packages/flutter/test/services/asset_bundle_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 'dart:convert';

import 'package:flutter/foundation.dart';
import 'package:flutter/painting.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';

class TestAssetBundle extends CachingAssetBundle {
  Map<String, int> loadCallCount = <String, int>{};

  @override
  Future<ByteData> load(String key) async {
    loadCallCount[key] = (loadCallCount[key] ?? 0) + 1;
    if (key == 'AssetManifest.json') {
      return ByteData.view(Uint8List.fromList(const Utf8Encoder().convert('{"one": ["one"]}')).buffer);
    }

    if (key == 'AssetManifest.bin') {
      return const StandardMessageCodec().encodeMessage(<String, Object>{
        'one': <Object>[]
      })!;
    }

    if (key == 'counter') {
      return ByteData.view(Uint8List.fromList(const Utf8Encoder().convert(loadCallCount[key]!.toString())).buffer);
    }

    if (key == 'one') {
      return ByteData(1)..setInt8(0, 49);
    }

    throw FlutterError('key not found');
  }

}

void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  test('Caching asset bundle test', () async {
    final TestAssetBundle bundle = TestAssetBundle();

    final ByteData assetData = await bundle.load('one');
    expect(assetData.getInt8(0), equals(49));

    expect(bundle.loadCallCount['one'], 1);

    final String assetString = await bundle.loadString('one');
    expect(assetString, equals('1'));

    expect(bundle.loadCallCount['one'], 2);

    late Object loadException;
    try {
      await bundle.loadString('foo');
    } catch (e) {
      loadException = e;
    }
    expect(loadException, isFlutterError);
  });

  test('AssetImage.obtainKey succeeds with ImageConfiguration.empty', () async {
    // This is a regression test for https://github.com/flutter/flutter/issues/12392
    final AssetImage assetImage = AssetImage('one', bundle: TestAssetBundle());
    final AssetBundleImageKey key = await assetImage.obtainKey(ImageConfiguration.empty);
    expect(key.name, 'one');
    expect(key.scale, 1.0);
  });

  test('NetworkAssetBundle control test', () async {
    final Uri uri = Uri.http('example.org', '/path');
    final NetworkAssetBundle bundle = NetworkAssetBundle(uri);
    late FlutterError error;
    try {
      await bundle.load('key');
    } on FlutterError catch (e) {
      error = e;
    }
    expect(error, isNotNull);
    expect(error.diagnostics.length, 2);
    expect(error.diagnostics.last, isA<IntProperty>());
    expect(
      error.toStringDeep(),
      'FlutterError\n'
      '   Unable to load asset: "key".\n'
      '   HTTP status code: 400\n',
    );
  }, skip: isBrowser); // https://github.com/flutter/flutter/issues/39998

  test('toString works as intended', () {
    final Uri uri = Uri.http('example.org', '/path');
    final NetworkAssetBundle bundle = NetworkAssetBundle(uri);

    expect(bundle.toString(), 'NetworkAssetBundle#${shortHash(bundle)}($uri)');
  }, skip: isBrowser); // https://github.com/flutter/flutter/issues/39998

  test('Throws expected exceptions when loading not exists asset', () async {
    late final FlutterError error;
    try {
      await rootBundle.load('not-exists');
    } on FlutterError catch (e) {
      error = e;
    }
    expect(
      error.message,
      equals(
        'Unable to load asset: "not-exists".\n'
        'The asset does not exist or has empty data.',
      ),
    );
  }, skip: isBrowser); // https://github.com/flutter/flutter/issues/56314

  test('CachingAssetBundle caches results for loadString, loadStructuredData, and loadBinaryStructuredData', () async {
    final TestAssetBundle bundle = TestAssetBundle();

    final String firstLoadStringResult = await bundle.loadString('counter');
    final String secondLoadStringResult = await bundle.loadString('counter');
    expect(firstLoadStringResult, '1');
    expect(secondLoadStringResult, '1');

    final String firstLoadStructuredDataResult = await bundle.loadStructuredData('AssetManifest.json', (String value) => Future<String>.value('one'));
    final String secondLoadStructuredDataResult = await bundle.loadStructuredData('AssetManifest.json', (String value) => Future<String>.value('two'));
    expect(firstLoadStructuredDataResult, 'one');
    expect(secondLoadStructuredDataResult, 'one');

    final String firstLoadStructuredBinaryDataResult = await bundle.loadStructuredBinaryData('AssetManifest.bin', (ByteData value) => Future<String>.value('one'));
    final String secondLoadStructuredBinaryDataResult = await bundle.loadStructuredBinaryData('AssetManifest.bin', (ByteData value) => Future<String>.value('two'));
    expect(firstLoadStructuredBinaryDataResult, 'one');
    expect(secondLoadStructuredBinaryDataResult, 'one');
  });

  test("CachingAssetBundle.clear clears all cached values'", () async {
    final TestAssetBundle bundle = TestAssetBundle();

    await bundle.loadString('counter');
    bundle.clear();
    final String secondLoadStringResult = await bundle.loadString('counter');
    expect(secondLoadStringResult, '2');

    await bundle.loadStructuredData('AssetManifest.json', (String value) => Future<String>.value('one'));
    bundle.clear();
    final String secondLoadStructuredDataResult = await bundle.loadStructuredData('AssetManifest.json', (String value) => Future<String>.value('two'));
    expect(secondLoadStructuredDataResult, 'two');

    await bundle.loadStructuredBinaryData('AssetManifest.bin', (ByteData value) => Future<String>.value('one'));
    bundle.clear();
    final String secondLoadStructuredBinaryDataResult = await bundle.loadStructuredBinaryData('AssetManifest.bin', (ByteData value) => Future<String>.value('two'));
    expect(secondLoadStructuredBinaryDataResult, 'two');
  });

  test('CachingAssetBundle.evict evicts a particular key from the cache', () async {
    final TestAssetBundle bundle = TestAssetBundle();

    await bundle.loadString('counter');
    bundle.evict('counter');
    final String secondLoadStringResult = await bundle.loadString('counter');
    expect(secondLoadStringResult, '2');

    await bundle.loadStructuredData('AssetManifest.json', (String value) => Future<String>.value('one'));
    bundle.evict('AssetManifest.json');
    final String secondLoadStructuredDataResult = await bundle.loadStructuredData('AssetManifest.json', (String value) => Future<String>.value('two'));
    expect(secondLoadStructuredDataResult, 'two');

    await bundle.loadStructuredBinaryData('AssetManifest.bin', (ByteData value) => Future<String>.value('one'));
    bundle.evict('AssetManifest.bin');
    final String secondLoadStructuredBinaryDataResult = await bundle.loadStructuredBinaryData('AssetManifest.bin', (ByteData value) => Future<String>.value('two'));
    expect(secondLoadStructuredBinaryDataResult, 'two');
  });

  test('loadStructuredBinaryData correctly loads ByteData', () async {
    final TestAssetBundle bundle = TestAssetBundle();
    final Map<Object?, Object?> assetManifest =
      await bundle.loadStructuredBinaryData('AssetManifest.bin', (ByteData data) => const StandardMessageCodec().decodeMessage(data) as Map<Object?, Object?>);
    expect(assetManifest.keys.toList(), equals(<String>['one']));
    expect(assetManifest['one'], <Object>[]);
  });
}