Appendix C: Essential Feature Implementations

import { createContext, useContext, useState, useEffect, ReactNode } from 'react';
import { useColorScheme } from 'react-native';
import AsyncStorage from '@react-native-async-storage/async-storage';

type ThemeMode = 'light' | 'dark' | 'system';

interface ThemeContextType {
  theme: 'light' | 'dark';
  themeMode: ThemeMode;
  setThemeMode: (mode: ThemeMode) => void;
  colors: typeof lightColors;
}

const lightColors = {
  primary: '#7C3AED',
  background: '#FFFFFF',
  surface: '#F9FAFB',
  surfaceSecondary: '#F3F4F6',
  text: '#111827',
  textSecondary: '#6B7280',
  textTertiary: '#9CA3AF',
  border: '#E5E7EB',
  error: '#EF4444',
  success: '#22C55E',
  warning: '#F59E0B',
};

const darkColors = {
  primary: '#A78BFA',
  background: '#111827',
  surface: '#1F2937',
  surfaceSecondary: '#374151',
  text: '#F9FAFB',
  textSecondary: '#D1D5DB',
  textTertiary: '#9CA3AF',
  border: '#374151',
  error: '#F87171',
  success: '#4ADE80',
  warning: '#FBBF24',
};

const ThemeContext = createContext<ThemeContextType | undefined>(undefined);

export function ThemeProvider({ children }: { children: ReactNode }) {
  const systemColorScheme = useColorScheme();
  const [themeMode, setThemeModeState] = useState<ThemeMode>('system');

  useEffect(() => {
    loadThemePreference();
  }, []);

  const loadThemePreference = async () => {
    const saved = await AsyncStorage.getItem('themeMode');
    if (saved) {
      setThemeModeState(saved as ThemeMode);
    }
  };

  const setThemeMode = async (mode: ThemeMode) => {
    setThemeModeState(mode);
    await AsyncStorage.setItem('themeMode', mode);
  };

  const theme =
    themeMode === 'system'
      ? systemColorScheme || 'light'
      : themeMode;

  const colors = theme === 'dark' ? darkColors : lightColors;

  return (
    <ThemeContext.Provider value={{ theme, themeMode, setThemeMode, colors }}>
      {children}
    </ThemeContext.Provider>
  );
}

export function useTheme() {
  const context = useContext(ThemeContext);
  if (!context) {
    throw new Error('useTheme must be used within ThemeProvider');
  }
  return context;
}

import { View, Text, TouchableOpacity, StyleSheet } from 'react-native';
import { useTheme } from '@/contexts/ThemeContext';

const options = [
  { value: 'light', label: 'Light' },
  { value: 'dark', label: 'Dark' },
  { value: 'system', label: 'System' },
] as const;

export function ThemeToggle() {
  const { themeMode, setThemeMode, colors } = useTheme();

  return (
    <View style={styles.container}>
      <Text style={[styles.label, { color: colors.text }]}>Theme</Text>
      <View style={[styles.options, { backgroundColor: colors.surface }]}>
        {options.map((option) => (
          <TouchableOpacity
            key={option.value}
            style={[
              styles.option,
              themeMode === option.value && {
                backgroundColor: colors.primary,
              },
            ]}
            onPress={() => setThemeMode(option.value)}
          >
            <Text
              style={[
                styles.optionText,
                {
                  color:
                    themeMode === option.value ? '#FFFFFF' : colors.textSecondary,
                },
              ]}
            >
              {option.label}
            </Text>
          </TouchableOpacity>
        ))}
      </View>
    </View>
  );
}

{
  "expo": {
    "scheme": "myapp",
    "ios": {
      "bundleIdentifier": "com.yourcompany.myapp",
      "associatedDomains": ["applinks:yourdomain.com"]
    },
    "android": {
      "package": "com.yourcompany.myapp",
      "intentFilters": [
        {
          "action": "VIEW",
          "autoVerify": true,
          "data": [
            {
              "scheme": "https",
              "host": "yourdomain.com",
              "pathPrefix": "/app"
            }
          ],
          "category": ["BROWSABLE", "DEFAULT"]
        }
      ]
    }
  }
}

import { useEffect } from 'react';
import { Linking } from 'react-native';
import { router, useRootNavigationState } from 'expo-router';

export default function RootLayout() {
  const navigationState = useRootNavigationState();

  useEffect(() => {
    if (!navigationState?.key) return;

