react-native-implementation

name	react-native-implementation
description	React Native and Expo implementation guidance for FE Dev. Use after fe-framework-coding-standard selects React Native, when building or reviewing screens, components, navigation, state, styling, accessibility, selectors, and ordinary tests without changing native modules.
agents	["fe-dev"]
sdlc_phase	implementation
owner	Platform Eng
status	active

React Native Implementation

When to use

Use this after fe-framework-coding-standard selects React Native for the task surface. This is the default React Native implementation skill for UI, state, navigation, styling, accessibility, instrumentation, and normal component/unit test work.

For native modules, permissions, deep links, app config, or platform files, also load react-native-platform-integration. For large lists, image-heavy screens, animations, slow interactions, startup, or memory issues, also load react-native-performance.

Inputs and outputs

• Inputs: task file, SRS Frontend-Framework: and §3.4.5 source layout, §3.4.6 frontend env keys, design handoff, Design Element Manifest, visual spec, instrumentation contract, API contracts, current RN/Expo source tree.
• Outputs: React Native/Expo code that fits the existing app architecture, implements every manifest row, uses declared runtime config, exposes stable selectors, preserves accessibility, and updates relevant unit/component tests.

Procedure

1. Identify the app shape before editing:
   • Expo managed / Expo prebuild / bare React Native;
   • routing: Expo Router, React Navigation, or project wrapper;
   • state: project server-state and client-state libraries;
   • styling: design system, tokens, StyleSheet, NativeWind, Tamagui, Dripsy, Restyle, or local convention.
2. Keep screen boundaries thin:
   • screens own route params, navigation, permissions, data loading, and orchestration;
   • feature components render manifest sections and emit typed events;
   • hooks/services own reusable data access and side effects.
3. Implement from the Design Element Manifest:
   • render every field, label, placeholder, action, state copy, list/card item, and modal/toast row;
   • preserve Figma order unless product behavior requires a documented deviation;
   • include loading, empty, validation error, recoverable error, disabled, permission-denied, and optimistic rollback states where applicable.
4. Use project-native state and data patterns:
   • do not add a store/query library for one task;
   • guard stale async results when route params change or screens unmount;
   • keep optimistic updates reversible and user-visible on failure;
   • store only durable preferences in async storage and secrets only in approved secure storage.
5. Build mobile-safe UI:
   • handle safe areas, status bars, keyboard overlap, home indicators, scroll insets, orientation, and text scaling;
   • use Pressable or project button components for interactions;
   • use FlatList / SectionList for dynamic or large lists with stable keys and empty/refresh states.
6. Add accessibility and instrumentation:
   • use accessibilityRole, accessibilityLabel, and accessibilityHint when visible content is insufficient;
   • add testID values only from docs/instrumentation-contract.md;
   • keep a minimum 44 x 44 logical pixel touch target unless the project standard is stricter.
7. Test and verify:
   • update Jest / React Native Testing Library tests for rendering, validation, and state transitions;
   • update Detox/Maestro only when the task changes a critical flow, following ui-test-execution;
   • run the project's lint, typecheck, Jest, and relevant platform build/test command when touched files require it.

Hard rules

• Do not mix routing approaches or introduce a new state/styling/test framework without an approved ADR.
• Do not hardcode API URLs, environment names, platform domains, secrets, or selector IDs.
• Do not scatter Platform.OS branches through UI trees when a platform adapter or .ios.tsx / .android.tsx file is clearer.
• Do not use DOM APIs, browser-only globals, or CSS assumptions in shared React Native code.
• Do not close the task while any required manifest row is missing from source or tests.

References

• ../fe-framework-coding-standard/SKILL.md - framework router and universal FE rules.
• ../react-native-performance/SKILL.md - React Native render, list, image, animation, and startup performance.
• ../react-native-platform-integration/SKILL.md - native modules, permissions, deep links, app config, storage, and platform files.
• ../ui-test-execution/SKILL.md - Detox/Maestro selector, fixture, determinism, and reporting rules.