packages/flutter/test/painting/image_cache_resize_test.dart

// Copyright 2016 The Chromium 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/painting.dart';
import 'package:test/test.dart';

import '../rendering/rendering_tester.dart';
import 'mocks_for_image_cache.dart';

void main() {
  new TestRenderingFlutterBinding(); // initializes the imageCache
  group(ImageCache, () {
     tearDown(() {
       imageCache.clear();
       imageCache.maximumSize = 1000;
       imageCache.maximumSizeBytes = 10485760;
     });

     test('Image cache resizing based on count', () async {
       imageCache.maximumSize = 2;

       final TestImageInfo a = await extractOneFrame(const TestImageProvider(1, 1).resolve(ImageConfiguration.empty));
       final TestImageInfo b = await extractOneFrame(const TestImageProvider(2, 2).resolve(ImageConfiguration.empty));
       final TestImageInfo c = await extractOneFrame(const TestImageProvider(3, 3).resolve(ImageConfiguration.empty));
       final TestImageInfo d = await extractOneFrame(const TestImageProvider(1, 4).resolve(ImageConfiguration.empty));
       expect(a.value, equals(1));
       expect(b.value, equals(2));
       expect(c.value, equals(3));
       expect(d.value, equals(4));

       imageCache.maximumSize = 0;

       final TestImageInfo e = await extractOneFrame(const TestImageProvider(1, 5).resolve(ImageConfiguration.empty));
       expect(e.value, equals(5));

       final TestImageInfo f = await extractOneFrame(const TestImageProvider(1, 6).resolve(ImageConfiguration.empty));
       expect(f.value, equals(6));

       imageCache.maximumSize = 3;

       final TestImageInfo g = await extractOneFrame(const TestImageProvider(1, 7).resolve(ImageConfiguration.empty));
       expect(g.value, equals(7));

       final TestImageInfo h = await extractOneFrame(const TestImageProvider(1, 8).resolve(ImageConfiguration.empty));
       expect(h.value, equals(7));
     });

     test('Image cache resizing based on size', () async {
       const TestImage testImage = const TestImage(width: 8, height: 8); // 256 B.
       imageCache.maximumSizeBytes = 256 * 2;

       final TestImageInfo a = await extractOneFrame(const TestImageProvider(1, 1, image: testImage).resolve(ImageConfiguration.empty));
       final TestImageInfo b = await extractOneFrame(const TestImageProvider(2, 2, image: testImage).resolve(ImageConfiguration.empty));
       final TestImageInfo c = await extractOneFrame(const TestImageProvider(3, 3, image: testImage).resolve(ImageConfiguration.empty));
       final TestImageInfo d = await extractOneFrame(const TestImageProvider(1, 4, image: testImage).resolve(ImageConfiguration.empty));
       expect(a.value, equals(1));
       expect(b.value, equals(2));
       expect(c.value, equals(3));
       expect(d.value, equals(4));

       imageCache.maximumSizeBytes = 0;

       final TestImageInfo e = await extractOneFrame(const TestImageProvider(1, 5, image: testImage).resolve(ImageConfiguration.empty));
       expect(e.value, equals(5));

       final TestImageInfo f = await extractOneFrame(const TestImageProvider(1, 6, image: testImage).resolve(ImageConfiguration.empty));
       expect(f.value, equals(6));

       imageCache.maximumSizeBytes = 256 * 3;

       final TestImageInfo g = await extractOneFrame(const TestImageProvider(1, 7, image: testImage).resolve(ImageConfiguration.empty));
       expect(g.value, equals(7));

       final TestImageInfo h = await extractOneFrame(const TestImageProvider(1, 8, image: testImage).resolve(ImageConfiguration.empty));
       expect(h.value, equals(7));
     });
  });
}