fix(types): improve with strict mode (#1041)

src/runtime/components/overlays/Tooltip.vue

@@ -13,7 +13,7 @@
             <slot name="text">
               {{ text }}
             </slot>
-  
+
             <span v-if="shortcuts?.length" :class="ui.shortcuts">
               <span class="mx-1 text-gray-700 dark:text-gray-200">&middot;</span>
               <UKbd v-for="shortcut of shortcuts" :key="shortcut" size="xs">
@@ -74,11 +74,11 @@ export default defineComponent({
     },
     class: {
       type: [String, Object, Array] as PropType<any>,
-      default: undefined
+      default: () => ''
     },
     ui: {
-      type: Object as PropType<Partial<typeof config & { strategy?: Strategy }>>,
-      default: undefined
+      type: Object as PropType<Partial<typeof config> & { strategy?: Strategy }>,
+      default: () => ({})
     }
   },
   setup (props) {