Code smells

Spot and fix structural code smells — duplicated code, long functions, god objects, feature envy, primitive obsession, shotgun surgery, and Fowler's other named symptoms of a design under strain — without rewriting working code that just happens to look unusual. Triggers when reviewing existing code for maintainability, when a change touches the same handful of files every time (a smell in itself), or when explicitly asked to clean up or refactor. Scoped to the code in front of you — for a standing-back audit of a whole codebase, that is engineering-assessment. Not for new code being written for the first time (a smell is a pattern that emerged under real use; guessing at…