fix(music): convert SAF content:// downloads for gapless arming

setNext() appended raw content:// URIs that mpv cannot open, stalling
playback at the SD-card-download track boundary. Convert to fdclose://
like open(), track the armed fd, and reclaim it via a new closeContentFd
method when the entry is dropped unplayed (close only when provably
unconsumed — playlist-pos 0 before and after the remove; leak on doubt).
The playlist-pos pre-check also keeps the clear path from removing the
playing entry when mpv rolls into the armed track mid-clear.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

android/app/src/main/kotlin/com/edde746/plezy/mpv/MpvPlayerPlugin.kt

@@ -5,6 +5,7 @@ import android.content.Context
 import android.net.Uri
 import android.os.Handler
 import android.os.Looper
+import android.os.ParcelFileDescriptor
 import android.util.Log
 import io.flutter.embedding.engine.plugins.FlutterPlugin
 import io.flutter.embedding.engine.plugins.activity.ActivityAware
@@ -156,6 +157,7 @@ open class MpvPlayerPlugin(
       "requestAudioFocus" -> handleRequestAudioFocus(result)
       "abandonAudioFocus" -> handleAbandonAudioFocus(result)
       "openContentFd" -> handleOpenContentFd(call, result)
+      "closeContentFd" -> handleCloseContentFd(call, result)
       "isInitialized" -> result.success(playerCore?.isInitialized ?: false)
       "setLogLevel" -> result.success(null)
       else -> result.notImplemented()
@@ -454,6 +456,26 @@ open class MpvPlayerPlugin(
     }.start()
   }
 
+  // Reclaims a detached fd from handleOpenContentFd that mpv will never
+  // consume (a gapless-armed entry dropped before mpv opened it). The Dart
+  // side guarantees single-close and only calls this when the entry provably
+  // never played.
+  private fun handleCloseContentFd(call: MethodCall, result: MethodChannel.Result) {
+    val fd = call.argument<Int>("fd")
+    if (fd == null || fd < 0) {
+      result.error("INVALID_ARGS", "Missing 'fd'", null)
+      return
+    }
+    try {
+      ParcelFileDescriptor.adoptFd(fd).close()
+      Log.d(tag, "Closed content FD $fd")
+      result.success(null)
+    } catch (e: Exception) {
+      Log.e(tag, "Failed to close content FD $fd: ${e.message}", e)
+      result.error("CLOSE_FAILED", e.message, null)
+    }
+  }
+
   // PlayerDelegate
 
   override fun onPropertyChange(name: String, value: Any?) {

lib/mpv/player/player_native.dart

@@ -2,6 +2,7 @@ import 'dart:async' show unawaited;
 import 'dart:convert';
 import 'dart:io' show Platform;
 
+import 'package:flutter/foundation.dart' show visibleForTesting;
 import 'package:flutter/services.dart';
 
 import '../../media/media_display_criteria.dart';
@@ -32,8 +33,17 @@ class PlayerNative extends PlayerBase {
 
   // Gapless-audio arming state (audioOnly). The native playlist is always
   // [current, next?]; these track whether entry 1 exists and what it plays.
+  // _armedNextUri keeps the ORIGINAL media URI (the music service matches
+  // trackTransition events against it); _armedNextFd is the content-fd claim
+  // when the armed URI needed fdclose:// conversion (see _toPlayableUri).
   bool _hasArmedNext = false;
   String? _armedNextUri;
+  int? _armedNextFd;
+
+  /// Host tests aren't Android, so the content:// → fdclose:// path would be
+  /// unreachable; forces the conversion regardless of platform.
+  @visibleForTesting
+  static bool debugForceContentFdConversion = false;
 
   // Set by open() and consumed by that load's file-loaded event, so it is
   // not mistaken for a gapless advance (see _handleAudioFileLoaded).
@@ -222,6 +232,34 @@ class PlayerNative extends PlayerBase {
     }
   }
 
