Use names that clearly reflect the thing being identified, and ensure renamed identifiers don’t accidentally couple to old data or misleading conventions. - **When an identifier backs persisted/external state (e.g., `localStorage` keys), rename the storage key as well** to prevent reusing stale values after refactors. ```ts // Before: reads old stored values const [sortDesc, setSortDesc] = useLocalStorage('reactQueryDevtoolsSortDesc', '') // After: new state name, use a new storage key const [baseSort, setBaseSort] = useLocalStorage('reactQueryDevtoolsBaseSort', '') ``` - **Name test files/identifiers for the specific scenario being tested; avoid redundant labels** when the suffix/extension already implies the category. ```txt # Prefer a scenario/feature name mutations.test-d.tsx ``` Applying this keeps naming semantically aligned with behavior and prevents accidental cross-contamination from previously persisted names.