use classes

src/compiler/index.js

@@ -14,7 +14,6 @@ import { generate } from './codegen'
  *                 - getTagNamespace
  *                 - delimiters
  */
-
 export function compile (template, options) {
   const ast = parse(template.trim(), options)
   optimize(ast, options)

src/compiler/optimizer.js

@@ -13,7 +13,6 @@ let isPlatformReservedTag
  *    create fresh nodes for them on each re-render;
  * 2. Completely skip them in the patching process.
  */
-
 export function optimize (root, options) {
   isPlatformReservedTag = options.isReservedTag || (() => false)
   // first pass: mark all non-static nodes.

src/compiler/parser/index.js

@@ -37,7 +37,6 @@ let delimiters
  * @param {Object} options
  * @return {Object}
  */
-
 export function parse (template, options) {
   warn = options.warn || baseWarn
   platformGetTagNamespace = options.getTagNamespace || (() => null)

src/core/config.js

@@ -3,7 +3,6 @@ export default {
   /**
    * Preserve whitespaces between elements.
    */
-
   preserveWhitespace: true,
 
   /**
@@ -11,21 +10,18 @@ export default {
    *
    * @type {Boolean}
    */
-
   silent: false,
 
   /**
    * Check if a tag is reserved so that it cannot be registered as a
    * component. This is platform-dependent and may be overwritten.
    */
-
   isReservedTag: () => false,
 
   /**
    * Check if a tag is an unknown element.
    * Platform-dependent.
    */
-
   isUnknownElement: () => false,
 
   /**
@@ -33,7 +29,6 @@ export default {
    *
    * @type {Array}
    */
-
   _assetTypes: [
     'component',
     'directive',
@@ -46,7 +41,6 @@ export default {
    *
    * @type {Array}
    */
-
   _lifecycleHooks: [
     'init',
     'created',
@@ -62,6 +56,5 @@ export default {
   /**
    * Max circular updates allowed in a batcher flush cycle.
    */
-
   _maxUpdateCount: 100
 }

src/core/global-api/assets.js

@@ -3,13 +3,12 @@ import { warn, isPlainObject } from '../util/index'
 
 export function initAssetRegisters (Vue) {
   /**
-     * Create asset registration methods with the following
-     * signature:
-     *
-     * @param {String} id
-     * @param {*} definition
-     */
-
+   * Create asset registration methods with the following
+   * signature:
+   *
+   * @param {String} id
+   * @param {*} definition
+   */
   config._assetTypes.forEach(function (type) {
     Vue[type] = function (id, definition) {
       if (!definition) {

src/core/global-api/extend.js

@@ -7,7 +7,6 @@ export function initExtend (Vue) {
    * cid. This enables us to create wrapped "child
    * constructors" for prototypal inheritance and cache them.
    */
-
   Vue.cid = 0
   let cid = 1
 
@@ -16,7 +15,6 @@ export function initExtend (Vue) {
    *
    * @param {Object} extendOptions
    */
-
   Vue.extend = function (extendOptions) {
     extendOptions = extendOptions || {}
     const Super = this

src/core/global-api/use.js

@@ -6,7 +6,6 @@ export function initUse (Vue) {
    *
    * @param {Object} plugin
    */
-
   Vue.use = function (plugin) {
     /* istanbul ignore if */
     if (plugin.installed) {

src/core/instance/events.js

@@ -26,7 +26,6 @@ export function eventsMixin (Vue) {
    * @param {String} event
    * @param {Function} fn
    */
-
   Vue.prototype.$once = function (event, fn) {
     const self = this
     function on () {
@@ -45,7 +44,6 @@ export function eventsMixin (Vue) {
    * @param {String} event
    * @param {Function} fn
    */
-
   Vue.prototype.$off = function (event, fn) {
     // all
     if (!arguments.length) {
@@ -79,7 +77,6 @@ export function eventsMixin (Vue) {
    *
    * @param {String} event
    */
-
   Vue.prototype.$emit = function (event) {
     let cbs = this._events[event]
     if (cbs) {

src/core/instance/index.js

@@ -3,40 +3,38 @@ import { initState, stateMixin } from './state'
 import { initRender, renderMixin } from './render'
 import { initEvents, eventsMixin } from './events'
 import { initLifecycle, lifecycleMixin, callHook } from './lifecycle'
-import { nextTick, mergeOptions } from '../util/index'
+import { mergeOptions } from '../util/index'
 
 let uid = 0
 
-export default function Vue (options) {
-  this._init(options)
-}
-
-Vue.prototype._init = function (options) {
-  // a uid
-  this._uid = uid++
-  // a flag to avoid this being observed
-  this._isVue = true
-  // merge options
-  this.$options = mergeOptions(
-    this.constructor.options,
-    options || {},
-    this
-  )
-  if (process.env.NODE_ENV !== 'production') {
-    initProxy(this)
-  } else {
-    this._renderProxy = this
+export default class Vue {
+  constructor (options) {
+    this._init(options)
   }
-  initLifecycle(this)
-  initEvents(this)
-  callHook(this, 'init')
-  initState(this)
-  callHook(this, 'created')
-  initRender(this)
-}
 
