30 Pertanyaan Wawancara React Native Teratas: Panduan Lengkap 2026
30 pertanyaan wawancara React Native yang paling sering diajukan. Jawaban terperinci dengan contoh kode untuk meraih posisi sebagai pengembang mobile.

Wawancara teknis React Native menilai keterampilan pengembangan mobile lintas platform, kekhususan iOS/Android, serta pola performa. Panduan ini membahas 30 pertanyaan yang paling sering diajukan, lengkap dengan jawaban terperinci dan contoh kode untuk persiapan yang efektif.
Pertanyaan-pertanyaan ini mencakup hal mendasar hingga konsep lanjutan. Penguasaan arsitektur React Native dan pemahaman perbedaannya dengan React web menjadi kunci utama keberhasilan dalam wawancara.
Dasar-Dasar React Native
1. Apa perbedaan antara React dan React Native?
React merupakan pustaka untuk membangun antarmuka web, sedangkan React Native memungkinkan pengembangan aplikasi mobile native untuk iOS maupun Android.
Perbedaan mendasarnya terletak pada proses rendering: React menggunakan Virtual DOM yang diterjemahkan menjadi elemen HTML, sementara React Native memanfaatkan jembatan (bridge) yang berkomunikasi dengan komponen native pada masing-masing platform.
// React (Web) - uses HTML elements
function WebComponent() {
return (
<div className="container">
<span>Web text</span>
<button onClick={handleClick}>Click</button>
</div>
)
}
// React Native - uses native components
import { View, Text, TouchableOpacity, StyleSheet } from 'react-native'
function NativeComponent() {
return (
<View style={styles.container}>
<Text>Native text</Text>
<TouchableOpacity onPress={handlePress}>
<Text>Press</Text>
</TouchableOpacity>
</View>
)
}
const styles = StyleSheet.create({
container: {
flex: 1,
padding: 16
}
})Komponen React Native diterjemahkan menjadi UIView pada iOS dan android.view pada Android, sehingga menghasilkan performa setara aplikasi native.
2. Bagaimana cara kerja arsitektur React Native?
React Native menggunakan arsitektur tiga lapis: JavaScript, Bridge (atau JSI pada arsitektur baru), dan Native.
Kode JavaScript dijalankan pada mesin JS (Hermes atau JavaScriptCore). Komunikasi dengan kode native melalui serialisasi JSON pada arsitektur lama, atau melalui JSI (JavaScript Interface) pada arsitektur baru.
// Old architecture: asynchronous communication via Bridge
// The Bridge serializes messages as JSON between JS and Native
// New architecture (Fabric + TurboModules)
// JSI enables synchronous direct calls to native modules
// Example TurboModule usage
import { TurboModuleRegistry } from 'react-native'
// Synchronous access to native module
const DeviceInfo = TurboModuleRegistry.get('DeviceInfo')
const deviceName = DeviceInfo.getDeviceName() // Synchronous call
// With Fabric, rendering is smoother
// Components can be created synchronously
// Reducing jank during animationsArsitektur baru meningkatkan performa secara signifikan dengan menghilangkan serialisasi JSON dan memungkinkan pemanggilan sinkron.
3. Apa itu Metro bundler?
Metro adalah bundler JavaScript yang digunakan oleh React Native. Bundler ini mengubah kode sumber menjadi bundle yang dioptimalkan untuk eksekusi di perangkat mobile.
Metro menangani resolusi modul, transformasi kode (melalui Babel), serta hot reloading selama pengembangan.
const { getDefaultConfig } = require('expo/metro-config')
const config = getDefaultConfig(__dirname)
// Custom configuration
config.resolver.assetExts.push('db') // Add extensions
config.resolver.sourceExts.push('cjs') // CommonJS support
// Transformer configuration
config.transformer.babelTransformerPath = require.resolve(
'react-native-svg-transformer'
)
// Production optimizations
config.transformer.minifierConfig = {
keep_classnames: true,
keep_fnames: true,
mangle: {
keep_classnames: true,
keep_fnames: true
}
}
module.exports = configMetro mendukung Fast Refresh, sehingga perubahan dapat diterapkan secara langsung tanpa kehilangan state aplikasi.
4. Jelaskan StyleSheet.create dan keuntungannya
StyleSheet.create mengoptimalkan style dengan memvalidasinya dan mengonversinya menjadi referensi numerik, sehingga mengurangi beban pada bridge.
// ❌ Inline styles - recreated on every render
function BadExample() {
return (
<View style={{ flex: 1, padding: 16, backgroundColor: '#fff' }}>
<Text style={{ fontSize: 18, fontWeight: 'bold' }}>Title</Text>
</View>
)
}
// ✅ StyleSheet.create - optimized and validated
const styles = StyleSheet.create({
container: {
flex: 1,
padding: 16,
backgroundColor: '#fff'
},
title: {
fontSize: 18,
fontWeight: 'bold'
},
// Style composition
row: {
flexDirection: 'row',
alignItems: 'center',
gap: 8
}
})
function GoodExample() {
return (
<View style={styles.container}>
<Text style={styles.title}>Title</Text>
{/* Style combination */}
<View style={[styles.row, { marginTop: 10 }]}>
<Text>Content</Text>
</View>
</View>
)
}
// StyleSheet.absoluteFillObject for absolute positioning
const overlayStyles = StyleSheet.create({
overlay: {
...StyleSheet.absoluteFillObject,
backgroundColor: 'rgba(0,0,0,0.5)'
}
})5. Apa perbedaan antara Flexbox web dan React Native?
React Native menggunakan Flexbox tetapi dengan nilai default yang berbeda dari versi web, disesuaikan untuk antarmuka mobile vertikal.
// Key differences from web
const styles = StyleSheet.create({
container: {
// flexDirection: 'column' by default (vs 'row' on web)
// alignItems: 'stretch' by default
flex: 1
},
// React Native Flexbox
row: {
flexDirection: 'row', // Horizontal
justifyContent: 'space-between', // Main axis
alignItems: 'center', // Cross axis
flexWrap: 'wrap', // Line wrapping
gap: 8 // Supported since RN 0.71
},
// Flex grow/shrink
flexItem: {
flex: 1, // Equivalent to flex: 1 1 0
flexGrow: 1, // Grow to fill
flexShrink: 0, // Don't shrink
flexBasis: 100 // Base size
},
// Absolute positioning
absolute: {
position: 'absolute',
top: 0,
left: 0,
right: 0,
bottom: 0
}
})
// Practical example: card with image and content
function Card() {
return (
<View style={cardStyles.container}>
<Image source={{ uri: imageUrl }} style={cardStyles.image} />
<View style={cardStyles.content}>
<Text style={cardStyles.title}>Title</Text>
<Text style={cardStyles.description}>Description</Text>
</View>
</View>
)
}
const cardStyles = StyleSheet.create({
container: {
flexDirection: 'row',
backgroundColor: '#fff',
borderRadius: 8,
overflow: 'hidden'
},
image: {
width: 100,
height: 100
},
content: {
flex: 1, // Takes remaining space
padding: 12,
justifyContent: 'center'
},
title: {
fontSize: 16,
fontWeight: '600'
},
description: {
fontSize: 14,
color: '#666'
}
})Navigasi dan Komponen
6. Bagaimana cara mengimplementasikan navigasi dengan React Navigation?
React Navigation merupakan solusi standar untuk navigasi pada React Native. Pustaka ini menyediakan berbagai jenis navigator yang sesuai dengan pola mobile.
