Smells to Refactorings Cheatsheet (.pdf) We developed this handy cheat sheet as a teaching aid while teaching our Refactoring Challenge Activity. You’ll find a table that maps code smells to their likely refactorings with corresponding page references to source material contained in the books Refactoring: Improving the Design of Existing Code by Martin Fowler and Refactoring to Patterns by Joshua Kerievsky.