SimpleCov

SimpleCov is a code coverage analysis tool for Ruby. It uses Ruby’s built-in Coverage library to gather coverage data, and makes processing the results much easier by providing a clean API to filter, group, merge, format and display them.

A full coverage setup runs with a couple of lines of code at the start of the test helper, and works with test frameworks such as RSpec, Minitest and Cucumber. Line and branch coverage are measured, results from several test suites are merged, files are grouped, for example into models and controllers in a Rails application, and a minimum coverage can be required. The default HTML formatter produces a browsable report, and other formatters export data for CI and coverage services.

SimpleCov is free and open source under the MIT licence.