-Vue.prototype.$nextTick = function (fn) {
-  nextTick(fn, this)
+  _init (options) {
+    // a uid
+    this._uid = uid++
+    // a flag to avoid this being observed
+    this._isVue = true
+    // merge options
+    this.$options = mergeOptions(
+      this.constructor.options,
+      options || {},
+      this
+    )
+    if (process.env.NODE_ENV !== 'production') {
+      initProxy(this)
+    } else {
+      this._renderProxy = this
+    }
+    initLifecycle(this)
+    initEvents(this)
+    callHook(this, 'init')
+    initState(this)
+    callHook(this, 'created')
+    initRender(this)
+  }
 }
 
 stateMixin(Vue)

src/core/instance/render.js

@@ -1,7 +1,7 @@
 import createElement from '../vdom/create-element'
 import { flatten } from '../vdom/helpers'
 import { bind, isArray, isObject, renderString } from 'shared/util'
-import { resolveAsset } from '../util/options'
+import { resolveAsset, nextTick } from '../util/index'
 
 export const renderState = {
   activeInstance: null
@@ -21,6 +21,10 @@ export function initRender (vm) {
 }
 
 export function renderMixin (Vue) {
+  Vue.prototype.$nextTick = function (fn) {
+    nextTick(fn, this)
+  }
+
   Vue.prototype._render = function () {
     const prev = renderState.activeInstance
     renderState.activeInstance = this

src/core/observer/array.js

@@ -6,7 +6,6 @@ export const arrayMethods = Object.create(arrayProto)
 /**
  * Intercept mutating methods and emit events
  */
-
 ;[
   'push',
   'pop',

src/core/observer/batcher.js

@@ -20,7 +20,6 @@ let waiting = false
 /**
  * Reset the batcher's state.
  */
-
 function resetBatcherState () {
   queue.length = 0
   userQueue.length = 0
@@ -34,7 +33,6 @@ function resetBatcherState () {
 /**
  * Flush both queues and run the watchers.
  */
-
 function flushBatcherQueue () {
   runBatcherQueue(queue.sort(queueSorter))
   queue.length = 0
@@ -53,7 +51,6 @@ function flushBatcherQueue () {
  * pushed into the queue first and then its parent's props
  * changed.
  */
-
 function queueSorter (a, b) {
   return a.id - b.id
 }
@@ -63,7 +60,6 @@ function queueSorter (a, b) {
  *
  * @param {Array} queue
  */
-
 function runBatcherQueue (queue) {
   // do not cache length because more watchers might be pushed
   // as we run existing watchers
@@ -97,7 +93,6 @@ function runBatcherQueue (queue) {
  *   - {Number} id
  *   - {Function} run
  */
-
 export function pushWatcher (watcher) {
   const id = watcher.id
   if (has[id] == null) {

src/core/observer/dep.js

@@ -8,53 +8,34 @@ let uid = 0
  *
  * @constructor
  */
+export default class Dep {
+  constructor () {
+    this.id = uid++
+    this.subs = []
+  }
+
+  addSub (sub) {
+    this.subs.push(sub)
+  }
+
+  removeSub (sub) {
+    remove(this.subs, sub)
+  }
+
+  depend () {
+    Dep.target.addDep(this)
+  }
 
-export default function Dep () {
-  this.id = uid++
-  this.subs = []
+  notify () {
+    // stablize the subscriber list first
+    const subs = this.subs.slice()
+    for (let i = 0, l = subs.length; i < l; i++) {
+      subs[i].update()
+    }
+  }
 }
 
