MissCleo

Miss Cleo is a test failure predictor based on Tenderlove's idea. The idea is to give you a reasonable amount of confidence that your code changes are ok without having to run your full CI build.

Miss Cleo depends on Ruby 2.3.x (currently trunk Ruby) for its Coverage.peek_result functionality.

Add this line to your application's Gemfile:

gem 'miss_cleo'

And then execute:

$ bundle

Or install it yourself as:

$ gem install miss_cleo

Right now Miss Cleo only supports Cucumber and RSpec tests. To use Miss Cleo:

Before you can use Miss Cleo with your Cucumber tests, add the following line to your support/env.rb file:

MissCleo::TestConfigurations::CucumberConfig.setup_hooks(self)

Before you can use Miss Cleo with your RSpec tests, add the following line to your spec/spec_helper.rb file:

MissCleo::TestConfigurations::RspecConfig.setup_hooks(self)

To use Miss Cleo, you'll need to first build a coverage diff of your green build. Do this by running your tests with the COVERAGE environment variable set to true.

Examples:

• COVERAGE=true cucumber features/user.feature
• COVERAGE=true rspec spec/user_spec.rb

With your coverage diffs built, you'll need to generate a coverage map, which we're calling a deck. To build your deck, run: miss_cleo build_deck <list of coverage diff files>

After you've made some code changes, run miss_cleo predict to be shown the relevant tests to run.

Note: Miss Cleo only tries to predict tests failures for uncommitted changes. Make sure your build is green before committing code!

Like the real Miss Cleo, we can't predict everything. Things we can't predict include:

• Rails views
• ActiveRecord methods
• ActiveRecord concerns
• Anything that generally runs only through gem code
• Any external library code

1. Fork it ( https://github.com/[my-github-username]/miss_cleo/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request