// Installing dependencies
// npm install @react-navigation/native @react-navigation/native-stack
// npm install react-native-screens react-native-safe-area-context
import { NavigationContainer } from '@react-navigation/native'
import { createNativeStackNavigator } from '@react-navigation/native-stack'
import { createBottomTabNavigator } from '@react-navigation/bottom-tabs'
// TypeScript typing for navigation params
type RootStackParamList = {
Home: undefined
Profile: { userId: string }
Settings: { section?: string }
}
const Stack = createNativeStackNavigator<RootStackParamList>()
const Tab = createBottomTabNavigator()
// Tab navigation
function TabNavigator() {
return (
<Tab.Navigator
screenOptions={({ route }) => ({
tabBarIcon: ({ focused, color, size }) => {
// Dynamic icon based on tab
const iconName = route.name === 'Home' ? 'home' : 'settings'
return <Icon name={iconName} size={size} color={color} />
},
tabBarActiveTintColor: '#007AFF',
tabBarInactiveTintColor: 'gray'
})}
>
<Tab.Screen name="Home" component={HomeScreen} />
<Tab.Screen name="Settings" component={SettingsScreen} />
</Tab.Navigator>
)
}
// Stack navigation
function App() {
return (
<NavigationContainer>
<Stack.Navigator
initialRouteName="Home"
screenOptions={{
headerStyle: { backgroundColor: '#007AFF' },
headerTintColor: '#fff',
animation: 'slide_from_right' // Native animation
}}
>
<Stack.Screen
name="Home"
component={TabNavigator}
options={{ headerShown: false }}
/>
<Stack.Screen
name="Profile"
component={ProfileScreen}
options={({ route }) => ({
title: `Profile ${route.params.userId}`
})}
/>
</Stack.Navigator>
</NavigationContainer>
)
}7. Bagaimana cara menangani daftar performa tinggi dengan FlatList?
FlatList dioptimalkan untuk daftar panjang melalui virtualisasi otomatis, hanya merender elemen yang terlihat di layar.
import { FlatList, RefreshControl } from 'react-native'
function ProductList() {
const [products, setProducts] = useState([])
const [refreshing, setRefreshing] = useState(false)
const [loading, setLoading] = useState(false)
// Initial loading
const fetchProducts = async (page = 1) => {
const response = await api.getProducts(page)
return response.data
}
// Pull-to-refresh
const onRefresh = useCallback(async () => {
setRefreshing(true)
const data = await fetchProducts(1)
setProducts(data)
setRefreshing(false)
}, [])
// Infinite pagination
const loadMore = useCallback(async () => {
if (loading) return
setLoading(true)
const nextPage = Math.ceil(products.length / 20) + 1
const data = await fetchProducts(nextPage)
setProducts(prev => [...prev, ...data])
setLoading(false)
}, [products.length, loading])
// Item rendering
const renderItem = useCallback(({ item }) => (
<ProductCard product={item} />
), [])
// Key extraction
const keyExtractor = useCallback((item) => item.id.toString(), [])
// Item separator
const ItemSeparator = useCallback(() => (
<View style={{ height: 12 }} />
), [])
return (
<FlatList
data={products}
renderItem={renderItem}
keyExtractor={keyExtractor}
ItemSeparatorComponent={ItemSeparator}
// Performance optimizations
removeClippedSubviews={true}
maxToRenderPerBatch={10}
updateCellsBatchingPeriod={50}
windowSize={5}
// Pull-to-refresh
refreshControl={
<RefreshControl
refreshing={refreshing}
onRefresh={onRefresh}
tintColor="#007AFF"
/>
}
// Infinite pagination
onEndReached={loadMore}
onEndReachedThreshold={0.5}
ListFooterComponent={loading ? <ActivityIndicator /> : null}
// Empty list
ListEmptyComponent={<EmptyState message="No products" />}
/>
)
}Selalu memoisasi renderItem menggunakan useCallback dan ekstrak komponen yang berat. Hindari fungsi inline pada renderItem yang dapat memicu re-render yang tidak perlu.
8. Apa perbedaan antara TouchableOpacity, Pressable, dan TouchableHighlight?
Komponen-komponen ini menangani interaksi sentuh dengan umpan balik visual yang berbeda.
import {
TouchableOpacity,
TouchableHighlight,
Pressable,
StyleSheet
} from 'react-native'
function InteractionExamples() {
return (
<View style={styles.container}>
{/* TouchableOpacity: reduces opacity on touch */}
<TouchableOpacity
activeOpacity={0.7}
onPress={() => console.log('Pressed')}
style={styles.button}
>
<Text>TouchableOpacity</Text>
</TouchableOpacity>
{/* TouchableHighlight: adds background color */}
<TouchableHighlight
underlayColor="#ddd"
onPress={() => console.log('Pressed')}
style={styles.button}
>
<Text>TouchableHighlight</Text>
</TouchableHighlight>
{/* Pressable: modern API with more control */}
<Pressable
onPress={() => console.log('Pressed')}
onLongPress={() => console.log('Long press')}
delayLongPress={500}
style={({ pressed }) => [
styles.button,
pressed && styles.buttonPressed
]}
>
{({ pressed }) => (
<Text style={pressed && styles.textPressed}>
{pressed ? 'Pressed!' : 'Pressable'}
</Text>
)}
</Pressable>
{/* Pressable with hitSlop to enlarge touch area */}
<Pressable
hitSlop={{ top: 10, bottom: 10, left: 10, right: 10 }}
onPress={() => console.log('Pressed')}
style={styles.smallButton}
>
<Text>Small button</Text>
</Pressable>
</View>
)
}
const styles = StyleSheet.create({
container: {
gap: 16,
padding: 20
},
button: {
backgroundColor: '#007AFF',
padding: 16,
borderRadius: 8,
alignItems: 'center'
},
buttonPressed: {
backgroundColor: '#0056b3',
transform: [{ scale: 0.98 }]
},
textPressed: {
color: '#fff'
},
smallButton: {
padding: 8,
backgroundColor: '#eee'
}
})Pressable direkomendasikan untuk proyek baru karena menawarkan kontrol lebih luas dan API yang lebih konsisten.
9. Bagaimana cara membuat animasi yang halus?
React Native menyediakan beberapa API animasi: Animated (bawaan) dan Reanimated (lebih performan).
import { Animated, Easing } from 'react-native'
import Reanimated, {
useSharedValue,
useAnimatedStyle,
withSpring,
withTiming
} from 'react-native-reanimated'
// Animation with Animated (native API)
function FadeInView({ children }) {
const fadeAnim = useRef(new Animated.Value(0)).current
useEffect(() => {
Animated.timing(fadeAnim, {
toValue: 1,
duration: 500,
easing: Easing.ease,
useNativeDriver: true // Performant on UI thread
}).start()
}, [])
return (
<Animated.View style={{ opacity: fadeAnim }}>
{children}
</Animated.View>
)
}
// Animation with Reanimated (recommended for complex animations)
function BouncyButton() {
const scale = useSharedValue(1)
const animatedStyle = useAnimatedStyle(() => ({
transform: [{ scale: scale.value }]
}))
const handlePressIn = () => {
scale.value = withSpring(0.95, {
damping: 10,
stiffness: 400
})
}
const handlePressOut = () => {
scale.value = withSpring(1, {
damping: 10,
stiffness: 400
})
}
return (
<Pressable onPressIn={handlePressIn} onPressOut={handlePressOut}>
<Reanimated.View style={[styles.button, animatedStyle]}>
<Text style={styles.buttonText}>Press</Text>
</Reanimated.View>
</Pressable>
)
}
// List animation with LayoutAnimation
import { LayoutAnimation, UIManager, Platform } from 'react-native'
// Enable on Android
if (Platform.OS === 'android') {
UIManager.setLayoutAnimationEnabledExperimental?.(true)
}
function AnimatedList() {
const [items, setItems] = useState([])
const addItem = () => {
// Configure animation before state change
LayoutAnimation.configureNext(LayoutAnimation.Presets.spring)
setItems(prev => [...prev, { id: Date.now() }])
}
const removeItem = (id) => {
LayoutAnimation.configureNext(LayoutAnimation.Presets.easeInEaseOut)
setItems(prev => prev.filter(item => item.id !== id))
}
return (
<View>
<Button title="Add" onPress={addItem} />
{items.map(item => (
<TouchableOpacity key={item.id} onPress={() => removeItem(item.id)}>
<View style={styles.item}>
<Text>Item {item.id}</Text>
</View>
</TouchableOpacity>
))}
</View>
)
}Siap menguasai wawancara React Native Anda?
