Upgrading React Native

# Upgrading React Native

## Overview

Covers the full React Native upgrade workflow: template diffs via Upgrade Helper, dependency updates, Expo SDK steps, and common pitfalls.

## Typical Upgrade Sequence

1. **Route**: Choose the right upgrade path via [upgrading-react-native.md][upgrading-react-native]
2. **Diff**: Fetch the canonical template diff using Upgrade Helper via [upgrade-helper-core.md][upgrade-helper-core]
3. **Dependencies**: Assess and update third-party packages via [upgrading-dependencies.md][upgrading-dependencies]
4. **React**: Align React version if upgraded via [react.md][react]
5. **Expo** (if applicable): Apply Expo SDK layer via [expo-sdk-upgrade.md][expo-sdk-upgrade]
6. **Verify**: Run post-upgrade checks via [upgrade-verification.md][upgrade-verification]

```bash
# Quick start: detect current version and fetch diff
npm pkg get dependencies.react-native --prefix "$APP_DIR"
npm view react-native dist-tags.latest

# Example: upgrading from 0.76.9 to 0.78.2
# 1. Fetch the template diff
curl -L -f -o /tmp/rn-diff.diff \
  "https://raw.githubusercontent.com/react-native-community/rn-diff-purge/diffs/diffs/0.76.9..0.78.2.diff" \
  && echo "Diff downloaded OK" || echo "ERROR: diff not found, check versions"
# 2. Review changed files
grep -n "^diff --git" /tmp/rn-diff.diff
# 3. Update package.json, apply native changes, then install + rebuild
npm install --prefix "$APP_DIR"
cd "$APP_DIR/ios" && pod install
# 4. Validate: both platforms must build successfully
npx react-native build-android --mode debug --no-packager
xcodebuild -workspace "$APP_DIR/ios/App.xcworkspace" -scheme App -sdk iphonesimulator build
```

## When to Apply

Reference these guidelines when:
- Moving a React Native app to a newer version
- Reconciling native config changes from Upgrade Helper
- Validating release notes for breaking changes

## Quick Reference

| File | Description |
|------|-------------|
| [upgrading-react-native.md][upgrading-react-native] | Router: choose the right upgrade path |
| [upgrade-helper-core.md][upgrade-helper-core] | Core Upgrade Helper workflow and reliability gates |
| [upgrading-dependencies.md][upgrading-dependencies] | Dependency compatibility checks and migration planning |
| [react.md][react] | React and React 19 upgrade alignment rules |
| [expo-sdk-upgrade.md][expo-sdk-upgrade] | Expo SDK-specific upgrade layer (conditional) |
| [upgrade-verification.md][upgrade-verification] | Post-upgrade verification checklist, including agent-device-assisted checks |
| [monorepo-singlerepo-targeting.md][monorepo-singlerepo-targeting] | Monorepo and single-repo app targeting and command scoping |

## Problem → Skill Mapping

| Problem | Start With |
|---------|------------|
| Need to upgrade React Native | [upgrade-helper-core.md][upgrade-helper-core] |
| Need dependency risk triage and migration options | [upgrading-dependencies.md][upgrading-dependencies] |
| Need React/React 19 package alignment | [react.md][react] |
| Need workflow routing first | [upgrading-react-native.md][upgrading-react-native] |
| Need Expo SDK-specific steps | [expo-sdk-upgrade.md][expo-sdk-upgrade] |
| Need manual or agent-assisted regression validation | [upgrade-verification.md][upgrade-verification] |
| Need repo/app command scoping | [monorepo-singlerepo-targeting.md][monorepo-singlerepo-targeting] |

[upgrading-react-native]: references/upgrading-react-native.md
[upgrade-helper-core]: references/upgrade-helper-core.md
[upgrading-dependencies]: references/upgrading-dependencies.md
[react]: references/react.md
[expo-sdk-upgrade]: references/expo-sdk-upgrade.md
[upgrade-verification]: references/upgrade-verification.md
[monorepo-singlerepo-targeting]: references/monorepo-singlerepo-targeting.md