free_mutant/lib/mutant/differ.rb
Markus Schirp 2842d0e5ee Fix differ edge case
Closes #57
2013-07-02 19:06:03 +02:00

121 lines
2.1 KiB
Ruby

module Mutant
# Class to create diffs from source code
class Differ
include Adamantium::Flat, Concord.new(:old, :new)
# Return source diff
#
# @return [String]
#
# @api private
#
def diff
output = ''
case diffs.length
when 0
nil
when 1
output = Diff::LCS::Hunk.new(old, new, diffs.first, max_length, 0).diff(:unified)
output << "\n"
else
raise 'Mutation resulted in more than one diff, should not happen!'
end
end
memoize :diff
# Return colorized source diff
#
# @return [String]
#
# @api private
#
def colorized_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.new(old, new)
super(lines(old), lines(new))
end
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.length > new.length ? old.length : new.length
end
# Return length difference
#
# @return [Fixnum]
#
# @api private
#
def length_difference
new.size - old.size
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
# Return colorized diff line
#
# @param [String] line
#
# @return [String]
# returns colorized line
#
# @api private
#
def self.colorize_line(line)
case line[0].chr
when '+'
Color::GREEN
when '-'
Color::RED
when '@'
line[1].chr == '@' ? Color::BLUE : Color::NONE
else
Color::NONE
end.format(line)
end
end # Differ
end # Mutant