+  /// Closes a detached content fd that mpv will never consume. Fire-and-forget
+  /// safe: a failure only leaks one fd.
+  Future<void> _closeContentFd(int fd) async {
+    try {
+      await invoke('closeContentFd', {'fd': fd});
+    } catch (e) {
+      appLogger.d('$logPrefix: closeContentFd($fd) failed', error: e);
+    }
+  }
+
+  /// Converts Android SAF content:// URIs to `fdclose://<fd>` — mpv owns the fd
+  /// and closes it when it opens the entry. Returns the loadfile URI and the
+  /// opened fd (null when no conversion applied). [strict] throws instead of
+  /// falling back to the raw URI when the fd cannot be opened: mpv cannot
+  /// open content:// itself, so arming one would stall playback at the track
+  /// boundary — setNext must fail loudly so the music service falls back to
+  /// an explicit open.
+  Future<(String, int?)> _toPlayableUri(String uri, {bool strict = false}) async {
+    final convert = (Platform.isAndroid || debugForceContentFdConversion) && uri.startsWith('content://');
+    if (!convert) return (uri, null);
+    final fd = await _openContentFd(uri);
+    if (fd == null) {
+      if (strict) throw StateError('openContentFd failed for ${_uriTail(uri)}');
+      return (uri, null);
+    }
+    return ('fdclose://$fd', fd);
+  }
+
   @override
   Future<void> open(
     Media media, {
@@ -234,9 +272,9 @@ class PlayerNative extends PlayerBase {
     if (disposed) return;
     await _ensureInitialized();
     // `loadfile replace` (below) clears the native playlist, dropping any
-    // gapless entry armed via setNext.
-    _hasArmedNext = false;
-    _armedNextUri = null;
+    // gapless entry armed via setNext — settle its content-fd claim first.
+    // No transition is surfaced: the caller is replacing playback anyway.
+    await _clearArmedNext(adoptIfRolledIn: false);
     final startPosition = media.start ?? Duration.zero;
     configureTimeline(offset: timelineOffset, duration: timelineDuration);
     clearTracks();
@@ -276,14 +314,10 @@ class PlayerNative extends PlayerBase {
     await setProperty('sid', 'no');
     await setProperty('secondary-sid', 'no');
 
-    // Convert content:// URIs to fdclose:// for MPV on Android (SAF SD card downloads)
-    var uri = media.uri;
-    if (Platform.isAndroid && uri.startsWith('content://')) {
-      final fd = await _openContentFd(uri);
-      if (fd != null) {
-        uri = 'fdclose://$fd';
-      }
-    }
+    // Convert content:// URIs to fdclose:// for MPV on Android (SAF SD card
+    // downloads). The immediate `loadfile replace` consumes the fd, so no
+    // claim tracking is needed here (unlike setNext).
+    final (uri, _) = await _toPlayableUri(media.uri);
 
     final loadfileArgs = ['loadfile', uri, 'replace'];
     final loadfileOption = _externalSubtitlesLoadfileOption(externalSubtitles);
@@ -314,8 +348,9 @@ class PlayerNative extends PlayerBase {
 
   @override
   Future<void> stop() async {
-    _hasArmedNext = false;
-    _armedNextUri = null;
+    // `stop` tears down the playlist without mpv opening the armed entry —
+    // settle its content-fd claim first. No transition: playback is ending.
+    await _clearArmedNext(adoptIfRolledIn: false);
     await command(['stop']);
     setSeekable(false);
     if (!audioOnly) await invoke('setVisible', {'visible': false});
@@ -331,34 +366,102 @@ class PlayerNative extends PlayerBase {
   Future<void> setNext(Media? media) async {
     if (!audioOnly || disposed || !initialized) return;
 
-    if (_hasArmedNext) {
-      _hasArmedNext = false;
-      _armedNextUri = null;
-      appLogger.d('MPV-audio: clearing armed entry (playlist-remove 1)');
-      try {
-        await command(['playlist-remove', '1']);
-      } on PlatformException {
-        // Entry 1 can vanish in the arm/advance race (mpv already rolled into
-        // it); the append below still lands after the current entry.
-      }
-    }
+    await _clearArmedNext();
     if (media == null) return;
 
