packages/flutter/test/widgets/status_transitions_test.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/widgets.dart';
import 'package:flutter_test/flutter_test.dart';

class TestStatusTransitionWidget extends StatusTransitionWidget {
  const TestStatusTransitionWidget({super.key, required this.builder, required super.animation});

  final WidgetBuilder builder;

  @override
  Widget build(BuildContext context) => builder(context);
}

void main() {
  testWidgets('Status transition control test', (WidgetTester tester) async {
    var didBuild = false;
    final controller = AnimationController(
      duration: const Duration(seconds: 1),
      vsync: const TestVSync(),
    );
    addTearDown(controller.dispose);

    await tester.pumpWidget(
      TestStatusTransitionWidget(
        animation: controller,
        builder: (BuildContext context) {
          expect(didBuild, isFalse);
          didBuild = true;
          return Container();
        },
      ),
    );

    expect(didBuild, isTrue);
    didBuild = false;

    controller.forward();

    expect(didBuild, isFalse);
    await tester.pump();
    expect(didBuild, isTrue);
    didBuild = false;
    await tester.pump(const Duration(milliseconds: 100));
    expect(didBuild, isFalse);
    await tester.pump(const Duration(milliseconds: 850));
    expect(didBuild, isFalse);
    await tester.pump(const Duration(milliseconds: 100));
    expect(didBuild, isTrue);
    didBuild = false;
    controller.forward();
    await tester.pump(const Duration(milliseconds: 100));
    expect(didBuild, isFalse);
    controller.stop();
    await tester.pump(const Duration(milliseconds: 100));
    expect(didBuild, isFalse);

    final anotherController = AnimationController(
      duration: const Duration(seconds: 1),
      vsync: const TestVSync(),
    );
    addTearDown(anotherController.dispose);

    await tester.pumpWidget(
      TestStatusTransitionWidget(
        animation: anotherController,
        builder: (BuildContext context) {
          expect(didBuild, isFalse);
          didBuild = true;
          return Container();
        },
      ),
    );

    expect(didBuild, isTrue);
    didBuild = false;
    controller.reverse();
    await tester.pump(const Duration(milliseconds: 100));
    expect(didBuild, isFalse);
    anotherController.forward();
    await tester.pump(const Duration(milliseconds: 100));
    expect(didBuild, isTrue);
    didBuild = false;

    controller.stop();
    anotherController.stop();
  });
}