Mobile App Development Interview Questions in Hyderabad

import { render, screen, fireEvent } from '@testing-library/react-native'; test('shows error when email is empty', () => { render(<LoginScreen onSubmit={jest.fn()} />); fireEvent.press(screen.getByRole('button', { name: 'Login' })); expect(screen.getByText('Email is required')).toBeTruthy(); });

testWidgets('increments counter on tap', (tester) async { await tester.pumpWidget(const MaterialApp(home: Scaffold(body: Counter()))); expect(find.text('Count: 0'), findsOneWidget); await tester.tap(find.text('Add')); await tester.pump(); expect(find.text('Count: 1'), findsOneWidget); });

sealed class ProductState {} class ProductLoading extends ProductState {} class ProductLoaded extends ProductState { ProductLoaded(this.items); final List<Product> items; } class ProductError extends ProductState { ProductError(this.message); final String message; } class ProductCubit extends Cubit<ProductState> { ProductCubit(this._repo) : super(ProductLoading()); final ProductRepository _repo; Future<void> load() async { emit(ProductLoading()); try { emit(ProductLoaded(await _repo.fetchProducts())); } catch (_) { emit(ProductError('Could not load products')); } } }

import * as Location from 'expo-location'; export function MyLocation() { const [coords, setCoords] = useState(null); const [error, setError] = useState(null); useEffect(() => { (async () => { const { status } = await Location.requestForegroundPermissionsAsync(); if (status !== 'granted') { setError('Location permission denied'); return; } const pos = await Location.getCurrentPositionAsync({}); setCoords(pos.coords); })(); }, []); if (error) return <Text>{error}</Text>; if (!coords) return <ActivityIndicator />; return <Text>{coords.latitude}, {coords.longitude}</Text>; }