[verified] Publish ReelBox source under GPLv3

test/player_brightness_handoff_test.dart

@@ -0,0 +1,51 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:reelbox/media/media_helpers.dart';
+import 'package:reelbox/media/media_platform.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+  test('player handoff retains pre-player brightness rather than an earlier override', () async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.android;
+    addTearDown(() {
+      debugDefaultTargetPlatformOverride = null;
+      TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+          .setMockMethodCallHandler(MediaPlatform.channel, null);
+    });
+    var windowBrightness = -1.0;
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(MediaPlatform.channel, (call) async {
+          switch (call.method) {
+            case 'getBrightness':
+              return windowBrightness;
+            case 'getEffectiveBrightness':
+              return .55;
+            case 'getVolume':
+              return .5;
+            case 'setBrightness':
+              windowBrightness = (call.arguments as Map)['value'] as double;
+              return null;
+          }
+          return null;
+        });
+    final old = PlaybackLifecycle(), current = PlaybackLifecycle();
+    final oldControls = PlayerSystemControls(),
+        currentControls = PlayerSystemControls();
+    await old.setup([oldControls.capture]);
+    await MediaPlatform.invoke<void>('setBrightness', {'value': .8});
+    await current.setup([currentControls.capture]);
+    expect(currentControls.brightness, .8);
+    await old.dispose(oldControls.restore);
+    expect(
+      windowBrightness,
+      .8,
+      reason: 'Old teardown must not disturb the current owner',
+    );
+    await current.dispose(currentControls.restore);
+    expect(
+      windowBrightness,
+      -1.0,
+      reason: 'Last owner must restore the original activity baseline',
+    );
+  });
+}