Berlatih dengan simulator interaktif, flashcards, dan tes teknis kami.
Manajemen State dan Data
10. Bagaimana cara mengelola state global pada React Native?
Solusi yang sama dengan React web dapat diterapkan: Context API, Redux, Zustand, atau MobX.
// Lightweight solution with Zustand
import { create } from 'zustand'
import { persist, createJSONStorage } from 'zustand/middleware'
import AsyncStorage from '@react-native-async-storage/async-storage'
// Store with persistence
const useAuthStore = create(
persist(
(set, get) => ({
user: null,
token: null,
isAuthenticated: false,
login: async (email, password) => {
const response = await api.login(email, password)
set({
user: response.user,
token: response.token,
isAuthenticated: true
})
},
logout: () => {
set({ user: null, token: null, isAuthenticated: false })
},
updateProfile: (updates) => {
set(state => ({
user: { ...state.user, ...updates }
}))
}
}),
{
name: 'auth-storage',
storage: createJSONStorage(() => AsyncStorage)
}
)
)
// Usage in a component
function ProfileScreen() {
const { user, logout, updateProfile } = useAuthStore()
if (!user) return <LoginPrompt />
return (
<View style={styles.container}>
<Text style={styles.name}>{user.name}</Text>
<Text style={styles.email}>{user.email}</Text>
<TouchableOpacity onPress={logout} style={styles.logoutButton}>
<Text>Logout</Text>
</TouchableOpacity>
</View>
)
}
// Cart store
const useCartStore = create((set, get) => ({
items: [],
addItem: (product) => set(state => {
const existing = state.items.find(i => i.id === product.id)
if (existing) {
return {
items: state.items.map(i =>
i.id === product.id
? { ...i, quantity: i.quantity + 1 }
: i
)
}
}
return { items: [...state.items, { ...product, quantity: 1 }] }
}),
removeItem: (id) => set(state => ({
items: state.items.filter(i => i.id !== id)
})),
getTotal: () => {
return get().items.reduce(
(sum, item) => sum + item.price * item.quantity,
0
)
},
clearCart: () => set({ items: [] })
}))11. Bagaimana cara melakukan panggilan API dengan manajemen cache?
React Query (TanStack Query) merupakan solusi yang direkomendasikan untuk manajemen data server.
import { QueryClient, QueryClientProvider, useQuery, useMutation } from '@tanstack/react-query'
// Client configuration
const queryClient = new QueryClient({
defaultOptions: {
queries: {
staleTime: 5 * 60 * 1000, // 5 minutes
cacheTime: 30 * 60 * 1000, // 30 minutes
retry: 2,
refetchOnWindowFocus: false // Mobile doesn't have "window focus"
}
}
})
// Provider in App.tsx
function App() {
return (
<QueryClientProvider client={queryClient}>
<NavigationContainer>
<AppNavigator />
</NavigationContainer>
</QueryClientProvider>
)
}
// Custom hook for products
function useProducts(categoryId) {
return useQuery({
queryKey: ['products', categoryId],
queryFn: async () => {
const response = await fetch(`/api/products?category=${categoryId}`)
if (!response.ok) throw new Error('Network error')
return response.json()
},
enabled: !!categoryId // Don't execute if no categoryId
})
}
// Mutation with cache invalidation
function useAddToCart() {
const queryClient = useQueryClient()
return useMutation({
mutationFn: async (product) => {
const response = await fetch('/api/cart', {
method: 'POST',
body: JSON.stringify(product)
})
return response.json()
},
onSuccess: () => {
// Invalidate cart cache to force refetch
queryClient.invalidateQueries({ queryKey: ['cart'] })
},
onError: (error) => {
Alert.alert('Error', error.message)
}
})
}
// Usage in a component
function ProductListScreen({ categoryId }) {
const { data: products, isLoading, error, refetch } = useProducts(categoryId)
const addToCart = useAddToCart()
if (isLoading) return <LoadingSpinner />
if (error) return <ErrorView error={error} onRetry={refetch} />
return (
<FlatList
data={products}
renderItem={({ item }) => (
<ProductCard
product={item}
onAddToCart={() => addToCart.mutate(item)}
isAddingToCart={addToCart.isPending}
/>
)}
refreshing={isLoading}
onRefresh={refetch}
/>
)
}12. Bagaimana cara menyimpan data secara lokal?
Terdapat beberapa opsi tergantung jenis data: AsyncStorage untuk data sederhana, MMKV untuk performa tinggi, dan SQLite untuk data terstruktur.
// AsyncStorage - simple but slow for large volumes
import AsyncStorage from '@react-native-async-storage/async-storage'
const storage = {
async get(key) {
const value = await AsyncStorage.getItem(key)
return value ? JSON.parse(value) : null
},
async set(key, value) {
await AsyncStorage.setItem(key, JSON.stringify(value))
},
async remove(key) {
await AsyncStorage.removeItem(key)
},
async clear() {
await AsyncStorage.clear()
}
}
// MMKV - very performant (recommended)
import { MMKV } from 'react-native-mmkv'
const mmkv = new MMKV()
const fastStorage = {
get(key) {
const value = mmkv.getString(key)
return value ? JSON.parse(value) : null
},
set(key, value) {
mmkv.set(key, JSON.stringify(value))
},
remove(key) {
mmkv.delete(key)
},
// Primitive type support
getNumber(key) {
return mmkv.getNumber(key)
},
setNumber(key, value) {
mmkv.set(key, value)
},
getBoolean(key) {
return mmkv.getBoolean(key)
}
}
// Hook to use MMKV with React
function useMMKVStorage(key, defaultValue) {
const [value, setValue] = useState(() => {
const stored = fastStorage.get(key)
return stored ?? defaultValue
})
const setStoredValue = useCallback((newValue) => {
setValue(newValue)
fastStorage.set(key, newValue)
}, [key])
return [value, setStoredValue]
}
// Usage
function SettingsScreen() {
const [theme, setTheme] = useMMKVStorage('theme', 'light')
const [notifications, setNotifications] = useMMKVStorage('notifications', true)
return (
<View>
<Switch
value={theme === 'dark'}
onValueChange={(v) => setTheme(v ? 'dark' : 'light')}
/>
<Switch
value={notifications}
onValueChange={setNotifications}
/>
</View>
)
}Untuk token dan data sensitif lainnya, sebaiknya gunakan expo-secure-store atau react-native-keychain yang mengenkripsi data melalui Keychain (iOS) maupun Keystore (Android).
