add test

Author: StevenSorial

packages/go_router/test/route_data_test.dart

@@ -280,6 +280,76 @@ void main() {
         expect(routeWithDefaultCaseSensitivity.caseSensitive, false);
       },
     );
+
+    testWidgets(
+      'It should throw beacuase there is no code generated',
+      (WidgetTester tester) async {
+        final List<FlutterErrorDetails> errors = <FlutterErrorDetails>[];
+
+        FlutterError.onError =
+            (FlutterErrorDetails details) => errors.add(details);
+
+        const String errorText = 'Should be generated';
+
+        Widget buildWidget(void Function(BuildContext) onTap) {
+          return MaterialApp(
+            home: Builder(
+              builder: (BuildContext context) => GestureDetector(
+                child: const Text('Tap'),
+                onTap: () => onTap(context),
+              ),
+            ),
+          );
+        }
+
+        final Widget pushThrower = buildWidget((BuildContext context) {
+          const _GoRouteDataBuild().push<void>(context);
+        });
+        await tester.pumpWidget(pushThrower);
+        await tester.tap(find.text('Tap'));
+
+        expect(errors.first.exception, isA<UnimplementedError>());
+        expect(errors.first.exception.toString(), contains(errorText));
+
+        errors.clear();
+
+        final Widget goThrower = buildWidget((BuildContext context) {
+          const _GoRouteDataBuild().go(context);
+        });
+        await tester.pumpWidget(goThrower);
+        await tester.tap(find.text('Tap'));
+
+        expect(errors.first.exception, isA<UnimplementedError>());
+        expect(errors.first.exception.toString(), contains(errorText));
+
+        errors.clear();
+
+        final Widget pushReplacementThrower =
+            buildWidget((BuildContext context) {
+          const _GoRouteDataBuild().pushReplacement(context);
+        });
+        await tester.pumpWidget(pushReplacementThrower);
+        await tester.tap(find.text('Tap'));
+
+        expect(errors.first.exception, isA<UnimplementedError>());
+        expect(errors.first.exception.toString(), contains(errorText));
+
+        errors.clear();
+
+        final Widget replaceThrower = buildWidget((BuildContext context) {
+          const _GoRouteDataBuild().pushReplacement(context);
+        });
+        await tester.pumpWidget(replaceThrower);
+        await tester.tap(find.text('Tap'));
+
+        expect(errors.first.exception, isA<UnimplementedError>());
+        expect(errors.first.exception.toString(), contains(errorText));
+
+        errors.clear();
+
+        FlutterError.onError = FlutterError.dumpErrorToConsole;
+      },
+    );
   });
 
   group('ShellRouteData', () {