feat(editor): 斜杠命令空状态显示「无匹配命令」

搜索无结果时浮层显示居中提示(非空白卡片)。同步修两个空列表 bug:
- ArrowUp/Down 对 % 0 产生 NaN(除零)
- Enter 被吞(preventDefault 后无项可选,用户回车无反应)

空列表时方向键/回车放行(return false),仅 Escape 拦截关闭。
导出 createPopup 补 6 个 happy-dom 用例。

libs/tiptap-editor/src/__tests__/slash-command.test.ts

@@ -1,5 +1,6 @@
-import { describe, expect, it } from 'vitest';
+import type { SuggestionProps } from '@tiptap/suggestion';
-import { isValidUrl, matchCommand } from '../slash-command';
+import { afterEach, describe, expect, it } from 'vitest';
+import { createPopup, isValidUrl, matchCommand } from '../slash-command';
 
 /**
  * isValidUrl 纯函数测试。
@@ -133,3 +134,82 @@ describe('matchCommand', () => {
     });
   });
 });
+
+/**
+ * createPopup 空状态测试（happy-dom）。
+ *
+ * 搜索无结果时浮层应显示「无匹配命令」提示，而非空白卡片。
+ */
+describe('createPopup 空状态', () => {
+  afterEach(() => {
+    document.body.innerHTML = '';
+  });
+
+  /** 构造最小 SuggestionProps mock。 */
+  function mockProps(
+    items: Parameters<typeof matchCommand>[0][],
+  ): SuggestionProps<Parameters<typeof matchCommand>[0]> {
+    return {
+      items,
+      editor: {} as any,
+      range: {} as any,
+      query: '',
+      text: '',
+      command: () => {},
+      clientRect: () => null,
+    } as unknown as SuggestionProps<Parameters<typeof matchCommand>[0]>;
+  }
+
+  it('items 为空时显示「无匹配命令」提示', () => {
+    const popup = createPopup(mockProps([]));
+    document.body.appendChild(popup.component);
+    const empty = document.querySelector('.slash-command-empty');
+    expect(empty).not.toBeNull();
+    expect(empty?.textContent).toBe('无匹配命令');
+    // 且不渲染任何列表项
+    expect(document.querySelectorAll('.slash-command-item')).toHaveLength(0);
+  });
+
+  it('items 非空时不显示空状态提示', () => {
+    const item = { title: '代码块', description: '插入代码块', icon: '<>', command: () => {} };
+    const popup = createPopup(mockProps([item]));
+    document.body.appendChild(popup.component);
+    expect(document.querySelector('.slash-command-empty')).toBeNull();
+    expect(document.querySelectorAll('.slash-command-item')).toHaveLength(1);
+  });
+
+  it('空列表时 Enter 不被拦截（return false，让回车正常输入）', () => {
+    const popup = createPopup(mockProps([]));
+    const handled = popup.onKeyDown({
+      event: new KeyboardEvent('keydown', { key: 'Enter' }),
+    } as any);
+    expect(handled).toBe(false);
+  });
+
+  it('空列表时 ArrowUp/Down 不被拦截（避免 % 0 产生 NaN）', () => {
+    const popup = createPopup(mockProps([]));
+    expect(
+      popup.onKeyDown({ event: new KeyboardEvent('keydown', { key: 'ArrowUp' }) } as any),
+    ).toBe(false);
+    expect(
+      popup.onKeyDown({ event: new KeyboardEvent('keydown', { key: 'ArrowDown' }) } as any),
+    ).toBe(false);
+  });
+
+  it('空列表时 Escape 仍关闭浮层（return true）', () => {
+    const popup = createPopup(mockProps([]));
+    const handled = popup.onKeyDown({
+      event: new KeyboardEvent('keydown', { key: 'Escape' }),
+    } as any);
+    expect(handled).toBe(true);
+  });
+
+  it('updateItems 传空数组时切换到空状态', () => {
+    const item = { title: '代码块', description: '插入代码块', icon: '<>', command: () => {} };
+    const popup = createPopup(mockProps([item]));
+    document.body.appendChild(popup.component);
+    expect(document.querySelector('.slash-command-empty')).toBeNull();
+    popup.updateItems([]);
+    expect(document.querySelector('.slash-command-empty')).not.toBeNull();
+  });
+});

libs/tiptap-editor/src/slash-command.ts

@@ -298,7 +298,7 @@ export function isValidUrl(url: string): boolean {
   return /^https?:\/\//i.test(url) || /^data:image\//i.test(url);
 }
 
-function createPopup(props: SuggestionProps<CommandItem>): SlashPopup {
+export function createPopup(props: SuggestionProps<CommandItem>): SlashPopup {
   const component = document.createElement('div');
   component.classList.add('slash-command');
 
@@ -314,6 +314,15 @@ function createPopup(props: SuggestionProps<CommandItem>): SlashPopup {
     list.innerHTML = '';
     selectedIndex = 0;
 
+    // 空状态：显示提示，不渲染列表项。
+    if (items.length === 0) {
+      const empty = document.createElement('div');
+      empty.classList.add('slash-command-empty');
+      empty.textContent = '无匹配命令';
+      list.appendChild(empty);
+      return;
+    }
+
     items.forEach((item, index) => {
       const el = document.createElement('div');
       el.classList.add('slash-command-item');
@@ -376,6 +385,15 @@ function createPopup(props: SuggestionProps<CommandItem>): SlashPopup {
     },
     updatePosition,
     onKeyDown({ event }: SuggestionKeyDownProps): boolean {
+      // 空列表时不拦截键盘：避免 % 0 产生 NaN，也避免吞掉 Enter（让用户正常输入）。
+      // Escape 仍拦截（关闭浮层）。
+      if (event.key === 'Escape') {
+        event.preventDefault();
+        return true;
+      }
+      if (currentItems.length === 0) {
+        return false;
+      }
       if (event.key === 'ArrowUp') {
         event.preventDefault();
         selectedIndex = (selectedIndex - 1 + currentItems.length) % currentItems.length;
@@ -393,10 +411,6 @@ function createPopup(props: SuggestionProps<CommandItem>): SlashPopup {
         selectItem();
         return true;
       }
-      if (event.key === 'Escape') {
-        event.preventDefault();
-        return true;
-      }
       return false;
     },
     destroy() {

libs/tiptap-editor/src/style.css

@@ -347,6 +347,19 @@
   line-height: 1.3;
 }
 
+.slash-command-empty {
+  padding: 12px 16px;
+  font-size: 13px;
+  /* Latte overlay0 */
+  color: #9ca0b0;
+  text-align: center;
+}
+
+.dark .slash-command-empty {
+  /* Mocha overlay0 */
+  color: #6c7086;
+}
+
 /* ========== Task List (Enhanced) ========== */
 .tiptap-editor ul[data-type='taskList'] {
   list-style: none;