Refactoring Legacy code with tests

(This page is a collection of notes and references taken from discussions during a 5 Day Training)

Concepts:

• Trusting Eclipse's Refactoring Support to help us find a testable "Seam" in the code
• Sunk-cost fallacy
• "Respond to pain by changing the source code, not masking the pain in the test or with testing tools"
• "Never trust a test you haven't seen fail"
• Primitive Obsession
• Sandi Metz's Squint Test: changes in shape indicate high complexity (loops and branching), while changes in color suggest the code operates at multiple levels of abstraction simultaneously

References:

• Michael Feathers' book, "Working Effectively with Legacy Code"
• Sandi Metz's RailsConf 2014 presentation: "All the small things", in which she explains her approach to the Gilded Rose Kata