create test

packages/remix/lib/src/components/scaffold/scaffold_widget.dart

@@ -85,14 +85,11 @@ class _ScaffoldLayoutDelegate extends MultiChildLayoutDelegate {
   @override
   void performLayout(Size size) {
     final BoxConstraints looseConstraints = BoxConstraints.loose(size);
-    final BoxConstraints fullWidthConstraints =
-        looseConstraints.tighten(width: size.width);
-
     double appBarHeight = 0.0;
 
     const headerKey = _ScaffoldElement.header;
     if (hasChild(headerKey)) {
-      appBarHeight = layoutChild(headerKey, fullWidthConstraints).height;
+      appBarHeight = layoutChild(headerKey, looseConstraints).height;
       positionChild(headerKey, Offset.zero);
     }
 
@@ -101,7 +98,7 @@ class _ScaffoldLayoutDelegate extends MultiChildLayoutDelegate {
       final listHeight = size.height - appBarHeight;
 
       final bodyConstraints = BoxConstraints.tightFor(
-        width: fullWidthConstraints.maxWidth,
+        width: looseConstraints.maxWidth,
         height: listHeight,
       );
 

packages/remix/test/components/scaffold/scafold_widget_test.dart

@@ -0,0 +1,161 @@
+import 'package:flutter/material.dart' as m;
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:remix/remix.dart';
+
+void main() {
+  group('Scaffold', () {
+    testWidgets('renders header and body', (WidgetTester tester) async {
+      tester.view.physicalSize = const Size(800, 600);
+      tester.view.devicePixelRatio = 1.0;
+
+      await tester.pumpWidget(
+        RemixApp(
+          home: Scaffold(
+            header: const SizedBox(
+              key: Key('header'),
+              height: 100,
+              child: Center(child: Text('Header')),
+            ),
+            body: Container(
+              key: const Key('body'),
+              child: const Center(child: Text('Body')),
+            ),
+          ),
+        ),
+      );
+
+      final headerFinder = find.byKey(const Key('header'));
+      expect(headerFinder, findsOneWidget);
+
+      final Size headerSize = tester.getSize(headerFinder);
+      expect(headerSize, const Size(800, 100));
+
+      final bodyFinder = find.byKey(const Key('body'));
+      expect(bodyFinder, findsOneWidget);
+
+      final Size bodySize = tester.getSize(bodyFinder);
+      expect(bodySize, const Size(800, 500));
+
+      expect(find.text('Header'), findsOneWidget);
+      expect(find.text('Body'), findsOneWidget);
+    });
+
+    testWidgets('ListView scrolls correctly', (WidgetTester tester) async {
+      // Build our custom scaffold with a ListView as its body.
+      await tester.pumpWidget(
+        RemixApp(
+          home: Scaffold(
+            header: const SizedBox(
+              key: Key('header'),
+              height: 100,
+              child: Center(child: Text('Header')),
+            ),
+            body: ListView.builder(
+              key: const Key('listView'),
+              itemCount: 300,
+              itemBuilder: (context, index) {
+                return Text('Item $index');
+              },
+            ),
+          ),
+        ),
+      );
+
+      // Verify the first item is visible.
+      expect(find.text('Item 0'), findsOneWidget);
+
+      // Scroll down the ListView.
+      await tester.drag(
+          find.byKey(const Key('listView')), const Offset(0, -700));
+      await tester.pumpAndSettle();
+
+      // Verify that an item further down is now visible.
+      expect(find.text('Item 80'), findsOneWidget);
+    });
+
+    testWidgets('PageView swipes correctly', (WidgetTester tester) async {
+      // Build our custom scaffold with a PageView as its body.
+      await tester.pumpWidget(
+        RemixApp(
+          home: Scaffold(
+            header: Container(
+              key: const Key('header'),
+              height: 100,
+              color: m.Colors.green,
+              child: const Center(child: Text('Header')),
+            ),
+            body: PageView(
+              key: const Key('pageView'),
+              children: [
+                Container(
+                  key: const Key('page_1'),
+                  color: m.Colors.red,
+                  child: const Center(child: Text('Page 1')),
+                ),
+                Container(
+                  key: const Key('page_2'),
+                  color: m.Colors.blue,
+                  child: const Center(child: Text('Page 2')),
+                ),
+                Container(
+                  key: const Key('page_3'),
+                  color: m.Colors.yellow,
+                  child: const Center(child: Text('Page 3')),
+                ),
+              ],
+            ),
+          ),
+        ),
+      );
+
+      // Initially, Page 1 should be visible.
+      expect(find.text('Page 1'), findsOneWidget);
+
+      // Swipe left to show Page 2.
+      await tester.drag(
+          find.byKey(const Key('pageView')), const Offset(-400, 0));
+      await tester.pumpAndSettle();
+      expect(find.text('Page 2'), findsOneWidget);
+
+      // Swipe left again to show Page 3.
+      await tester.drag(
+          find.byKey(const Key('pageView')), const Offset(-400, 0));
+      await tester.pumpAndSettle();
+      expect(find.text('Page 3'), findsOneWidget);
+    });
+
+    testWidgets('responsive layout test', (WidgetTester tester) async {
+      // For example, set a custom window size.
+      tester.view.physicalSize = const Size(200, 200);
+      tester.view.devicePixelRatio = 1.0;
+
+      await tester.pumpWidget(
+        RemixApp(
+          home: Scaffold(
+            header: Container(
+              key: const Key('header'),
+              height: 100,
+              color: m.Colors.green,
+              child: const Center(child: Text('Header')),
+            ),
+            body: Container(
+              key: const Key('body'),
+              color: m.Colors.blue,
+              child: const Center(child: Text('Body')),
+            ),
+          ),
+        ),
+      );
+
+      // Verify that the Scaffold adapts to the window size.
+      final Size scaffoldSize = tester.getSize(find.byType(Scaffold));
+      expect(scaffoldSize.width, 200);
+      expect(scaffoldSize.height, 200);
+
+      // Verify header height is exactly 100
+      final Size headerSize = tester.getSize(find.byKey(const Key('header')));
+      expect(headerSize.height, 100);
+    });
+  });
+}