enhanced route transition gate because of a syncfusion viewer bug

2026-08-08 22:13:19 +02:00
parent b9cb1df473
commit 39c16bd4ea
3 changed files with 134 additions and 24 deletions
@@ -0,0 +1,86 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:marianum_mobile/widget/route_transition_gate.dart';
+
+void main() {
+  const gated = Key('gated-child');
+  const placeholder = Key('gate-placeholder');
+
+  Widget gatedPage() => Scaffold(
+    body: RouteTransitionGate(
+      placeholder: const SizedBox(key: placeholder),
+      builder: (_) => const SizedBox(key: gated),
+    ),
+  );
+
+  Future<void> pumpApp(WidgetTester tester) async {
+    await tester.pumpWidget(
+      MaterialApp(home: Builder(builder: (_) => const Scaffold())),
+    );
+  }
+
+  NavigatorState navigator(WidgetTester tester) =>
+      tester.state<NavigatorState>(find.byType(Navigator));
+
+  testWidgets('shows placeholder during push, child once settled', (
+    tester,
+  ) async {
+    await pumpApp(tester);
+    unawaited(
+      navigator(tester).push(MaterialPageRoute<void>(builder: (_) => gatedPage())),
+    );
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 50));
+
+    expect(find.byKey(placeholder), findsOneWidget);
+    expect(find.byKey(gated), findsNothing);
+
+    await tester.pumpAndSettle();
+    expect(find.byKey(gated), findsOneWidget);
+    expect(find.byKey(placeholder), findsNothing);
+  });
+
+  testWidgets('swaps back to placeholder while the route pops', (tester) async {
+    await pumpApp(tester);
+    unawaited(
+      navigator(tester).push(MaterialPageRoute<void>(builder: (_) => gatedPage())),
+    );
+    await tester.pumpAndSettle();
+    expect(find.byKey(gated), findsOneWidget);
+
+    navigator(tester).pop();
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 50));
+
+    expect(find.byKey(gated), findsNothing);
+    expect(find.byKey(placeholder), findsOneWidget);
+  });
+
+  testWidgets('gates during a secondary transition and recovers after pop', (
+    tester,
+  ) async {
+    await pumpApp(tester);
+    unawaited(
+      navigator(tester).push(MaterialPageRoute<void>(builder: (_) => gatedPage())),
+    );
+    await tester.pumpAndSettle();
+    expect(find.byKey(gated), findsOneWidget);
+
+    unawaited(
+      navigator(tester).push(MaterialPageRoute<void>(builder: (_) => const Scaffold())),
+    );
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 50));
+    // Mid secondary transition the fragile subtree must be unmounted.
+    expect(find.byKey(gated), findsNothing);
+
+    await tester.pumpAndSettle();
+    navigator(tester).pop();
+    await tester.pumpAndSettle();
+    // Back at rest on the gated route: child is mounted again.
+    expect(find.byKey(gated), findsOneWidget);
+    expect(find.byKey(placeholder), findsNothing);
+  });
+}