Flutter测试指南

dev_dependencies:
  test:

class Counter {
  int count = 0;
  void increase() => count++;
  void decrease() => count--;
}

import 'package:test/test.dart';
import 'package:flutter_app/main.dart';

void main() {
  test('Increase counter to 1', () {
    final counter = Counter();
    counter.increase();
    expect(counter.count, 1); // 验证结果
  });
}

group('Counter', () {
  test('Increase to 1', () {
    final counter = Counter();
    counter.increase();
    expect(counter.count, 1);
  });

  test('Decrease to -1', () {
    final counter = Counter();
    counter.decrease();
    expect(counter.count, -1);
  });
});

dev_dependencies:
  mockito:

import 'package:mockito/mockito.dart';
import 'package:http/http.dart' as http;

class MockClient extends Mock implements http.Client {}

void main() {
  test('Fetch Todo successfully', () async {
    final client = MockClient();
    when(client.get('https://xxx.com/todos/1'))
      .thenAnswer((_) async => http.Response('{"title": "test"}', 200));
    
    final todo = await fetchTodo(client);
    expect(todo.title, 'test');
  });

  test('Fetch Todo with error', () {
    final client = MockClient();
    when(client.get('https://xxx.com/todos/1'))
      .thenAnswer((_) async => http.Response('', 403));
    
    expect(fetchTodo(client), throwsException);
  });
}

dev_dependencies:
  flutter_test:
    sdk: flutter

import 'package:flutter_test/flutter_test.dart';
import 'package:flutter_app/main.dart';

void main() {
  testWidgets('Counter increments', (WidgetTester tester) async {
    await tester.pumpWidget(MyApp());
    expect(find.text('0'), findsOneWidget);
    
    await tester.tap(find.byIcon(Icons.add));
    await tester.pump();
    expect(find.text('1'), findsOneWidget);
  });
}

flutter test --coverage

genhtml coverage/lcov.info -o coverage/html
open coverage/html/index.html