diff --git a/client/test/finance_partner_filter_test.dart b/client/test/finance_partner_filter_test.dart
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+// test/finance_partner_filter_test.dart — 财务「往来单位」筛选回归（Task 6 补审查）。
+//
+// 覆盖两类回归防护：
+// 1. 交互行为：桌面 ComboSearchField 路径 + 移动 chip→sheet 路径，均驱动到
+//    financeListProvider 真实的 setPartner → repository.listRecords(partnerId:…)
+//    请求参数链路；清除（×/「全部往来单位」）后回 null 并触发新一轮请求。
+// 2. 视口防裁剪：移动财务屏（390 宽）首屏（未手动滚动）渲染后，直接用
+//    RenderBox 探针断言「往来单位」chip 的全局 bounds 落在视口宽度内——
+//    对齐 task-6-report.md「自审发现」记录的方法：analyze/test 全绿、
+//    widget 树里组件确实存在，但因父级裁剪导致用户实际看不到，
+//    这类回归只有量像素位置才能抓到。
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lucide_icons_flutter/lucide_icons.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import 'package:jiu_client/core/api/api_client.dart';
+import 'package:jiu_client/core/auth/auth_state.dart';
+import 'package:jiu_client/core/models/page_result.dart';
+import 'package:jiu_client/core/theme/themes.dart';
+import 'package:jiu_client/models/finance.dart';
+import 'package:jiu_client/models/partner.dart';
+import 'package:jiu_client/models/stock_summary.dart';
+import 'package:jiu_client/providers/finance_provider.dart';
+import 'package:jiu_client/providers/partner_provider.dart';
+import 'package:jiu_client/providers/stock_in_provider.dart';
+import 'package:jiu_client/providers/stock_out_provider.dart';
+import 'package:jiu_client/repositories/finance_repository.dart';
+import 'package:jiu_client/screens/finance/finance_screen.dart';
+import 'package:jiu_client/widgets/combo_search_field.dart';
+import 'package:jiu_client/widgets/ds/ds_atoms.dart' show DsChip;
+
+/// 不打真实网络：仅用于满足 FinanceRepository 构造签名，方法全部被覆写。
+class _DummyApiClient extends ApiClient {
+  _DummyApiClient() : super(token: 'test-token');
+}
+
+/// 记录每次 listRecords 调用实际收到的 partnerId 实参——用来断言
+/// financeListProvider.setPartner 真的把筛选值透传到了请求参数（partner_id）。
+class _RecordingFinanceRepository extends FinanceRepository {
+  _RecordingFinanceRepository() : super(_DummyApiClient());
+
+  final List<int?> partnerIdCalls = [];
+
+  @override
+  Future<PageResult<FinanceRecord>> listRecords({
+    String? type,
+    String? month,
+    String? startDate,
+    String? endDate,
+    int? partnerId,
+    int page = 1,
+    int pageSize = 50,
+  }) async {
+    partnerIdCalls.add(partnerId);
+    return const PageResult(data: [], total: 0, page: 1, pageSize: 50);
+  }
+
+  @override
+  Future<List<PartnerFinanceSummary>> partnerSummary() async => const [];
+
+  @override
+  Future<List<TrendPoint>> trend({int months = 6}) async => const [];
+}
+
+/// allPartnersProvider fixture：桌面 ComboSearchField / 移动 sheet 共用同一
+/// 数据源，固定 2 个往来单位供选择。
+class _FakeAllPartners extends PartnerListNotifier {
+  @override
+  Future<PageResult<Partner>> build() async => const PageResult(
+        data: [
+          Partner(id: 1, name: '华东酒类批发', type: 'customer'),
+          Partner(id: 2, name: '金樽商贸', type: 'customer'),
+        ],
+        total: 2,
+        page: 1,
+        pageSize: 1000,
+      );
+}
+
+List<Override> _overrides(_RecordingFinanceRepository repo) => [
+      financeRepositoryProvider.overrideWith((ref) => repo),
+      allPartnersProvider.overrideWith(() => _FakeAllPartners()),
+      stockOutSummaryProvider.overrideWith(
+          (ref) async => const StockSummary(monthAmount: 0, lastMonthAmount: 0)),
+      stockInSummaryProvider.overrideWith(
+          (ref) async => const StockSummary(monthAmount: 0, lastMonthAmount: 0)),
+      isReadonlyProvider.overrideWithValue(false),
+    ];
+
+Future<void> _pumpFinance(
+  WidgetTester tester,
+  List<Override> overrides, {
+  required Size size,
+}) async {
+  tester.view.physicalSize = size;
+  tester.view.devicePixelRatio = 1.0;
+  addTearDown(tester.view.resetPhysicalSize);
+  addTearDown(tester.view.resetDevicePixelRatio);
+
+  await tester.pumpWidget(ProviderScope(
+    overrides: overrides,