+    final (loadUri, fd) = await _toPlayableUri(media.uri, strict: true);
+
     // Per-entry options are the 4th loadfile argument on mpv >= 0.38
     // (`loadfile <url> append -1 opt=val`), exactly like open() passes
     // sub-files. `gapless-audio=weak` splices the armed entry into the
     // running audio stream when formats match.
-    final args = ['loadfile', media.uri, 'append'];
+    final args = ['loadfile', loadUri, 'append'];
     final headerOption = _httpHeaderFieldsLoadfileOption(media.headers);
     if (headerOption != null) {
       args.addAll(['-1', headerOption]);
     }
-    await command(args);
+    try {
+      await command(args);
+    } catch (e) {
+      // The entry never joined the playlist, so the fd has no consumer.
+      if (fd != null) unawaited(_closeContentFd(fd));
+      rethrow;
+    }
     _hasArmedNext = true;
     _armedNextUri = media.uri;
+    _armedNextFd = fd;
     appLogger.d('MPV-audio: armed next ${_uriTail(media.uri)}');
   }
 
+  /// Clears the armed entry (if any), resolving the arm/advance race and the
+  /// content-fd claim. mpv may have already rolled into the armed entry
+  /// before this runs; blindly removing index 1 then would remove the
+  /// PLAYING entry, so playlist-pos is checked first. fd ownership: mpv owns
+  /// the fd from the moment it opens the entry (fdclose closes it at stream
+  /// close); Dart may close only when the entry provably never opened —
+  /// playlist-pos 0 both before and after a successful remove. Anything
+  /// ambiguous leaks the fd (one fd, ms-wide window) rather than risk
+  /// closing an fd mpv holds. The remove's success cannot be the ownership
+  /// signal: Android's command bridge never surfaces mpv command failures.
+  ///
+  /// [adoptIfRolledIn]: when mpv already advanced into the armed entry,
+  /// surface the transition here (the pending file-loaded event becomes a
+  /// no-op once the flags are cleared) — without this a queue edit landing
+  /// exactly at the gapless boundary desyncs the music service from the
+  /// audio for the whole next track. Callers that replace or stop playback
+  /// pass false: no one is listening for that entry anymore.
+  Future<void> _clearArmedNext({bool adoptIfRolledIn = true}) async {
+    if (!_hasArmedNext) return;
+    final uri = _armedNextUri;
+    final fd = _armedNextFd;
+    _hasArmedNext = false;
+    _armedNextUri = null;
+    _armedNextFd = null;
+
+    String? pos;
+    try {
+      pos = await getProperty('playlist-pos');
+    } catch (_) {
+      // Unknown state — fall through to the remove, never close the fd.
+    }
+    if (pos == '1') {
+      appLogger.d('MPV-audio: clear requested but armed entry already playing');
+      if (adoptIfRolledIn) _completeArmedAdvance(uri);
+      return;
+    }
+
+    appLogger.d('MPV-audio: clearing armed entry (playlist-remove 1)');
+    try {
+      await command(['playlist-remove', '1']);
+    } on PlatformException {
+      // Entry 1 vanished in the arm/advance race — mpv rolled into it and
+      // the file-loaded handler already rebased. The fd (if any) is mpv's.
+      return;
+    }
+    if (fd == null) return;
+    String? postPos;
+    try {
+      postPos = await getProperty('playlist-pos');
+    } catch (_) {}
+    if (pos == '0' && postPos == '0') {
+      unawaited(_closeContentFd(fd));
+    }
+    // Any other combination is ambiguous (mpv advanced mid-clear, idle
+    // playlist, property error): leak on doubt.
+  }
+
+  /// The armed entry became the playing one (mpv rolled into it): clear the
+  /// arm — the fd (if any) was consumed by mpv — remove the spent entry so
+  /// the playing entry rebases to index 0, and surface the transition.
+  void _completeArmedAdvance(String? uri) {
+    _hasArmedNext = false;
+    _armedNextUri = null;
+    _armedNextFd = null;
+    appLogger.d('MPV-audio: armed entry advanced → playlist-remove 0, ${_uriTail(uri ?? '')}');
+    unawaited(command(['playlist-remove', '0']));
+    if (uri != null) trackTransitionController.add(uri);
+  }
+
   @override
   void handlePropertyChange(String name, dynamic value) {
     if (audioOnly && name == 'playlist-pos') {
@@ -402,13 +505,23 @@ class PlayerNative extends PlayerBase {
       appLogger.d('MPV-audio: file-loaded (nothing armed, ignored)');
       return;
     }
+    _completeArmedAdvance(_armedNextUri);
+  }
 
