fix(测试数据生成器): 修复规则覆盖保存误创建重复规则

覆盖同名规则时 handleSave(true) 未传入已有规则 id，save() 走新建分支
导致旧规则保留且产生同名重复项，getByName 仍返回旧数据。

src/pages/TestDataGenerator/components/FieldList.tsx

@@ -234,29 +234,38 @@ export default function FieldList({
       if (!ruleName.trim()) return;
 
       const trimmedName = ruleName.trim();
+      const existingRule = ruleStorage.getByName(trimmedName);
 
       // 检查名称是否重复
-      if (!overwrite) {
+      if (!overwrite && existingRule) {
-        const existingRule = ruleStorage.getByName(trimmedName);
-        if (existingRule) {
         setShowConfirmOverwrite(true);
         return;
       }
-      }
 
-      const newRule = ruleStorage.save({
+      const savedRule = ruleStorage.save(
+        overwrite && existingRule
+          ? {
+              id: existingRule.id,
               name: trimmedName,
               description: ruleDescription.trim(),
               fields: fields,
-      });
+            }
+          : {
+              name: trimmedName,
+              description: ruleDescription.trim(),
+              fields: fields,
+            },
+      );
 
-      if (newRule) {
+      if (savedRule) {
         setShowSaveDialog(false);
         setShowConfirmOverwrite(false);
         setRuleName('');
         setRuleDescription('');
-        toast.success('规则已保存');
+        toast.success(overwrite ? '规则已覆盖' : '规则已保存');
         onRuleSaved?.();
+      } else {
+        toast.error('规则保存失败');
       }
     },
     [ruleName, ruleDescription, fields, onRuleSaved],

src/pages/TestDataGenerator/components/__tests__/FieldList.test.tsx

@@ -0,0 +1,92 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import type { FieldConfig } from '@/types/testDataGenerator';
+
+vi.mock('@/utils/ruleStorage', () => ({
+  getByName: vi.fn(),
+  save: vi.fn(),
+  update: vi.fn(),
+}));
+
+vi.mock('sonner', () => ({
+  toast: {
+    success: vi.fn(),
+    error: vi.fn(),
+  },
+}));
+
+import FieldList from '../FieldList';
+import * as ruleStorage from '@/utils/ruleStorage';
+import { toast } from 'sonner';
+
+const mockedRuleStorage = vi.mocked(ruleStorage);
+const mockedToast = vi.mocked(toast);
+
+const mockFields: FieldConfig[] = [
+  {
+    id: 'field-1',
+    name: 'username',
+    generatorId: 'string',
+    params: {},
+    required: true,
+    nullRate: 0,
+    unique: false,
+  },
+];
+
+const defaultProps = {
+  fields: mockFields,
+  onUpdate: vi.fn(),
+  onRemove: vi.fn(),
+  onAdd: vi.fn(),
+  onEdit: vi.fn(),
+  onReorder: vi.fn(),
+};
+
+describe('FieldList 规则保存', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockedRuleStorage.getByName.mockReturnValue(undefined);
+    mockedRuleStorage.save.mockReturnValue({
+      id: 'rule-1',
+      name: 'My Rule',
+      fields: mockFields,
+      createdAt: Date.now(),
+      updatedAt: Date.now(),
+      useCount: 0,
+    });
+  });
+
+  it('覆盖同名规则时应更新已有规则而非新建', async () => {
+    const user = userEvent.setup();
+    const existingRule = {
+      id: 'existing-rule-id',
+      name: 'My Rule',
+      fields: mockFields,
+      createdAt: Date.now(),
+      updatedAt: Date.now(),
+      useCount: 0,
+    };
+
+    mockedRuleStorage.getByName.mockReturnValue(existingRule);
+
+    render(<FieldList {...defaultProps} />);
+
+    await user.click(screen.getByRole('button', { name: /保存规则/ }));
+    await user.type(screen.getByPlaceholderText('规则名称'), 'My Rule');
+    await user.click(screen.getByRole('button', { name: '确认' }));
+
+    expect(screen.getByText('已存在同名规则，是否覆盖保存？')).toBeInTheDocument();
+
+    await user.click(screen.getByRole('button', { name: '覆盖' }));
+
+    expect(mockedRuleStorage.save).toHaveBeenCalledWith({
+      id: 'existing-rule-id',
+      name: 'My Rule',
+      description: '',
+      fields: mockFields,
+    });
+    expect(mockedToast.success).toHaveBeenCalledWith('规则已覆盖');
+  });
+});

src/utils/__tests__/ruleStorage.test.ts

@@ -48,6 +48,27 @@ describe('ruleStorage', () => {
     expect(updated).toBeNull();
   });
 
+  it('save 带 id 时应更新已有规则而非新建', () => {
+    const first = ruleStorage.save({
+      name: 'Test Rule',
+      fields: [mockField],
+    });
+    expect(first).not.toBeNull();
+
+    const updatedField = { ...mockField, name: 'email' };
+    const updated = ruleStorage.save({
+      id: first!.id,
+      name: 'Test Rule',
+      description: 'Updated',
+      fields: [updatedField],
+    });
+
+    expect(updated).not.toBeNull();
+    expect(ruleStorage.getCount()).toBe(1);
+    expect(ruleStorage.getById(first!.id)?.fields[0].name).toBe('email');
+    expect(ruleStorage.getById(first!.id)?.description).toBe('Updated');
+  });
+
   it('deleteRule 在 localStorage 写入失败时应返回 false', () => {
     const saved = ruleStorage.save({
       name: 'Test Rule',