Noise Paper

Declare war on everything with Chaser

Andrew Grimm, University of New South Wales

Lightweight mutation testing in any flavor of ruby

Mutation testing

Evaluates thoroughness of unit tests

Changes code being unit tested

If changes don't cause test failures, it isn't totally thorough

Main ruby mutation tester is Heckle

Chaser is a new lightweight alternative

Chaser != Bradbury

Chaser is about a different set of mutations

Bradbury about making the unit tests faster

!=

Reasons for creating Chaser

Heckle currently relies on ParseTree

ParseTree relies on MRI Ruby 1.8 and doesn't work under Windows

100% pure ruby

Yay:Chaser uses plain old metaprogramming

Works under ruby 1.9, Windows, JRuby

Boo:Doesn't mutate every piece of code in a method

Currently only modifies the methods' return values