simplify array change detection

Author: yyx990803

Diff for: src/runtime/observer/index.js

@@ -1,16 +1,13 @@
+import './patch-array'
 import Dep from './dep'
-import { arrayMethods } from './array'
 import {
   def,
   isArray,
   isObject,
   isPlainObject,
-  hasProto,
   hasOwn
 } from '../util/index'
 
-const arrayKeys = Object.getOwnPropertyNames(arrayMethods)
-
 /**
  * By default, when a reactive property is set, the new value is
  * also converted to become reactive. However in certain cases, e.g.
@@ -43,10 +40,6 @@ export function Observer (value) {
   this.dep = new Dep()
   def(value, '__ob__', this)
   if (isArray(value)) {
-    var augment = hasProto
-      ? protoAugment
-      : copyAugment
-    augment(value, arrayMethods, arrayKeys)
     this.observeArray(value)
   } else {
     this.walk(value)
@@ -118,37 +111,6 @@ Observer.prototype.removeVm = function (vm) {
   this.vms.$remove(vm)
 }
 
-// helpers
-
-/**
- * Augment an target Object or Array by intercepting
- * the prototype chain using __proto__
- *
- * @param {Object|Array} target
- * @param {Object} src
- */
-
-function protoAugment (target, src) {
-  /* eslint-disable no-proto */
-  target.__proto__ = src
-  /* eslint-enable no-proto */
-}
-
-/**
- * Augment an target Object or Array by defining
- * hidden properties.
- *
- * @param {Object|Array} target
- * @param {Object} proto
- */
-
-function copyAugment (target, src, keys) {
-  for (var i = 0, l = keys.length; i < l; i++) {
-    var key = keys[i]
-    def(target, key, src[key])
-  }
-}
-
 /**
  * Attempt to create an observer instance for a value,
  * returns the new observer if successfully observed,

Diff for: src/runtime/observer/array.js renamed to src/runtime/observer/patch-array.js

@@ -1,32 +1,18 @@
-import { def } from '../util/index'
+import { def, toArray } from '../util/index'
 
 const arrayProto = Array.prototype
-export const arrayMethods = Object.create(arrayProto)
+const mutationMethods = ['push', 'pop', 'shift', 'unshift', 'splice', 'sort', 'reverse']
 
 /**
- * Intercept mutating methods and emit events
+ * Intercept mutating methods and notify change
  */
 
-;[
-  'push',
-  'pop',
-  'shift',
-  'unshift',
-  'splice',
-  'sort',
-  'reverse'
-]
-.forEach(function (method) {
+mutationMethods.forEach(function (method) {
   // cache original method
   var original = arrayProto[method]
-  def(arrayMethods, method, function mutator () {
-    // avoid leaking arguments:
-    // http://jsperf.com/closure-with-arguments
-    var i = arguments.length
-    var args = new Array(i)
-    while (i--) {
-      args[i] = arguments[i]
-    }
+
+  var interceptor = function arrayMutationInterceptor () {
+    var args = toArray(arguments)
     var result = original.apply(this, args)
     var ob = this.__ob__
     var inserted
@@ -45,7 +31,12 @@ export const arrayMethods = Object.create(arrayProto)
     // notify change
     ob.dep.notify()
     return result
-  })
+  }
+
+  arrayProto[method] = function () {
+    let fn = this && this.__ob__ ? interceptor : original
+    return fn.apply(this, arguments)
+  }
 })
 
 /**

Diff for: src/runtime/util/env.js

@@ -1,8 +1,5 @@
 /* global MutationObserver */
 
-// can we use __proto__?
-export const hasProto = '__proto__' in {}
-
 // Browser environment sniffing
 export const inBrowser =
   typeof window !== 'undefined' &&