halkyon/packages/halkyon_ui/test/widget/tinted_frame_test.dart

import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_ui/halkyon_ui.dart';
import 'package:material_ui/material_ui.dart';

void main() {
  /// A screen with something typed into it, as a study session or a card
  /// being written holds what was done.
  Future<void> typeIn(
    WidgetTester tester,
    Widget Function(Widget) around,
  ) async {
    tester.view.physicalSize = const Size(1200, 800);
    tester.view.devicePixelRatio = 1;
    addTearDown(tester.view.reset);
    await tester.pumpWidget(
      MaterialApp(
        theme: appTheme(Brightness.light),
        home: around(const Scaffold(body: TextField())),
      ),
    );
    await tester.enterText(find.byType(TextField), 'kept');
  }

  /// Crosses every line where the frame or the snack bars change: medium,
  /// compact, medium again.
  Future<void> resize(WidgetTester tester) async {
    for (final width in const [700.0, 400.0, 1200.0]) {
      tester.view.physicalSize = Size(width, 800);
      await tester.pumpAndSettle();
    }
  }

  testWidgets('a framed screen keeps what it holds when the window crosses '
      'from medium to compact and back', (tester) async {
    await typeIn(tester, (screen) => FramedScreen(child: screen));
    await resize(tester);

    expect(find.text('kept'), findsOneWidget);
  });

  testWidgets('so does every screen under the snack bars fitted to the '
      'window', (tester) async {
    await typeIn(tester, (screen) => FittedSnackBars(child: screen));
    await resize(tester);

    expect(find.text('kept'), findsOneWidget);
  });
}