-    final uri = _armedNextUri;
-    _hasArmedNext = false;
-    _armedNextUri = null;
-    appLogger.d('MPV-audio: transition (file-loaded) → playlist-remove 0, ${_uriTail(uri ?? '')}');
-    unawaited(command(['playlist-remove', '0']));
-    if (uri != null) trackTransitionController.add(uri);
+  @override
+  Future<void> dispose({bool preserveDisplayMode = false}) async {
+    if (disposed) return;
+    // Settle an armed-but-unconsumed content fd before the base teardown
+    // disables invoke() — the playlist is torn down without mpv ever opening
+    // the entry.
+    if (_hasArmedNext) {
+      try {
+        await _clearArmedNext(adoptIfRolledIn: false);
+      } catch (_) {
+        // Leak on doubt.
+      }
+    }
+    await super.dispose(preserveDisplayMode: preserveDisplayMode);
   }
 
   @override

test/mpv/player_gapless_test.dart

@@ -0,0 +1,308 @@
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:plezy/mpv/mpv.dart';
+import 'package:plezy/mpv/player/player_native.dart';
+import 'package:plezy/services/settings_service.dart';
+
+import '../test_helpers/mock_player_channels.dart';
+import '../test_helpers/prefs.dart';
+
+/// Gapless arming (setNext) on the audio core: content:// → fdclose://
+/// conversion and the content-fd ownership rules — Dart closes an armed fd
+/// only when the entry provably never played (playlist-pos 0 before and
+/// after the remove); every ambiguous outcome leaks rather than risking a
+/// close of an fd mpv holds.
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  setUp(() async {
+    resetSharedPreferencesForTest();
+    SettingsService.resetForTesting();
+    await SettingsService.getInstance();
+    PlayerNative.debugForceContentFdConversion = true;
+  });
+
+  tearDown(() {
+    PlayerNative.debugForceContentFdConversion = false;
+  });
+
+  Future<void> run(_AudioCoreMock core, Future<void> Function(PlayerNative player, List<String> transitions) body) {
+    return withMockPlayerChannels(
+      methodChannelName: 'com.plezy/mpv_audio_player',
+      eventChannelName: 'com.plezy/mpv_audio_player/events',
+      methodHandler: core.handle,
+      testBody: () async {
+        final player = PlayerNative.audio();
+        final transitions = <String>[];
+        final sub = player.streams.trackTransition.listen(transitions.add);
+        try {
+          await body(player, transitions);
+        } finally {
+          await sub.cancel();
+          await player.dispose();
+        }
+      },
+    );
+  }
+
+  /// Opens a first track and consumes its own file-loaded so later
+  /// file-loaded events read as gapless roll-ins.
+  Future<void> openFirst(PlayerNative player, [String uri = 'https://example.test/t1.flac']) async {
+    await player.open(Media(uri));
+    player.handlePlayerEvent('file-loaded', null);
+  }
+
+  group('setNext content:// conversion', () {
+    test('arms fdclose:// and surfaces the ORIGINAL uri on transition', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        expect(core.openedContentUris, ['content://downloads/t2']);
+        expect(core.commands('loadfile').last, ['loadfile', 'fdclose://7', 'append']);
+
+        player.handlePlayerEvent('file-loaded', null);
+        await Future<void>.delayed(Duration.zero);
+
+        // The service matches transitions against the resolver's URL, so the
+        // original content:// uri must surface — never the fdclose:// form.
+        expect(transitions, ['content://downloads/t2']);
+        expect(core.commands('playlist-remove').last, ['playlist-remove', '0']);
+        expect(core.closedFds, isEmpty, reason: 'mpv consumed the fd');
+      });
+    });
+
+    test('open() still converts content:// (regression)', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await player.open(Media('content://downloads/t1'));
+        expect(core.commands('loadfile').single, ['loadfile', 'fdclose://7', 'replace']);
+        expect(core.closedFds, isEmpty);
+      });
+    });
+
+    test('non-content arm opens no fd and re-arm still clears entry 1', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('https://example.test/t2.flac'));
+        await player.setNext(Media('https://example.test/t3.flac'));
+
+        expect(core.openedContentUris, isEmpty);
+        expect(core.closedFds, isEmpty);
+        expect(core.commands('playlist-remove'), [
+          ['playlist-remove', '1'],
+        ]);
+        expect(core.commands('loadfile').last, ['loadfile', 'https://example.test/t3.flac', 'append']);
+      });
+    });
+
+    test('openContentFd failure throws instead of arming a raw content:// uri', () async {
+      final core = _AudioCoreMock()..failOpenContentFd = true;
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await expectLater(player.setNext(Media('content://downloads/t2')), throwsStateError);
+        expect(core.commands('loadfile'), hasLength(1), reason: 'only the open() load');
+      });
+    });
+  });
+
+  group('armed fd ownership', () {
+    test('clearing an unconsumed arm closes the fd (pos 0 before and after)', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        core.playlistPosResponses.addAll(['0', '0']);
+        await player.setNext(null);
+
+        expect(core.commands('playlist-remove'), [
+          ['playlist-remove', '1'],
+        ]);
+        expect(core.closedFds, [7]);
+        expect(transitions, isEmpty);
+      });
+    });
+
+    test('clear while mpv already rolled in adopts the transition, keeps the fd', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        core.playlistPosResponses.add('1');
