Halkyon's shared packages

A pub workspace of the Dart packages Halkyon's apps share: halkyon_ui,
Halkyon's look (the theme, fonts, layout and shared widgets, with texts
in English and German), halkyon_core's low-level primitives and
halkyon_interop's cross-app contracts. Dart 3.13 with LeanCode's lints,
configured once at the root; apps take a package by git, pinned to a
signed commit.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

packages/halkyon_ui/test/widget/adaptive_sheet_test.dart

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+import 'package:flutter/foundation.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_ui/halkyon_ui.dart';
+import 'package:material_ui/material_ui.dart';
+
+void main() {
+  /// Opens a sheet titled "New studyset" with [body] and a Create button, in
+  /// a window [width] wide, with a status bar [statusBar] high on top.
+  Future<void> open(
+    WidgetTester tester, {
+    required double width,
+    Widget body = const Text('Body'),
+    double statusBar = 0,
+    bool busy = false,
+  }) async {
+    tester.view.physicalSize = Size(width, 900);
+    tester.view.devicePixelRatio = 1;
+    tester.view.padding = FakeViewPadding(top: statusBar);
+    tester.view.viewPadding = FakeViewPadding(top: statusBar);
+    addTearDown(tester.view.reset);
+    await tester.pumpWidget(
+      MaterialApp(
+        localizationsDelegates: HalkyonUiLocalizations.localizationsDelegates,
+        supportedLocales: HalkyonUiLocalizations.supportedLocales,
+        home: Scaffold(
+          body: Builder(
+            builder: (context) => TextButton(
+              onPressed: () => showAdaptiveSheet<void>(
+                context,
+                swipeable: !busy,
+                builder: (context) => SheetScaffold(
+                  title: 'New studyset',
+                  busy: busy,
+                  body: body,
+                  footer: FilledButton(
+                    onPressed: () {},
+                    child: const Text('Create'),
+                  ),
+                ),
+              ),
+              child: const Text('Open'),
+            ),
+          ),
+        ),
+      ),
+    );
+    await tester.tap(find.text('Open'));
+    await tester.pumpAndSettle();
+  }
+
+  testWidgets('is a bottom sheet below expanded windows', (tester) async {
+    await open(tester, width: 839);
+
+    expect(find.byType(BottomSheet), findsOneWidget);
+    expect(find.byType(Dialog), findsNothing);
+  });
+
+  testWidgets('is a dialog from expanded windows on', (tester) async {
+    await open(tester, width: 840);
+
+    expect(find.byType(Dialog), findsOneWidget);
+    expect(find.byType(BottomSheet), findsNothing);
+  });
+
+  for (final width in [400.0, 1200.0]) {
+    testWidgets('keeps its close button and footer in view above a long body '
+        '(${width.round()} wide)', (tester) async {
+      await open(
+        tester,
+        width: width,
+        body: Column(
+          children: [for (var i = 0; i < 80; i++) Text('Line $i')],
+        ),
+      );
+
+      expect(find.byTooltip('Close').hitTestable(), findsOneWidget);
+      expect(find.text('Create').hitTestable(), findsOneWidget);
+    });
+  }
+
+  testWidgets('stays below the status bar with the keyboard open', (
+    tester,
+  ) async {
+    await open(
+      tester,
+      width: 400,
+      statusBar: 48,
+      body: Column(
+        children: [for (var i = 0; i < 80; i++) Text('Line $i')],
+      ),
+    );
+
+    tester.view.viewInsets = const FakeViewPadding(bottom: 400);
+    await tester.pumpAndSettle();
+
+    expect(tester.getTopLeft(find.byType(BottomSheet)).dy, 48);
+    expect(find.byTooltip('Close').hitTestable(), findsOneWidget);
+    expect(find.text('Create').hitTestable(), findsOneWidget);
+  });
+
+  testWidgets('closes with its close button', (tester) async {
