This project was born out of the need to display a coverage summary in the plain text output of CI jobs, along the lines of:

--------------------------------------------------------------------------------
Incomplete test coverage
--------------------------------------------------------------------------------

/lib/my-app/data/groups/calculated.rb: 44.9% (missed: 33,34,35,36,37,38,48,49,61,62,64,67,68,70,71,72,74,77,78,83,86,101,102,103,104,106,108)
/lib/my-app/data/groups/file.rb: 60.87% (missed: 21,22,23,24,25,36,47,48,49)
/lib/my-app/data/groups/ldap.rb: 45.65% (missed: 23,24,25,26,27,38,39,42,49,50,51,52,54,57,69,70,73,81,82,83,84,88,99,109,121)
/lib/my-app/data/ldap.rb: 68.63% (missed: 93,95,96,97,98,99,100,102,103,104,105,106,107,109,113,115)

However, since the most flexible way to generate this output was via a template, this project generalizes the approach to render the output from the user's choice of ERB file. The default template produces output like above, but it's possible to configure the ERB file anywhere on the file system. For use in CI, perhaps you'll want your template right there in your project next to your tests.

Add this line to your application's Gemfile:

gem "simplecov-erb", require: false

To pull in the dependencies:

script/bootstrap

Or install it yourself as:

gem install simplecov-erb

At this point, it's assumed you've already set up SimpleCov and that it's all configured and working. Once you're to that point, edit your spec_helper.rb, test_helper.rb, or .simplecov like this. This default configuration outputs to a file named coverage/coverage.txt in the format from the example above.

# spec_helper.rb

require "simplecov-erb"

SimpleCov.start do
  SimpleCov.formatter = SimpleCov::Formatter::ERBFormatter
end

If you need to exercise more control over the settings, consult this fully-commented example that demonstrates all of the additional settings:

# spec_helper.rb

require "simplecov-erb"

SimpleCov.start do
  # You need this line for sure.
  SimpleCov.formatter = SimpleCov::Formatter::ERBFormatter

  # You can choose a different template if you don't want to use the default.
  SimpleCov::Formatter::ERBFormatter.erb_file = "/some/path/template.erb"

  # Sometimes it's handy to have the ERB file be relative to *this* file. So instead
  # of the previous line, you could do this instead.
  SimpleCov::Formatter::ERBFormatter.erb_file = File.expand_path("./templates/template.erb", __dir__)

  # You can choose a different output filename if you don't want to use "coverage.txt".
  # This file will still appear in the "coverage" directory (or whatever directory
  # you configured SimpleCov to output to).
  SimpleCov::Formatter::ERBFormatter.output_filename = "my-custom-coverage.report.txt"
end

This project is mature. It's simple, it works, and it's feature-complete as per its original vision.

Maintenance at this point is pretty much limited to updating the vendored dependencies as vulnerabilities are reported by GitHub. I do intend to update this if it ever becomes incompatible with a new release of simplecov. Except as required to maintain compatibility, I am not planning to add new features.

Contributions are welcome. If you're planning to make any substantial changes or additions, please consider opening an Issue first to make sure whatever you're planning is compatible with the objectives of this project.

Fork the repo and run script/bootstrap to install dependencies. Then, run script/cibuild to run the tests.

Bug reports and pull requests are welcome on GitHub at https://github.com/kpaulisse/simplecov-erb. Contributors are expected to adhere to the code of conduct published in this repository.

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