Performa dan Optimasi
13. Bagaimana cara mengoptimalkan performa aplikasi React Native?
Optimasi mencakup beberapa aspek: rendering, memori, dan interaksi.
const ProductCard = React.memo(function ProductCard({ product, onPress }) {
return (
<TouchableOpacity onPress={() => onPress(product.id)}>
<View style={styles.card}>
<Image source={{ uri: product.image }} style={styles.image} />
<Text style={styles.title}>{product.name}</Text>
<Text style={styles.price}>{product.price}$</Text>
</View>
</TouchableOpacity>
)
}, (prevProps, nextProps) => {
// Custom comparison
return prevProps.product.id === nextProps.product.id
})
// 2. Memoize callbacks
function ProductList({ products }) {
// ❌ New function on every render
// onPress={(id) => handlePress(id)}
// ✅ Stable function
const handlePress = useCallback((id) => {
navigation.navigate('Product', { id })
}, [navigation])
return (
<FlatList
data={products}
renderItem={({ item }) => (
<ProductCard product={item} onPress={handlePress} />
)}
/>
)
}
// 3. Optimize images
import FastImage from 'react-native-fast-image'
function OptimizedImage({ uri }) {
return (
<FastImage
source={{
uri,
priority: FastImage.priority.normal,
cache: FastImage.cacheControl.immutable
}}
style={styles.image}
resizeMode={FastImage.resizeMode.cover}
/>
)
}
// 4. Use InteractionManager for heavy tasks
import { InteractionManager } from 'react-native'
function HeavyScreen() {
const [data, setData] = useState(null)
useEffect(() => {
// Wait for animations to complete
const task = InteractionManager.runAfterInteractions(() => {
const result = performHeavyComputation()
setData(result)
})
return () => task.cancel()
}, [])
return data ? <DataView data={data} /> : <LoadingView />
}
// 5. Lazy loading screens
const HeavyScreen = React.lazy(() => import('./HeavyScreen'))
function Navigator() {
return (
<Stack.Navigator>
<Stack.Screen
name="Heavy"
component={HeavyScreen}
options={{ lazy: true }}
/>
</Stack.Navigator>
)
}14. Bagaimana cara melakukan debug masalah performa?
React Native menyediakan beberapa alat untuk mengidentifikasi penyebab kemacetan.
// Configuration in android/app/build.gradle and ios/Podfile
// See: https://fbflipper.com/
// 2. Console.time to measure operations
function fetchData() {
console.time('fetchData')
const data = await api.getData()
console.timeEnd('fetchData') // fetchData: 234ms
return data
}
// 3. Performance monitor (shake device → Show Perf Monitor)
// Shows JS and UI FPS
// 4. Hermes profiler for CPU
// Enable in metro.config.js
module.exports = {
transformer: {
hermesParser: true
}
}
// 5. Identify re-renders with why-did-you-render
// Installation: npm install @welldone-software/why-did-you-render
import React from 'react'
if (__DEV__) {
const whyDidYouRender = require('@welldone-software/why-did-you-render')
whyDidYouRender(React, {
trackAllPureComponents: true
})
}
// Mark a component to monitor
ProductCard.whyDidYouRender = true
// 6. Measure mount time
function useComponentTiming(componentName) {
const mountTime = useRef(Date.now())
useEffect(() => {
const duration = Date.now() - mountTime.current
console.log(`${componentName} mounted in ${duration}ms`)
return () => {
console.log(`${componentName} unmounted`)
}
}, [componentName])
}
// Usage
function MyComponent() {
useComponentTiming('MyComponent')
// ...
}15. Bagaimana cara menangani mode offline?
Penanganan mode offline membutuhkan strategi caching dan sinkronisasi yang baik.
import NetInfo from '@react-native-community/netinfo'
// Hook to monitor connectivity
function useNetworkStatus() {
const [isConnected, setIsConnected] = useState(true)
const [connectionType, setConnectionType] = useState(null)
useEffect(() => {
const unsubscribe = NetInfo.addEventListener(state => {
setIsConnected(state.isConnected)
setConnectionType(state.type)
})
return () => unsubscribe()
}, [])
return { isConnected, connectionType }
}
// Service with offline queue
class OfflineQueue {
constructor() {
this.queue = []
this.isProcessing = false
}
async add(action) {
this.queue.push({
id: Date.now(),
action,
timestamp: new Date().toISOString()
})
await this.persist()
}
async persist() {
await AsyncStorage.setItem('offline_queue', JSON.stringify(this.queue))
}
async load() {
const data = await AsyncStorage.getItem('offline_queue')
this.queue = data ? JSON.parse(data) : []
}
async process() {
if (this.isProcessing || this.queue.length === 0) return
this.isProcessing = true
const { isConnected } = await NetInfo.fetch()
if (!isConnected) {
this.isProcessing = false
return
}
while (this.queue.length > 0) {
const item = this.queue[0]
try {
await this.executeAction(item.action)
this.queue.shift()
await this.persist()
} catch (error) {
console.error('Failed to process action:', error)
break
}
}
this.isProcessing = false
}
async executeAction(action) {
switch (action.type) {
case 'CREATE_ORDER':
return api.createOrder(action.payload)
case 'UPDATE_PROFILE':
return api.updateProfile(action.payload)
default:
throw new Error(`Unknown action: ${action.type}`)
}
}
}
const offlineQueue = new OfflineQueue()
// Network status banner component
function NetworkBanner() {
const { isConnected } = useNetworkStatus()
if (isConnected) return null
return (
<View style={styles.banner}>
<Text style={styles.bannerText}>
Offline mode - Changes will be synchronized
</Text>
</View>
)
}Kekhususan Mobile
16. Bagaimana cara menangani permission pada iOS dan Android?
Permission ditangani secara berbeda pada masing-masing platform. Pustaka seperti react-native-permissions menyatukan API tersebut.
import { Platform, Alert, Linking } from 'react-native'
import {
check,
request,
PERMISSIONS,
RESULTS,
openSettings
} from 'react-native-permissions'
// Permission configuration per platform
const PERMISSION_TYPES = {
camera: Platform.select({
ios: PERMISSIONS.IOS.CAMERA,
android: PERMISSIONS.ANDROID.CAMERA
}),
photos: Platform.select({
ios: PERMISSIONS.IOS.PHOTO_LIBRARY,
android: PERMISSIONS.ANDROID.READ_MEDIA_IMAGES
}),
location: Platform.select({
ios: PERMISSIONS.IOS.LOCATION_WHEN_IN_USE,
android: PERMISSIONS.ANDROID.ACCESS_FINE_LOCATION
})
}
// Hook to manage permissions
function usePermission(type) {
const [status, setStatus] = useState(RESULTS.UNAVAILABLE)
const permission = PERMISSION_TYPES[type]
useEffect(() => {
check(permission).then(setStatus)
}, [permission])
const requestPermission = useCallback(async () => {
const result = await request(permission)
setStatus(result)
if (result === RESULTS.BLOCKED) {
Alert.alert(
'Permission required',
`This feature requires ${type} access. Do you want to open settings?`,
[
{ text: 'No', style: 'cancel' },
{ text: 'Open', onPress: openSettings }
]
)
}
return result
}, [permission, type])
return {
status,
isGranted: status === RESULTS.GRANTED,
isDenied: status === RESULTS.DENIED,
isBlocked: status === RESULTS.BLOCKED,
requestPermission
}
}
// Usage
function CameraButton() {
const { isGranted, requestPermission } = usePermission('camera')
const handlePress = async () => {
if (!isGranted) {
const result = await requestPermission()
if (result !== RESULTS.GRANTED) return
}
// Open camera
navigation.navigate('Camera')
}
return (
<TouchableOpacity onPress={handlePress}>
<Text>Take a photo</Text>
</TouchableOpacity>
)
}17. Bagaimana cara mengimplementasikan push notification?