 // the current target watcher being evaluated.
 // this is globally unique because there could be only one
 // watcher being evaluated at any time.
 Dep.target = null
-
-/**
- * Add a directive subscriber.
- *
- * @param {Directive} sub
- */
-
-Dep.prototype.addSub = function (sub) {
-  this.subs.push(sub)
-}
-
-/**
- * Remove a directive subscriber.
- *
- * @param {Directive} sub
- */
-
-Dep.prototype.removeSub = function (sub) {
-  remove(this.subs, sub)
-}
-
-/**
- * Add self as a dependency to the target watcher.
- */
-
-Dep.prototype.depend = function () {
-  Dep.target.addDep(this)
-}
-
-/**
- * Notify all subscribers of a new value.
- */
-
-Dep.prototype.notify = function () {
-  // stablize the subscriber list first
-  const subs = this.subs.slice()
-  for (let i = 0, l = subs.length; i < l; i++) {
-    subs[i].update()
-  }
-}

src/core/observer/index.js

@@ -19,7 +19,6 @@ const arrayKeys = Object.getOwnPropertyNames(arrayMethods)
  * we don't want to force conversion because the value may be a nested value
  * under a frozen data structure. Converting it would defeat the optimization.
  */
-
 export const observerState = {
   shouldConvert: true
 }
@@ -33,84 +32,69 @@ export const observerState = {
  * @param {Array|Object} value
  * @constructor
  */
-
-export function Observer (value) {
-  this.value = value
-  this.dep = new Dep()
-  def(value, '__ob__', this)
-  if (isArray(value)) {
-    const augment = hasProto
-      ? protoAugment
-      : copyAugment
-    augment(value, arrayMethods, arrayKeys)
-    this.observeArray(value)
-  } else {
-    this.walk(value)
+export class Observer {
+  constructor (value) {
+    this.value = value
+    this.dep = new Dep()
+    this.vms = null
+    def(value, '__ob__', this)
+    if (isArray(value)) {
+      const augment = hasProto
+        ? protoAugment
+        : copyAugment
+      augment(value, arrayMethods, arrayKeys)
+      this.observeArray(value)
+    } else {
+      this.walk(value)
+    }
   }
-}
-
-// Instance methods
 
-/**
- * Walk through each property and convert them into
- * getter/setters. This method should only be called when
- * value type is Object.
- *
- * @param {Object} obj
- */
-
-Observer.prototype.walk = function (obj) {
-  for (const key in obj) {
-    this.convert(key, obj[key])
+  /**
+   * Walk through each property and convert them into
+   * getter/setters. This method should only be called when
+   * value type is Object.
+   *
+   * @param {Object} obj
+   */
+  walk (obj) {
+    const val = this.value
+    for (const key in obj) {
+      defineReactive(val, key, obj[key])
+    }
   }
-}
-
-/**
- * Observe a list of Array items.
- *
- * @param {Array} items
- */
 
-Observer.prototype.observeArray = function (items) {
-  for (let i = 0, l = items.length; i < l; i++) {
-    observe(items[i])
+  /**
+   * Observe a list of Array items.
+   *
+   * @param {Array} items
+   */
+  observeArray (items) {
+    for (let i = 0, l = items.length; i < l; i++) {
+      observe(items[i])
+    }
   }
-}
 
-/**
- * Convert a property into getter/setter so we can emit
- * the events when the property is accessed/changed.
- *
- * @param {String} key
- * @param {*} val
- */
-
-Observer.prototype.convert = function (key, val) {
-  defineReactive(this.value, key, val)
-}
-
-/**
- * Add an owner vm, so that when $set/$delete mutations
- * happen we can notify owner vms to proxy the keys and
- * digest the watchers. This is only called when the object
- * is observed as an instance's root $data.
- *
- * @param {Vue} vm
- */
-
-Observer.prototype.addVm = function (vm) {
-  (this.vms || (this.vms = [])).push(vm)
-}
-
-/**
- * Remove an owner vm. This is called when the object is
- * swapped out as an instance's $data object.
- *
- * @param {Vue} vm
- */
+  /**
+   * Add an owner vm, so that when $set/$delete mutations
+   * happen we can notify owner vms to proxy the keys and
+   * digest the watchers. This is only called when the object
+   * is observed as an instance's root $data.
+   *
+   * @param {Vue} vm
+   */
+  addVm (vm) {
+    (this.vms || (this.vms = [])).push(vm)
+  }
 
-Observer.prototype.removeVm = function (vm) {
-  remove(this.vms, vm)
+  /**
+   * Remove an owner vm. This is called when the object is
+   * swapped out as an instance's $data object.
+   *
+   * @param {Vue} vm
+   */
+  removeVm (vm) {
+    remove(this.vms, vm)
+  }
 }
 
