refactor(core): Replace "var" (#8299)

Replaces instances of "var" with "let" and "const" where applicable using the eslint 'no-var' and
'prefer-const' rules

scripts/build.js

@@ -48,7 +48,7 @@ function buildEntry (config) {
     .then(bundle => bundle.generate(output))
     .then(({ code }) => {
       if (isProd) {
-        var minified = (banner ? banner + '\n' : '') + terser.minify(code, {
+        const minified = (banner ? banner + '\n' : '') + terser.minify(code, {
           output: {
             ascii_only: true
           },

scripts/get-weex-version.js

@@ -1,7 +1,7 @@
-var coreVersion = require('../package.json').version
-var weexVersion = require('../packages/weex-vue-framework/package.json').version
-var weexBaseVersion = weexVersion.match(/^[\d.]+/)[0]
-var weexSubVersion = Number(weexVersion.match(/-weex\.(\d+)$/)[1])
+const coreVersion = require('../package.json').version
+const weexVersion = require('../packages/weex-vue-framework/package.json').version
+let weexBaseVersion = weexVersion.match(/^[\d.]+/)[0]
+let weexSubVersion = Number(weexVersion.match(/-weex\.(\d+)$/)[1])
 
 if (weexBaseVersion === coreVersion) {
   // same core version, increment sub version

src/platforms/web/runtime/components/transition-group.js

@@ -111,8 +111,8 @@ export default {
 
     children.forEach((c: VNode) => {
       if (c.data.moved) {
-        var el: any = c.elm
-        var s: any = el.style
+        const el: any = c.elm
+        const s: any = el.style
         addTransitionClass(el, moveClass)
         s.transform = s.WebkitTransform = s.transitionDuration = ''
         el.addEventListener(transitionEndEvent, el._moveCb = function cb (e) {

src/platforms/web/util/style.js

@@ -8,7 +8,7 @@ export const parseStyleText = cached(function (cssText) {
   const propertyDelimiter = /:(.+)/
   cssText.split(listDelimiter).forEach(function (item) {
     if (item) {
-      var tmp = item.split(propertyDelimiter)
+      const tmp = item.split(propertyDelimiter)
       tmp.length > 1 && (res[tmp[0].trim()] = tmp[1].trim())
     }
   })

src/platforms/weex/runtime/modules/style.js

@@ -70,7 +70,7 @@ function updateStyle (oldVnode: VNodeWithData, vnode: VNodeWithData) {
 
 function toObject (arr) {
   const res = {}
-  for (var i = 0; i < arr.length; i++) {
+  for (let i = 0; i < arr.length; i++) {
     if (arr[i]) {
       extend(res, arr[i])
     }

test/e2e/runner.js

@@ -1,25 +1,25 @@
-var path = require('path')
-var spawn = require('cross-spawn')
-var httpServer = require('http-server')
-var server = httpServer.createServer({
+const path = require('path')
+const spawn = require('cross-spawn')
+const httpServer = require('http-server')
+const server = httpServer.createServer({
   root: path.resolve(__dirname, '../../')
 })
 
 server.listen(8080)
 
-var args = process.argv.slice(2)
+let args = process.argv.slice(2)
 if (args.indexOf('--config') === -1) {
   args = args.concat(['--config', 'test/e2e/nightwatch.config.js'])
 }
 if (args.indexOf('--env') === -1) {
   args = args.concat(['--env', 'chrome,phantomjs'])
 }
-var i = args.indexOf('--test')
+const i = args.indexOf('--test')
 if (i > -1) {
   args[i + 1] = 'test/e2e/specs/' + args[i + 1] + '.js'
 }
 