Push notification membutuhkan konfigurasi native serta backend untuk pengirimannya.
import messaging from '@react-native-firebase/messaging'
import notifee, { AndroidImportance } from '@notifee/react-native'
// Notification service
class NotificationService {
async initialize() {
// Request permission (iOS)
const authStatus = await messaging().requestPermission()
const enabled = authStatus === messaging.AuthorizationStatus.AUTHORIZED
if (enabled) {
// Get FCM token
const token = await messaging().getToken()
await this.registerToken(token)
// Listen for token changes
messaging().onTokenRefresh(this.registerToken)
// Create Android channel
await notifee.createChannel({
id: 'default',
name: 'Notifications',
importance: AndroidImportance.HIGH
})
}
return enabled
}
async registerToken(token) {
// Send token to backend
await api.registerPushToken(token)
}
// Setup handlers
setupHandlers() {
// Notification received in foreground
messaging().onMessage(async (remoteMessage) => {
await this.displayNotification(remoteMessage)
})
// Notification tapped (app in background)
messaging().onNotificationOpenedApp((remoteMessage) => {
this.handleNotificationPress(remoteMessage)
})
// App opened from notification (app closed)
messaging()
.getInitialNotification()
.then((remoteMessage) => {
if (remoteMessage) {
this.handleNotificationPress(remoteMessage)
}
})
}
async displayNotification(remoteMessage) {
const { title, body } = remoteMessage.notification
await notifee.displayNotification({
title,
body,
android: {
channelId: 'default',
pressAction: { id: 'default' }
},
data: remoteMessage.data
})
}
handleNotificationPress(remoteMessage) {
const { type, id } = remoteMessage.data
switch (type) {
case 'order':
navigation.navigate('OrderDetail', { orderId: id })
break
case 'message':
navigation.navigate('Chat', { conversationId: id })
break
}
}
}
// Usage in App.tsx
function App() {
useEffect(() => {
const notificationService = new NotificationService()
notificationService.initialize()
notificationService.setupHandlers()
}, [])
return <AppNavigator />
}18. Bagaimana cara menangani deep link?
Deep link memungkinkan aplikasi terbuka langsung pada layar tertentu dari URL eksternal.
import { Linking } from 'react-native'
import { NavigationContainer } from '@react-navigation/native'
// Deep link configuration
const linking = {
prefixes: ['myapp://', 'https://myapp.com'],
config: {
screens: {
Home: 'home',
Product: {
path: 'product/:id',
parse: {
id: (id) => parseInt(id, 10)
}
},
Profile: 'profile/:userId?',
Settings: {
path: 'settings',
screens: {
Notifications: 'notifications',
Privacy: 'privacy'
}
}
}
},
// Custom function to get initial URL
async getInitialURL() {
// Check if app was opened via deep link
const url = await Linking.getInitialURL()
if (url) return url
// Check notifications
const message = await messaging().getInitialNotification()
if (message?.data?.link) return message.data.link
return null
},
// Subscribe to incoming links
subscribe(listener) {
// Standard deep links
const linkingSubscription = Linking.addEventListener('url', ({ url }) => {
listener(url)
})
// Links from notifications
const unsubscribeNotification = messaging().onNotificationOpenedApp(
(message) => {
const link = message.data?.link
if (link) listener(link)
}
)
return () => {
linkingSubscription.remove()
unsubscribeNotification()
}
}
}
// Usage
function App() {
return (
<NavigationContainer linking={linking} fallback={<LoadingScreen />}>
<Stack.Navigator>
<Stack.Screen name="Home" component={HomeScreen} />
<Stack.Screen name="Product" component={ProductScreen} />
<Stack.Screen name="Profile" component={ProfileScreen} />
</Stack.Navigator>
</NavigationContainer>
)
}
// Testing deep links
// myapp://product/123
// https://myapp.com/profile/user456Siap menguasai wawancara React Native Anda?
Berlatih dengan simulator interaktif, flashcards, dan tes teknis kami.
Kode dan Modul Native
19. Kapan dan bagaimana menulis kode native?
Kode native dibutuhkan untuk mengakses fitur yang tidak tersedia di JavaScript atau untuk mengoptimalkan performa kritis.
// iOS - Native module in Swift
// ios/MyModule.swift
import Foundation
@objc(MyModule)
class MyModule: NSObject {
@objc
func getDeviceInfo(_ resolve: @escaping RCTPromiseResolveBlock,
rejecter reject: @escaping RCTPromiseRejectBlock) {
let info: [String: Any] = [
"model": UIDevice.current.model,
"systemVersion": UIDevice.current.systemVersion,
"name": UIDevice.current.name
]
resolve(info)
}
@objc
static func requiresMainQueueSetup() -> Bool {
return false
}
}
// ios/MyModule.m (Bridge)
#import <React/RCTBridgeModule.h>
@interface RCT_EXTERN_MODULE(MyModule, NSObject)
RCT_EXTERN_METHOD(getDeviceInfo:(RCTPromiseResolveBlock)resolve
rejecter:(RCTPromiseRejectBlock)reject)
@end
// Android - Native module in Kotlin
// android/app/src/main/java/com/myapp/MyModule.kt
package com.myapp
import com.facebook.react.bridge.*
class MyModule(reactContext: ReactApplicationContext) :
ReactContextBaseJavaModule(reactContext) {
override fun getName() = "MyModule"
@ReactMethod
fun getDeviceInfo(promise: Promise) {
val info = Arguments.createMap().apply {
putString("model", android.os.Build.MODEL)
putString("systemVersion", android.os.Build.VERSION.RELEASE)
putString("manufacturer", android.os.Build.MANUFACTURER)
}
promise.resolve(info)
}
}
// JavaScript - Using native module
import { NativeModules } from 'react-native'
const { MyModule } = NativeModules
async function getDeviceInfo() {
try {
const info = await MyModule.getDeviceInfo()
console.log('Device info:', info)
return info
} catch (error) {
console.error('Error getting device info:', error)
throw error
}
}20. Apa itu Expo dan kapan sebaiknya digunakan?
Expo merupakan framework yang menyederhanakan pengembangan React Native dengan mengelola konfigurasi native.
// Expo benefits
// - No need for Android Studio or Xcode to start
// - OTA (over-the-air) updates without app stores
// - Rich SDK with preconfigured modules
// - EAS Build for cloud builds
// Creating an Expo project
// npx create-expo-app@latest MyApp
// Using Expo modules
import * as ImagePicker from 'expo-image-picker'
import * as Location from 'expo-location'
import * as Notifications from 'expo-notifications'
async function pickImage() {
// Request permission
const { status } = await ImagePicker.requestMediaLibraryPermissionsAsync()
if (status !== 'granted') {
alert('Permission denied')
return
}
// Open image picker
const result = await ImagePicker.launchImageLibraryAsync({
mediaTypes: ImagePicker.MediaTypeOptions.Images,
allowsEditing: true,
aspect: [4, 3],
quality: 0.8
})
if (!result.canceled) {
return result.assets[0].uri
}
}
// Build configuration
// app.json
{
"expo": {
"name": "MyApp",
"slug": "myapp",
"version": "1.0.0",
"orientation": "portrait",
"icon": "./assets/icon.png",
"splash": {
"image": "./assets/splash.png",
"resizeMode": "contain",
"backgroundColor": "#ffffff"
},
"ios": {
"supportsTablet": true,
"bundleIdentifier": "com.company.myapp"
},
"android": {
"adaptiveIcon": {
"foregroundImage": "./assets/adaptive-icon.png",
"backgroundColor": "#ffffff"
},
"package": "com.company.myapp"
},
"plugins": [
"expo-router",
[
"expo-camera",
{
"cameraPermission": "Allow camera access"
}
]
]
}
}
// When NOT to use Expo
// - Need for complex custom native modules
// - Integration with specific native SDKs
// - Total control over native configuration
// - Very lightweight application (Expo adds weight)21. Bagaimana cara kerja Hot Reloading?
