test sliver fill remaining examples (#148041)

Par of #130459. Adds tests all `SliverFillRemaining` examples.

dev/bots/check_code_samples.dart

@@ -433,10 +433,6 @@ final Set<String> _knownMissingTests = <String>{
   'examples/api/test/widgets/scrollbar/raw_scrollbar.desktop.0_test.dart',
   'examples/api/test/widgets/scrollbar/raw_scrollbar.shape.0_test.dart',
   'examples/api/test/widgets/scrollbar/raw_scrollbar.0_test.dart',
-  'examples/api/test/widgets/sliver_fill/sliver_fill_remaining.2_test.dart',
-  'examples/api/test/widgets/sliver_fill/sliver_fill_remaining.1_test.dart',
-  'examples/api/test/widgets/sliver_fill/sliver_fill_remaining.3_test.dart',
-  'examples/api/test/widgets/sliver_fill/sliver_fill_remaining.0_test.dart',
   'examples/api/test/widgets/interactive_viewer/interactive_viewer.constrained.0_test.dart',
   'examples/api/test/widgets/interactive_viewer/interactive_viewer.transformation_controller.0_test.dart',
   'examples/api/test/widgets/interactive_viewer/interactive_viewer.0_test.dart',

examples/api/test/widgets/sliver_fill/sliver_fill_remaining.0_test.dart

@@ -0,0 +1,42 @@
+// 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/widgets/sliver_fill/sliver_fill_remaining.0.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('shows how SliverFillRemaining takes up remaining space', (WidgetTester tester) async {
+    await tester.pumpWidget(const example.SliverFillRemainingExampleApp());
+    expect(find.text('SliverFillRemaining Sample'), findsOneWidget);
+    expect(find.byType(CustomScrollView), findsOneWidget);
+
+    expect(find.descendant(
+      of: find.byType(SliverToBoxAdapter),
+      matching: find.byType(Container)), findsOneWidget);
+    final Container upperContainer = tester.widget(find.descendant(
+      of: find.byType(SliverToBoxAdapter),
+      matching: find.byType(Container)));
+    expect(upperContainer.color, Colors.amber[300]);
+
+    expect(find.byType(SliverFillRemaining), findsOneWidget);
+    expect(find.descendant(
+      of: find.byType(SliverFillRemaining),
+      matching: find.byType(Container)), findsOneWidget);
+    expect(find.byIcon(Icons.sentiment_very_satisfied), findsOneWidget);
+    final Icon lowerIcon = tester.widget(find.descendant(
+      of: find.byType(SliverFillRemaining),
+      matching: find.byType(Icon)));
+    expect(lowerIcon.color, Colors.blue[900]);
+
+    final double total = tester.getSize(find.byType(CustomScrollView)).height;
+    final double upperHeight = tester.getSize(find.descendant(
+      of: find.byType(SliverToBoxAdapter),
+      matching: find.byType(Container))).height;
+    final double lowerHeight = tester.getSize(find.descendant(
+      of: find.byType(SliverFillRemaining),
+      matching: find.byType(Icon))).height;
+    expect(upperHeight + lowerHeight, equals(total));
+  });
+}