 // helpers
@@ -122,7 +106,6 @@ Observer.prototype.removeVm = function (vm) {
  * @param {Object|Array} target
  * @param {Object} src
  */
-
 function protoAugment (target, src) {
   /* eslint-disable no-proto */
   target.__proto__ = src
@@ -136,7 +119,6 @@ function protoAugment (target, src) {
  * @param {Object|Array} target
  * @param {Object} proto
  */
-
 function copyAugment (target, src, keys) {
   for (let i = 0, l = keys.length; i < l; i++) {
     const key = keys[i]
@@ -154,7 +136,6 @@ function copyAugment (target, src, keys) {
  * @return {Observer|undefined}
  * @static
  */
-
 export function observe (value, vm) {
   if (!isObject(value)) {
     return
@@ -183,7 +164,6 @@ export function observe (value, vm) {
  * @param {String} key
  * @param {*} val
  */
-
 export function defineReactive (obj, key, val) {
   const dep = new Dep()
 
@@ -242,7 +222,6 @@ export function defineReactive (obj, key, val) {
  * @param {*} val
  * @public
  */
-
 export function set (obj, key, val) {
   if (isArray(obj)) {
     return obj.splice(key, 1, val)
@@ -260,7 +239,7 @@ export function set (obj, key, val) {
     obj[key] = val
     return
   }
-  ob.convert(key, val)
+  defineReactive(ob.value, key, val)
   ob.dep.notify()
   if (ob.vms) {
     let i = ob.vms.length
@@ -279,7 +258,6 @@ export function set (obj, key, val) {
  * @param {Object} obj
  * @param {String} key
  */
-
 export function del (obj, key) {
   if (!hasOwn(obj, key)) {
     return

src/core/observer/watcher.js

@@ -32,206 +32,184 @@ let prevTarget
  *                 - {Function} [postProcess]
  * @constructor
  */
-
-export default function Watcher (vm, expOrFn, cb, options) {
-  // mix in options
-  if (options) {
-    extend(this, options)
-  }
-  const isFn = typeof expOrFn === 'function'
-  this.vm = vm
-  vm._watchers.push(this)
-  this.expression = expOrFn
-  this.cb = cb
-  this.id = ++uid // uid for batching
-  this.active = true
-  this.dirty = this.lazy // for lazy watchers
-  this.deps = []
-  this.newDeps = []
-  this.depIds = new Set()
-  this.newDepIds = new Set()
-  // parse expression for getter
-  if (isFn) {
-    this.getter = expOrFn
-  } else {
-    this.getter = parsePath(expOrFn)
-    if (!this.getter) {
-      this.getter = function () {}
-      process.env.NODE_ENV !== 'production' && warn(
-        'Failed watching path: ' + expOrFn +
-        'Watcher only accepts simple dot-delimited paths. ' +
-        'For full control, use a function instead.',
-        vm
-      )
+export default class Watcher {
+  constructor (vm, expOrFn, cb, options) {
+    // mix in options
+    if (options) {
+      extend(this, options)
+    }
+    const isFn = typeof expOrFn === 'function'
+    this.vm = vm
+    vm._watchers.push(this)
+    this.expression = expOrFn
+    this.cb = cb
+    this.id = ++uid // uid for batching
+    this.active = true
+    this.dirty = this.lazy // for lazy watchers
+    this.deps = []
+    this.newDeps = []
+    this.depIds = new Set()
+    this.newDepIds = new Set()
+    // parse expression for getter
+    if (isFn) {
+      this.getter = expOrFn
+    } else {
+      this.getter = parsePath(expOrFn)
+      if (!this.getter) {
+        this.getter = function () {}
+        process.env.NODE_ENV !== 'production' && warn(
+          'Failed watching path: ' + expOrFn +
+          'Watcher only accepts simple dot-delimited paths. ' +
+          'For full control, use a function instead.',
+          vm
+        )
+      }
     }
+    this.value = this.lazy
+      ? undefined
+      : this.get()
   }
-  this.value = this.lazy
-    ? undefined
-    : this.get()
-  // state for avoiding false triggers for deep and Array
-  // watchers during vm._digest()
-  this.queued = this.shallow = false
-}
-
-/**
- * Evaluate the getter, and re-collect dependencies.
- */
 
-Watcher.prototype.get = function () {
-  this.beforeGet()
-  const value = this.getter.call(this.vm, this.vm)
-  // "touch" every property so they are all tracked as
-  // dependencies for deep watching
-  if (this.deep) {
-    traverse(value)
+  /**
+   * Evaluate the getter, and re-collect dependencies.
+   */
+  get () {
+    this.beforeGet()
+    const value = this.getter.call(this.vm, this.vm)
+    // "touch" every property so they are all tracked as
+    // dependencies for deep watching
+    if (this.deep) {
+      traverse(value)
+    }
+    this.afterGet()
+    return value
   }
-  this.afterGet()
-  return value
-}
-
-/**
- * Prepare for dependency collection.
- */
-
-Watcher.prototype.beforeGet = function () {
-  prevTarget = Dep.target
-  Dep.target = this
-}
 
