feat(Cascader): add options-bottom slot (#9804)

packages/vant/src/cascader/Cascader.tsx

@@ -259,10 +259,9 @@ export default defineComponent({
             unselected: !selected,
           })}
         >
-          {slots['options-top']
+          {slots['options-top']?.({ tabIndex })}
-            ? slots['options-top']({ tabIndex: activeTab.value })
-            : null}
           {renderOptions(options, selected, tabIndex)}
+          {slots['options-bottom']?.({ tabIndex })}
         </Tab>
       );
     };

packages/vant/src/cascader/README.md

@@ -282,7 +282,8 @@ export default {
 | --- | --- | --- |
 | title | Custom title | - |
 | option `v3.1.4` | Custom option text | _{ option: Option, selected: boolean }_ |
-| options-top `v3.2.7` | Custom the content above options | _{ tabIndex: number }_ |
+| options-top `v3.2.7` | Custom the content above the options | _{ tabIndex: number }_ |
+| options-bottom `v3.2.8` | Custom the content below the options | _{ tabIndex: number }_ |
 
 ### Types
 

packages/vant/src/cascader/README.zh-CN.md

@@ -295,6 +295,7 @@ export default {
 | title | 自定义顶部标题 | - |
 | option `v3.1.4` | 自定义选项文字 | _{ option: Option, selected: boolean }_ |
 | options-top `v3.2.7` | 自定义选项上方的内容 | _{ tabIndex: number }_ |
+| options-bottom `v3.2.8` | 自定义选项下方的内容 | _{ tabIndex: number }_ |
 
 ### 类型定义
 

packages/vant/src/cascader/test/__snapshots__/index.spec.ts.snap

@@ -1,8 +1,19 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[` should allow more custom content 1`] = `
+exports[`should change close icon when using close-icon prop 1`] = `
+<i class="van-badge__wrapper van-icon van-icon-success van-cascader__close-icon van-haptics-feedback">
+</i>
+`;
+
+exports[`should render option slot correctly 1`] = `
+<li class="van-cascader__option">
+  Custom Option foo
+</li>
+`;
+
+exports[`should render options-top、options-bottom slots correctly 1`] = `
 <div class="van-tab__pane">
-  tab index: 1
+  Top, tab index: 0
   <ul class="van-cascader__options">
     <li class="van-cascader__option van-cascader__option--selected">
       <span>
@@ -17,20 +28,10 @@ exports[` should allow more custom content 1`] = `
       </span>
     </li>
   </ul>
+  Bottom, tab index: 0
 </div>
 `;
 
-exports[`should change close icon when using close-icon prop 1`] = `
-<i class="van-badge__wrapper van-icon van-icon-success van-cascader__close-icon van-haptics-feedback">
-</i>
-`;
-
-exports[`should render option slot correctly 1`] = `
-<li class="van-cascader__option">
-  Custom Option foo
-</li>
-`;
-
 exports[`should render title slot correctly 1`] = `
 <h2 class="van-cascader__title">
   Custom Title

packages/vant/src/cascader/test/index.spec.ts

@@ -242,10 +242,11 @@ test('should allow to custom the color of option', async () => {
   expect(option.style.color).toEqual('red');
 });
 
-test(' should allow more custom content', async () => {
+test('should render options-top、options-bottom slots correctly', async () => {
   const wrapper = mount(Cascader, {
     slots: {
-      'options-top': ({ tabIndex }) => `tab index: ${tabIndex}`,
+      'options-top': ({ tabIndex }) => `Top, tab index: ${tabIndex}`,
+      'options-bottom': ({ tabIndex }) => `Bottom, tab index: ${tabIndex}`,
     },
     props: {
       options,