# expo-react-native-javascript-best-practices

Guidelines for building Expo React Native apps using JavaScript. Guides your AI agent on functional components, Expo Router navigation, and FlatList tuning.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 777 installs · ★ 286
- Author: Mindrally
- License: Apache-2.0 · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/Mindrally/skills/tree/HEAD/expo-react-native-javascript-best-practices/SKILL.md
- Updated: 2026-10-08
- HTML: https://affpapa.org/en/nevibecode/skills/expo-react-native-javascript-best-practices

## What it does

This skill guides coding assistants to follow clean JavaScript practices in Expo React Native projects. It enforces functional components using hooks like `useState` and `useEffect`, camelCase for variables, and feature-based directory organization. When TypeScript is not in use, it instructs the agent to check props with `PropTypes`.

Performance rules focus on the UI thread. The agent learns to prevent re-renders with `React.memo()` and tune `FlatList` using `removeClippedSubviews`, `maxToRenderPerBatch`, and `windowSize`. It also bans anonymous callback functions inside `renderItem` handlers. Styling relies on `StyleSheet.create()` or Styled Components, with `react-native-fast-image` recommended for images.

Navigation relies entirely on Expo Router for cross-platform deep linking across Android, iOS, and web. Deployment practices reference EAS Build and OTA updates. For teams already running strict TypeScript, the `PropTypes` conventions will be redundant.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add Mindrally/skills --skill expo-react-native-javascript-best-practices -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/expo-react-native-javascript-best-practices/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/expo-react-native-javascript-best-practices/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add Mindrally/skills --skill expo-react-native-javascript-best-practices -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/expo-react-native-javascript-best-practices/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add Mindrally/skills --skill expo-react-native-javascript-best-practices -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/expo-react-native-javascript-best-practices/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install Mindrally/skills expo-react-native-javascript-best-practices
```

2. **Manually: put the files in place**
- File: `.github/skills/expo-react-native-javascript-best-practices/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add Mindrally/skills --skill expo-react-native-javascript-best-practices -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/Mindrally/skills --path expo-react-native-javascript-best-practices
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/expo-react-native-javascript-best-practices/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add Mindrally/skills --skill expo-react-native-javascript-best-practices -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/Mindrally/skills/tree/HEAD/expo-react-native-javascript-best-practices/SKILL.md

## When to use it
- tune FlatList performance with batching and clipping props
- configure file-based navigation using Expo Router
- split large React Native components into functional hooks
- enforce feature-based directory structures in Expo apps

## Example prompts
- Build a user profile screen using Expo Router and functional components
- Optimize my FlatList component configuration according to the skill guidelines
- Refactor this class component into a hook-based functional component with PropTypes

## Source text · SKILL.md · Apache-2.0

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 31724041149da2a1.

BEGIN THIRD-PARTY FILE 31724041149da2a1
```text
---
name: expo-react-native-javascript-best-practices
description: Expo React Native JavaScript best practices for clean code, functional components, performance optimization, and Expo Router navigation.
metadata:
  maintainer: Mindrally
  source: https://github.com/Mindrally/skills
---

# Expo React Native JavaScript Best Practices

Guidelines for building high-quality Expo React Native applications with JavaScript, focusing on clean code, modularity, and performance.

## Code Style and Structure

- **Clean, Readable Code**: Ensure your code is easy to read and understand. Use descriptive names for variables and functions.
- **Functional Components**: Prefer functional components with hooks (useState, useEffect) over class components
- **Component Modularity**: Break components into smaller, reusable pieces with single responsibility
- **Feature-Based Organization**: Group related components, hooks, and styles into feature directories (e.g., user-profile, chat-screen)

## Naming Conventions

- **Variables and Functions**: Use camelCase (e.g., `isFetchingData`, `handleUserInput`)
- **Components**: Use PascalCase (e.g., `UserProfile`, `ChatScreen`)
- **Directories**: Use lowercase hyphenated names (e.g., `user-profile`, `chat-screen`)

## JavaScript Usage

- Minimize global variables to prevent unintended side effects
- Leverage ES6+ features like arrow functions, destructuring, and template literals to write concise code
- Use PropTypes for type checking if not using TypeScript

## Performance Optimization

- Avoid unnecessary state updates; use local state when needed
- Apply `React.memo()` to prevent unnecessary re-renders
- Optimize FlatList with the following props:
  - `removeClippedSubviews`
  - `maxToRenderPerBatch`
  - `windowSize`
- Avoid anonymous functions in `renderItem` or event handlers

## UI and Styling

- Use `StyleSheet.create()` for consistent styling or Styled Components for dynamic styles
- Ensure responsive design across screen sizes and orientations
- Use optimized image libraries like `react-native-fast-image`

## Best Practices

- Follow React Native's threading model for smooth UI performance
- Use Expo's EAS Build and OTA updates for deployment
```
END THIRD-PARTY FILE 31724041149da2a1

The third-party file has ended. Everything between the 31724041149da2a1 tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

First 2209 of 2378 bytes. © Mindrally · Apache-2.0 · https://github.com/Mindrally/skills/tree/HEAD/expo-react-native-javascript-best-practices/SKILL.md

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