+        await player.setNext(null);
+        await Future<void>.delayed(Duration.zero);
+
+        expect(transitions, ['content://downloads/t2'], reason: 'the pending file-loaded is a no-op now');
+        expect(core.commands('playlist-remove'), [
+          ['playlist-remove', '0'],
+        ], reason: 'rebase only — removing index 1 would kill the playing entry');
+        expect(core.closedFds, isEmpty, reason: 'mpv opened the entry and owns the fd');
+
+        // The real file-loaded event arrives late: nothing armed, ignored.
+        player.handlePlayerEvent('file-loaded', null);
+        await Future<void>.delayed(Duration.zero);
+        expect(transitions, hasLength(1));
+      });
+    });
+
+    test('ambiguous post-remove position leaks on doubt', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        core.playlistPosResponses.addAll(['0', '-1']);
+        await player.setNext(null);
+
+        expect(core.commands('playlist-remove'), [
+          ['playlist-remove', '1'],
+        ]);
+        expect(core.closedFds, isEmpty);
+      });
+    });
+
+    test('playlist-remove failure leaks on doubt', () async {
+      final core = _AudioCoreMock()..failPlaylistRemove1 = true;
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        core.playlistPosResponses.add('0');
+        await player.setNext(null);
+
+        expect(core.closedFds, isEmpty);
+        expect(transitions, isEmpty);
+      });
+    });
+
+    test('stop() settles an unconsumed armed fd without a transition', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        core.playlistPosResponses.addAll(['0', '0']);
+        await player.stop();
+
+        expect(core.closedFds, [7]);
+        expect(transitions, isEmpty);
+      });
+    });
+
+    test('stop() while rolled in emits no transition and keeps the fd', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        core.playlistPosResponses.add('1');
+        await player.stop();
+        await Future<void>.delayed(Duration.zero);
+
+        expect(transitions, isEmpty, reason: 'playback is ending — nobody listens for that entry');
+        expect(core.closedFds, isEmpty);
+      });
+    });
+
+    test('open() replace settles an unconsumed armed fd', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        core.playlistPosResponses.addAll(['0', '0']);
+        await player.open(Media('https://example.test/t3.flac'));
+
+        expect(core.closedFds, [7]);
+        expect(transitions, isEmpty);
+        expect(core.commands('loadfile').last, ['loadfile', 'https://example.test/t3.flac', 'replace']);
+      });
+    });
+
+    test('dispose() settles an unconsumed armed fd', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        core.playlistPosResponses.addAll(['0', '0']);
+        await player.dispose();
+
+        expect(core.closedFds, [7]);
+      });
+    });
+
+    test('replacing an unconsumed content arm closes the old fd only', () async {
+      final core = _AudioCoreMock();
+      await run(core, (player, transitions) async {
+        await openFirst(player);
+        await player.setNext(Media('content://downloads/t2'));
+
+        core.playlistPosResponses.addAll(['0', '0']);
+        await player.setNext(Media('content://downloads/t3'));
+
+        expect(core.openedContentUris, ['content://downloads/t2', 'content://downloads/t3']);
+        expect(core.closedFds, [7]);
+        expect(core.commands('loadfile').last, ['loadfile', 'fdclose://8', 'append']);
+
+        player.handlePlayerEvent('file-loaded', null);
+        await Future<void>.delayed(Duration.zero);
+        expect(transitions, ['content://downloads/t3']);
+        expect(core.closedFds, [7], reason: 'the consumed fd stays with mpv');
+      });
+    });
+  });
+}
+
+/// Scriptable mock of the native audio core: records calls, hands out
+/// incrementing content fds, and answers playlist-pos reads from a queue
+/// (defaulting to '0').
+class _AudioCoreMock {
+  final calls = <MethodCall>[];
+  final openedContentUris = <String>[];
+  final closedFds = <int>[];
+  final playlistPosResponses = <String>[];
+  int _nextFd = 7;
+  bool failOpenContentFd = false;
+  bool failPlaylistRemove1 = false;
+
+  Future<Object?> handle(MethodCall call) async {
+    calls.add(call);
+    switch (call.method) {
+      case 'initialize':
+        return true;
+      case 'openContentFd':
+        if (failOpenContentFd) throw PlatformException(code: 'OPEN_FAILED');
+        openedContentUris.add(_args(call)['uri'] as String);
+        return _nextFd++;
+      case 'closeContentFd':
+        closedFds.add(_args(call)['fd'] as int);
+        return null;
+      case 'getProperty':
+        if (_args(call)['name'] == 'playlist-pos') {
+          return playlistPosResponses.isEmpty ? '0' : playlistPosResponses.removeAt(0);
+        }
+        return null;
+      case 'command':
+        final args = (_args(call)['args'] as List).cast<Object?>();
+        if (failPlaylistRemove1 && args.length >= 2 && args[0] == 'playlist-remove' && args[1] == '1') {
+          throw PlatformException(code: 'error', message: 'playlist-remove failed');
+        }
+        return null;
+      default:
+        return null;
+    }
+  }
+
+  List<List<Object?>> commands(String first) => calls
+      .where((c) => c.method == 'command')
+      .map((c) => (_args(c)['args'] as List).cast<Object?>())
+      .where((args) => args.isNotEmpty && args.first == first)
+      .toList();
+
+  static Map<Object?, Object?> _args(MethodCall call) => Map<Object?, Object?>.from(call.arguments as Map);
+}

