cover_rage is a Ruby code coverage tool designed to be simple and easy to use. It can be used not only for test coverage but also in production services to identify unused code.
Key features:
-
Runs in continuous processes (e.g., Rails servers)
-
Zero dependencies
-
Supports forking and daemonization without additional setup
require 'cover_rage'AND THAT’S IT!
No rack middleware, no fork callbacks, no configuration files, and no additional setup required.
It starts collecting coverage data and periodically writes to ./cover_rage.pstore.
To change the store type and location, refer to COVER_RAGE_STORE_URL below.
To export results to HTML later, run cover_rage.
cat >main.rb <<RUBY
s = 0
10.times do |x|
s += x
end
fork
if s == 45
p :ok
else
p :ng
end
RUBY
gem install cover_rage
ruby -r cover_rage main.rb
cover_rage > cover_rage.htmlNo additional setup is required because Rails loads gems automatically, but you can customize the behavior by updating Gemfile.
To run cover_rage only in the test environment:
gem 'cover_rage', group: :testTo manually start cover_rage:
gem 'cover_rage', require: falserequire 'cover_rage'-
COVER_RAGE_STORE_URLAvailable URL schemes:
-
pstore://ABSOLUTE_PATH_TO_PSTORE_FILE -
redis://REDIS_HOST -
sqlite://ABSOLUTE_PATH_TO_SQLITE_DB_FILE
Ensure you have the necessary gems (e.g.,
sqlite3,redis) installed to use other store types.Defaults to
pstore:$(pwd)/cover_rage.pstore. -
-
COVER_RAGE_INTERVALIt sets The interval in seconds between each write to the store.
Defaults to
60. -
COVER_RAGE_PATH_PREFIXcover_rage will only record files that match the specified prefix.
Defaults to
Rails.rootif theRailsconstant is defined; otherwise, defaults toDir.pwd.