+    await open(tester, width: 400);
+
+    await tester.tap(find.byTooltip('Close'));
+    await tester.pumpAndSettle();
+
+    expect(find.text('New studyset'), findsNothing);
+  });
+
+  testWidgets('while busy, its close button is off and back keeps it open', (
+    tester,
+  ) async {
+    await open(tester, width: 400, busy: true);
+
+    expect(
+      tester
+          .widget<IconButton>(
+            find.ancestor(
+              of: find.byTooltip('Close'),
+              matching: find.byType(IconButton),
+            ),
+          )
+          .onPressed,
+      isNull,
+    );
+    await tester.binding.handlePopRoute();
+    await tester.pumpAndSettle();
+    expect(find.text('New studyset'), findsOneWidget);
+  });
+
+  group('a body longer than the sheet', () {
+    final tall = Column(
+      children: [for (var i = 0; i < 40; i++) const Text('Line')],
+    );
+    Finder below() => find.byKey(SheetScaffold.moreBelowKey);
+    Finder above() => find.byKey(SheetScaffold.moreAboveKey);
+
+    testWidgets('shows a line above the buttons while more lies below, and '
+        'one under the title while more lies above', (tester) async {
+      // As a dialog: a modal bottom sheet takes a test's drag itself.
+      await open(tester, width: 1000, body: tall);
+
+      expect(below(), findsOneWidget);
+      expect(above(), findsNothing);
+
+      await tester.drag(
+        find.byType(SingleChildScrollView),
+        const Offset(0, -300),
+      );
+      await tester.pumpAndSettle();
+      expect(below(), findsOneWidget);
+      expect(above(), findsOneWidget);
+      expect(
+        tester
+            .state<ScrollableState>(
+              find.descendant(
+                of: find.byType(SingleChildScrollView),
+                matching: find.byType(Scrollable),
+              ),
+            )
+            .position
+            .pixels,
+        greaterThan(0),
+        reason: 'the line coming keeps where the body was scrolled to',
+      );
+
+      await tester.drag(
+        find.byType(SingleChildScrollView),
+        const Offset(0, -5000),
+      );
+      await tester.pumpAndSettle();
+      expect(below(), findsNothing);
+      expect(above(), findsOneWidget);
+    });
+
+    testWidgets('has a scrollbar, always shown on the desktop', (tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.linux;
+      addTearDown(() => debugDefaultTargetPlatformOverride = null);
+      await open(tester, width: 1000, body: tall);
+
+      final scrollbar = tester.widget<Scrollbar>(find.byType(Scrollbar));
+      expect(scrollbar.thumbVisibility, isTrue);
+      debugDefaultTargetPlatformOverride = null;
+    });
+  });
+
+  testWidgets('a body that fits shows no lines', (tester) async {
+    await open(tester, width: 400);
+
+    expect(find.byKey(SheetScaffold.moreBelowKey), findsNothing);
+    expect(find.byKey(SheetScaffold.moreAboveKey), findsNothing);
+  });
+
+  testWidgets("the body keeps clear of the scroll view's edges, where it is "
+      'cut and the scrollbar runs', (tester) async {
+    for (final width in [400.0, 1000.0]) {
+      await open(
+        tester,
+        width: width,
+        body: const TextField(
+          decoration: InputDecoration(border: OutlineInputBorder()),
+        ),
+      );
+
+      final scrolling = tester.getRect(find.byType(SingleChildScrollView));
+      final field = tester.getRect(find.byType(TextField));
+      expect(field.left - scrolling.left, greaterThanOrEqualTo(16));
+      expect(scrolling.right - field.right, greaterThanOrEqualTo(16));
+      // The title and the button stay in line with the body.
+      expect(tester.getTopLeft(find.text('New studyset')).dx, field.left);
+      expect(tester.getTopRight(find.byType(FilledButton)).dx, field.right);
+      await tester.tap(find.byTooltip('Close'));
+      await tester.pumpAndSettle();
+    }
+  });
+}