fix(theme): deep watch sidebar groups and force render on match change

closes #3613

src/client/theme-default/components/VPSidebar.vue

@@ -3,7 +3,7 @@ import { useScrollLock } from '@vueuse/core'
 import { inBrowser } from 'vitepress'
 import { ref, watch } from 'vue'
 import { useSidebar } from '../composables/sidebar'
-import VPSidebarItem from './VPSidebarItem.vue'
+import VPSidebarGroup from './VPSidebarGroup.vue'
 
 const { sidebarGroups, hasSidebar } = useSidebar()
 
@@ -25,6 +25,16 @@ watch(
   },
   { immediate: true, flush: 'post' }
 )
+
+const key = ref(0)
+
+watch(
+  sidebarGroups,
+  () => {
+    key.value += 1
+  },
+  { deep: true }
+)
 </script>
 
 <template>
@@ -37,17 +47,18 @@ watch(
   >
     <div class="curtain" />
 
-    <nav class="nav" id="VPSidebarNav" aria-labelledby="sidebar-aria-label" tabindex="-1">
+    <nav
+      class="nav"
+      id="VPSidebarNav"
+      aria-labelledby="sidebar-aria-label"
+      tabindex="-1"
+    >
       <span class="visually-hidden" id="sidebar-aria-label">
         Sidebar Navigation
       </span>
 
       <slot name="sidebar-nav-before" />
-
+      <VPSidebarGroup :items="sidebarGroups" :key="key" />
-      <div v-for="item in sidebarGroups" :key="item.text" class="group">
-        <VPSidebarItem :item="item" :depth="0" />
-      </div>
-
       <slot name="sidebar-nav-after" />
     </nav>
   </aside>
@@ -122,16 +133,4 @@ watch(
 .nav {
   outline: 0;
 }
-
-.group + .group {
-  border-top: 1px solid var(--vp-c-divider);
-  padding-top: 10px;
-}
-
-@media (min-width: 960px) {
-  .group {
-    padding-top: 10px;
-    width: calc(var(--vp-sidebar-width) - 64px);
-  }
-}
 </style>

src/client/theme-default/components/VPSidebarGroup.vue

@@ -0,0 +1,56 @@
+<script setup lang="ts">
+import type { DefaultTheme } from 'vitepress/theme'
+import { onBeforeUnmount, onMounted, ref } from 'vue'
+import VPSidebarItem from './VPSidebarItem.vue'
+
+defineProps<{
+  items: DefaultTheme.SidebarItem[]
+}>()
+
+const disableTransition = ref(true)
+
+let timer: ReturnType<typeof setTimeout> | null = null
+
+onMounted(() => {
+  timer = setTimeout(() => {
+    timer = null
+    disableTransition.value = false
+  }, 300)
+})
+
+onBeforeUnmount(() => {
+  if (timer != null) {
+    clearTimeout(timer)
+    timer = null
+  }
+})
+</script>
+
+<template>
+  <div
+    v-for="item in items"
+    :key="item.text"
+    class="group"
+    :class="{ 'no-transition': disableTransition }"
+  >
+    <VPSidebarItem :item="item" :depth="0" />
+  </div>
+</template>
+
+<style scoped>
+.no-transition :deep(.caret-icon) {
+  transition: none;
+}
+
+.group + .group {
+  border-top: 1px solid var(--vp-c-divider);
+  padding-top: 10px;
+}
+
+@media (min-width: 960px) {
+  .group {
+    padding-top: 10px;
+    width: calc(var(--vp-sidebar-width) - 64px);
+  }
+}
+</style>

src/client/theme-default/components/VPSidebarItem.vue

@@ -1,6 +1,6 @@
 <script setup lang="ts">
-import { computed } from 'vue'
 import type { DefaultTheme } from 'vitepress/theme'
+import { computed } from 'vue'
 import { useSidebarControl } from '../composables/sidebar'
 import VPLink from './VPLink.vue'