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test/home_appbar_test.dart

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+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+/// Home's app bar carries the rider's identity **and the ON/OFF duty toggle**,
+/// and it used to be the first sliver inside the page's `CustomScrollView` — so
+/// it scrolled away the moment he looked at his second stop, taking the duty
+/// control with it.
+///
+/// The fix is structural: the bar becomes the first child of a `Column` and the
+/// scrollable takes the rest via `Expanded`. `_HomePageState` cannot be built in
+/// a test (Get, SharedPreferences, Geolocator, live fetches), so — as in
+/// `card_stripe_layout_test.dart` — these pin the *idiom* rather than the widget.
+void main() {
+  const barKey = ValueKey('appbar');
+  const contentKey = ValueKey('tall-content');
+
+  // The default test viewport is 800×600 and the bar is 96 tall, so this point
+  // is always inside the scroll area below it. Gestures are aimed here rather
+  // than at the content's centre: the content is 2000pt tall, so its centre is
+  // off-screen and a drag there hit-tests against nothing.
+  const inScrollArea = Offset(400, 350);
+
+  /// The shape Home now uses.
+  Widget pinned({Future<void> Function()? onRefresh}) {
+    final scroller = CustomScrollView(
+      physics: const AlwaysScrollableScrollPhysics(),
+      slivers: [
+        SliverToBoxAdapter(
+          child: Container(key: contentKey, height: 2000, color: Colors.grey),
+        ),
+      ],
+    );
+
+    return MaterialApp(
+      home: Scaffold(
+        body: Stack(
+          children: [
+            Column(
+              children: [
+                Container(key: barKey, height: 96, color: Colors.white),
+                Expanded(
+                  child: onRefresh == null
+                      ? scroller
+                      : RefreshIndicator(onRefresh: onRefresh, child: scroller),
+                ),
+              ],
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  /// The shape it used to use — bar as a sliver.
+  Widget scrolling() {
+    return MaterialApp(
+      home: Scaffold(
+        body: CustomScrollView(
+          physics: const AlwaysScrollableScrollPhysics(),
+          slivers: [
+            SliverToBoxAdapter(
+              child: Container(key: barKey, height: 96, color: Colors.white),
+            ),
+            SliverToBoxAdapter(
+              child: Container(key: contentKey, height: 2000, color: Colors.grey),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  testWidgets('as a sliver, the bar scrolls off the top', (tester) async {
+    await tester.pumpWidget(scrolling());
+    expect(find.byKey(barKey), findsOneWidget);
+
+    await tester.dragFrom(inScrollArea, const Offset(0, -300));
+    await tester.pumpAndSettle();
+
+    // Not merely pushed off-screen — a sliver that leaves the viewport and its
+    // cache extent is unmounted outright, so the duty toggle stopped existing
+    // rather than just moving. This is the behaviour being fixed.
+    expect(find.byKey(barKey), findsNothing,
+        reason: 'this is the behaviour that hid the duty toggle');
+  });
+
+  testWidgets('as a Column child, the bar does not move', (tester) async {
+    await tester.pumpWidget(pinned());
+    final before = tester.getRect(find.byKey(barKey));
+    final contentBefore = tester.getRect(find.byKey(contentKey)).top;
+
+    await tester.dragFrom(inScrollArea, const Offset(0, -300));
+    await tester.pumpAndSettle();
+
+    expect(tester.getRect(find.byKey(barKey)), before,
+        reason: 'the app bar is fixed');
+    // And the page really did scroll underneath it.
+    expect(tester.getRect(find.byKey(contentKey)).top,
+        lessThan(contentBefore - 200));
+  });
+
+  testWidgets('the bar stays put through a long scroll and back',
+      (tester) async {
+    await tester.pumpWidget(pinned());
+    final rect = tester.getRect(find.byKey(barKey));
+
+    for (final dy in [-600.0, -600.0, 400.0, -900.0, 1200.0]) {
+      await tester.dragFrom(inScrollArea, Offset(0, dy));
+      await tester.pumpAndSettle();
+      expect(tester.getRect(find.byKey(barKey)), rect);
+    }
+  });
+
+  testWidgets('pull to refresh still fires below the fixed bar',
+      (tester) async {
+    var fired = 0;
+    await tester.pumpWidget(pinned(onRefresh: () async {
+      fired++;
+      await Future<void>.delayed(const Duration(milliseconds: 50));
+    }));
+    final rect = tester.getRect(find.byKey(barKey));
+
+    await tester.flingFrom(inScrollArea, const Offset(0, 320), 1200);
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    expect(fired, 1, reason: 'the gesture still reaches the scroll view');
+    // The spinner must not drag the bar down with it, which is what the old
+    // unbounded-overscroll page did to the whole header.
+    expect(tester.getRect(find.byKey(barKey)), rect);
+    await tester.pumpAndSettle();
+  });
+
+  testWidgets('the refresh spinner comes down below the bar, not behind it',
+      (tester) async {
+    await tester.pumpWidget(pinned(onRefresh: () async {
+      await Future<void>.delayed(const Duration(milliseconds: 400));
+    }));
+
+    await tester.flingFrom(inScrollArea, const Offset(0, 320), 1200);
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 200));
+
+    final spinner = find.byType(RefreshProgressIndicator);
+    expect(spinner, findsOneWidget);
+    // `edgeOffset` is no longer needed precisely because the scroll viewport now
+    // starts under the bar — so the indicator is already in clear space.
+    expect(tester.getRect(spinner).top,
+        greaterThanOrEqualTo(tester.getRect(find.byKey(barKey)).bottom - 0.01));
+    await tester.pumpAndSettle();
+  });
+}