Brent Sordyl's blog

rcov is a code coverage tool for Ruby. It is commonly used for viewing overall test coverage of target code. It features:

* fast execution: 20-300 times faster than previous tools
* multiple analysis modes: standard, bogo-profile, “intentional testing”, dependency analysis…
* detection of uncovered code introduced since the last run (“differential code coverage”)
* fairly accurate coverage information through code linkage inference using simple heuristics
* cross-referenced XHTML and several kinds of text reports
* support for easy automation with Rake and Rant
* colorblind-friendliness
(Link: rcov: code coverage for Ruby)

Heckle is a great new library from Kevin Clark (though Ryan Davis wrote a proof of concept at RubyConf) that ‘torments your tests’. It uses ParseRuby and RubyToRuby to rip your code apart and forces random data into your code (currently it does this for strings, symbols, regexps, ranges, booleans, and numbers) to see how good your tests really are.

Simply, it’s fuzz testing for your Ruby tests, and that’s a good thing if you want your test suites to be strong and far-reaching.
(Link: Heckle: Tortures Your Tests For Revealing Confessions)