free_mutant/lib/mutant/differ.rb
2013-10-20 21:56:30 -07:00

122 lines
2.1 KiB
Ruby

# encoding: utf-8
module Mutant
# Class to create diffs from source code
class Differ
include Adamantium::Flat, Concord.new(:old, :new)
# Return source diff
#
# @return [String]
# if there is a diff
#
# @return [nil]
# otherwise
#
# @api private
#
def diff
case diffs.length
when 0
nil
when 1
Diff::LCS::Hunk.new(old, new, diffs.first, max_length, 0)
.diff(:unified) << "\n"
else
$stderr.puts(
'Mutation resulted in more than one diff, should not happen! ' +
'PLS report a bug!'
)
nil
end
end
memoize :diff
# Return colorized source diff
#
# @return [String]
# if there is a diff
#
# @return [nil]
# otherwise
#
# @api private
#
def colorized_diff
return unless diff
diff.lines.map do |line|
self.class.colorize_line(line)
end.join
end
memoize :colorized_diff
# Return new object
#
# @param [String] old
# @param [String] new
#
# @return [Differ]
#
# @api private
#
def self.build(old, new)
new(lines(old), lines(new))
end
# Break up source into lines
#
# @param [String] source
#
# @return [Array<String>]
#
# @api private
#
def self.lines(source)
source.lines.map { |line| line.chomp }
end
private_class_method :lines
private
# Return diffs
#
# @return [Array<Array>]
#
# @api private
#
def diffs
Diff::LCS.diff(old, new)
end
memoize :diffs
# Return max length
#
# @return [Fixnum]
#
# @api private
#
def max_length
[old, new].map(&:length).max
end
# Return colorized diff line
#
# @param [String] line
#
# @return [String]
#
# @api private
#
def self.colorize_line(line)
case line[0]
when '+'
Color::GREEN
when '-'
Color::RED
else
Color::NONE
end.format(line)
end
end # Differ
end # Mutant