Hot Reloading (Fast Refresh) memungkinkan perubahan diterapkan secara langsung tanpa kehilangan state aplikasi.
// Fast Refresh preserves hooks state
function Counter() {
const [count, setCount] = useState(0)
// Modify this text and save
// The count state will be preserved
return (
<View>
<Text>Counter: {count}</Text>
<Button title="+1" onPress={() => setCount(c => c + 1)} />
</View>
)
}
// ⚠️ Cases where Fast Refresh does full reload
// 1. Syntax error
// 2. Modifying a class component
// 3. File with mixed non-component exports
// ❌ This file will do full reload because of mixed exports
export const API_URL = 'https://api.example.com'
export function MyComponent() { /* ... */ }
// ✅ Separate into distinct files
// constants.js
export const API_URL = 'https://api.example.com'
// MyComponent.js
export function MyComponent() { /* ... */ }
// Force remount if needed
// Add this comment at top of file:
// @refresh reset
// Metro configuration for Fast Refresh
// metro.config.js
module.exports = {
transformer: {
experimentalImportSupport: false,
inlineRequires: true
}
}Pengujian dan Kualitas
22. Bagaimana cara menguji aplikasi React Native?
Pengujian React Native menggunakan Jest beserta pustaka khusus untuk rendering dan interaksi.
// Jest configuration
// jest.config.js
module.exports = {
preset: 'react-native',
setupFilesAfterEnv: ['@testing-library/jest-native/extend-expect'],
transformIgnorePatterns: [
'node_modules/(?!(react-native|@react-native|@react-navigation)/)'
],
moduleNameMapper: {
'\\.(jpg|jpeg|png|gif|webp|svg)$': '<rootDir>/__mocks__/fileMock.js'
}
}
// Component test with React Native Testing Library
import { render, screen, fireEvent, waitFor } from '@testing-library/react-native'
import { ProductCard } from './ProductCard'
describe('ProductCard', () => {
const mockProduct = {
id: '1',
name: 'iPhone 15',
price: 999,
image: 'https://example.com/iphone.jpg'
}
it('renders product information', () => {
render(<ProductCard product={mockProduct} />)
expect(screen.getByText('iPhone 15')).toBeOnTheScreen()
expect(screen.getByText('$999')).toBeOnTheScreen()
})
it('calls onPress when tapped', () => {
const onPress = jest.fn()
render(<ProductCard product={mockProduct} onPress={onPress} />)
fireEvent.press(screen.getByTestId('product-card'))
expect(onPress).toHaveBeenCalledWith('1')
})
it('shows loading state when adding to cart', async () => {
const onAddToCart = jest.fn(() => new Promise(r => setTimeout(r, 100)))
render(<ProductCard product={mockProduct} onAddToCart={onAddToCart} />)
fireEvent.press(screen.getByText('Add to cart'))
expect(screen.getByTestId('loading-indicator')).toBeOnTheScreen()
await waitFor(() => {
expect(screen.queryByTestId('loading-indicator')).not.toBeOnTheScreen()
})
})
})
// Navigation test
import { NavigationContainer } from '@react-navigation/native'
import { createNativeStackNavigator } from '@react-navigation/native-stack'
const Stack = createNativeStackNavigator()
function renderWithNavigation(component, { initialRouteName = 'Test' } = {}) {
return render(
<NavigationContainer>
<Stack.Navigator initialRouteName={initialRouteName}>
<Stack.Screen name="Test" component={component} />
<Stack.Screen name="Detail" component={DetailScreen} />
</Stack.Navigator>
</NavigationContainer>
)
}
// Custom hook test
import { renderHook, act } from '@testing-library/react-native'
import { useCounter } from './useCounter'
test('increments counter', () => {
const { result } = renderHook(() => useCounter(0))
act(() => {
result.current.increment()
})
expect(result.current.count).toBe(1)
})23. Bagaimana cara mengimplementasikan pengujian E2E dengan Detox?
Detox memungkinkan pengujian aplikasi pada simulator atau emulator nyata.
// Installation
// npm install detox --save-dev
// detox init -r jest
// .detoxrc.js
module.exports = {
testRunner: {
args: {
$0: 'jest',
config: 'e2e/jest.config.js'
},
jest: {
setupTimeout: 120000
}
},
apps: {
'ios.debug': {
type: 'ios.app',
binaryPath: 'ios/build/MyApp.app',
build: 'xcodebuild -workspace ios/MyApp.xcworkspace -scheme MyApp -configuration Debug -sdk iphonesimulator -derivedDataPath ios/build'
},
'android.debug': {
type: 'android.apk',
binaryPath: 'android/app/build/outputs/apk/debug/app-debug.apk',
build: 'cd android && ./gradlew assembleDebug assembleAndroidTest -DtestBuildType=debug'
}
},
devices: {
simulator: {
type: 'ios.simulator',
device: { type: 'iPhone 15' }
},
emulator: {
type: 'android.emulator',
device: { avdName: 'Pixel_5_API_34' }
}
}
}
// e2e/login.test.js
describe('Login Flow', () => {
beforeAll(async () => {
await device.launchApp()
})
beforeEach(async () => {
await device.reloadReactNative()
})
it('should login successfully with valid credentials', async () => {
// Fill the form
await element(by.id('email-input')).typeText('test@example.com')
await element(by.id('password-input')).typeText('password123')
// Submit
await element(by.id('login-button')).tap()
// Verify navigation to dashboard
await waitFor(element(by.text('Welcome')))
.toBeVisible()
.withTimeout(5000)
})
it('should show error with invalid credentials', async () => {
await element(by.id('email-input')).typeText('wrong@example.com')
await element(by.id('password-input')).typeText('wrongpassword')
await element(by.id('login-button')).tap()
await expect(element(by.text('Invalid credentials'))).toBeVisible()
})
it('should navigate to forgot password', async () => {
await element(by.id('forgot-password-link')).tap()
await expect(element(by.text('Reset Password'))).toBeVisible()
})
})
// Detox commands
// detox build --configuration ios.debug
// detox test --configuration ios.debugDeployment dan Produksi
24. Bagaimana cara mengelola environment (dev, staging, prod)?
Manajemen environment memerlukan variabel konfigurasi yang berbeda untuk masing-masing tahap.