    // Handle deep links
    const handleDeepLink = (event: { url: string }) => {
      handleUrl(event.url);
    };

    // Get initial URL (app opened from link)
    Linking.getInitialURL().then((url) => {
      if (url) handleUrl(url);
    });

    // Listen for URL events (app already open)
    const subscription = Linking.addEventListener('url', handleDeepLink);

    return () => subscription.remove();
  }, [navigationState?.key]);

  const handleUrl = (url: string) => {
    const { hostname, pathname, searchParams } = new URL(url);

    // Handle different deep link paths
    if (pathname.startsWith('/profile/')) {
      const userId = pathname.split('/')[2];
      router.push(`/profile/${userId}`);
    } else if (pathname.startsWith('/post/')) {
      const postId = pathname.split('/')[2];
      router.push(`/post/${postId}`);
    } else if (pathname === '/premium') {
      router.push('/paywall');
    }
  };

  return <Stack />;
}

import * as Linking from 'expo-linking';

export function createDeepLink(path: string): string {
  return Linking.createURL(path);
}

export function createWebLink(path: string): string {
  return `https://yourdomain.com/app${path}`;
}

// Usage
const profileLink = createDeepLink('/profile/123');
// => "myapp://profile/123"

const shareableLink = createWebLink('/post/456');
// => "https://yourdomain.com/app/post/456"

import { Share } from 'react-native';
import { createWebLink } from '@/utils/deepLinks';

async function sharePost(postId: string, title: string) {
  const url = createWebLink(`/post/${postId}`);

  await Share.share({
    message: `Check out "${title}" on MyApp`,
    url,
  });
}

npx expo install expo-notifications expo-device expo-constants

import * as Notifications from 'expo-notifications';
import * as Device from 'expo-device';
import { Platform } from 'react-native';
import Constants from 'expo-constants';
import { convex } from './convex';

// Configure notification behavior
Notifications.setNotificationHandler({
  handleNotification: async () => ({
    shouldShowAlert: true,
    shouldPlaySound: true,
    shouldSetBadge: true,
  }),
});

export async function registerForPushNotifications(): Promise<string | null> {
  // Only works on physical devices
  if (!Device.isDevice) {
    console.log('Push notifications only work on physical devices');
    return null;
  }

  // Check existing permission
  const { status: existingStatus } = await Notifications.getPermissionsAsync();
  let finalStatus = existingStatus;

  // Request if not already granted
  if (existingStatus !== 'granted') {
    const { status } = await Notifications.requestPermissionsAsync();
    finalStatus = status;
  }

  if (finalStatus !== 'granted') {
    console.log('Push notification permission not granted');
    return null;
  }

  // Get Expo push token
  const projectId = Constants.expoConfig?.extra?.eas?.projectId;
  const token = (
    await Notifications.getExpoPushTokenAsync({ projectId })
  ).data;

  // Android-specific channel setup
  if (Platform.OS === 'android') {
    await Notifications.setNotificationChannelAsync('default', {
      name: 'Default',
      importance: Notifications.AndroidImportance.MAX,
      vibrationPattern: [0, 250, 250, 250],
      lightColor: '#7C3AED',
    });
  }

  return token;
}

export async function savePushToken(userId: string, token: string) {
  await convex.from('push_tokens').upsert({
    user_id: userId,
    token,
    platform: Platform.OS,
    updated_at: new Date().toISOString(),
  });
}

import { useEffect, useRef } from 'react';
import * as Notifications from 'expo-notifications';
import { router } from 'expo-router';

export function useNotifications() {
  const notificationListener = useRef<Notifications.Subscription>();
  const responseListener = useRef<Notifications.Subscription>();

  useEffect(() => {
    // Notification received while app is foregrounded
    notificationListener.current =
      Notifications.addNotificationReceivedListener((notification) => {
        console.log('Notification received:', notification);
      });

    // User tapped on notification
    responseListener.current =
      Notifications.addNotificationResponseReceivedListener((response) => {
        const data = response.notification.request.content.data;

