When code review finds duplicated logic or repeated formatting/constants, treat it as a “single source of truth” violation. Factor shared logic into a helper/module and reuse it everywhere; avoid hardcoded literals where an existing helper/constant exists; and keep established idioms consistent. Guidelines: - **Duplicate logic across code paths** (e.g., launch vs resume, attach vs subscribe) should be extracted into a shared helper function placed near related constants/contracts. - **Duplicate protocol/type definitions** should be aliased to one canonical type (e.g., `type New = Old;`) or imported from a shared module. - **Hardcoded strings/format separators used for assertions or UI formatting** should become shared constants (or reuse an existing formatter helper) so updates don’t require hunting multiple sites. - **Maintain consistent style/idioms** for readability (e.g., prefer the existing `timer.unref?.()` pattern over verbose type guards when they’re equivalent). - **Don’t keep misleading no-op steps** (e.g., assigning `undefined` immediately overwritten on the next line); remove dead assignments when refactoring. Example (helper extraction): ```ts // helpers.ts export function extractParentToolNames(generationConfig: unknown): string[] { // ... shared extraction logic ... return names; } // call sites const names = extractParentToolNames(generationConfig); ``` Example (constant for repeated literals in tests): ```ts const INITIAL_CONTENT = 'original content'; expect(input.content).not.toBe(INITIAL_CONTENT); ```