轻松拥抱Flutter和Native混合工程持续集成的最佳实践

2023-11-09 08:54:44

拥抱Flutter和Native混合工程持续集成的最佳实践

引言

在之前的文章《Flutter混合工程改造实践》中，有些同学留言想了解抽取Flutter依赖到远程的一些实现细节，所以本文重点来讲一讲Flutter混合工程中的Flutter直接依赖解除的一些具体实现。

思考

因为目前我们闲鱼是Flutter和Native混合开发的，Flutter的产物是一个 aar 包，Native工程通过 aar 包来依赖Flutter，但是很多同学反映每次Flutter升级后，aar包每次都会变大，甚至导致Native App增大几十M，这是非常不合理的。为了解决这个问题，我们将Flutter产物抽取出来，变更为远程依赖的方式，这样的话只需要升级Flutter SDK版本就可以了。

实践

1. Dart FFI

Dart FFI的全称是Dart Foreign Function Interface，Dart FFI是一套用于从Dart调用原生代码的库，它允许Dart与C、Objective-C、Swift等语言编写的原生库进行交互。

2. Gradle插件

为了实现Flutter产物抽取出来，我们使用Gradle插件实现了该功能，具体实现如下：

// build.gradle
dependencies {
  implementation project(':flutter')  // 在这里添加Flutter项目作为依赖
}

3. Flutter模块化

为了实现Flutter产物抽取出来，我们对Flutter项目进行了模块化改造，具体实现如下：

// flutter/pubspec.yaml
name: flutter_module  // 定义Flutter模块的名称

// flutter/lib/main.dart
import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set the appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and it centers them vertically.
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

4. Flutter集成测试

为了保证Flutter产物抽取出来后的质量，我们对Flutter项目进行了集成测试，具体实现如下：

// flutter/test/widget_test.dart
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
    // Build our app and trigger a frame.
    await tester.pumpWidget(MyApp());

    // Verify that our counter starts at 0.
    expect(find.text('0'), findsOneWidget);

    // Tap the '+' icon and trigger a frame.
    await tester.tap(find.byIcon(Icons.add));
    await tester.pump();

    // Verify that our counter has incremented.
    expect(find.text('1'), findsOneWidget);
  });
}