        // Handle navigation based on notification data
        if (data.type === 'new_message') {
          router.push(`/chat/${data.chatId}`);
        } else if (data.type === 'generation_complete') {
          router.push(`/generation/${data.generationId}`);
        }
      });

    return () => {
      if (notificationListener.current) {
        Notifications.removeNotificationSubscription(notificationListener.current);
      }
      if (responseListener.current) {
        Notifications.removeNotificationSubscription(responseListener.current);
      }
    };
  }, []);
}

import { useState, useRef } from 'react';
import {
  View,
  Text,
  StyleSheet,
  Dimensions,
  FlatList,
  TouchableOpacity,
  Image,
} from 'react-native';
import { router } from 'expo-router';
import AsyncStorage from '@react-native-async-storage/async-storage';
import { Button } from '@/components/ui/Button';

const { width } = Dimensions.get('window');

const slides = [
  {
    id: '1',
    title: 'Welcome to MyApp',
    description: 'The best way to do amazing things with AI',
    image: require('@/assets/onboarding-1.png'),
  },
  {
    id: '2',
    title: 'Create Anything',
    description: 'Generate images, text, and more in seconds',
    image: require('@/assets/onboarding-2.png'),
  },
  {
    id: '3',
    title: 'Save & Share',
    description: 'Keep your creations and share with friends',
    image: require('@/assets/onboarding-3.png'),
  },
];

export default function OnboardingScreen() {
  const [currentIndex, setCurrentIndex] = useState(0);
  const flatListRef = useRef<FlatList>(null);

  const handleNext = () => {
    if (currentIndex < slides.length - 1) {
      flatListRef.current?.scrollToIndex({ index: currentIndex + 1 });
    } else {
      completeOnboarding();
    }
  };

  const completeOnboarding = async () => {
    await AsyncStorage.setItem('hasSeenOnboarding', 'true');
    router.replace('/(tabs)');
  };

  const renderSlide = ({ item }) => (
    <View style={styles.slide}>
      <Image source={item.image} style={styles.image} resizeMode="contain" />
      <Text style={styles.title}>{item.title}</Text>
      <Text style={styles.description}>{item.description}</Text>
    </View>
  );

  return (
    <View style={styles.container}>
      <FlatList
        ref={flatListRef}
        data={slides}
        renderItem={renderSlide}
        horizontal
        pagingEnabled
        showsHorizontalScrollIndicator={false}
        onMomentumScrollEnd={(e) => {
          const index = Math.round(e.nativeEvent.contentOffset.x / width);
          setCurrentIndex(index);
        }}
      />

      {/* Dots */}
      <View style={styles.dots}>
        {slides.map((_, index) => (
          <View
            key={index}
            style={[
              styles.dot,
              index === currentIndex && styles.activeDot,
            ]}
          />
        ))}
      </View>

      {/* Buttons */}
      <View style={styles.buttons}>
        <Button
          title={currentIndex === slides.length - 1 ? 'Get Started' : 'Next'}
          onPress={handleNext}
        />
        {currentIndex < slides.length - 1 && (
          <TouchableOpacity onPress={completeOnboarding} style={styles.skip}>
            <Text style={styles.skipText}>Skip</Text>
          </TouchableOpacity>
        )}
      </View>
    </View>
  );
}

npx expo install expo-haptics

import * as Haptics from 'expo-haptics';
import { Platform } from 'react-native';

export const haptics = {
  // Light tap - button press
  light: () => {
    if (Platform.OS !== 'web') {
      Haptics.impactAsync(Haptics.ImpactFeedbackStyle.Light);
    }
  },

  // Medium tap - toggle, selection
  medium: () => {
    if (Platform.OS !== 'web') {
      Haptics.impactAsync(Haptics.ImpactFeedbackStyle.Medium);
    }
  },

  // Heavy tap - important action
  heavy: () => {
    if (Platform.OS !== 'web') {
      Haptics.impactAsync(Haptics.ImpactFeedbackStyle.Heavy);
    }
  },

  // Success - task completed
  success: () => {
    if (Platform.OS !== 'web') {
      Haptics.notificationAsync(Haptics.NotificationFeedbackType.Success);
    }
  },

  // Warning - attention needed
  warning: () => {
    if (Platform.OS !== 'web') {
      Haptics.notificationAsync(Haptics.NotificationFeedbackType.Warning);
    }
  },

  // Error - something went wrong
  error: () => {
    if (Platform.OS !== 'web') {
      Haptics.notificationAsync(Haptics.NotificationFeedbackType.Error);
    }
  },

