deathnote gem receive 2 commit hash and compare those dead code from each version of project code. This will be helpful if you have a lot false-positive result.

You may get better understanding with this slide.

deathnote assumes you are using git. It will use git checkout to switch to each revision.

Add this line to your application's Gemfile:

gem 'deathnote', require: false

Or install it yourself as:

$ gem install deathnote

Usage: deathnote [options] files_or_dirs
    -h, --help                       Display this help.
    -p, --past-commit=[commit hash]  Specify past commit hash.
    -n, --newer-commit=[commit hash] Specify newer commit hash.
    -r, --rails                      Filter some rails call conversions.
    -w, --whitelist=FILE             Whitelist with separated by \n
    -e, --exclude=FILE1,FILE2,...    Exclude files or directories in comma-separated list.

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/riseshia/deathnote.

The gem is available as open source under the terms of the MIT License.