SimpleCov is a code coverage analysis tool for Ruby.  It uses Ruby's
built-in Coverage library to gather coverage data, but makes processing the
results much easier by providing a clean API to filter, group, merge,
format, and display them -- a complete coverage suite you can set up in just
a couple of lines.

SimpleCov tracks covered Ruby code; gathering coverage for templating
solutions like ERB, Slim, and Haml is not supported (though see Eval
coverage for ERB).

In most cases you'll want overall coverage results spanning all of your
tests -- unit tests, Cucumber features, and so on.  SimpleCov handles this
automatically by caching and merging results as it generates reports, so a
report reflects coverage across your whole test suite and gives you a truer
picture of your blank spots.

SimpleCov bundles two formatters that need no extra gems: the default HTML
formatter (which renders the browsable report) and a JSON formatter.  Both
were once separate gems (simplecov-html and simplecov_json_formatter) but
are now built into SimpleCov and configured automatically when you launch
it.

Homepage:
https://github.com/colszowka/simplecov
