
end

context "arrays nested arrays only one level deep" do
 setup do
   @ary = [[1],2,[:symbol],'foo']
   @random = []
   10.times do
     n = rand(100)
     @random << (rand > 0.5 ? n : [n] )
   end
 end

 specify "should flatten1 the same as flatten" do
   flatten1(@ary).should    == @ary.flatten
   flatten1(@random).should == @random.flatten
 end
end

context "arrays nested multiple levels" do
 specify "should only loose 1 level of arrays" do
   flatten1([1, [2, [3]]]).should == [1,2,[3]]
   flatten1([[[[[1]]]]]).should   == [[[[1]]]]
 end
end

def shuffle(quiz)
  quiz.sort_by { rand }
end

context "An array with several elements" do
  setup do
    @rands = [3,2,1,6,5,4,9,8,7,10]
    @a     = (1..@rands.length).to_a
    x      = -1

    self.stub!(:rand).and_return { @rands[x+= 1] }
  end

  specify "should sort randomly w/ shuffle" do
    shuffle(@a).should == @rands[0..@a.length-1]
  end
end


module GhostWheel
 module Expression
   class LookAhead
   end
 end
end

def to_class(quiz)
 quiz.split(/::/).inject(Object) {|s,c| s.const_get(c.to_sym)}
end

context %{given a "class expression"} do
  specify "to_class should return that class" do
    GhostWheel.should_receive(:const_get).with(:Expression).and_return(GhostWheel::Expression)
    GhostWheel::Expression.should_receive(:const_get).with(:LookAhead).and_return(GhostWheel::Expression::LookAhead)

    to_class("GhostWheel::Expression::LookAhead")
  end

  specify "to_class should work for built-in classes" do
    to_class("Net::HTTP").should == Net::HTTP
  end
end

def wrap(quiz)
  quiz.gsub(/(.{1,40})\s+/){ "$1\n" }
end

context "A paragraph of text w/ less than 40 lines" do
  setup do
    @text = 'f' * 40
  end

  specify "should not be changed by wrap" do
    wrap(@text).should == @text
  end
end

context "A paragraph with more than 40 characters" do
  setup do
    @paragraph = <<-END_PARA.gsub(/\s+/, ' ').strip
       Given a wondrous number Integer, produce the sequence (in an
       Array).  A wondrous number is a number that eventually
       reaches one, if you apply the following rules to build a
       sequence from it.  If the current number in the sequence is
       even, the next number is that number divided by two.  When
       the current number is odd, multiply that number by three and
       add one to get the next number in the sequence.  Therefore,
       if we start with the wondrous number 15, the sequence is
       [15, 46, 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5, 16, 8,
       4, 2, 1].
    END_PARA
  end

  specify "should have no lines longer than 40 wide after wrapping" do
    wrap(@paragraph).split(/\n/).each do |line|
      line.length.should_not > 40
    end
  end
end

context "An paragraph with a word longer than 40 characters" do
  setup do
    @text = 'f' * 60
  end

  specify "should not be split mid word" do
    wrap(@text).should_not_include '\n'
  end
end

def anagrams(quiz)
  n=quiz[0].split(//).sort; quiz.select {|i| i.split(//).sort == n }
end

context "An array of words" do
  setup do
    @a = %w/silly lilsi looloo yllis yuf silly2 islyl/
  end

  specify "anagrams should contain words with same letters same number
of times" do
    anagrams(@a).should == %w/silly yllis islyl/
  end
end

def to_bin(quiz)
  quiz.scan(/\w/).collect {|c| sprintf "%b", c[0] }.join('')
end

context "A ascii string" do
  setup do
    @str = "you are dumb"
  end

  specify "should be converted to binary by to_bin" do
    to_bin(@str).should == '111100111011111110101' +
                           '110000111100101100101' +
                           '1100100111010111011011100010'
  end
end

def rand_line(quiz)
  z=0;quiz.each{z+=1};quiz.seek 0;n=rand
z;quiz.each_with_index{|x,i|;return x if i==n}
end

context "an open file handle" do
  setup do
    require 'stringio'
    @fh = StringIO.new <<-END
      one
      two
      three
      four
    END
  end

  specify "should return a random line" do
    line = rand_line(@fh).strip
    %w/one two three four/.should_include(line)
  end
end

def wonder(quiz)
  @a=[quiz];until quiz==1;@a<< quiz=quiz%2==0?quiz/2: quiz*3+1 end;@a
end

context "The wonderous sequence for 15" do
  setup { @w = wonder(15) }
  specify "should end with 1" do
    @w[@w.length-1].should == 1
  end
  specify "should match the test data" do
    @w.should == [15, 46, 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5,
16, 8, 4, 2, 1]
  end
end

def hashify(quiz)
  quiz.reverse.inject(){|m,i|{i=>m}}
end

context "An array of strings" do
  specify "should return nested hashes when hashified" do
    hashify(%w/one two three four five/).should ==
        {"one" => {"two" => {"three" => {"four" => "five"}}}}
  end
end