free_mutant/lib/mutant/differ.rb
Dan Kubb 7293386c26 Add magic encoding header to all ruby files
* rubocop still warns about this on ruby 1.9.3, so it was fixed so
  it produces less output on travis.
2013-07-28 16:03:06 -07:00

127 lines
2.2 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
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
$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]
# returns colorized line
#
# @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