Extend String class with unindent method to tidy HEREDOC

string_unindent_for_heredoc.rb

## Credit to SpiralOfHope for bugfix
###  https://twitter.com/#!/spiralofhope
## Credit to Rene Sarsoo for original code 
###  http://stackoverflow.com/users/15982/rene-saarsoo
###  http://stackoverflow.com/questions/3772864/how-do-i-remove-leading-whitespace-chars-from-ruby-heredoc/4465640#4465640


class String
  # Bug-fixed:  If there is no indenting, this explodes.  I changed \s+ to \s*
 
  # Removes beginning-whitespace from each line of a string.
  # But only as many whitespace as the first line of text has.
  #
  # Meant to be used with heredoc strings like so:
  #
  # text = <<-EOS.unindent
  #   This line has no indentation
  #     This line has 2 spaces of indentation
  #   This line is also not indented
  # EOS
  def unindent()
    lines = Array.new
    self.each_line { |ln| lines << ln }
    first_line_ws = lines[0].match( /^\s*/ )[0]
    rx = Regexp.new( '^\s{0,' + first_line_ws.length.to_s + '}' )
    lines.collect { |line| line.sub( rx, '' ) }.join
  end