// Option 1: react-native-config
// .env.development
API_URL=https://dev-api.myapp.com
ANALYTICS_KEY=dev_key
// .env.staging
API_URL=https://staging-api.myapp.com
ANALYTICS_KEY=staging_key
// .env.production
API_URL=https://api.myapp.com
ANALYTICS_KEY=prod_key
// Usage
import Config from 'react-native-config'
const api = {
baseUrl: Config.API_URL,
analyticsKey: Config.ANALYTICS_KEY
}
// Option 2: JavaScript configuration file
// config/index.js
const ENV = {
development: {
apiUrl: 'https://dev-api.myapp.com',
analyticsEnabled: false,
logLevel: 'debug'
},
staging: {
apiUrl: 'https://staging-api.myapp.com',
analyticsEnabled: true,
logLevel: 'info'
},
production: {
apiUrl: 'https://api.myapp.com',
analyticsEnabled: true,
logLevel: 'error'
}
}
const getEnv = () => {
if (__DEV__) return 'development'
// Logic to determine staging vs prod
return 'production'
}
export const config = ENV[getEnv()]
// Option 3: Expo with app.config.js
// app.config.js
export default ({ config }) => {
const env = process.env.APP_ENV || 'development'
const envConfig = {
development: {
apiUrl: 'https://dev-api.myapp.com',
bundleId: 'com.myapp.dev'
},
production: {
apiUrl: 'https://api.myapp.com',
bundleId: 'com.myapp'
}
}
return {
...config,
extra: {
...envConfig[env],
env
},
ios: {
bundleIdentifier: envConfig[env].bundleId
},
android: {
package: envConfig[env].bundleId
}
}
}25. Bagaimana cara melakukan deployment ke app store?
Deployment melibatkan konfigurasi build, metadata, serta proses pengajuan.
# Option 1: EAS Build (Expo)
# Installation
npm install -g eas-cli
# Configuration
eas build:configure
# eas.json
{
"cli": {
"version": ">= 5.0.0"
},
"build": {
"development": {
"developmentClient": true,
"distribution": "internal"
},
"preview": {
"distribution": "internal",
"android": {
"buildType": "apk"
}
},
"production": {
"autoIncrement": true
}
},
"submit": {
"production": {
"ios": {
"appleId": "your@email.com",
"ascAppId": "1234567890"
},
"android": {
"serviceAccountKeyPath": "./google-services.json",
"track": "production"
}
}
}
}
# Production build
eas build --platform all --profile production
# Store submission
eas submit --platform all --profile production
# Option 2: Fastlane (React Native CLI)
# Gemfile
source "https://rubygems.org"
gem "fastlane"
# ios/fastlane/Fastfile
default_platform(:ios)
platform :ios do
desc "Deploy to TestFlight"
lane :beta do
increment_build_number(xcodeproj: "MyApp.xcodeproj")
build_app(scheme: "MyApp")
upload_to_testflight
end
desc "Deploy to App Store"
lane :release do
increment_build_number(xcodeproj: "MyApp.xcodeproj")
build_app(scheme: "MyApp")
upload_to_app_store(
skip_screenshots: true,
skip_metadata: true
)
end
end
# android/fastlane/Fastfile
default_platform(:android)
platform :android do
desc "Deploy to Play Store internal"
lane :beta do
gradle(task: "clean bundleRelease")
upload_to_play_store(
track: "internal",
aab: "app/build/outputs/bundle/release/app-release.aab"
)
end
end26. Bagaimana cara mengimplementasikan OTA update?
Over-The-Air update memungkinkan distribusi kode JavaScript baru tanpa melalui app store.
// With Expo Updates
import * as Updates from 'expo-updates'
async function checkForUpdates() {
if (__DEV__) return // Not in development
try {
const update = await Updates.checkForUpdateAsync()
if (update.isAvailable) {
// Download update
await Updates.fetchUpdateAsync()
// Ask user to restart
Alert.alert(
'Update available',
'A new version is available. Restart now?',
[
{ text: 'Later', style: 'cancel' },
{
text: 'Restart',
onPress: () => Updates.reloadAsync()
}
]
)
}
} catch (error) {
console.error('Update check error:', error)
}
}
// Automatic check on startup
function App() {
useEffect(() => {
checkForUpdates()
}, [])
return <AppNavigator />
}
// eas.json configuration for update channels
{
"build": {
"production": {
"channel": "production"
},
"preview": {
"channel": "preview"
}
}
}
// Command to publish an update
// eas update --branch production --message "Bug fix"
// With CodePush (Microsoft)
import codePush from 'react-native-code-push'
const codePushOptions = {
checkFrequency: codePush.CheckFrequency.ON_APP_RESUME,
installMode: codePush.InstallMode.ON_NEXT_RESTART
}
function App() {
return <AppNavigator />
}
export default codePush(codePushOptions)(App)Pertanyaan Lanjutan
27. Bagaimana cara mengoptimalkan waktu startup aplikasi?
Waktu startup merupakan faktor kritis terhadap pengalaman pengguna.
// android/app/build.gradle
project.ext.react = [
enableHermes: true
]
// ios/Podfile
:hermes_enabled => true
// 2. Lazy loading screens
const HeavyScreen = React.lazy(() => import('./HeavyScreen'))
// 3. Defer non-critical initializations
import { InteractionManager } from 'react-native'
function App() {
useEffect(() => {
// Execute after first render
InteractionManager.runAfterInteractions(() => {
// Initialize analytics
Analytics.init()
// Prefetch data
prefetchCriticalData()
})
}, [])
return <AppNavigator />
}
// 4. Optimize splash screen
import * as SplashScreen from 'expo-splash-screen'
// Prevent automatic hiding
SplashScreen.preventAutoHideAsync()
function App() {
const [appIsReady, setAppIsReady] = useState(false)
useEffect(() => {
async function prepare() {
try {
// Load critical resources
await Font.loadAsync(customFonts)
await Image.prefetch(criticalImages)
// Restore authentication
await restoreAuth()
} catch (e) {
console.warn(e)
} finally {
setAppIsReady(true)
}
}
prepare()
}, [])
const onLayoutRootView = useCallback(async () => {
if (appIsReady) {
// Hide splash screen
await SplashScreen.hideAsync()
}
}, [appIsReady])
if (!appIsReady) return null
return (
<View style={{ flex: 1 }} onLayout={onLayoutRootView}>
<AppNavigator />
</View>
)
}
// 5. Inline requires to defer imports
// metro.config.js
module.exports = {
transformer: {
inlineRequires: true
}
}
// Manual usage
function loadHeavyModule() {
const HeavyModule = require('./HeavyModule').default
return HeavyModule
}28. Bagaimana cara menangani keamanan pada aplikasi React Native?
Keamanan mobile membutuhkan beberapa lapisan perlindungan.
import * as SecureStore from 'expo-secure-store'
// or
import * as Keychain from 'react-native-keychain'
async function saveToken(token) {
await SecureStore.setItemAsync('auth_token', token)
}
async function getToken() {
return await SecureStore.getItemAsync('auth_token')
}
// 2. Certificate pinning for network calls
// android/app/src/main/res/xml/network_security_config.xml
/*
<network-security-config>
<domain-config>
<domain includeSubdomains="true">api.myapp.com</domain>
<pin-set>
<pin digest="SHA-256">AAAAAA...</pin>
<pin digest="SHA-256">BBBBBB...</pin>
</pin-set>
</domain-config>
</network-security-config>
*/
// 3. Jailbreak/root detection
import JailMonkey from 'jail-monkey'
function SecurityCheck() {
useEffect(() => {
if (JailMonkey.isJailBroken()) {
Alert.alert(
'Insecure device',
'This application cannot run on a rooted/jailbroken device'
)
}
}, [])
}
// 4. Code obfuscation
// metro.config.js (for Hermes)
module.exports = {
transformer: {
minifierConfig: {
mangle: true,
output: {
ascii_only: true
}
}
}
}
// 5. Screenshot/recording protection
import { usePreventScreenCapture } from 'expo-screen-capture'
function SensitiveScreen() {
usePreventScreenCapture() // iOS only
return <View>{/* Sensitive data */}</View>
}
// 6. Session timeout
function useSessionTimeout(timeoutMs = 5 * 60 * 1000) {
const lastActivity = useRef(Date.now())
const { logout } = useAuth()
useEffect(() => {
const subscription = AppState.addEventListener('change', (state) => {
if (state === 'active') {
const elapsed = Date.now() - lastActivity.current
if (elapsed > timeoutMs) {
logout()
}
} else {
lastActivity.current = Date.now()
}
})
return () => subscription.remove()
}, [timeoutMs, logout])
}29. Bagaimana cara mengimplementasikan aksesibilitas?
