Building the App - PokéDex Fleek

Overview

PokéDex Fleek uses Expo Application Services (EAS) for building and deploying the app. EAS handles the complex native build process in the cloud, so you don’t need to set up Xcode or Android Studio locally.

Prerequisites

1. Create an Expo Account

# Sign up at https://expo.dev/signup

# Login to EAS CLI
eas login

2. Install EAS CLI

# Install globally
npm install -g eas-cli

# Verify installation
eas --version

3. Configure Project

The project is already configured with eas.json. Verify the configuration:

eas.json

{
  "cli": {
    "version": ">= 18.0.6",
    "appVersionSource": "remote"
  },
  "build": {
    "development": {
      "developmentClient": true,
      "distribution": "internal"
    },
    "preview": {
      "distribution": "internal"
    },
    "production": {
      "autoIncrement": true
    }
  },
  "submit": {
    "production": {}
  }
}

The project is linked to EAS Project ID: 48249dfc-e43a-4b6c-bb06-0f1ac9742e05 (configured in app.json).

Build Profiles

EAS supports three build profiles, each serving a different purpose:

Development
Preview
Production

Purpose: Testing with dev tools and debuggingFeatures:

Includes Expo Dev Client
Fast Refresh enabled
Debug mode
Internal distribution only

When to use:

Testing native modules on real devices
Debugging camera features
Development iteration

Building for Android

Development Build

# Build development APK
eas build --profile development --platform android

This creates a debug APK that you can install on devices via:

Direct download from EAS dashboard
QR code scan
adb install app-debug.apk

Preview Build

# Build preview APK (internal testing)
eas build --profile preview --platform android

Production Build (APK)

# Build production APK (for direct distribution)
eas build --profile production --platform android

APK vs AAB:

APK - Direct installation, larger file size
AAB (Android App Bundle) - Required for Play Store, smaller downloads

Production Build (AAB for Play Store)

# Build Android App Bundle for Google Play
eas build --profile production --platform android --android-app-bundle

Building for iOS

iOS builds require an Apple Developer Account ($99/year). Simulator builds are free but have limited functionality (no camera).

Development Build

# Build development IPA
eas build --profile development --platform ios

Options:

Simulator build (free, no Apple account needed):
```
eas build --profile development --platform ios --simulator
```
Drag .app file to Simulator to install.
Device build (requires Apple Developer account):
- EAS will prompt for credentials
- Builds are signed with development certificate
- Install via TestFlight or direct download

Preview Build

# Build preview IPA (internal testing)
eas build --profile preview --platform ios

Distribute via:

TestFlight (recommended)
Ad-hoc installation (limited to 100 devices)

Production Build (App Store)

# Build for App Store submission
eas build --profile production --platform ios

Production builds use App Store distribution certificate and must be submitted through App Store Connect.

Build Process Details

What Happens During a Build?

Code Upload

EAS uploads your source code to cloud build servers.

Dependency Installation

Installs all npm packages and native dependencies.

Native Code Generation

Runs expo prebuild to generate iOS/Android projects.

Compilation

Android: Gradle builds APK/AAB with ProGuard/R8 optimization
iOS: Xcode builds IPA with bitcode and symbols

Code Signing

Signs the app with appropriate certificates/provisioning profiles.

Upload

Uploads build artifacts to EAS servers for download.

Build times:

Android: 5-15 minutes
iOS: 10-20 minutes

Monitoring Build Progress

# Watch build logs in real-time
eas build --profile production --platform android

# Or view in dashboard
https://expo.dev/accounts/[your-account]/projects/Pokedex-Fleek/builds

Build logs show:

Dependency resolution
Native compilation output
Errors and warnings
Download URLs when complete

Credentials Management

Android Credentials

EAS automatically manages Android keystores:

# View Android credentials
eas credentials

# Or manage manually
eas credentials --platform android

What’s stored:

Keystore - Used to sign APKs/AABs
Key alias - Identifier for signing key
Key password - Protects the keystore

CRITICAL: Never lose your Android keystore! You cannot publish updates to the Play Store without the original keystore.

iOS Credentials

For iOS, EAS manages:

# View iOS credentials
eas credentials --platform ios

What’s stored:

Distribution Certificate - Signs app for App Store
Provisioning Profile - Device and entitlements configuration
Push Notification keys - For push notifications

Options:

Let EAS manage (recommended) - Automatic credential creation
Bring your own - Use existing certificates from Apple Developer

Platform-Specific Configuration

Android Configuration

Update Version Code/Name

app.json

{
  "expo": {
    "version": "1.0.0",
    "android": {
      "versionCode": 1,
      "package": "com.matudev.pokedexfleek"
    }
  }
}

With "autoIncrement": true in eas.json, version codes increment automatically on production builds.

