Heckle
RSpec has tight integration with Heckle. Heckle is a tool inspired from
Jester.
RSpec’s Heckle support will run your specs many times, each time with a tiny mutation to your code (the
application code, not the spec code).
The idea is that if your specs still pass after the code has been mutated, then your specs are incomplete,
and RSpec will tell you.
Running specs with Heckle
Just use the —heckle option and give it an argument, which should be the full name of a module
or a method. Run spec —help for further details.