SpotiFLAC-Mobile/test/playback_normalization_test.dart

import 'package:flutter_test/flutter_test.dart';
import 'package:spotiflac_android/services/playback_normalization.dart';

void main() {
  test(
    'descriptor normalization uses hint and caches by original URI',
    () async {
      var reads = 0;
      final cache = PlaybackNormalizationCache(
        readMetadata: (path, {displayName}) async {
          reads++;
          expect(path, '/proc/self/fd/42');
          expect(displayName, 'Song.flac');
          return {
            'replaygain_track_gain': '-6.00 dB',
            'replaygain_album_gain': '-3.00 dB',
          };
        },
      );
      expect(
        await cache.volumeFor(
          '/proc/self/fd/42',
          displayName: 'Song.flac',
          cacheKey: 'content://music/song',
        ),
        closeTo(0.501187, 0.000001),
      );
      expect(
        await cache.volumeFor(
          '/proc/self/fd/99',
          displayName: 'Song.flac',
          cacheKey: 'content://music/song',
        ),
        closeTo(0.501187, 0.000001),
      );
      expect(reads, 1);
    },
  );

  test(
    'failed descriptor metadata does not poison local fallback cache',
    () async {
      var reads = 0;
      final cache = PlaybackNormalizationCache(
        readMetadata: (path, {displayName}) async {
          reads++;
          if (path.startsWith('/proc/')) {
            return {'error': 'descriptor access denied'};
          }
          return {'replaygain_album_gain': '-6.00 dB'};
        },
      );
      expect(
        await cache.volumeFor(
          '/proc/self/fd/42',
          displayName: 'Song.mp3',
          cacheKey: 'song',
        ),
        1.0,
      );
      expect(
        await cache.volumeFor('/cache/Song.mp3', cacheKey: 'song'),
        closeTo(0.501187, 0.000001),
      );
      expect(reads, 2);
    },
  );

  test('exceptions are retried and positive gain only attenuates', () async {
    var reads = 0;
    final cache = PlaybackNormalizationCache(
      readMetadata: (path, {displayName}) async {
        if (++reads == 1) throw StateError('temporarily unavailable');
        return {'replaygain_track_gain': '+6.00 dB'};
      },
    );
    expect(await cache.volumeFor('song'), 1.0);
    expect(await cache.volumeFor('song'), 1.0);
    expect(reads, 2);
  });
}