Building - NearYou

Overview

NearYou uses Expo’s build system to create production-ready apps for multiple platforms. This guide covers local development builds and production builds.

Prerequisites

Node.js

Node.js 18+ requiredCheck version: node --version

Package Manager

npm or yarn installedAlready configured in the project

Expo CLI

Included via expo@~54.0.20No global install needed

EAS CLI (Optional)

For cloud builds: npm install -g eas-cliNot required for local development

Development Scripts

NearYou includes several npm scripts for development:

package.json

{
  "scripts": {
    "start": "expo start",
    "android": "expo start --android",
    "ios": "expo start --ios",
    "web": "expo start --web",
    "lint": "expo lint"
  }
}

Local Development

Start Development Server

All Platforms
Android
iOS
Web

Start the Expo development server and choose a platform:

npm start

This opens the Expo Developer Tools where you can:

Press i for iOS simulator
Press a for Android emulator
Press w for web browser
Scan QR code with Expo Go app

Start directly on Android emulator or device:

npm run android

Requires Android Studio and a running emulator, or a connected device with USB debugging enabled.

Start directly on iOS simulator:

npm run ios

iOS builds only work on macOS with Xcode installed.

Start in web browser:

npm run web

Opens http://localhost:8081 in your default browser.

Development Features

Fast Refresh

Automatically reloads when you save files. Changes appear instantly without losing app state.

Error Overlay

Red screen shows errors with stack traces. Click to jump to the source file.

Developer Menu

Shake device or press Cmd+D (iOS) / Cmd+M (Android) for debug options.

Element Inspector

Press Cmd+D > “Toggle Element Inspector” to inspect component layout.

Clear Cache

If you encounter strange issues, clear the Metro bundler cache:

npx expo start --clear

Use --clear after installing new dependencies or changing native configuration.

Platform-Specific Builds

iOS Build Setup

Install Xcode

Download Xcode from the Mac App Store (macOS only)Minimum version: Xcode 14+

Install iOS Simulator

Open Xcode > Preferences > Components > Install iOS simulator versions

Accept Xcode License

sudo xcodebuild -license accept

Install CocoaPods

sudo gem install cocoapods

Run Prebuild (if needed)

Generate native iOS project:

npx expo prebuild --platform ios

NearYou uses the New Architecture (newArchEnabled: true), which requires iOS 13.4 or higher.

Android Build Setup

Install Android Studio

Download from developer.android.com/studio

Install Android SDK

Open Android Studio > More Actions > SDK ManagerInstall:

Android SDK Platform 34 (minimum)
Android SDK Build-Tools
Android Emulator

Set Environment Variables

Add to ~/.bashrc or ~/.zshrc:

export ANDROID_HOME=$HOME/Library/Android/sdk
export PATH=$PATH:$ANDROID_HOME/emulator
export PATH=$PATH:$ANDROID_HOME/platform-tools

Create Virtual Device

Android Studio > Device Manager > Create DeviceRecommended: Pixel 6 with Android 13+

Run Prebuild (if needed)

Generate native Android project:

npx expo prebuild --platform android

The Android configuration enables edge-to-edge UI (edgeToEdgeEnabled: true), requiring Android API 31+.

Web Build

Web builds work without additional setup:

npm run web

The web configuration uses static output:

app.json

{
  "web": {
    "output": "static",
    "favicon": "./assets/images/favicon.png"
  }
}

Production Builds

Using EAS Build (Recommended)

Expo Application Services (EAS) provides cloud-based builds:

Install EAS CLI

npm install -g eas-cli

eas login

Configure EAS

eas build:configure

This creates eas.json with build profiles.

Build for Platform

eas build --platform ios

EAS Build handles signing, native dependencies, and produces app store-ready artifacts automatically.

