FlutterのGoldenテストの雛形

common.dart

import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';

// フォントの読み込み
Future<void> loadJapaneseFont() async {
  TestWidgetsFlutterBinding.ensureInitialized();
  final binary = rootBundle.load('assets/fonts/NotoSansJP-Black.otf');
  final loader = FontLoader('Roboto')..addFont(binary);
  await loader.load();
}

flutter_golden_test.dart

import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:golden_toolkit/golden_toolkit.dart';

import '../../common/common.dart';

void main() {
  late Widget testWidget;

  // テストするスクリーンサイズ
  var testScreenSize = Device.phone.size;

  // 日本語フォントの読み込み
  setUpAll(() async {
    await loadJapaneseFont();
  });

  // 読み込み時に実行
  setUp(() {
    testWidget = MaterialApp(
      home: ScreenUtilInit(
        designSize: testScreenSize,
        minTextAdapt: true,
        builder: (context, child) {
          return Scaffold(
            body: Container(
              color: Colors.white,
              child: Center(
                child: Text(
                  'テスト',
                  style: TextStyle(
                    fontSize: 16.sp,
                    fontWeight: FontWeight.w600,
                  ),
                ),
              ),
            ),
          );
        },
      ),
    );
  });

  // テスト終了時に実行
  tearDown(() {});

  testGoldens('', (WidgetTester tester) async {
    await tester.pumpWidgetBuilder(
      testWidget,
      surfaceSize: testScreenSize,
    );
    await screenMatchesGolden(tester, 'apply_complete_screen');
  });
}