Aksesibilitas merupakan hal penting agar aplikasi dapat digunakan oleh semua orang.
import { AccessibilityInfo } from 'react-native'
// 1. Basic accessibility props
function AccessibleButton({ label, onPress, disabled }) {
return (
<TouchableOpacity
onPress={onPress}
disabled={disabled}
accessible={true}
accessibilityLabel={label}
accessibilityRole="button"
accessibilityState={{ disabled }}
accessibilityHint={`Tap to ${label.toLowerCase()}`}
>
<Text>{label}</Text>
</TouchableOpacity>
)
}
// 2. Group elements for screen readers
function ProductCard({ product }) {
return (
<View
accessible={true}
accessibilityLabel={`${product.name}, ${product.price} dollars`}
>
<Image
source={{ uri: product.image }}
accessibilityIgnoresInvertColors={true}
/>
<Text>{product.name}</Text>
<Text>${product.price}</Text>
</View>
)
}
// 3. Announce dynamic changes
function NotificationBadge({ count }) {
useEffect(() => {
if (count > 0) {
AccessibilityInfo.announceForAccessibility(
`${count} new notification${count > 1 ? 's' : ''}`
)
}
}, [count])
return (
<View accessibilityLabel={`${count} notifications`}>
<Text>{count}</Text>
</View>
)
}
// 4. Detect accessibility preferences
function useAccessibilityPreferences() {
const [isScreenReaderEnabled, setIsScreenReaderEnabled] = useState(false)
const [isReduceMotionEnabled, setIsReduceMotionEnabled] = useState(false)
useEffect(() => {
AccessibilityInfo.isScreenReaderEnabled().then(setIsScreenReaderEnabled)
AccessibilityInfo.isReduceMotionEnabled().then(setIsReduceMotionEnabled)
const screenReaderListener = AccessibilityInfo.addEventListener(
'screenReaderChanged',
setIsScreenReaderEnabled
)
const reduceMotionListener = AccessibilityInfo.addEventListener(
'reduceMotionChanged',
setIsReduceMotionEnabled
)
return () => {
screenReaderListener.remove()
reduceMotionListener.remove()
}
}, [])
return { isScreenReaderEnabled, isReduceMotionEnabled }
}
// 5. Adapt animations based on preferences
function AnimatedComponent() {
const { isReduceMotionEnabled } = useAccessibilityPreferences()
const animation = useSharedValue(0)
useEffect(() => {
animation.value = withTiming(1, {
duration: isReduceMotionEnabled ? 0 : 300
})
}, [isReduceMotionEnabled])
return <Animated.View style={animatedStyle} />
}30. Bagaimana cara menyusun proyek React Native berskala besar?
Arsitektur yang terstruktur memudahkan pemeliharaan dan skalabilitas aplikasi.
// Recommended structure
src/
├── app/ # App configuration
│ ├── App.tsx
│ ├── Navigation.tsx
│ └── Providers.tsx
│
├── features/ # Feature modules
│ ├── auth/
│ │ ├── screens/
│ │ │ ├── LoginScreen.tsx
│ │ │ └── RegisterScreen.tsx
│ │ ├── components/
│ │ │ └── AuthForm.tsx
│ │ ├── hooks/
│ │ │ └── useAuth.ts
│ │ ├── services/
│ │ │ └── authService.ts
│ │ └── index.ts # Public export
│ │
│ ├── products/
│ │ ├── screens/
│ │ ├── components/
│ │ ├── hooks/
│ │ └── services/
│ │
│ └── cart/
│ └── ...
│
├── shared/ # Shared code
│ ├── components/
│ │ ├── Button.tsx
│ │ ├── Input.tsx
│ │ └── Card.tsx
│ ├── hooks/
│ │ ├── useDebounce.ts
│ │ └── useNetworkStatus.ts
│ ├── utils/
│ │ ├── format.ts
│ │ └── validation.ts
│ └── types/
│ └── index.ts
│
├── services/ # Global services
│ ├── api/
│ │ ├── client.ts
│ │ └── interceptors.ts
│ ├── storage/
│ │ └── secureStorage.ts
│ └── analytics/
│ └── analytics.ts
│
├── store/ # Global state
│ ├── slices/
│ └── index.ts
│
└── theme/ # Design system
├── colors.ts
├── typography.ts
├── spacing.ts
└── index.ts// Example feature module organization
// features/products/index.ts
export { ProductListScreen } from './screens/ProductListScreen'
export { ProductDetailScreen } from './screens/ProductDetailScreen'
export { useProducts } from './hooks/useProducts'
export { ProductCard } from './components/ProductCard'
// features/products/hooks/useProducts.ts
import { useQuery } from '@tanstack/react-query'
import { productService } from '../services/productService'
export function useProducts(categoryId?: string) {
return useQuery({
queryKey: ['products', categoryId],
queryFn: () => productService.getProducts(categoryId)
})
}
// features/products/services/productService.ts
import { apiClient } from '@/services/api/client'
import { Product } from '../types'
export const productService = {
async getProducts(categoryId?: string): Promise<Product[]> {
const params = categoryId ? { category: categoryId } : {}
const response = await apiClient.get('/products', { params })
return response.data
},
async getProduct(id: string): Promise<Product> {
const response = await apiClient.get(`/products/${id}`)
return response.data
}
}
// Import alias configuration
// babel.config.js
module.exports = {
presets: ['module:@react-native/babel-preset'],
plugins: [
[
'module-resolver',
{
alias: {
'@': './src',
'@features': './src/features',
'@shared': './src/shared',
'@services': './src/services'
}
}
]
]
}Kesimpulan
30 pertanyaan ini mencakup pengetahuan inti React Native yang umum diharapkan dalam wawancara. Beberapa poin utama yang perlu dikuasai:
- ✅ Arsitektur: Memahami bridge, JSI, dan arsitektur baru
- ✅ Komponen: Navigasi, daftar berperforma tinggi, animasi
- ✅ State dan data: Zustand/Redux, React Query, penyimpanan lokal
- ✅ Performa: Optimasi FlatList, memoisasi, profiling
- ✅ Kekhususan mobile: Permission, notifikasi, deep link
- ✅ Pengujian: Jest, Testing Library, Detox
- ✅ Deployment: EAS Build, app store, OTA update
- ✅ Keamanan dan aksesibilitas: Penyimpanan aman, kepatuhan WCAG
Persiapan wawancara React Native menuntut pemahaman aspek mobile yang melampaui pengetahuan React web. Latihan menggunakan proyek nyata dan pengujian pada perangkat sebenarnya akan memperkuat penguasaan konsep-konsep tersebut.
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