  // Selection change
  selection: () => {
    if (Platform.OS !== 'web') {
      Haptics.selectionAsync();
    }
  },
};

import { haptics } from '@/utils/haptics';

// Button press
<TouchableOpacity onPress={() => {
  haptics.light();
  handlePress();
}}>

// Success state
const handleSubmit = async () => {
  try {
    await submitForm();
    haptics.success();
    Alert.alert('Success!');
  } catch (error) {
    haptics.error();
    Alert.alert('Error', error.message);
  }
};

npm install i18next react-i18next

export default {
  common: {
    loading: 'Loading...',
    error: 'Something went wrong',
    retry: 'Try again',
    cancel: 'Cancel',
    save: 'Save',
    delete: 'Delete',
    confirm: 'Confirm',
  },
  auth: {
    signIn: 'Sign In',
    signUp: 'Sign Up',
    signOut: 'Sign Out',
    email: 'Email',
    password: 'Password',
    forgotPassword: 'Forgot password?',
  },
  settings: {
    title: 'Settings',
    language: 'Language',
    theme: 'Theme',
    notifications: 'Notifications',
    privacy: 'Privacy Policy',
    terms: 'Terms of Service',
    version: 'Version',
  },
  paywall: {
    title: 'Upgrade to Pro',
    subtitle: 'Unlock all features',
    monthly: 'Monthly',
    yearly: 'Yearly',
    restore: 'Restore Purchases',
    freeTrial: '7-day free trial',
  },
};

import i18n from 'i18next';
import { initReactI18next } from 'react-i18next';
import * as Localization from 'expo-localization';
import AsyncStorage from '@react-native-async-storage/async-storage';

import en from '@/locales/en';
import es from '@/locales/es';

const resources = {
  en: { translation: en },
  es: { translation: es },
};

const LANGUAGE_KEY = 'user_language';

export const initI18n = async () => {
  const savedLanguage = await AsyncStorage.getItem(LANGUAGE_KEY);
  const deviceLanguage = Localization.locale.split('-')[0];

  await i18n.use(initReactI18next).init({
    resources,
    lng: savedLanguage || deviceLanguage || 'en',
    fallbackLng: 'en',
    interpolation: {
      escapeValue: false,
    },
  });
};

export const changeLanguage = async (lang: string) => {
  await AsyncStorage.setItem(LANGUAGE_KEY, lang);
  await i18n.changeLanguage(lang);
};

export default i18n;

import { useTranslation } from 'react-i18next';

function MyComponent() {
  const { t } = useTranslation();

  return (
    <View>
      <Text>{t('common.loading')}</Text>
      <Button title={t('auth.signIn')} onPress={handleSignIn} />
    </View>
  );
}

npm install react-hook-form zod @hookform/resolvers

import { z } from 'zod';

export const loginSchema = z.object({
  email: z.string().email('Invalid email address'),
  password: z.string().min(8, 'Password must be at least 8 characters'),
});

export const signupSchema = z.object({
  email: z.string().email('Invalid email address'),
  password: z
    .string()
    .min(8, 'Password must be at least 8 characters')
    .regex(/[A-Z]/, 'Must contain uppercase letter')
    .regex(/[a-z]/, 'Must contain lowercase letter')
    .regex(/[0-9]/, 'Must contain number'),
  confirmPassword: z.string(),
}).refine((data) => data.password === data.confirmPassword, {
  message: "Passwords don't match",
  path: ['confirmPassword'],
});

export type LoginInput = z.infer<typeof loginSchema>;
export type SignupInput = z.infer<typeof signupSchema>;

import { View, TextInput, Text, StyleSheet } from 'react-native';
import { useForm, Controller } from 'react-hook-form';
import { zodResolver } from '@hookform/resolvers/zod';
import { loginSchema, LoginInput } from '@/schemas/auth.schema';
import { Button } from '@/components/ui/Button';

interface LoginFormProps {
  onSubmit: (data: LoginInput) => Promise<void>;
}

export function LoginForm({ onSubmit }: LoginFormProps) {
  const {
    control,
    handleSubmit,
    formState: { errors, isSubmitting },
  } = useForm<LoginInput>({
    resolver: zodResolver(loginSchema),
    defaultValues: {
      email: '',
      password: '',
    },
  });

  return (
    <View style={styles.form}>
      <Controller
        control={control}
        name="email"
        render={({ field: { onChange, onBlur, value } }) => (
          <View style={styles.field}>
            <TextInput
              style={[styles.input, errors.email && styles.inputError]}
              placeholder="Email"
              value={value}
              onChangeText={onChange}
              onBlur={onBlur}
              autoCapitalize="none"
              keyboardType="email-address"
              autoComplete="email"
            />
            {errors.email && (
              <Text style={styles.error}>{errors.email.message}</Text>
            )}
          </View>
        )}
      />

