cupid-code-reviewlisted

# CUPID as a Code Review and Refactoring Lens ## Overview CUPID is a set of five properties — **C**omposable, **U**nix philosophy, **P**redictable, **I**diomatic, **D**omain-based — described by Daniel Terhorst-North as things good code *tends toward*, not rules it must comply with. That makes them ideal review lenses: you are asking "how strongly does this code exhibit this property?" and "what would moving it further in this direction look like?" Use them as questions, not verdicts. --- ## The Five Lenses ### C — Composable: plays well with others Code is composable when it can be combined with other code in many contexts without modification. **Review questions:** - Can I use this function/module independently, without pulling in unrelated state? - Is the API surface the minimum needed — no accidental exposure? - Are dependencies explicit (passed in) rather than implicit (global/ambient)? - Does it work at multiple call sites, or does it secretly assume one? **Refactoring signals:** - Many parameters that describe context rather than the operation itself - Functions that only make sense when called in a specific order - Hidden global state or singleton dependencies - "God object" arguments that carry everything **Move toward:** Smaller surface area. Dependencies injected. Works in isolation. --- ### U — Unix philosophy: does one thing well Not just single responsibility — the function does its one thing *completely* and *well*, with a clear, nameable purpose