What problem does it solve? React Native and Expo codebases accumulate subtle mistakes—unsafe type casts, auth redirects in render, scattered error handling, hardcoded values—that pass review and cause bugs later. This Skill provides a concrete checklist of wrong-versus-right patterns so reviewers and debuggers catch these issues consistently. ## Core Features & Use Cases - Type Safety Rules: Replaces as casts and non-null assertions with discriminated unions, nullish coalescing, and shared API response types. - Architecture Patterns: Enforces auth redirects in useEffect, mutations via TanStack Query useMutation, and token access only through the auth store with expo-secure-store. - UI & Styling Conventions: Flags hardcoded colors/spacing, inline maps for fixed UI sets, oversized route pages, and mock data in components. - Use Case: During a pull request review of a new exam screen, load this Skill to verify the route page stays under 80 lines, API calls use useMutation, and audio uses hidden controls per VSTEP exam rules. ## Quick Start Review this React Native screen component against the mobile anti-patterns checklist and list every violation with the corrected code.
