of the fear involved in making changes to large code bases is fear of introducing subtle bugs; fear of changing things inadvertently. Without test, you just don’t know whether things are getting better or worse. » — Michael Feathers
to refactor This is the « boy scout rule » 01. 03. When you found a bug, fi rst write a test that triggers it, then fi x it. 04. Beware of the broken windows syndrome Developing a new feature and refactoring doesn’t mix well! 02.
E ff ectively with Legacy Code • Refactoring Going further Thanks to Michael C. Feather, Adam Thornhill, Cyrille Martraire, Thomas Pierrain, Martin Fowler, Jean-Baptiste Dusseaut, Ola Ellnestam, Daniel Brolund, Adrian Bolboaca