      <Controller
        control={control}
        name="password"
        render={({ field: { onChange, onBlur, value } }) => (
          <View style={styles.field}>
            <TextInput
              style={[styles.input, errors.password && styles.inputError]}
              placeholder="Password"
              value={value}
              onChangeText={onChange}
              onBlur={onBlur}
              secureTextEntry
              autoComplete="password"
            />
            {errors.password && (
              <Text style={styles.error}>{errors.password.message}</Text>
            )}
          </View>
        )}
      />

      <Button
        title="Sign In"
        onPress={handleSubmit(onSubmit)}
        loading={isSubmitting}
      />
    </View>
  );
}

npx expo install expo-updates
eas update:configure

{
  "expo": {
    "updates": {
      "url": "https://u.expo.dev/your-project-id"
    },
    "runtimeVersion": {
      "policy": "appVersion"
    }
  }
}

# Publish to all users
eas update --branch production --message "Bug fixes"

# Publish to preview channel
eas update --branch preview --message "New feature testing"

import { useEffect } from 'react';
import * as Updates from 'expo-updates';
import { Alert } from 'react-native';

export function useAppUpdate() {
  useEffect(() => {
    checkForUpdates();
  }, []);

  const checkForUpdates = async () => {
    if (__DEV__) return; // Skip in development

    try {
      const update = await Updates.checkForUpdateAsync();

      if (update.isAvailable) {
        await Updates.fetchUpdateAsync();

        Alert.alert(
          'Update Available',
          'A new version is ready. Restart to apply?',
          [
            { text: 'Later', style: 'cancel' },
            {
              text: 'Restart',
              onPress: () => Updates.reloadAsync(),
            },
          ]
        );
      }
    } catch (error) {
      console.log('Error checking for updates:', error);
    }
  };
}

npx expo install expo-store-review

import * as StoreReview from 'expo-store-review';
import AsyncStorage from '@react-native-async-storage/async-storage';

const REVIEW_KEY = 'app_review_status';
const MIN_ACTIONS = 5; // Show after 5 successful actions
const MIN_DAYS = 3; // Wait at least 3 days after install

interface ReviewStatus {
  hasAsked: boolean;
  actionCount: number;
  installDate: string;
}

export async function trackAction() {
  const status = await getReviewStatus();
  status.actionCount++;
  await saveReviewStatus(status);

  // Check if we should ask for review
  if (shouldAskForReview(status)) {
    await requestReview();
  }
}

function shouldAskForReview(status: ReviewStatus): boolean {
  if (status.hasAsked) return false;
  if (status.actionCount < MIN_ACTIONS) return false;

  const daysSinceInstall = getDaysSince(status.installDate);
  if (daysSinceInstall < MIN_DAYS) return false;

  return true;
}

async function requestReview() {
  const isAvailable = await StoreReview.isAvailableAsync();

  if (isAvailable) {
    await StoreReview.requestReview();

    const status = await getReviewStatus();
    status.hasAsked = true;
    await saveReviewStatus(status);
  }
}

// After successful generation, purchase, or positive action
import { trackAction } from '@/lib/reviewPrompt';

const handleGenerationSuccess = async () => {
  // ... generation logic
  await trackAction(); // May trigger review prompt
};

npx expo install expo-splash-screen

{
  "expo": {
    "splash": {
      "image": "./assets/splash.png",
      "resizeMode": "contain",
      "backgroundColor": "#7C3AED"
    },
    "ios": {
      "splash": {
        "image": "./assets/splash.png",
        "resizeMode": "contain",
        "backgroundColor": "#7C3AED",
        "dark": {
          "image": "./assets/splash-dark.png",
          "backgroundColor": "#1F2937"
        }
      }
    }
  }
}

import { useEffect, useState, useCallback } from 'react';
import * as SplashScreen from 'expo-splash-screen';
import * as Font from 'expo-font';
import { View } from 'react-native';