-/**
- * Add a dependency to this directive.
- *
- * @param {Dep} dep
- */
+  /**
+   * Prepare for dependency collection.
+   */
+  beforeGet () {
+    prevTarget = Dep.target
+    Dep.target = this
+  }
 
-Watcher.prototype.addDep = function (dep) {
-  const id = dep.id
-  if (!this.newDepIds.has(id)) {
-    this.newDepIds.add(id)
-    this.newDeps.push(dep)
-    if (!this.depIds.has(id)) {
-      dep.addSub(this)
+  /**
+   * Add a dependency to this directive.
+   *
+   * @param {Dep} dep
+   */
+  addDep (dep) {
+    const id = dep.id
+    if (!this.newDepIds.has(id)) {
+      this.newDepIds.add(id)
+      this.newDeps.push(dep)
+      if (!this.depIds.has(id)) {
+        dep.addSub(this)
+      }
     }
   }
-}
-
-/**
- * Clean up for dependency collection.
- */
 
-Watcher.prototype.afterGet = function () {
-  Dep.target = prevTarget
-  let i = this.deps.length
-  while (i--) {
-    const dep = this.deps[i]
-    if (!this.newDepIds.has(dep.id)) {
-      dep.removeSub(this)
+  /**
+   * Clean up for dependency collection.
+   */
+  afterGet () {
+    Dep.target = prevTarget
+    let i = this.deps.length
+    while (i--) {
+      const dep = this.deps[i]
+      if (!this.newDepIds.has(dep.id)) {
+        dep.removeSub(this)
+      }
     }
+    let tmp = this.depIds
+    this.depIds = this.newDepIds
+    this.newDepIds = tmp
+    this.newDepIds.clear()
+    tmp = this.deps
+    this.deps = this.newDeps
+    this.newDeps = tmp
+    this.newDeps.length = 0
   }
-  let tmp = this.depIds
-  this.depIds = this.newDepIds
-  this.newDepIds = tmp
-  this.newDepIds.clear()
-  tmp = this.deps
-  this.deps = this.newDeps
-  this.newDeps = tmp
-  this.newDeps.length = 0
-}
-
-/**
- * Subscriber interface.
- * Will be called when a dependency changes.
- *
- * @param {Boolean} shallow
- */
 
-Watcher.prototype.update = function (shallow) {
-  if (this.lazy) {
-    this.dirty = true
-  } else if (this.sync) {
-    this.run()
-  } else {
-    // if queued, only overwrite shallow with non-shallow,
-    // but not the other way around.
-    this.shallow = this.queued
-      ? shallow
-        ? this.shallow
-        : false
-      : !!shallow
-    this.queued = true
-    pushWatcher(this)
+  /**
+   * Subscriber interface.
+   * Will be called when a dependency changes.
+   */
+  update () {
+    if (this.lazy) {
+      this.dirty = true
+    } else if (this.sync) {
+      this.run()
+    } else {
+      pushWatcher(this)
+    }
   }
-}
-
-/**
- * Batcher job interface.
- * Will be called by the batcher.
- */
 
-Watcher.prototype.run = function () {
-  if (this.active) {
-    const value = this.get()
-    if (
-      value !== this.value ||
-      // Deep watchers and watchers on Object/Arrays should fire even
-      // when the value is the same, because the value may
-      // have mutated; but only do so if this is a
-      // non-shallow update (caused by a vm digest).
-      ((isObject(value) || this.deep) && !this.shallow)
-    ) {
-      // set new value
-      const oldValue = this.value
-      this.value = value
-      this.cb.call(this.vm, value, oldValue)
+  /**
+   * Batcher job interface.
+   * Will be called by the batcher.
+   */
+  run () {
+    if (this.active) {
+      const value = this.get()
+      if (
+        value !== this.value ||
+        // Deep watchers and watchers on Object/Arrays should fire even
+        // when the value is the same, because the value may
+        // have mutated.
+        isObject(value) ||
+        this.deep
+      ) {
+        // set new value
+        const oldValue = this.value
+        this.value = value
+        this.cb.call(this.vm, value, oldValue)
+      }
     }
-    this.queued = this.shallow = false
   }
-}
-
-/**
- * Evaluate the value of the watcher.
- * This only gets called for lazy watchers.
- */
-
-Watcher.prototype.evaluate = function () {
-  // avoid overwriting another watcher that is being
-  // collected.
-  const current = Dep.target
-  this.value = this.get()
-  this.dirty = false
-  Dep.target = current
-}
 
