perf(select): support rendering children when group title is not exist (#3445)

Author: RSS1102

src/select/hooks/useSelectOptions.ts

@@ -49,7 +49,7 @@ export default function useSelectOptions(
         dynamicIndex += 1;
         return res;
       };
-      if ((option as SelectOptionGroup).group && (option as SelectOptionGroup).children) {
+      if ((option as SelectOptionGroup).children) {
         return {
           ...option,
           children: (option as SelectOptionGroup).children.map((child) => getFormatOption(child)),
@@ -122,7 +122,7 @@ export default function useSelectOptions(
     const res: TdOptionProps[] = [];
     const getOptionsList = (options: TdOptionProps[]) => {
       options.forEach((option) => {
-        if ((option as SelectOptionGroup).group) {
+        if ((option as SelectOptionGroup).children) {
           getOptionsList((option as SelectOptionGroup).children);
         } else {
           res.push(option);

src/select/option-group-props.ts

@@ -13,6 +13,5 @@ export default {
   /** 分组别名 */
   label: {
     type: String,
-    default: '',
   },
 };

src/select/optionGroup.tsx

@@ -43,7 +43,7 @@ export default defineComponent({
     const children: ScopedSlotReturnValue = renderTNode('default');
     return (
       <li class={this.classes}>
-        <div class={`${this.componentName}-option-group__header`}>{this.label}</div>
+        {(this.label ?? false) && <div class={`${this.componentName}-option-group__header`}>{this.label}</div>}
         {children}
       </li>
     );

src/select/select-panel.tsx

@@ -270,7 +270,7 @@ export default defineComponent({
                 } & OptionsType,
               index,
             ) => {
-              if (item.group) {
+              if (item.children) {
                 return (
                   <TOptionGroup label={item.group} divider={item.divider}>
                     {this.renderOptionsContent(item.children)}