feat: add test for get_main

+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:get/get.dart';
+
+import 'util/wrapper.dart';
+
+void main() {
+  testWidgets("Get.to smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(child: Container()),
+    );
+
+    Get.to(SecondScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(SecondScreen), findsOneWidget);
+  });
+  testWidgets("Get.toNamed smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(
+        initialRoute: '/',
+        namedRoutes: {
+          '/': GetRoute(page: FirstScreen()),
+          '/second': GetRoute(page: SecondScreen()),
+          '/third': GetRoute(page: ThirdScreen())
+        },
+        child: Container(),
+      ),
+    );
+
+    Get.toNamed('/second');
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(SecondScreen), findsOneWidget);
+  });
+
+  testWidgets("Get.off smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(child: Container()),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    Get.off(SecondScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(SecondScreen), findsOneWidget);
+  });
+
+  testWidgets("Get.offNamed smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(
+        initialRoute: '/',
+        namedRoutes: {
+          '/': GetRoute(page: Container()),
+          '/first': GetRoute(page: FirstScreen()),
+          '/second': GetRoute(page: SecondScreen()),
+          '/third': GetRoute(page: ThirdScreen())
+        },
+        child: Container(),
+      ),
+    );
+
+    Get.toNamed('/first');
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    Get.offNamed('/second');
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(SecondScreen), findsOneWidget);
+  });
+
+  testWidgets("Get.offAll smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(child: Container()),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    Get.to(SecondScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(SecondScreen), findsOneWidget);
+
+    Get.offAll(ThirdScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(ThirdScreen), findsOneWidget);
+  });
+
+  testWidgets("Get.offAllNamed smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(
+        initialRoute: '/',
+        namedRoutes: {
+          '/': GetRoute(page: Container()),
+          '/first': GetRoute(page: FirstScreen()),
+          '/second': GetRoute(page: SecondScreen()),
+          '/third': GetRoute(page: ThirdScreen())
+        },
+        child: Container(),
+      ),
+    );
+
+    Get.toNamed('/first');
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    Get.toNamed('/second');
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(SecondScreen), findsOneWidget);
+
+    Get.offAllNamed('/third');
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(ThirdScreen), findsOneWidget);
+  });
+
+  testWidgets("Get.offAndToNamed smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(
+        initialRoute: '/',
+        namedRoutes: {
+          '/': GetRoute(page: Container()),
+          '/first': GetRoute(page: FirstScreen()),
+          '/second': GetRoute(page: SecondScreen()),
+          '/third': GetRoute(page: ThirdScreen())
+        },
+        child: Container(),
+      ),
+    );
+
+    Get.toNamed('/first');
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    Get.offAndToNamed('/second');
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(SecondScreen), findsOneWidget);
+  });
+
+  testWidgets("Get.offUntil smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(
+        child: Container(),
+      ),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    Get.offUntil(
+        MaterialPageRoute(builder: (BuildContext context) => SecondScreen()),
+        ModalRoute.withName('/'));
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(SecondScreen), findsOneWidget);
+  });
+
+  testWidgets("Get.offNamedUntil smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(
+        initialRoute: '/',
+        namedRoutes: {
+          '/': GetRoute(page: Container()),
+          '/first': GetRoute(page: FirstScreen()),
+          '/second': GetRoute(page: SecondScreen()),
+          '/third': GetRoute(page: ThirdScreen())
+        },
+        child: Container(),
+      ),
+    );
+
+    Get.toNamed('/first');
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    Get.offNamedUntil('/first', ModalRoute.withName('/'));
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+  });
+
+  testWidgets("Get.back smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(child: Container()),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    Get.to(SecondScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(SecondScreen), findsOneWidget);
+
+    Get.back();
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+  });
+
+  testWidgets("Get.defaultTransition smoke test", (tester) async {
+    await tester.pumpWidget(
+      Wrapper(
+        child: Container(),
+        defaultTransition: Transition.cupertino,
+      ),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    await tester.pumpWidget(
+      Wrapper(
+        child: Container(),
+        defaultTransition: Transition.downToUp,
+      ),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    await tester.pumpWidget(
+      Wrapper(
+        child: Container(),
+        defaultTransition: Transition.fade,
+      ),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    await tester.pumpWidget(
+      Wrapper(
+        child: Container(),
+        defaultTransition: Transition.leftToRight,
+      ),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    await tester.pumpWidget(
+      Wrapper(
+        child: Container(),
+        defaultTransition: Transition.leftToRightWithFade,
+      ),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    await tester.pumpWidget(
+      Wrapper(
+        child: Container(),
+        defaultTransition: Transition.rightToLeft,
+      ),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+
+    await tester.pumpWidget(
+      Wrapper(
+        child: Container(),
+        defaultTransition: Transition.rightToLeftWithFade,
+      ),
+    );
+
+    Get.to(FirstScreen());
+
+    await tester.pumpAndSettle();
+
+    expect(find.byType(FirstScreen), findsOneWidget);
+  });
+}
+
+class FirstScreen extends StatelessWidget {
+  const FirstScreen({Key key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Container();
+  }
+}
+
+class SecondScreen extends StatelessWidget {
+  const SecondScreen({Key key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Container();
+  }
+}
+
+class ThirdScreen extends StatelessWidget {
+  const ThirdScreen({Key key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Container();
+  }
+}