-/**
- * Depend on all deps collected by this watcher.
- */
-
-Watcher.prototype.depend = function () {
-  let i = this.deps.length
-  while (i--) {
-    this.deps[i].depend()
+  /**
+   * Evaluate the value of the watcher.
+   * This only gets called for lazy watchers.
+   */
+  evaluate () {
+    // avoid overwriting another watcher that is being
+    // collected.
+    const current = Dep.target
+    this.value = this.get()
+    this.dirty = false
+    Dep.target = current
   }
-}
-
-/**
- * Remove self from all dependencies' subcriber list.
- */
 
-Watcher.prototype.teardown = function () {
-  if (this.active) {
-    // remove self from vm's watcher list
-    // this is a somewhat expensive operation so we skip it
-    // if the vm is being destroyed or is performing a v-for
-    // re-render (the watcher list is then filtered by v-for).
-    if (!this.vm._isBeingDestroyed && !this.vm._vForRemoving) {
-      remove(this.vm._watchers, this)
-    }
+  /**
+   * Depend on all deps collected by this watcher.
+   */
+  depend () {
     let i = this.deps.length
     while (i--) {
-      this.deps[i].removeSub(this)
+      this.deps[i].depend()
+    }
+  }
+
+  /**
+   * Remove self from all dependencies' subcriber list.
+   */
+  teardown () {
+    if (this.active) {
+      // remove self from vm's watcher list
+      // this is a somewhat expensive operation so we skip it
+      // if the vm is being destroyed or is performing a v-for
+      // re-render (the watcher list is then filtered by v-for).
+      if (!this.vm._isBeingDestroyed && !this.vm._vForRemoving) {
+        remove(this.vm._watchers, this)
+      }
+      let i = this.deps.length
+      while (i--) {
+        this.deps[i].removeSub(this)
+      }
+      this.active = false
+      this.vm = this.cb = this.value = null
     }
-    this.active = false
-    this.vm = this.cb = this.value = null
   }
 }
 
@@ -243,7 +221,6 @@ Watcher.prototype.teardown = function () {
  * @param {*} val
  * @param {Set} seen
  */
-
 const seenObjects = new Set()
 function traverse (val, seen) {
   let i, keys

src/core/util/env.js

@@ -1,5 +1,4 @@
 /* global MutationObserver */
-
 // can we use __proto__?
 export const hasProto = '__proto__' in {}
 
@@ -25,7 +24,6 @@ const isWechat = UA && UA.indexOf('micromessenger') > 0
  * @param {Function} cb
  * @param {Object} ctx
  */
-
 export const nextTick = (function () {
   let callbacks = []
   let pending = false
@@ -78,17 +76,19 @@ if (typeof Set !== 'undefined' && Set.toString().match(/native code/)) {
   _Set = Set
 } else {
   // a non-standard Set polyfill that only works with primitive keys.
-  _Set = function () {
-    this.set = Object.create(null)
-  }
-  _Set.prototype.has = function (key) {
-    return this.set[key] !== undefined
-  }
-  _Set.prototype.add = function (key) {
-    this.set[key] = 1
-  }
-  _Set.prototype.clear = function () {
-    this.set = Object.create(null)
+  _Set = class Set {
+    constructor () {
+      this.set = Object.create(null)
+    }
+    has (key) {
+      return this.set[key] !== undefined
+    }
+    add (key) {
+      this.set[key] = 1
+    }
+    clear () {
+      this.set = Object.create(null)
+    }
   }
 }
 

src/core/util/lang.js

@@ -4,7 +4,6 @@
  * @param {String} str
  * @return {Boolean}
  */
-
 export function isReserved (str) {
   const c = (str + '').charCodeAt(0)
   return c === 0x24 || c === 0x5F
@@ -18,7 +17,6 @@ export function isReserved (str) {
  * @param {*} val
  * @param {Boolean} [enumerable]
  */
-
 export function def (obj, key, val, enumerable) {
   Object.defineProperty(obj, key, {
     value: val,
@@ -31,7 +29,6 @@ export function def (obj, key, val, enumerable) {
 /**
  * Parse simple path.
  */
-
 const bailRE = /[^\w\.]/
 export function parsePath (path) {
   if (bailRE.test(path)) {

src/core/util/options.js

@@ -23,13 +23,11 @@ import {
  * @param {*} childVal
  * @param {Vue} [vm]
  */
-
 const strats = config.optionMergeStrategies = Object.create(null)
 