-var runner = spawn('./node_modules/.bin/nightwatch', args, {
+const runner = spawn('./node_modules/.bin/nightwatch', args, {
   stdio: 'inherit'
 })
 

test/e2e/specs/grid.js

@@ -1,6 +1,6 @@
 module.exports = {
   'grid': function (browser) {
-    var columns = ['name', 'power']
+    const columns = ['name', 'power']
 
     browser
     .url('http://localhost:8080/examples/grid/')
@@ -92,8 +92,8 @@ module.exports = {
 
     function assertTable (data) {
       browser.assert.count('td', data.length * columns.length)
-      for (var i = 0; i < data.length; i++) {
-        for (var j = 0; j < columns.length; j++) {
+      for (let i = 0; i < data.length; i++) {
+        for (let j = 0; j < columns.length; j++) {
           browser.assert.containsText(
             'tr:nth-child(' + (i + 1) + ') td:nth-child(' + (j + 1) + ')',
             data[i][columns[j]]

test/e2e/specs/svg.js

@@ -12,8 +12,8 @@ module.exports = {
       .assert.count('button', 7)
       .assert.count('input[type="range"]', 6)
       .assert.evaluate(function () {
-        var points = stats.map(function (stat, i) {
-        var point = valueToPoint(stat.value, i, 6)
+        const points = stats.map(function (stat, i) {
+        const point = valueToPoint(stat.value, i, 6)
           return point.x + ',' + point.y
         }).join(' ')
         return document.querySelector('polygon').attributes[0].value === points
@@ -24,8 +24,8 @@ module.exports = {
       .assert.count('button', 6)
       .assert.count('input[type="range"]', 5)
       .assert.evaluate(function () {
-        var points = stats.map(function (stat, i) {
-        var point = valueToPoint(stat.value, i, 5)
+        const points = stats.map(function (stat, i) {
+        const point = valueToPoint(stat.value, i, 5)
           return point.x + ',' + point.y
         }).join(' ')
         return document.querySelector('polygon').attributes[0].value === points
@@ -37,8 +37,8 @@ module.exports = {
       .assert.count('button', 7)
       .assert.count('input[type="range"]', 6)
       .assert.evaluate(function () {
-        var points = stats.map(function (stat, i) {
-        var point = valueToPoint(stat.value, i, 6)
+        const points = stats.map(function (stat, i) {
+        const point = valueToPoint(stat.value, i, 6)
           return point.x + ',' + point.y
         }).join(' ')
         return document.querySelector('polygon').attributes[0].value === points

test/e2e/specs/tree.js

@@ -63,8 +63,8 @@ module.exports = {
       .assert.count('.item > ul', 5)
       .assert.containsText('#demo ul > .item:nth-child(1)', '[-]')
       .assert.evaluate(function () {
-        var firstItem = document.querySelector('#demo ul > .item:nth-child(1)')
-        var ul = firstItem.querySelector('ul')
+        const firstItem = document.querySelector('#demo ul > .item:nth-child(1)')
+        const ul = firstItem.querySelector('ul')
         return ul.children.length === 2
       })
       .end()

test/helpers/to-have-been-warned.js

@@ -14,8 +14,8 @@ let asserted
 
 function createCompareFn (spy) {
   const hasWarned = msg => {
-    var count = spy.calls.count()
-    var args
+    let count = spy.calls.count()
+    let args
     while (count--) {
       args = spy.calls.argsFor(count)
       if (args.some(containsMsg)) {
@@ -31,7 +31,7 @@ function createCompareFn (spy) {
   return {
     compare: msg => {
       asserted = asserted.concat(msg)
-      var warned = Array.isArray(msg)
+      const warned = Array.isArray(msg)
         ? msg.some(hasWarned)
         : hasWarned(msg)
       return {

test/helpers/trigger-event.js

@@ -1,5 +1,5 @@
 window.triggerEvent = function triggerEvent (target, event, process) {
-  var e = document.createEvent('HTMLEvents')
+  const e = document.createEvent('HTMLEvents')
   e.initEvent(event, true, true)
   if (process) process(e)
   target.dispatchEvent(e)

test/ssr/ssr-stream.spec.js

@@ -89,9 +89,9 @@ describe('SSR: renderToStream', () => {
       template: `<div></div>`,
       _scopeId: '_component2'
     })
-    var stream1 = renderToStream(component1)
-    var stream2 = renderToStream(component2)
-    var res = ''
+    const stream1 = renderToStream(component1)
+    const stream2 = renderToStream(component2)
+    let res = ''
     stream1.on('data', (text) => {
       res += text.toString('utf-8').replace(/x/g, '')
     })

test/unit/features/component/component-async.spec.js

@@ -79,7 +79,7 @@ describe('Component async', () => {
   })
 
   it('dynamic', done => {
-    var vm = new Vue({
+    const vm = new Vue({
       template: '<component :is="view"></component>',
       data: {
         view: 'view-a'
@@ -103,7 +103,7 @@ describe('Component async', () => {
         }
       }
     }).$mount()
-    var aCalled = false
+    let aCalled = false
     function step1 () {
       // ensure A is resolved only once
       expect(aCalled).toBe(false)

test/unit/features/component/component-keep-alive.spec.js

@@ -140,7 +140,7 @@ describe('Component keep-alive', () => {
       components
     }).$mount()
 