test/mpv/player_open_test.dart

@@ -9,6 +9,7 @@ import 'package:plezy/mpv/player/platform/player_android.dart';
 import 'package:plezy/mpv/player/player_native.dart';
 import 'package:plezy/services/settings_service.dart';
 
+import '../test_helpers/mock_player_channels.dart';
 import '../test_helpers/prefs.dart';
 
 void main() {
@@ -22,7 +23,7 @@ void main() {
 
   group('player open', () {
     test('ExoPlayer clears stale Dart track state before opening new media', () async {
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/exo_player',
         eventChannelName: 'com.plezy/exo_player/events',
         testBody: () async {
@@ -48,7 +49,7 @@ void main() {
     test('ExoPlayer forwards external subtitle metadata at open', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/exo_player',
         eventChannelName: 'com.plezy/exo_player/events',
         methodHandler: (call) {
@@ -98,7 +99,7 @@ void main() {
     });
 
     test('ExoPlayer backend switch clears stale tracks before fallback tracks arrive', () async {
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/exo_player',
         eventChannelName: 'com.plezy/exo_player/events',
         testBody: () async {
@@ -137,7 +138,7 @@ void main() {
       final initialize = Completer<bool>();
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/exo_player',
         eventChannelName: 'com.plezy/exo_player/events',
         methodHandler: (call) {
@@ -183,7 +184,7 @@ void main() {
     test('ExoPlayer maps copyts transcode streams as absolute timeline positions', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/exo_player',
         eventChannelName: 'com.plezy/exo_player/events',
         methodHandler: (call) {
@@ -235,7 +236,7 @@ void main() {
       final calls = <MethodCall>[];
       late PlayerAndroid player;
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/exo_player',
         eventChannelName: 'com.plezy/exo_player/events',
         methodHandler: (call) {
@@ -280,7 +281,7 @@ void main() {
     test('ExoPlayer marks explicit non-zero media starts for native fallback', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/exo_player',
         eventChannelName: 'com.plezy/exo_player/events',
         methodHandler: (call) {
@@ -309,7 +310,7 @@ void main() {
     });
 