 /**
  * Options with restrictions
  */
-
 if (process.env.NODE_ENV !== 'production') {
   strats.el = strats.propsData = function (parent, child, vm, key) {
     if (!vm) {
@@ -55,7 +53,6 @@ if (process.env.NODE_ENV !== 'production') {
 /**
  * Helper that recursively merges two data objects together.
  */
-
 function mergeData (to, from) {
   let key, toVal, fromVal
   for (key in from) {
@@ -73,7 +70,6 @@ function mergeData (to, from) {
 /**
  * Data
  */
-
 strats.data = function (parentVal, childVal, vm) {
   if (!vm) {
     // in a Vue.extend merge, both should be functions
@@ -124,7 +120,6 @@ strats.data = function (parentVal, childVal, vm) {
 /**
  * Hooks and param attributes are merged as arrays.
  */
-
 function mergeHook (parentVal, childVal) {
   return childVal
     ? parentVal
@@ -146,7 +141,6 @@ config._lifecycleHooks.forEach(hook => {
  * a three-way merge between constructor options, instance
  * options and parent options.
  */
-
 function mergeAssets (parentVal, childVal) {
   const res = Object.create(parentVal || null)
   return childVal
@@ -164,7 +158,6 @@ config._assetTypes.forEach(function (type) {
  * Watchers hashes should not overwrite one
  * another, so we merge them as arrays.
  */
-
 strats.watch = function (parentVal, childVal) {
   if (!childVal) return parentVal
   if (!parentVal) return childVal
@@ -186,7 +179,6 @@ strats.watch = function (parentVal, childVal) {
 /**
  * Other object hashes.
  */
-
 strats.props =
 strats.methods =
 strats.computed = function (parentVal, childVal) {
@@ -201,7 +193,6 @@ strats.computed = function (parentVal, childVal) {
 /**
  * Default strategy.
  */
-
 const defaultStrat = function (parentVal, childVal) {
   return childVal === undefined
     ? parentVal
@@ -214,7 +205,6 @@ const defaultStrat = function (parentVal, childVal) {
  *
  * @param {Object} options
  */
-
 function guardComponents (options) {
   if (options.components) {
     const components = options.components
@@ -241,7 +231,6 @@ function guardComponents (options) {
  *
  * @param {Object} options
  */
-
 function guardProps (options) {
   const props = options.props
   if (!props) return
@@ -290,7 +279,6 @@ function guardDirectives (options) {
  * @param {Vue} [vm] - if vm is present, indicates this is
  *                     an instantiation merge.
  */
-
 export function mergeOptions (parent, child, vm) {
   guardComponents(child)
   guardProps(child)
@@ -339,7 +327,6 @@ export function mergeOptions (parent, child, vm) {
  * @param {Boolean} warnMissing
  * @return {Object|Function}
  */
-
 export function resolveAsset (options, type, id, warnMissing) {
   /* istanbul ignore if */
   if (typeof id !== 'string') {

src/core/util/props.js

@@ -29,7 +29,6 @@ export function validateProp (vm, key, propsData) {
  * @param {Object} prop
  * @return {*}
  */
-
 function getPropDefaultValue (vm, prop, name) {
   // no default, return undefined
   if (!hasOwn(prop, 'default')) {
@@ -63,7 +62,6 @@ function getPropDefaultValue (vm, prop, name) {
  * @param {Vue} vm
  * @param {Boolean} absent
  */
-
 function assertProp (prop, name, value, vm, absent) {
   if (prop.required && absent) {
     process.env.NODE_ENV !== 'production' && warn(
@@ -119,7 +117,6 @@ function assertProp (prop, name, value, vm, absent) {
  * @param {Function} type
  * @return {Object}
  */
-
 function assertType (value, type) {
   let valid
   let expectedType
@@ -156,7 +153,6 @@ function assertType (value, type) {
  * @param {String} type
  * @return {String}
  */
-
 function formatType (type) {
   return type
     ? type.charAt(0).toUpperCase() + type.slice(1)
@@ -169,7 +165,6 @@ function formatType (type) {
  * @param {*} value
  * @return {String}
  */
-
 function formatValue (val) {
   return Object.prototype.toString.call(val).slice(8, -1)
 }

src/core/vdom/patch.js

@@ -3,7 +3,6 @@
  * Simon Friis Vindum (@paldepind)
  * with custom modifications.
  */
-
 import VNode from './vnode'
 import { isPrimitive, renderString, warn } from '../util/index'
 

src/entries/web-runtime-with-compiler.js

@@ -45,7 +45,6 @@ Vue.prototype.$mount = function (el) {
  * @param {Element} el
  * @return {String}
  */
-
 function getOuterHTML (el) {
   if (el.outerHTML) {
     return el.outerHTML