-    var oneInstance = vm.$refs.one
+    const oneInstance = vm.$refs.one
     expect(vm.$el.textContent).toBe('two')
     assertHookCalls(one, [1, 1, 1, 0, 0])
     assertHookCalls(two, [1, 1, 1, 0, 0])

test/unit/features/directives/class.spec.js

@@ -5,7 +5,7 @@ function assertClass (assertions, done) {
     template: '<div class="foo" :class="value"></div>',
     data: { value: '' }
   }).$mount()
-  var chain = waitForUpdate()
+  const chain = waitForUpdate()
   assertions.forEach(([value, expected], i) => {
     chain.then(() => {
       if (typeof value === 'function') {

test/unit/features/directives/for.spec.js

@@ -330,7 +330,7 @@ describe('Directive v-for', () => {
     }).then(done)
 
     function assertMarkup () {
-      var markup = vm.list.map(function (item) {
+      const markup = vm.list.map(function (item) {
         return '<p>' + item.a + '</p><p>' + (item.a + 1) + '</p>'
       }).join('')
       expect(vm.$el.innerHTML).toBe(markup)
@@ -370,7 +370,7 @@ describe('Directive v-for', () => {
     }).then(done)
 
     function assertMarkup () {
-      var markup = vm.list.map(function (item) {
+      const markup = vm.list.map(function (item) {
         return `<p>${item.a}<span>${item.a}</span></p>`
       }).join('')
       expect(vm.$el.innerHTML).toBe(markup)

test/unit/features/directives/model-radio.spec.js

@@ -117,7 +117,7 @@ describe('Directive v-model radio', () => {
         '</div>'
     }).$mount()
     document.body.appendChild(vm.$el)
-    var inputs = vm.$el.getElementsByTagName('input')
+    const inputs = vm.$el.getElementsByTagName('input')
     inputs[1].click()
     waitForUpdate(() => {
       expect(vm.selections).toEqual(['b', '1'])
@@ -160,7 +160,7 @@ describe('Directive v-model radio', () => {
           '<input type="radio" value="true" v-model="test" name="test">' +
         '</div>'
     }).$mount()
-    var radioboxInput = vm.$el.children
+    const radioboxInput = vm.$el.children
     expect(radioboxInput[0].checked).toBe(false)
     expect(radioboxInput[1].checked).toBe(false)
     expect(radioboxInput[2].checked).toBe(true)

