testing localizations

localization_test.dart

// Copyright 2024 Fredrick Allan Hrott. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

import 'package:flutter/material.dart';
import 'package:flutter_localizations/flutter_localizations.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';
import 'package:flutter_test/flutter_test.dart';

// General idea is the localizations in the model are referred to as
// AppLocalizations.of(appRouterContext).localizationKey
// so then we set the same scaffoldMessengerKey var
// and appRouterContext as in the app via MaterialApp wrapper
// pump the MaterialApp wrapper and child Container and
// then we can run tests on models that are using localizations.
//
// Because I use the scaffoldMessengerKey instead, the MaterialApp
// wrapper for the tests can be different than the MaterialApp.router
// in the app without any headaches.

late final scaffoldMessengerKey; // = GlobalKey<ScaffoldMessengerState>();

void main() {
  group('localizations tests', () {
    setUpAll(() {
      // sets up scaffoldMessengerKey for the MaterialApp wrapper we use
      scaffoldMessengerKey = GlobalKey<ScaffoldMessengerState>();
    });
    testWidgets('so this would be a model test with localizations', (WidgetTester widgetTester) async {
      await widgetTester.pumpWidget(MaterialApp(
        scaffoldMessengerKey: scaffoldMessengerKey,
        localizationsDelegates: const [
          AppLocalizations.delegate,
          GlobalMaterialLocalizations.delegate,
          GlobalWidgetsLocalizations.delegate,
          GlobalCupertinoLocalizations.delegate,
        ],
        supportedLocales: AppLocalizations.supportedLocales,
        locale: const Locale('en', 'EN'),
        home: Container(),
      ));

      // still need this according to  bug issue 22193, large localizations file failure
      await widgetTester.pump();

      // we do not have to search for Container element for context as we can do
      BuildContext testContext = scaffoldMessengerKey.currentContext;

      // and we do our expect testing here
    });
  });
}