Crispr

Crispr is a mutation testing tool for Ruby. It introduces small mutations into your code to test whether your existing test suite can detect and fail on them. This helps reveal gaps in your test coverage and improve confidence in your codebase.

Installation

Add this line to your application’s Gemfile:

gem "crispr"

And then execute:

bundle install

Or install it yourself as:

gem install crispr

Usage

Run Crispr against a specific file or directory:

crispr run path/to/your/code.rb

The tool will:

• Parse the code into an AST
• Apply simple mutations
• Re-run your test suite for each mutation
• Report which mutations survived (i.e., were not detected by tests)

Development

After checking out the repo, run:

bin/setup

To run the tests:

rake spec

To install this gem onto your local machine:

bundle exec rake install

To release a new version, update the version number in version.rb, then run:

bundle exec rake release

Contributing

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

License

This project is licensed under the MIT License.