Update $refs type declaration (vuejs#3765)

* `$refs` is a dictionary of Vue instance or Element

* update $refs for array usage

Author: HerringtonDarkholme

types/test/vue-test.ts

@@ -13,6 +13,20 @@ class Test extends Vue {
     this.$isServer;
   }
 
+  // test property reification
+  $refs: {
+    vue: Vue,
+    element: HTMLInputElement,
+    vues: Vue[],
+    elements: HTMLInputElement[]
+  }
+  testReification() {
+    this.$refs.vue.$data;
+    this.$refs.element.value;
+    this.$refs.vues[0].$data;
+    this.$refs.elements[0].value;
+  }
+
   testMethods() {
     this.$mount("#app", false);
     this.$forceUpdate();

types/vue.d.ts

@@ -19,7 +19,7 @@ export declare class Vue {
   readonly $parent: Vue;
   readonly $root: Vue;
   readonly $children: Vue[];
-  readonly $refs: { [key: string]: Vue };
+  readonly $refs: { [key: string]: Vue | Element | Vue[] | Element[]};
   readonly $slots: { [key: string]: VNode[] };
   readonly $isServer: boolean;