fixed #2128

examples/routers/tree.vue

@@ -39,7 +39,8 @@
                                         render: (h) => {
                                             return h('Button', {
                                                 props: {
-                                                    type: 'primary'
+                                                    type: 'primary',
+                                                    size: 'small'
                                                 },
                                                 on: {
                                                     click: () => {

src/components/tree/tree.vue

@@ -49,10 +49,13 @@
             };
         },
         watch: {
-            data(){
-                this.stateTree = this.data;
-                this.flatState = this.compileFlatState();
-                this.rebuildTree();
+            data: {
+                deep: true,
+                handler () {
+                    this.stateTree = this.data;
+                    this.flatState = this.compileFlatState();
+                    this.rebuildTree();
+                }
             }
         },
         computed: {