Cucover

Cucover is a thin wrapper for Cucumber which makes it lazy.

Question: What does it mean for Cucumber to be lazy?

Answer: It will only run a scenario if it needs to.

How does it decide whether it needs to run a scenario? Every time you run a feature using Cucover, it watches the code in your application that is executed, and remembers. The next time you run Cucover, it skips a scenario if the source files (or the feature itself) have not been changed since it was last run.

Features

• Within a feature, Cucover will only re-run the Scenarios that have been affected by your changes
• Uses RCov to map features to covered source files
• Patches Rails to also map scenarios to covered .erb view templates
• Shows skipped Scenarios, for confidence
• Re-runs failing features, even when nothing has changed, for that good old red-bar feel.
• Allows you to see which lines of a source file are tested by which scenarios

Installation and Usage

sudo gem install mattwynne-cucover --source http://gems.github.com

To run your features lazily, use the cucover binary instead of cucumber:

cucover -- features/lamb_chops.feature

To see what Cucover has already recorded (in the cucover.data file):

cucover --show-recordings

To find out which tests cover which lines of a given source file:

cucover --coverage_of path/to/some_source_file.rb

Limitations

• Anything that runs out of process will not be covered, and therefore cannot trigger a re-run, so if you use Cucumber to drive Selenium, for example, you're out of luck.
• This is very new and experimental. There may be bugs. Feedback is welcome via github messages.

Todo

• Proper args parsing and command-line help
• Work on a way to include coverage from out-of-process ruby code run during a test
• Speed up the whole thing by only writing the recordings to disk when the process exits
• Run code coverage and remove any slop following refactoring
• Speed up the Rails test - maybe strip some guff out of the environment load?

Similar 'Selective Testing' Tools

• JTestMe
  • http://xircles.codehaus.org/projects/jtestme
  • Agile2008 conference submission
• Infinitest
  • http://code.google.com/p/infinitest/
  • Contact: Ben Rady
• Google Testar
  • http://code.google.com/p/google-testar/
  • Contact: Misha Dmitriev
• Clover test optimization
  • http://www.atlassian.com/software/clover/features/optimization.jsp
• JUnitMax
  • a selective testing tool by Kent Beck
  • http://junitmax.com/