fix(components): check subTree null, related to #1760

Author: Akryum

packages/app-backend-vue3/src/components/tree.ts

@@ -83,19 +83,21 @@ export class ComponentWalker {
    */
   private getInternalInstanceChildren (subTree, suspense = null) {
     const list = []
-    if (subTree.component) {
-      !suspense ? list.push(subTree.component) : list.push({ ...subTree.component, suspense })
-    } else if (subTree.suspense) {
-      const suspenseKey = !subTree.suspense.isInFallback ? 'suspense default' : 'suspense fallback'
-      list.push(...this.getInternalInstanceChildren(subTree.suspense.activeBranch, { ...subTree.suspense, suspenseKey }))
-    } else if (Array.isArray(subTree.children)) {
-      subTree.children.forEach(childSubTree => {
-        if (childSubTree.component) {
-          !suspense ? list.push(childSubTree.component) : list.push({ ...childSubTree.component, suspense })
-        } else {
-          list.push(...this.getInternalInstanceChildren(childSubTree, suspense))
-        }
-      })
+    if (subTree) {
+      if (subTree.component) {
+        !suspense ? list.push(subTree.component) : list.push({ ...subTree.component, suspense })
+      } else if (subTree.suspense) {
+        const suspenseKey = !subTree.suspense.isInFallback ? 'suspense default' : 'suspense fallback'
+        list.push(...this.getInternalInstanceChildren(subTree.suspense.activeBranch, { ...subTree.suspense, suspenseKey }))
+      } else if (Array.isArray(subTree.children)) {
+        subTree.children.forEach(childSubTree => {
+          if (childSubTree.component) {
+            !suspense ? list.push(childSubTree.component) : list.push({ ...childSubTree.component, suspense })
+          } else {
+            list.push(...this.getInternalInstanceChildren(childSubTree, suspense))
+          }
+        })
+      }
     }
     return list.filter(child => !isBeingDestroyed(child) && !child.type.devtools?.hide)
   }