ci: add integration tests for Windows

Author: domyd

.github/workflows/test.yml

@@ -30,3 +30,16 @@ jobs:
       - run: flutter test
       - run: flutter test
         working-directory: example
+
+  integration-test-windows:
+    name: 'Integration Test on windows-latest'
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: stable
+
+      - name: run integration test
+        run: .\run_integration_test_windows.ps1
+        working-directory: example

example/integration_test/local_timezone_test.dart

@@ -0,0 +1,25 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter_timezone_example/main.dart';
+import 'package:integration_test/integration_test.dart';
+
+void main() {
+  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
+
+  group('getLocalTimezone', () {
+    final expected = const String.fromEnvironment('EXPECTED_TZ');
+
+    testWidgets('check that the local timezone is $expected', (tester) async {
+      await tester.pumpWidget(MyApp());
+      await tester.pumpAndSettle();
+
+      Text tzTextWidget = find
+          .byKey(const ValueKey('timeZoneLabel'))
+          .evaluate()
+          .first
+          .widget as Text;
+
+      expect(tzTextWidget.data, expected);
+    });
+  });
+}

example/pubspec.yaml

@@ -16,6 +16,8 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
+  integration_test:
+    sdk: flutter
 
 flutter:
   uses-material-design: true

example/run_integration_test_windows.ps1

@@ -0,0 +1,47 @@
+# Runs the integration tests for this plugin on Windows.
+#
+# This script modifies the current system's time zone and region, and then runs
+# `integration_test/local_timezone_test.dart` with the expected IANA time zone as a parameter.
+#
+# See https://learn.microsoft.com/en-us/windows/win32/intl/table-of-geographical-locations for the
+# list of region integer codes.
+
+$json = @"
+[
+    {
+        "tz": "W. Europe Standard Time",
+        "region": 14, // Austria
+        "expected": "Europe/Vienna"
+    },
+    {
+        "tz": "W. Europe Standard Time",
+        "region": 223, // Switzerland
+        "expected": "Europe/Zurich"
+    },
+    {
+        "tz": "W. Europe Standard Time",
+        "region": 244, // United States
+        "expected": "Europe/Berlin"
+    },
+    {
+        "tz": "Tokyo Standard Time",
+        "region": 122,
+        "expected": "Asia/Tokyo"
+    }
+]
+"@;
+
+$inputJson = ConvertFrom-Json $json;
+
+foreach ($input in $inputJson) {
+    Write-Output "tz: $($input.tz), region: $($input.region), expected: $($input.expected)";
+
+    # set time zone
+    tzutil /s "$($input.tz)"
+
+    # set region
+    Set-WinHomeLocation $input.region
+
+    # test
+    flutter test integration_test/local_timezone_test.dart -d windows --dart-define EXPECTED_TZ="$($input.expected)"
+}