examples/api/test/widgets/transitions/scale_transition.0_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/material.dart';
import 'package:flutter_api_samples/widgets/transitions/scale_transition.0.dart' as example;
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets('Shows flutter logo in transition', (WidgetTester tester) async {
    await tester.pumpWidget(const example.ScaleTransitionExampleApp());
    expect(find.byType(FlutterLogo), findsOneWidget);
    expect(find.byType(Center), findsOneWidget);
    expect(find.descendant(
      of: find.byType(Center),
      matching: find.byType(ScaleTransition)
    ), findsOneWidget);
    expect(
      find.byWidgetPredicate((Widget widget) => widget is ScaleTransition
        && widget.scale is CurvedAnimation
        && (widget.scale as CurvedAnimation).curve == Curves.fastOutSlowIn,
      ), findsOneWidget);
  });

  testWidgets('Scales every 2 seconds', (WidgetTester tester) async {
    await tester.pumpWidget(const example.ScaleTransitionExampleApp());
    final Finder transformFinder = find.descendant(
      of: find.byType(Center),
      matching: find.byType(Transform)
    );

    Transform transform = tester.widget(transformFinder);
    expect(transform.transform[0], 0);

    await tester.pump(const Duration(seconds: 2));
    await tester.pump();

    transform = tester.widget(transformFinder);
    expect(transform.transform[0], 1.0);

    await tester.pump(const Duration(seconds: 2));
    await tester.pump();

    transform = tester.widget(transformFinder);
    expect(transform.transform[0], 0);
  });
}