     test('MPV clears stale Dart track state before opening new media', () async {
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         testBody: () async {
@@ -335,7 +336,7 @@ void main() {
     test('MPV disables subtitles before loading media', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         methodHandler: (call) {
@@ -373,7 +374,7 @@ void main() {
     test('MPV passes external subtitles through loadfile options', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         methodHandler: (call) {
@@ -416,7 +417,7 @@ void main() {
     });
 
     test('MPV preserves external subtitle metadata for loadfile sidecars', () async {
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         testBody: () async {
@@ -460,7 +461,7 @@ void main() {
     test('MPV open(play: true) unpauses after loadfile even when previously paused', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         methodHandler: (call) {
@@ -494,7 +495,7 @@ void main() {
     test('MPV open(play: false) opens paused and never unpauses', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         methodHandler: (call) {
@@ -526,7 +527,7 @@ void main() {
     });
 
     test('MPV exposes file-loaded events through PlayerStreams', () async {
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         testBody: () async {
@@ -547,7 +548,7 @@ void main() {
     test('MPV maps server-offset streams to absolute timeline positions', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         methodHandler: (call) {
@@ -590,7 +591,7 @@ void main() {
     test('MPV refresh seek preserves timeline offset position', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         methodHandler: (call) {
@@ -630,7 +631,7 @@ void main() {
     test('MPV forwards preserve display mode flag on dispose', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         methodHandler: (call) {
@@ -652,7 +653,7 @@ void main() {
     test('dispose continues when native event stream cancellation is already detached', () async {
       final calls = <MethodCall>[];
 
-      await _withMockChannels(
+      await withMockPlayerChannels(
         methodChannelName: 'com.plezy/mpv_player',
         eventChannelName: 'com.plezy/mpv_player/events',
         methodHandler: (call) {
@@ -679,46 +680,6 @@ void main() {
   });
 }
 
-Future<void> _withMockChannels({
-  required String methodChannelName,
-  required String eventChannelName,
-  Future<Object?> Function(MethodCall call)? methodHandler,
-  Future<Object?> Function(MethodCall call)? eventHandler,
-  required Future<void> Function() testBody,
-}) async {
-  final messenger = TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger;
-  final methodChannel = MethodChannel(methodChannelName);
-  final eventChannel = MethodChannel(eventChannelName);
-
-  messenger.setMockMethodCallHandler(
-    methodChannel,
-    methodHandler ??
-        (call) async {
-          switch (call.method) {
-            case 'initialize':
-              return true;
-            case 'observeProperty':
-            case 'setVisible':
-            case 'setProperty':
-            case 'command':
-            case 'open':
-            case 'dispose':
-              return null;
-            default:
-              return null;
-          }
-        },
-  );
-  messenger.setMockMethodCallHandler(eventChannel, eventHandler ?? (call) async => null);
-
-  try {
-    await testBody();
-  } finally {
-    messenger.setMockMethodCallHandler(methodChannel, null);
-    messenger.setMockMethodCallHandler(eventChannel, null);
-  }
-}
-
 void _seedTracks(dynamic player) {
   player.handlePropertyChange('track-list', const [
     {'type': 'audio', 'id': '2_0', 'title': 'English', 'lang': 'eng', 'selected': true},

test/test_helpers/mock_player_channels.dart

@@ -0,0 +1,37 @@
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+/// Installs mock method/event channel handlers for a native player for the
+/// duration of [testBody], then removes them.
+Future<void> withMockPlayerChannels({
+  required String methodChannelName,
+  required String eventChannelName,
+  Future<Object?> Function(MethodCall call)? methodHandler,
+  Future<Object?> Function(MethodCall call)? eventHandler,
+  required Future<void> Function() testBody,
+}) async {
+  final messenger = TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger;
+  final methodChannel = MethodChannel(methodChannelName);
+  final eventChannel = MethodChannel(eventChannelName);
+
+  messenger.setMockMethodCallHandler(
+    methodChannel,
+    methodHandler ??
+        (call) async {
+          switch (call.method) {
+            case 'initialize':
+              return true;
+            default:
+              return null;
+          }
+        },
+  );
+  messenger.setMockMethodCallHandler(eventChannel, eventHandler ?? (call) async => null);
+
+  try {
+    await testBody();
+  } finally {
+    messenger.setMockMethodCallHandler(methodChannel, null);
+    messenger.setMockMethodCallHandler(eventChannel, null);
+  }
+}