src/platforms/web/runtime/class-util.js

@@ -11,7 +11,6 @@ const svgNS = namespaceMap.svg
  * @param {Element} el
  * @param {String} cls
  */
-
 export function setClass (el, cls) {
   /* istanbul ignore else */
   if (!isIE9 || el.namespaceURI === svgNS) {
@@ -27,7 +26,6 @@ export function setClass (el, cls) {
  * @param {Element} el
  * @param {String} cls
  */
-
 export function addClass (el, cls) {
   if (el.classList) {
     if (cls.indexOf(' ') > -1) {
@@ -49,7 +47,6 @@ export function addClass (el, cls) {
  * @param {Element} el
  * @param {String} cls
  */
-
 export function removeClass (el, cls) {
   if (el.classList) {
     if (cls.indexOf(' ') > -1) {
@@ -78,7 +75,6 @@ export function removeClass (el, cls) {
  * @param {Element} el
  * @return {String}
  */
-
 function getClass (el) {
   let classname = el.className
   if (typeof classname === 'object') {

src/platforms/web/util/index.js

@@ -14,7 +14,6 @@ export const isAndroid = UA && UA.indexOf('android') > 0
  * @param {String|Element} el
  * @return {Element}
  */
-
 export function query (el) {
   if (typeof el === 'string') {
     const selector = el

src/server/render-stream.js

@@ -7,7 +7,6 @@ const MAX_STACK_DEPTH = 500
  * Licensed under the Apache License, Version 2.0
  * Modified by Evan You (@yyx990803)
  */
-
 export default class RenderStream extends stream.Readable {
   constructor (render) {
     super()

src/shared/util.js

@@ -4,7 +4,6 @@
  * @param {*} val
  * @return {String}
  */
-
 export function renderString (val) {
   return val == null
     ? ''
@@ -21,7 +20,6 @@ export function renderString (val) {
  * @param {Boolean} expectsLowerCase
  * @return {Function}
  */
-
 export function makeMap (str, expectsLowerCase) {
   const map = Object.create(null)
   const list = str.split(',')
@@ -36,7 +34,6 @@ export function makeMap (str, expectsLowerCase) {
 /**
  * Check if a tag is a built-in tag.
  */
-
 export const isBuiltInTag = makeMap('slot,component,render,transition', true)
 
 /**
@@ -45,7 +42,6 @@ export const isBuiltInTag = makeMap('slot,component,render,transition', true)
  * @param {Array} arr
  * @param {*} item
  */
-
 export function remove (arr, item) {
   if (arr.length) {
     const index = arr.indexOf(item)
@@ -73,7 +69,6 @@ export function hasOwn (obj, key) {
  * @param {*} value
  * @return {Boolean}
  */
-
 export function isPrimitive (value) {
   return typeof value === 'string' || typeof value === 'number'
 }
@@ -84,7 +79,6 @@ export function isPrimitive (value) {
  * @param {Function} fn
  * @return {Function}
  */
-
 export function cached (fn) {
   const cache = Object.create(null)
   return function cachedFn (str) {
@@ -99,7 +93,6 @@ export function cached (fn) {
  * @param {String} str
  * @return {String}
  */
-
 const camelizeRE = /-(\w)/g
 export const camelize = cached(str => {
   return str.replace(camelizeRE, toUpper)
@@ -115,7 +108,6 @@ function toUpper (_, c) {
  * @param {String} str
  * @return {String}
  */
-
 const hyphenateRE = /([a-z\d])([A-Z])/g
 export const hyphenate = cached(str => {
   return str
@@ -130,7 +122,6 @@ export const hyphenate = cached(str => {
  * @param {Object} ctx
  * @return {Function}
  */
-
 export function bind (fn, ctx) {
   return function (a) {
     const l = arguments.length
@@ -149,7 +140,6 @@ export function bind (fn, ctx) {
  * @param {Number} [start] - start index
  * @return {Array}
  */
-
 export function toArray (list, start) {
   start = start || 0
   let i = list.length - start
@@ -166,7 +156,6 @@ export function toArray (list, start) {
  * @param {Object} to
  * @param {Object} from
  */
-
 export function extend (to, _from) {
   for (const key in _from) {
     to[key] = _from[key]
@@ -182,7 +171,6 @@ export function extend (to, _from) {
  * @param {*} obj
  * @return {Boolean}
  */
-
 export function isObject (obj) {
   return obj !== null && typeof obj === 'object'
 }
@@ -194,7 +182,6 @@ export function isObject (obj) {
  * @param {*} obj
  * @return {Boolean}
  */
-
 const toString = Object.prototype.toString
 const OBJECT_STRING = '[object Object]'
 export function isPlainObject (obj) {
@@ -207,5 +194,4 @@ export function isPlainObject (obj) {
  * @param {*} obj
  * @return {Boolean}
  */
-
 export const isArray = Array.isArray