gistfile1.rb

# In reply to http://www.ultrasaurus.com/sarahblog/2009/08/ruby-unit-test-frameworks/
# Put this in test_helper.rb to compare two arbitrarily nested structures.
# Usage: compare_objects(o1, o2).  Raises an exception if it finds any differences.

  # recursivly compare two objects. raise if a difference was found, return if not.
  def compare_objects(wanted, actual, path=[])
    if wanted.kind_of?(Hash)
      raise "Objects differ at #{path.join(".")}: extra keys in wanted: #{(wanted.keys - actual.keys).inspect}" if (wanted.keys - actual.keys).length > 0
      raise "Objects differ at #{path.join(".")}: extra keys in actual: #{(actual.keys - wanted.keys).inspect}" if (actual.keys - wanted.keys).length > 0
      wanted.keys.sort.each do |key|
        compare_objects wanted[key], actual[key], path.dup << key
      end
    elsif (wanted.kind_of?(Enumerable) && !wanted.kind_of?(String)) && (actual.kind_of?(Enumerable) && !actual.kind_of?(String))
      raise "Objects differ at #{path.join(".")}: wanted has #{wanted.length} and actual has #{actual.length} items.\nWANTED=<<#{wanted.inspect}>>\nACTUAL=#{actual.inspect}" if wanted.length != actual.length
      (0..wanted.length).each do |i|
        compare_objects wanted[i], actual[i], path.dup << "[#{i}]"
      end
    elsif wanted != actual
      raise "Objects differ at #{path.join(".")}:\nWANTED=<<#{wanted.inspect}>>\nACTUAL=<<#{actual.inspect}>>"
    end
  end