【问题标题】：How to write test for flutter package Flutter WeChat Assets Picker如何为flutter包编写测试 Flutter WeChat Assets Picker
【发布时间】：2022-07-04 21:27:53
【问题描述】：

我正在尝试使用 Mocktail 包 https://pub.dev/packages/mocktail 对这个颤振包 https://pub.dev/packages/wechat_assets_picker 编写一个测试，但是这个包似乎在文档中没有测试。

我已经包含了最小的可重现示例。测试文件目前不工作，它包含在使用 Flutter Mocktail 包的示例测试代码中。

它应该模拟 AssetPicker.pickAssets 以测试它是否实际使用正确的参数调用。我是在IOS模拟器上运行的，我们需要在ios/Runer/Info.plist中添加这个key，否则点击添加按钮后模拟器会意外关闭。

main.dart

import 'package:flutter/material.dart';
import 'package:wechat_assets_picker/wechat_assets_picker.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

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

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: const [],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () async {
          final List<AssetEntity>? result =
              await AssetPicker.pickAssets(context);
        },
        tooltip: 'Add photo',
        child: const Icon(Icons.add),
      ),
    );
  }
}

widget_test.dart

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:mocktail/mocktail.dart';
import 'package:wechat/main.dart';
import 'package:wechat_assets_picker/wechat_assets_picker.dart';

class _MockAssetPicker extends Mock implements AssetPicker {}

void main() {
  testWidgets('It should call the WeChat asset picker',
      (WidgetTester tester) async {
    await tester.pumpWidget(const MyApp());
    final BuildContext context = tester.element(find.byType(MyApp));

    final assetPickerMock = _MockAssetPicker();
    when(() => assetPickerMock.pickAssets(context)).thenAnswer((_) => Future.value([
          const AssetEntity(
            id: 'id1',
            typeInt: 1,
            width: 100,
            height: 100,
          ),
        ]));
    AssetPicker.instance = assetPickerMock;

    await tester.tap(find.byIcon(Icons.add));
    await tester.pump();

    verify(() => assetPickerMock.pickAssets(context)).called(1);
  });
}

【问题讨论】：

标签： flutter testing package

【解决方案1】：

分离的选择器委托支持模拟选择器：https://github.com/fluttercandies/flutter_wechat_assets_picker/pull/315

【讨论】：