🔥 Minitest Heat 🔥

Minitest Heat helps you identify problems faster so you can more efficiently resolve test failures by generating a heat map that shows where failures are concentrated.

For a more detailed explanation of Minitest Heat with screenshots, head over to the wiki for the full story.

Or for some additional insight about priorities and how it works, this Twitter thread is a good read.

Add this line to your application's Gemfile:

gem 'minitest-heat'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install minitest-heat

And depending on your usage, you may need to require Minitest Heat in your test suite:

require 'minitest/heat'

Minitest Heat doesn't currently offer a significant set of configuration options, but the thresholds for "Slow" and "Painfully Slow" tests can be adjusted. By default, it considers anything over 1.0s to be 'slow' and anything over 3.0s to be 'painfully slow'.

You can add a configuration block to your test_helper.rb file after the require 'minitest/heat' line.

For example:

Minitest::Heat.configure do |config|
  config.slow_threshold = 0.01
  config.painfully_slow_threshold = 0.5
end

After checking out the repo, run bin/setup to install dependencies. Then, run rake test 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.

In order to easily see how Minitest Heat handles different combinations of different types of failures, the following environment variables can be used to force failures.

IMPLODE=true           # Every possible type of failure, skip, and slow is generated
FORCE_EXCEPTIONS=true  # Only exception-triggered failures
FORCE_FAILURES=true    # Only standard assertion failures
FORCE_SKIPS=true       # No errors, just the skipped tests
FORCE_SLOWS=true       # No errors or skipped tests, just slow tests

So to see the full context of a test suite, IMPLODE=true bundle exec rake will work its magic.

Bug reports and pull requests are welcome on GitHub at https://github.com/garrettdimon/minitest-heat. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

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

Everyone interacting in the Minitest::Heat project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.