Permissions

Required permissions are already configured in app.json:

"permissions": [
  "android.permission.CAMERA",
  "android.permission.RECORD_AUDIO"
]

ProGuard/R8 (Code Minification)

EAS automatically applies code shrinking in production builds.

iOS Configuration

Update Version/Build Number

app.json

{
  "expo": {
    "version": "1.0.0",
    "ios": {
      "buildNumber": "1",
      "bundleIdentifier": "com.anonymous.PokedexFleek",
      "supportsTablet": true
    }
  }
}

Info.plist Permissions

Camera permissions are configured:

"infoPlist": {
  "NSCameraUsageDescription": "Allow $(PRODUCT_NAME) to access your camera"
}

Bitcode

Bitcode is enabled by default for App Store optimization.

Testing Builds

Installing on Android

Direct Download
ADB Install
Internal Distribution

Build completes on EAS
Open build URL on your Android device
Download and install APK
Allow installation from unknown sources if prompted

# Download APK from EAS
# Connect device via USB
adb install path/to/app.apk

Share the EAS build URL with testers:

https://expo.dev/accounts/[account]/projects/Pokedex-Fleek/builds/[build-id]

Installing on iOS

Simulator
TestFlight (Recommended)
Ad-Hoc

# Build for simulator
eas build --profile development --platform ios --simulator

# Download .tar.gz and extract
tar -xvf build.tar.gz

# Drag .app to Simulator
open -a Simulator
# Then drag the .app file onto the simulator window

Submit build to TestFlight:
```
eas submit --platform ios --latest
```
Add testers in App Store Connect
Testers receive email with TestFlight link
Install TestFlight app and download build

Submitting to App Stores

Google Play Store

Create Play Console Account

Create App Listing

Add app name, description, screenshots
Set category and content rating
Add privacy policy URL

Build AAB

eas build --profile production --platform android --android-app-bundle

Submit via EAS

# Upload to Play Store
eas submit --platform android --latest

# EAS will prompt for service account credentials

Create Release

Go to Play Console → Production
Create new release with uploaded AAB
Review and roll out to production

Service Account Setup:

Go to Google Cloud Console
Create service account with Play Developer API access
Download JSON key
Upload to EAS when prompted

Apple App Store

Create App Store Connect Account

Requires Apple Developer Program membership ($99/year)

Create App Record

Go to App Store Connect
Click + to create new app
Set bundle ID: com.anonymous.PokedexFleek
Add app information

Build IPA

eas build --profile production --platform ios

Submit via EAS

# Upload to App Store Connect
eas submit --platform ios --latest

# Or use Transporter app manually

Complete App Review

Add screenshots and app preview video
Set pricing and availability
Submit for review
Wait 1-3 days for Apple review

Troubleshooting Build Errors

Common Android Errors

Gradle Out of Memory

Error: OutOfMemoryError: Java heap spaceSolution:

# Create/edit android/gradle.properties
org.gradle.jvmargs=-Xmx4096m -XX:MaxPermSize=512m

Dependency Conflict

Error: Version conflicts between librariesSolution:

# Clear node_modules and reinstall
rm -rf node_modules
npm install

# Rebuild
eas build --profile production --platform android --clear-cache

Keystore Issues

Error: Keystore signature mismatchSolution:

# Reset credentials (WARNING: only for new apps)
eas credentials --platform android
# Select "Remove Keystore"

# Build creates new keystore
eas build --profile production --platform android

Common iOS Errors

Provisioning Profile

Error: No matching provisioning profile foundSolution:

# Regenerate credentials
eas credentials --platform ios
# Select "Set up new credentials"

CocoaPods Errors

Error: Pod install failuresSolution:

# Update Podfile.lock
cd ios
pod install --repo-update
cd ..

# Rebuild
eas build --profile production --platform ios --clear-cache

Capabilities Issues

Error: Missing entitlementsCheck:

App ID has required capabilities (Camera)
Provisioning profile includes capabilities
app.json declares required permissions

Build Cache Issues

# Clear all EAS caches
eas build --profile production --platform android --clear-cache
eas build --profile production --platform ios --clear-cache

# Or clear specific caches
eas build --profile production --platform android --no-cache

CI/CD Integration

GitHub Actions Example

.github/workflows/build.yml

name: EAS Build

on:
  push:
    branches: [main]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      
      - uses: actions/setup-node@v3
        with:
          node-version: 18
      
      - name: Install dependencies
        run: npm install
      
      - name: Setup EAS
        uses: expo/expo-github-action@v8
        with:
          expo-version: latest
          eas-version: latest
          token: ${{ secrets.EXPO_TOKEN }}
      
      - name: Build Android
        run: eas build --platform android --non-interactive --no-wait
      
      - name: Build iOS
        run: eas build --platform ios --non-interactive --no-wait

Set EXPO_TOKEN in GitHub repository secrets. Generate token at https://expo.dev/accounts/[account]/settings/access-tokens

Best Practices

Version Control

Tag releases in Git: git tag v1.0.0
Keep eas.json in version control
Document build settings in README

Testing Strategy

Use development profile during feature work
Use preview for beta testing
Only use production for final releases

Security

Never commit keystores or certificates
Use EAS credential management
Enable 2FA on Expo account

Performance

Enable Hermes for faster startup
Use ProGuard/R8 on Android
Test on real devices, not just simulators

Build Checklist

Before submitting to stores:

Next Steps

Project Structure

Review the codebase architecture

Running Locally

Set up your development environment

Get Started

Core Concepts

Features

Development

Documentation Index

​Overview

​Prerequisites

​1. Create an Expo Account

​2. Install EAS CLI

​3. Configure Project

​Build Profiles

​Building for Android

​Development Build

​Preview Build

​Production Build (APK)

​Production Build (AAB for Play Store)

​Building for iOS

​Development Build

​Preview Build

​Production Build (App Store)

​Build Process Details

​What Happens During a Build?

​Monitoring Build Progress

​Credentials Management

​Android Credentials

​iOS Credentials

​Platform-Specific Configuration

​Android Configuration

​Update Version Code/Name

​Permissions

​ProGuard/R8 (Code Minification)

​iOS Configuration

​Update Version/Build Number

​Info.plist Permissions

​Bitcode

​Testing Builds

​Installing on Android

​Installing on iOS

​Submitting to App Stores

​Google Play Store

​Apple App Store

​Troubleshooting Build Errors

​Common Android Errors

​Common iOS Errors

​Build Cache Issues

​CI/CD Integration

​GitHub Actions Example

​Best Practices

Version Control

Testing Strategy

Security

Performance

​Build Checklist

​Next Steps

Project Structure

Running Locally

Build docs developers (and LLMs) love

Overview

Prerequisites

1. Create an Expo Account

2. Install EAS CLI

3. Configure Project

Build Profiles

Building for Android

Development Build

Preview Build

Production Build (APK)

Production Build (AAB for Play Store)

Building for iOS

Development Build

Preview Build

Production Build (App Store)

Build Process Details

What Happens During a Build?

Monitoring Build Progress

Credentials Management

Android Credentials

iOS Credentials

Platform-Specific Configuration

Android Configuration

Update Version Code/Name

Permissions

ProGuard/R8 (Code Minification)

iOS Configuration

Update Version/Build Number

Info.plist Permissions

Bitcode

Testing Builds

Installing on Android

Installing on iOS

Submitting to App Stores

Google Play Store

Apple App Store

Troubleshooting Build Errors

Common Android Errors

Common iOS Errors

Build Cache Issues

CI/CD Integration

GitHub Actions Example

Best Practices

Build Checklist

Next Steps