simplecov

https://github.com/simplecov-ruby/simplecov

Ruby

Code coverage for Ruby with a powerful configuration library and automatic merging of coverage across test suites

SimpleCov::Configuration#refuse_coverage_drop

Refuses any coverage drop. That is, coverage is only allowed to increase.
SimpleCov will return non-zero if the coverage decreases.

Source | Google | Stack overflow

Edit

git clone [email protected]:simplecov-ruby/simplecov.git
cd simplecov
open sig/simplecov.rbs

Contribute

# Make a new branch
git checkout -b -your-name--update-docs-SimpleCov--Configuration-refuse_coverage_drop-for-pr

# Commit to git
git add sig/simplecov.rbsgit commit -m "better docs for SimpleCov::Configuration#refuse_coverage_drop"

# Open pull request
gem install hub # on a mac you can `brew install hub`
hub fork
git push <your name> -your-name--update-docs-SimpleCov--Configuration-refuse_coverage_drop-for-pr
hub pull-request

# Celebrate!