Do not use es2015 rest paramters

Author: tangbc

dist/index.js

@@ -1,5 +1,5 @@
 /*!
- * vue-virtual-scroll-list v2.0.2
+ * vue-virtual-scroll-list v2.0.3
  * open source under the MIT license
  * https://github.com/tangbc/vue-virtual-scroll-list#readme
  */
@@ -34,55 +34,6 @@
     return Constructor;
   }
 
-  function _defineProperty(obj, key, value) {
-    if (key in obj) {
-      Object.defineProperty(obj, key, {
-        value: value,
-        enumerable: true,
-        configurable: true,
-        writable: true
-      });
-    } else {
-      obj[key] = value;
-    }
-
-    return obj;
-  }
-
-  function ownKeys(object, enumerableOnly) {
-    var keys = Object.keys(object);
-
-    if (Object.getOwnPropertySymbols) {
-      var symbols = Object.getOwnPropertySymbols(object);
-      if (enumerableOnly) symbols = symbols.filter(function (sym) {
-        return Object.getOwnPropertyDescriptor(object, sym).enumerable;
-      });
-      keys.push.apply(keys, symbols);
-    }
-
-    return keys;
-  }
-
-  function _objectSpread2(target) {
-    for (var i = 1; i < arguments.length; i++) {
-      var source = arguments[i] != null ? arguments[i] : {};
-
-      if (i % 2) {
-        ownKeys(Object(source), true).forEach(function (key) {
-          _defineProperty(target, key, source[key]);
-        });
-      } else if (Object.getOwnPropertyDescriptors) {
-        Object.defineProperties(target, Object.getOwnPropertyDescriptors(source));
-      } else {
-        ownKeys(Object(source)).forEach(function (key) {
-          Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key));
-        });
-      }
-    }
-
-    return target;
-  }
-
   /**
    * virtual list core calculating center.
    */
@@ -534,6 +485,10 @@
     }
   };
 
+  /**
+   * item and slot component both use similar wrapper
+   * we need to know their size change at any time.
+   */
   var Wrapper = {
     created: function created() {
       this.hasInitial = false;
@@ -578,12 +533,12 @@
     mixins: [Wrapper],
     props: ItemProps,
     render: function render(h) {
+      var itemProps = this.extraProps || {};
+      itemProps.source = this.source;
       return h(this.tag, {
         role: 'item'
       }, [h(this.component, {
-        props: _objectSpread2({}, this.extraProps, {
-          source: this.source
-        })
+        props: itemProps
       })]);
     }
   }); // wrapping for slot.

src/item.js

@@ -55,13 +55,13 @@ export const Item = Vue.component('virtual-list-item', {
   props: ItemProps,
 
   render (h) {
+    const itemProps = this.extraProps || {}
+    itemProps.source = this.source
+
     return h(this.tag, {
       role: 'item'
     }, [h(this.component, {
-      props: {
-        ...this.extraProps,
-        source: this.source
-      }
+      props: itemProps
     })])
   }
 })