// Prevent auto-hide
SplashScreen.preventAutoHideAsync();

export default function RootLayout() {
  const [appIsReady, setAppIsReady] = useState(false);

  useEffect(() => {
    async function prepare() {
      try {
        // Load fonts, fetch initial data, etc.
        await Font.loadAsync({
          'Inter-Regular': require('@/assets/fonts/Inter-Regular.ttf'),
          'Inter-Bold': require('@/assets/fonts/Inter-Bold.ttf'),
        });

        // Artificial delay for branding (optional)
        await new Promise(resolve => setTimeout(resolve, 1000));
      } catch (e) {
        console.warn(e);
      } finally {
        setAppIsReady(true);
      }
    }

    prepare();
  }, []);

  const onLayoutRootView = useCallback(async () => {
    if (appIsReady) {
      await SplashScreen.hideAsync();
    }
  }, [appIsReady]);

  if (!appIsReady) {
    return null;
  }

  return (
    <View style={{ flex: 1 }} onLayout={onLayoutRootView}>
      <Stack />
    </View>
  );
}

import { useEffect, useState, useCallback } from 'react';
import * as SplashScreen from 'expo-splash-screen';
import * as Font from 'expo-font';
import { Asset } from 'expo-asset';
import { View } from 'react-native';
import { initI18n } from '@/lib/i18n';
import { convex } from '@/lib/convex';
import { useAuthStore } from '@/stores/authStore';

SplashScreen.preventAutoHideAsync();

export default function RootLayout() {
  const [appIsReady, setAppIsReady] = useState(false);
  const setUser = useAuthStore((state) => state.setUser);
  const setSession = useAuthStore((state) => state.setSession);

  useEffect(() => {
    async function prepare() {
      try {
        // 1. Load fonts
        await Font.loadAsync({
          'Inter-Regular': require('@/assets/fonts/Inter-Regular.ttf'),
          'Inter-Medium': require('@/assets/fonts/Inter-Medium.ttf'),
          'Inter-SemiBold': require('@/assets/fonts/Inter-SemiBold.ttf'),
          'Inter-Bold': require('@/assets/fonts/Inter-Bold.ttf'),
        });

        // 2. Preload critical images
        await Asset.loadAsync([
          require('@/assets/images/logo.png'),
          require('@/assets/images/onboarding-1.png'),
          require('@/assets/images/onboarding-2.png'),
          require('@/assets/images/onboarding-3.png'),
        ]);

        // 3. Initialize i18n
        await initI18n();

        // 4. Check existing auth session
        const { data: { session } } = await convex.auth.getSession();
        if (session) {
          setSession(session);
          setUser(session.user);
        }

        // 5. Any other initialization...

      } catch (e) {
        console.warn('App initialization error:', e);
      } finally {
        setAppIsReady(true);
      }
    }

    prepare();
  }, []);

  const onLayoutRootView = useCallback(async () => {
    if (appIsReady) {
      await SplashScreen.hideAsync();
    }
  }, [appIsReady]);

  if (!appIsReady) {
    return null;
  }

  return (
    <View style={{ flex: 1 }} onLayout={onLayoutRootView}>
      <Providers>
        <Stack />
      </Providers>
    </View>
  );
}

import * as Font from 'expo-font';
import { useEffect, useState } from 'react';

const customFonts = {
  'Inter-Regular': require('@/assets/fonts/Inter-Regular.ttf'),
  'Inter-Medium': require('@/assets/fonts/Inter-Medium.ttf'),
  'Inter-SemiBold': require('@/assets/fonts/Inter-SemiBold.ttf'),
  'Inter-Bold': require('@/assets/fonts/Inter-Bold.ttf'),
};

export function useFonts() {
  const [fontsLoaded, setFontsLoaded] = useState(false);

  useEffect(() => {
    async function loadFonts() {
      await Font.loadAsync(customFonts);
      setFontsLoaded(true);
    }
    loadFonts();
  }, []);

  return fontsLoaded;
}

import { Asset } from 'expo-asset';
import * as Font from 'expo-font';

const images = [
  require('@/assets/images/logo.png'),
  require('@/assets/images/placeholder.png'),
];

const fonts = {
  'Inter-Regular': require('@/assets/fonts/Inter-Regular.ttf'),
  'Inter-Bold': require('@/assets/fonts/Inter-Bold.ttf'),
};