examples/api/test/widgets/sliver_fill/sliver_fill_remaining.1_test.dart

@@ -0,0 +1,43 @@
+// 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/widgets/sliver_fill/sliver_fill_remaining.1.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Shows all elements', (WidgetTester tester) async {
+    await tester.pumpWidget(const example.SliverFillRemainingExampleApp());
+    expect(find.text('SliverFillRemaining Sample'), findsOneWidget);
+    expect(find.byType(CustomScrollView), findsOneWidget);
+    expect(find.byWidgetPredicate((Widget widget) => (widget is Container)
+      && widget.color == Colors.amber[200]),
+      findsNWidgets(2));
+    expect(find.byWidgetPredicate((Widget widget) => (widget is Container)
+      && widget.color == Colors.blue[200]),
+      findsOneWidget);
+    expect(find.byWidgetPredicate((Widget widget) => (widget is Container)
+      && widget.color == Colors.orange[300]),
+      findsOneWidget);
+    expect(find.byType(SliverFixedExtentList), findsOneWidget);
+    expect(find.byType(SliverFillRemaining), findsOneWidget);
+    expect(find.byType(FlutterLogo), findsOneWidget);
+  });
+
+  testWidgets('Fills up all available space', (WidgetTester tester) async {
+    await tester.pumpWidget(const example.SliverFillRemainingExampleApp());
+
+    final double listSpace = tester.getSize(find.byType(CustomScrollView)).height;
+    double contentHeight = 0.0;
+    for (final Widget widget in tester.widgetList(find.byWidgetPredicate(
+      (Widget widget) =>
+        (widget is Container)
+        && <Color>[Colors.orange[300]!, Colors.blue[200]!, Colors.amber[200]!]
+          .contains(widget.color)))
+    ) {
+      contentHeight += tester.getSize(find.byWidget(widget)).height;
+    }
+    expectLater(contentHeight, equals(listSpace));
+  });
+}

examples/api/test/widgets/sliver_fill/sliver_fill_remaining.2_test.dart

@@ -0,0 +1,31 @@
+// 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/widgets/sliver_fill/sliver_fill_remaining.2.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Shows all elements', (WidgetTester tester) async {
+    await tester.pumpWidget(const example.SliverFillRemainingExampleApp());
+    expect(find.text('SliverFillRemaining Sample'), findsOneWidget);
+    expect(find.byType(CustomScrollView), findsOneWidget);
+    expect(find.byType(SliverFixedExtentList), findsOneWidget);
+
+    expect(find.byWidgetPredicate((Widget widget) => (widget is Container)
+      && widget.color == Colors.indigo[200],
+      skipOffstage: false,
+    ), findsNWidgets(3));
+    expect(find.byWidgetPredicate((Widget widget) => (widget is Container)
+      && widget.color == Colors.orange[200]
+    ), findsNWidgets(2));
+    expect(find.byType(Container, skipOffstage: false,), findsNWidgets(5));
+
+    expect(find.byType(SliverFillRemaining), findsNothing);
+    await tester.scrollUntilVisible(find.byType(SliverFillRemaining), 20);
+    expect(find.byType(SliverFillRemaining), findsOneWidget);
+    expect(find.byIcon(Icons.pan_tool), findsOneWidget);
+    expect(tester.widget<Icon>(find.byIcon(Icons.pan_tool)).color, Colors.blueGrey);
+  });
+}

examples/api/test/widgets/sliver_fill/sliver_fill_remaining.3_test.dart

@@ -0,0 +1,33 @@
+// 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/widgets/sliver_fill/sliver_fill_remaining.3.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Shows all elements', (WidgetTester tester) async {
+    await tester.pumpWidget(const example.SliverFillRemainingExampleApp());
+    expect(find.text('SliverFillRemaining Sample'), findsOneWidget);
+    expect(find.byType(ElevatedButton), findsOneWidget);
+    expect(find.text('Bottom Pinned Button!'), findsOneWidget);
+    expect(find.byType(CustomScrollView), findsOneWidget);
+    final CustomScrollView scroll = tester.widget(find.byType(CustomScrollView));
+    expect(scroll.physics, isA<BouncingScrollPhysics>().
+    having((BouncingScrollPhysics bsp) => bsp.parent, 'parent', isA<AlwaysScrollableScrollPhysics>()));
+
+    expect(find.byWidgetPredicate((Widget widget) => (widget is Container)
+      && widget.color == Colors.tealAccent[700],
+    ), findsOneWidget);
+    expect(find.byWidgetPredicate((Widget widget) => (widget is Container)
+      && widget.color == Colors.teal[100]
+    ), findsOneWidget);
+    expect(find.byType(Container), findsNWidgets(2));
+
+    expect(find.byType(SliverFillRemaining), findsOneWidget);
+    final SliverFillRemaining fill = tester.widget(find.byType(SliverFillRemaining));
+    expect(fill.hasScrollBody, false);
+    expect(fill.fillOverscroll, true);
+  });
+}