Add test for scaffold.1.dart (flutter#147966)

Contributes to flutter#130459

It adds test for `examples/api/lib/material/scaffold/scaffold.1.dart`

Author: ValentinVignal

dev/bots/check_code_samples.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 // To run this, from the root of the Flutter repository:
-//   bin/cache/dart-sdk/bin/dart --enable-asserts dev/bots/check_code_sample_links.dart
+//   bin/cache/dart-sdk/bin/dart --enable-asserts dev/bots/check_code_samples.dart
 
 import 'dart:io';
 
@@ -352,7 +352,6 @@ final Set<String> _knownMissingTests = <String>{
   'examples/api/test/material/selection_area/selection_area.0_test.dart',
   'examples/api/test/material/scaffold/scaffold.end_drawer.0_test.dart',
   'examples/api/test/material/scaffold/scaffold.drawer.0_test.dart',
-  'examples/api/test/material/scaffold/scaffold.1_test.dart',
   'examples/api/test/material/scaffold/scaffold.of.0_test.dart',
   'examples/api/test/material/scaffold/scaffold_messenger.of.0_test.dart',
   'examples/api/test/material/scaffold/scaffold_messenger.0_test.dart',

examples/api/test/material/scaffold/scaffold.1_test.dart

@@ -0,0 +1,25 @@
+// Copyright 2014 The Flutter Authors. 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_api_samples/material/scaffold/scaffold.1.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('The count should be incremented when the floating action button is tapped', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const example.ScaffoldExampleApp(),
+    );
+
+    expect(find.widgetWithText(AppBar, 'Sample Code'), findsOne);
+    expect(find.widgetWithIcon(FloatingActionButton, Icons.add), findsOne);
+    expect(find.text('You have pressed the button 0 times.'), findsOne);
+
+    for (int i = 1; i <= 5; i++) {
+      await tester.tap(find.byType(FloatingActionButton));
+      await tester.pump();
+      expect(find.text('You have pressed the button $i times.'), findsOne);
+    }
+  });
+}