feat(home): 顶部导航随翻页联动并把推荐更名为精选

test/core/animated_nav_label_test.dart

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+// Author: fruit.com.cn
+// 职责：验证顶部标签双向过渡、固定布局和减少动画行为。
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:fruitshorts/core/theme/app_colors.dart';
+import 'package:fruitshorts/core/widgets/animated_nav_label.dart';
+
+const _halfDuration = Duration(milliseconds: 90);
+const _duration = Duration(milliseconds: 180);
+const _style = TextStyle(fontSize: 20, color: AppColors.navSelected);
+const _firstKey = Key('first');
+const _secondKey = Key('second');
+
+Widget _labels(bool firstSelected, {bool reduceMotion = false}) {
+  return MaterialApp(
+    home: MediaQuery(
+      data: MediaQueryData(
+        devicePixelRatio: 3,
+        disableAnimations: reduceMotion,
+      ),
+      child: Center(
+        child: Row(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            AnimatedNavLabel(
+              key: _firstKey,
+              label: '精选 Featured',
+              selected: firstSelected,
+              style: _style,
+            ),
+            AnimatedNavLabel(
+              key: _secondKey,
+              label: '推荐 Rekomendasi',
+              selected: !firstSelected,
+              style: _style,
+            ),
+          ],
+        ),
+      ),
+    ),
+  );
+}
+
+double _scale(WidgetTester tester, Key key) {
+  final transform = tester.widget<Transform>(
+    find.descendant(of: find.byKey(key), matching: find.byType(Transform)),
+  );
+  return transform.transform.entry(0, 0);
+}
+
+Color _color(WidgetTester tester, Key key) {
+  return tester
+      .widget<Text>(
+        find.descendant(of: find.byKey(key), matching: find.byType(Text)),
+      )
+      .style!
+      .color!;
+}
+
+void main() {
+  testWidgets('should_cross_animate_without_relayout_when_selection_changes', (
+    tester,
+  ) async {
+    await tester.pumpWidget(_labels(true));
+    final firstRect = tester.getRect(find.byKey(_firstKey));
+    final secondRect = tester.getRect(find.byKey(_secondKey));
+    await tester.pumpWidget(_labels(false));
+    await tester.pump(_halfDuration);
+
+    expect(_scale(tester, _firstKey), inExclusiveRange(0.9, 1.0));
+    expect(_scale(tester, _secondKey), inExclusiveRange(0.9, 1.0));
+    expect(_color(tester, _firstKey), isNot(AppColors.navSelected));
+    expect(_color(tester, _firstKey), isNot(AppColors.textTabInactive));
+    expect(_color(tester, _secondKey), isNot(AppColors.navSelected));
+    expect(_color(tester, _secondKey), isNot(AppColors.textTabInactive));
+    expect(tester.getRect(find.byKey(_firstKey)), firstRect);
+    expect(tester.getRect(find.byKey(_secondKey)), secondRect);
+    await tester.pump(_duration);
+    expect(_scale(tester, _firstKey), closeTo(0.9, 0.0001));
+    expect(_scale(tester, _secondKey), 1);
+    expect(_color(tester, _secondKey), AppColors.navSelected);
+    expect(tester.getRect(find.byKey(_secondKey)), secondRect);
+  });
+
+  testWidgets('should_continue_from_current_value_when_selection_reverses', (
+    tester,
+  ) async {
+    await tester.pumpWidget(_labels(true));
+    await tester.pumpWidget(_labels(false));
+    await tester.pump(_halfDuration);
+    final scale = _scale(tester, _firstKey);
+    final color = _color(tester, _firstKey);
+    await tester.pumpWidget(_labels(true));
+    expect(_scale(tester, _firstKey), scale);
+    expect(_color(tester, _firstKey), color);
+    await tester.pump(_duration);
+    expect(_scale(tester, _firstKey), 1);
+  });
+
+  testWidgets('should_skip_transition_when_reduce_motion_is_enabled', (
+    tester,
+  ) async {
+    await tester.pumpWidget(_labels(true, reduceMotion: true));
+    await tester.pumpWidget(_labels(false, reduceMotion: true));
+    await tester.pump();
+    expect(_scale(tester, _firstKey), closeTo(0.9, 0.0001));
+    expect(_color(tester, _secondKey), AppColors.navSelected);
+    expect(tester.binding.hasScheduledFrame, isFalse);
+  });
+}