Build Profiles

Typical eas.json configuration:

eas.json

{
  "build": {
    "development": {
      "developmentClient": true,
      "distribution": "internal"
    },
    "preview": {
      "distribution": "internal",
      "android": {
        "buildType": "apk"
      }
    },
    "production": {
      "autoIncrement": true
    }
  }
}

Development Profile

For development builds with debug features:

Includes dev menu
Enables fast refresh
Internal distribution only

Preview Profile

For testing before production:

Internal distribution
APK format for Android (easier sharing)
Production-like build

Production Profile

For app store submission:

Auto-increments build number
Optimized and minified
Store-ready artifacts

Local Production Build

Build locally without EAS (requires native toolchains):

iOS
Android
Web

# Generate native projects
npx expo prebuild

# Build with Xcode
cd ios
xcodebuild -workspace nearyou.xcworkspace \
  -scheme nearyou \
  -configuration Release \
  -archivePath nearyou.xcarchive \
  archive

# Generate native projects
npx expo prebuild

# Build APK
cd android
./gradlew assembleRelease

# Build AAB (for Play Store)
./gradlew bundleRelease

Output location:

APK: android/app/build/outputs/apk/release/app-release.apk
AAB: android/app/build/outputs/bundle/release/app-release.aab

# Export static website
npx expo export:web

Output in web-build/ directory, ready for static hosting.

Local builds require proper signing credentials (certificates for iOS, keystore for Android).

Key Dependencies

NearYou uses these core dependencies (from package.json):

{
  "dependencies": {
    "expo": "~54.0.20",
    "expo-router": "~6.0.13",
    "react": "19.1.0",
    "react-native": "0.81.5",
    "react-native-reanimated": "~4.1.1",
    "react-native-gesture-handler": "~2.28.0"
  }
}

Expo SDK 54

Latest Expo features with React Native 0.81

Expo Router 6

File-based routing with type safety

React 19

Latest React with compiler support

Reanimated 4

Smooth 60fps animations

Build Optimization

Bundle Size Optimization

Enable Hermes

Hermes JavaScript engine is enabled by default in Expo 54 for better performance.

Tree Shaking

Import only what you need:

// Good
import { View } from 'react-native';

// Avoid
import * as RN from 'react-native';

Analyze Bundle

npx expo export --dump-sourcemap
npx react-native-bundle-visualizer

Performance Features

NearYou enables several performance optimizations:

app.json

{
  "newArchEnabled": true,
  "experiments": {
    "reactCompiler": true
  }
}

New Architecture: Better interop between JS and native code
React Compiler: Automatic memoization and optimization

Troubleshooting

Metro bundler port in use

Kill existing Metro process:

lsof -ti:8081 | xargs kill -9
npx expo start

iOS build fails

Clean and rebuild:

cd ios
pod deintegrate
pod install
cd ..
npx expo start --clear

Android build fails

Clean Gradle cache:

cd android
./gradlew clean
cd ..
npx expo start --clear

Module not found

Reinstall dependencies:

rm -rf node_modules package-lock.json
npm install
npx expo start --clear

Code Quality

Linting

Run ESLint to check code quality:

npm run lint

The project uses eslint-config-expo with flat config:

eslint.config.js

const { defineConfig } = require('eslint/config');
const expoConfig = require('eslint-config-expo/flat');

module.exports = defineConfig([
  expoConfig,
  {
    ignores: ['dist/*'],
  },
]);

Type Checking

Run TypeScript compiler:

npx tsc --noEmit

Add this as a pre-commit hook or CI check to catch errors early.

Next Steps

Configuration

Customize app.json and platform settings

Deployment

Deploy your built app to stores and web hosting

Get Started

Core Features

Development

Guides

​Overview

​Prerequisites

Node.js

Package Manager

Expo CLI

EAS CLI (Optional)

​Development Scripts

​Local Development

​Start Development Server

​Development Features

Fast Refresh

Error Overlay

Developer Menu

Element Inspector

​Clear Cache

​Platform-Specific Builds

​iOS Build Setup

​Android Build Setup

​Web Build

​Production Builds

​Using EAS Build (Recommended)

​Build Profiles

​Local Production Build

​Key Dependencies

Expo SDK 54

Expo Router 6

React 19

Reanimated 4

​Build Optimization

​Bundle Size Optimization

​Performance Features

​Troubleshooting

​Code Quality

​Linting

​Type Checking

​Next Steps

Configuration

Deployment

Build docs developers (and LLMs) love

Overview

Prerequisites

Development Scripts

Local Development

Start Development Server

Development Features

Clear Cache

Platform-Specific Builds

iOS Build Setup

Android Build Setup

Web Build

Production Builds

Using EAS Build (Recommended)

Build Profiles

Local Production Build

Key Dependencies

Build Optimization

Bundle Size Optimization

Performance Features

Troubleshooting

Code Quality

Linting

Type Checking

Next Steps