fix(player): 恢复随机飘心粒子模型

test/player/player_double_tap_hearts_test.dart

@@ -1,26 +1,34 @@
 // Author: fruit.com.cn
 
+import 'dart:math';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:fruitshorts/pages/player/widgets/player_double_tap_hearts.dart';
 
 void main() {
-  testWidgets('should_show_three_medium_hearts_when_double_tap_burst_starts', (
+  testWidgets('should_show_randomized_heart_particles_when_burst_starts', (
     tester,
   ) async {
     await tester.pumpWidget(
-      const MaterialApp(
+      MaterialApp(
         home: Scaffold(
-          body: PlayerDoubleTapHeartBurst(burstId: 1, onCompleted: _noop),
+          body: PlayerDoubleTapHeartBurst(
+            burstId: 1,
+            onCompleted: _noop,
+            random: Random(42),
+          ),
         ),
       ),
     );
-    await tester.pump(const Duration(milliseconds: 300));
+    await tester.pump(const Duration(milliseconds: 400));
 
-    expect(find.byIcon(Icons.favorite_rounded), findsNWidgets(3));
-    expect(_size(tester, 0), 44);
-    expect(_size(tester, 1), 34);
-    expect(_size(tester, 2), 38);
+    final hearts = find.byIcon(Icons.favorite_rounded);
+    final count = hearts.evaluate().length;
+    expect(count, inInclusiveRange(4, 5));
+    for (var index = 0; index < count; index++) {
+      expect(_size(tester, index), inInclusiveRange(22, 34));
+    }
     expect(
       tester
           .widgetList<Stack>(
@@ -34,14 +42,16 @@ void main() {
     );
   });
 
-  test('heart burst stays long and sparse', () {
-    expect(PlayerDoubleTapHeartBurst.singleHeartDurationMs, 1900);
+  test('heart particles fade from the start and scale in two phases', () {
+    expect(PlayerDoubleTapHeartBurst.opacityForProgress(0.5), lessThan(0.7));
+    expect(PlayerDoubleTapHeartBurst.scaleForProgress(0), 0.55);
     expect(
-      PlayerDoubleTapHeartBurst.animationDuration,
-      greaterThanOrEqualTo(const Duration(milliseconds: 1800)),
+      PlayerDoubleTapHeartBurst.scaleForProgress(0.3),
+      closeTo(1.15, 1e-9),
     );
-    expect(PlayerDoubleTapHeartBurst.particleCount, lessThanOrEqualTo(4));
-    expect(PlayerDoubleTapHeartBurst.particleCount, 3);
+    expect(PlayerDoubleTapHeartBurst.scaleForProgress(1), closeTo(0.2, 1e-9));
+    expect(PlayerDoubleTapHeartBurst.minParticleCount, 4);
+    expect(PlayerDoubleTapHeartBurst.maxParticleCount, 5);
   });
 }