1. /*
    2.  * not type checking this file because flow doesn't play well with
    3.  * dynamically accessing methods on Array prototype
    4.  */
    6. import { def } from '../util/index'
    8. const arrayProto = Array.prototype
    9. export const arrayMethods = Object.create(arrayProto)
    11. const methodsToPatch = [
    12.   'push',
    13.   'pop',
    14.   'shift',
    15.   'unshift',
    16.   'splice',
    17.   'sort',
    18.   'reverse'
    19. ]
    21. /**
    22.  * Intercept mutating methods and emit events
    23.  */
    24. methodsToPatch.forEach(function (method) {
    25.   // cache original method
    26.   const original = arrayProto[method]
    27.   def(arrayMethods, method, function mutator (...args) {
    28.     const result = original.apply(this, args)
    29.     const ob = this.__ob__
    30.     let inserted
    31.     switch (method) {
    32.       case 'push':
    33.       case 'unshift':
    34.         inserted = args
    35.         break
    36.       case 'splice':
    37.         inserted = args.slice(2)
    38.         break
    39.     }
    40.     if (inserted) ob.observeArray(inserted)
    41.     // notify change
    42.     ob.dep.notify()
    43.     return result
    44.   })
    45. })