vendor/gems/rspec-1.1.2/lib/spec/expectations/differs/default.rb

   1 begin
   2   require 'rubygems'
   3   require 'diff/lcs' #necessary due to loading bug on some machines - not sure why - DaC
   4   require 'diff/lcs/hunk'
   5 rescue LoadError ; raise "You must gem install diff-lcs to use diffing" ; end
   6
   7 require 'pp'
   8
   9 module Spec
  10   module Expectations
  11     module Differs
  12
  13       # TODO add some rdoc
  14       class Default
  15         def initialize(options)
  16           @options = options
  17         end
  18
  19         # This is snagged from diff/lcs/ldiff.rb (which is a commandline tool)
  20         def diff_as_string(data_old, data_new)
  21           data_old = data_old.split(/\n/).map! { |e| e.chomp }
  22           data_new = data_new.split(/\n/).map! { |e| e.chomp }
  23           output = ""
  24           diffs = Diff::LCS.diff(data_old, data_new)
  25           return output if diffs.empty?
  26           oldhunk = hunk = nil
  27           file_length_difference = 0
  28           diffs.each do |piece|
  29             begin
  30               hunk = Diff::LCS::Hunk.new(data_old, data_new, piece, context_lines,
  31                                          file_length_difference)
  32               file_length_difference = hunk.file_length_difference
  33               next unless oldhunk
  34               # Hunks may overlap, which is why we need to be careful when our
  35               # diff includes lines of context. Otherwise, we might print
  36               # redundant lines.
  37               if (context_lines > 0) and hunk.overlaps?(oldhunk)
  38                 hunk.unshift(oldhunk)
  39               else
  40                 output << oldhunk.diff(format)
  41               end
  42             ensure
  43               oldhunk = hunk
  44               output << "\n"
  45             end
  46           end
  47           #Handle the last remaining hunk
  48           output << oldhunk.diff(format) << "\n"
  49         end
  50
  51         def diff_as_object(target,expected)
  52           diff_as_string(PP.pp(target,""), PP.pp(expected,""))
  53         end
  54
  55         protected
  56         def format
  57           @options.diff_format
  58         end
  59
  60         def context_lines
  61           @options.context_lines
  62         end
  63       end
  64     end
  65   end
  66 end