+    child: MaterialApp(
+      debugShowCheckedModeBanner: false,
+      theme: buildTheme('a'),
+      home: const Scaffold(body: FinanceScreen()),
+    ),
+  ));
+  await tester.pumpAndSettle();
+}
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+  SharedPreferences.setMockInitialValues({});
+
+  group('桌面 ComboSearchField 往来单位筛选', () {
+    testWidgets('选中往来单位后请求带 partner_id，清除(×)后回 null', (tester) async {
+      final repo = _RecordingFinanceRepository();
+      await _pumpFinance(tester, _overrides(repo), size: const Size(1280, 900));
+
+      // 初始一次 build 请求：未选往来单位，partnerId 应为 null。
+      expect(repo.partnerIdCalls, isNotEmpty);
+      expect(repo.partnerIdCalls.last, isNull);
+
+      // 工具栏 ComboSearchField 位于流水表底部，先滚到视口内（留足空间给
+      // 下方展开的弹层，否则弹层会渲染到 root 视口之外，tap 无法命中）。
+      final comboFinder = find.widgetWithText(ComboSearchField, '往来单位');
+      await tester.ensureVisible(comboFinder);
+      await tester.pumpAndSettle();
+
+      // 打开工具栏 ComboSearchField 弹层，选中「华东酒类批发」(id=1)。
+      await tester.tap(comboFinder);
+      await tester.pumpAndSettle();
+      await tester.tap(find.text('华东酒类批发'));
+      await tester.pumpAndSettle();
+
+      expect(repo.partnerIdCalls.last, 1);
+
+      // 点触发器上的 × 清除选择 → 应回 null 并触发新一轮请求。
+      final clearIcon = find.descendant(
+        of: find.byType(ComboSearchField),
+        matching: find.byIcon(LucideIcons.x),
+      );
+      expect(clearIcon, findsOneWidget);
+      await tester.tap(clearIcon);
+      await tester.pumpAndSettle();
+
+      expect(repo.partnerIdCalls.last, isNull);
+    });
+  });
+
+  group('移动端 chip → sheet 往来单位筛选', () {
+    testWidgets('选中往来单位后请求带 partner_id，选「全部往来单位」清除后回 null',
+        (tester) async {
+      final repo = _RecordingFinanceRepository();
+      await _pumpFinance(tester, _overrides(repo), size: const Size(390, 1600));
+
+      expect(repo.partnerIdCalls, isNotEmpty);
+      expect(repo.partnerIdCalls.last, isNull);
+
+      final chipFinder = find.widgetWithText(DsChip, '往来单位');
+      expect(chipFinder, findsOneWidget);
+
+      // 时间行整行横向可滚（Task 6 报告记录的布局取舍）：先滚到可见再点击。
+      await tester.ensureVisible(chipFinder);
+      await tester.pumpAndSettle();
+      await tester.tap(chipFinder);
+      await tester.pumpAndSettle();
+
+      // sheet 打开：点选「华东酒类批发」。
+      await tester.tap(find.text('华东酒类批发'));
+      await tester.pumpAndSettle();
+
+      expect(repo.partnerIdCalls.last, 1);
+
+      // 再次打开 sheet，选「全部往来单位」清除（-1 → null 约定）。
+      await tester.ensureVisible(chipFinder);
+      await tester.pumpAndSettle();
+      await tester.tap(chipFinder);
+      await tester.pumpAndSettle();
+      await tester.tap(find.text('全部往来单位'));
+      await tester.pumpAndSettle();
+
+      expect(repo.partnerIdCalls.last, isNull);
+    });
+  });
+
+  group('移动财务屏视口防裁剪', () {
+    testWidgets('首屏（未手动滚动）「往来单位」chip 全局 bounds 落在 390 宽视口内',
+        (tester) async {
+      final repo = _RecordingFinanceRepository();
+      const width = 390.0;
+      await _pumpFinance(tester, _overrides(repo), size: const Size(width, 1600));
+
+      final chipFinder = find.widgetWithText(DsChip, '往来单位');
+      expect(chipFinder, findsOneWidget);
+
+      // 不调用 ensureVisible / drag：直接量首屏（默认滚动位置 0）渲染出的位置，
+      // 复刻 task-6-report.md 记录的 RenderBox 探针方法——
+      // 曾经「登记按钮钉死 + chips 区域 Expanded 压缩」的实现下，该 chip 的
+      // 全局 x 区间会完全落在 [0,390) 之外（100% 裁剪不可见），但
+      // analyze/golden diff 均判定通过，只有量像素位置才能抓到。
+      final box = tester.renderObject<RenderBox>(chipFinder);
+      final topLeft = box.localToGlobal(Offset.zero);
+      final rectRight = topLeft.dx + box.size.width;
+
+      expect(box.size.width, greaterThan(0));
+      expect(topLeft.dx, greaterThanOrEqualTo(0),
+          reason: 'chip 左边界不应裁剪出视口左侧');
+      expect(rectRight, lessThanOrEqualTo(width),
+          reason: '「往来单位」chip 右边界超出 390 视口，首屏会被裁剪不可见——'
+              '回归到 task-6-report 记录过的隐蔽 bug');
+    });
+  });
+}