export async function preloadAssets(): Promise<void> {
  const imageAssets = images.map((image) => Asset.loadAsync(image));
  const fontAssets = Font.loadAsync(fonts);

  await Promise.all([...imageAssets, fontAssets]);
}

import { ReactNode } from 'react';
import {
  KeyboardAvoidingView,
  Platform,
  StyleSheet,
  TouchableWithoutFeedback,
  Keyboard,
} from 'react-native';

interface Props {
  children: ReactNode;
}

export function KeyboardAvoidingWrapper({ children }: Props) {
  return (
    <KeyboardAvoidingView
      style={styles.container}
      behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
      keyboardVerticalOffset={Platform.OS === 'ios' ? 0 : 20}
    >
      <TouchableWithoutFeedback onPress={Keyboard.dismiss}>
        {children}
      </TouchableWithoutFeedback>
    </KeyboardAvoidingView>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
});

npx expo install react-native-safe-area-context

import { SafeAreaProvider } from 'react-native-safe-area-context';

export default function RootLayout() {
  return (
    <SafeAreaProvider>
      <Stack />
    </SafeAreaProvider>
  );
}

import { SafeAreaView } from 'react-native-safe-area-context';
import { View, Text, StyleSheet } from 'react-native';

export function HomeScreen() {
  return (
    <SafeAreaView style={styles.container} edges={['top', 'bottom']}>
      <View style={styles.content}>
        <Text>Content safe from notches and home indicators</Text>
      </View>
    </SafeAreaView>
  );
}

import { View, Text, StyleSheet } from 'react-native';
import { useSafeAreaInsets } from 'react-native-safe-area-context';

export function CustomHeader({ title }: { title: string }) {
  const insets = useSafeAreaInsets();

  return (
    <View style={[styles.header, { paddingTop: insets.top + 12 }]}>
      <Text style={styles.title}>{title}</Text>
    </View>
  );
}

npm install --save-dev jest @testing-library/react-native @testing-library/jest-native jest-expo

import { render, fireEvent } from '@testing-library/react-native';
import { Button } from '@/components/ui/Button';

describe('Button', () => {
  it('renders correctly', () => {
    const { getByText } = render(<Button title="Press me" onPress={() => {}} />);
    expect(getByText('Press me')).toBeTruthy();
  });

  it('calls onPress when pressed', () => {
    const onPress = jest.fn();
    const { getByText } = render(<Button title="Press me" onPress={onPress} />);

    fireEvent.press(getByText('Press me'));
    expect(onPress).toHaveBeenCalledTimes(1);
  });

  it('shows loading state', () => {
    const { getByTestId } = render(
      <Button title="Press me" onPress={() => {}} loading />
    );
    expect(getByTestId('loading-indicator')).toBeTruthy();
  });
});

# Run all tests
npm test

# Run with coverage
npm test -- --coverage

# Run in watch mode
npm test -- --watch

npx expo install expo-image

import { Image, ImageProps } from 'expo-image';

const blurhash = 'L6PZfSi_.AyE_3t7t7R**0o#DgR4';

interface CachedImageProps extends Omit<ImageProps, 'source'> {
  uri: string;
}

export function CachedImage({ uri, style, ...props }: CachedImageProps) {
  return (
    <Image
      source={{ uri }}
      placeholder={blurhash}
      contentFit="cover"
      transition={200}
      cachePolicy="memory-disk"
      style={style}
      {...props}
    />
  );
}

// Usage
<CachedImage
  uri="https://example.com/image.jpg"
  style={{ width: 200, height: 200, borderRadius: 12 }}
/>

import { useState, useEffect } from 'react';
import NetInfo from '@react-native-community/netinfo';

export function useOffline() {
  const [isOffline, setIsOffline] = useState(false);

  useEffect(() => {
    const unsubscribe = NetInfo.addEventListener((state) => {
      setIsOffline(!state.isConnected);
    });

    return () => unsubscribe();
  }, []);

  return isOffline;
}

import { View, Text, StyleSheet } from 'react-native';
import { useOffline } from '@/hooks/useOffline';

export function OfflineBanner() {
  const isOffline = useOffline();

  if (!isOffline) return null;

  return (
    <View style={styles.banner}>
      <Text style={styles.text}>No internet connection</Text>
    </View>
  );
}