test/unit/features/directives/model-select.spec.js

@@ -4,9 +4,9 @@ import { looseEqual } from 'shared/util'
 // Android 4.4 Chrome 30 has the bug that a multi-select option cannot be
 // deselected by setting its "selected" prop via JavaScript.
 function hasMultiSelectBug () {
-  var s = document.createElement('select')
+  const s = document.createElement('select')
   s.setAttribute('multiple', '')
-  var o = document.createElement('option')
+  const o = document.createElement('option')
   s.appendChild(o)
   o.selected = true
   o.selected = false
@@ -18,8 +18,8 @@ function hasMultiSelectBug () {
  * we have to manually loop through the options
  */
 function updateSelect (el, value) {
-  var options = el.options
-  var i = options.length
+  const options = el.options
+  let i = options.length
   while (i--) {
     if (looseEqual(getValue(options[i]), value)) {
       options[i].selected = true
@@ -245,7 +245,7 @@ describe('Directive v-model select', () => {
             '<option>c</option>' +
           '</select>'
       }).$mount()
-      var opts = vm.$el.options
+      const opts = vm.$el.options
       expect(opts[0].selected).toBe(false)
       expect(opts[1].selected).toBe(true)
       expect(opts[2].selected).toBe(false)
@@ -272,7 +272,7 @@ describe('Directive v-model select', () => {
             '<option v-for="o in opts">{{ o }}</option>' +
           '</select>'
       }).$mount()
-      var opts = vm.$el.options
+      const opts = vm.$el.options
       expect(opts[0].selected).toBe(false)
       expect(opts[1].selected).toBe(true)
       expect(opts[2].selected).toBe(false)
@@ -345,7 +345,7 @@ describe('Directive v-model select', () => {
         '<option selected>c</option>' +
       '</select>'
     }).$mount()
-    var opts = vm.$el.options
+    const opts = vm.$el.options
     expect(opts[0].selected).toBe(true)
     expect(opts[1].selected).toBe(true)
     expect(opts[2].selected).toBe(true)
@@ -379,8 +379,8 @@ describe('Directive v-model select', () => {
         '</div>'
     }).$mount()
     document.body.appendChild(vm.$el)
-    var selects = vm.$el.getElementsByTagName('select')
-    var select0 = selects[0]
+    const selects = vm.$el.getElementsByTagName('select')
+    const select0 = selects[0]
     select0.options[0].selected = true
     triggerEvent(select0, 'change')
     waitForUpdate(() => {
@@ -421,7 +421,7 @@ describe('Directive v-model select', () => {
           '<option value="true">c</option>' +
         '</select>'
     }).$mount()
-    var opts = vm.$el.options
+    const opts = vm.$el.options
     expect(opts[0].selected).toBe(false)
     expect(opts[1].selected).toBe(true)
     expect(opts[2].selected).toBe(false)

test/unit/features/directives/model-text.spec.js

@@ -167,7 +167,7 @@ describe('Directive v-model text', () => {
           '<span ref="rs">{{selections}}</span>' +
         '</div>'
     }).$mount()
-    var inputs = vm.$el.getElementsByTagName('input')
+    const inputs = vm.$el.getElementsByTagName('input')
     inputs[1].value = 'test'
     triggerEvent(inputs[1], 'input')
     waitForUpdate(() => {

test/unit/features/directives/style.spec.js

@@ -1,11 +1,11 @@
 import Vue from 'vue'
 
 function checkPrefixedProp (prop) {
-  var el = document.createElement('div')
-  var upper = prop.charAt(0).toUpperCase() + prop.slice(1)
+  const el = document.createElement('div')
+  const upper = prop.charAt(0).toUpperCase() + prop.slice(1)
   if (!(prop in el.style)) {
-    var prefixes = ['Webkit', 'Moz', 'ms']
-    var i = prefixes.length
+    const prefixes = ['Webkit', 'Moz', 'ms']
+    let i = prefixes.length
     while (i--) {
       if ((prefixes[i] + upper) in el.style) {
         prop = prefixes[i] + upper

test/unit/features/instance/methods-data.spec.js

@@ -73,7 +73,7 @@ describe('Instance methods data', () => {
     })
 
     it('deep watch', done => {
-      var oldA = vm.a
+      const oldA = vm.a
       vm.$watch('a', spy, { deep: true })
       vm.a.b = 2
       waitForUpdate(() => {
@@ -85,7 +85,7 @@ describe('Instance methods data', () => {
     })
 
     it('handler option', done => {
-      var oldA = vm.a
+      const oldA = vm.a
       vm.$watch('a', {
         handler: spy,
         deep: true

test/unit/features/instance/methods-events.spec.js

@@ -77,7 +77,7 @@ describe('Instance methods events', () => {
   })
 
   it('$off event + fn', () => {
-    var spy2 = jasmine.createSpy('emitter')
+    const spy2 = jasmine.createSpy('emitter')
     vm.$on('test', spy)
     vm.$on('test', spy2)
     vm.$off('test', spy)

test/unit/features/options/functional.spec.js

@@ -244,8 +244,8 @@ describe('Options functional', () => {
 
   it('should work with render fns compiled from template', done => {
     // code generated via vue-template-es2015-compiler
-    var render = function (_h, _vm) {
-      var _c = _vm._c
+    const render = function (_h, _vm) {
+      const _c = _vm._c
       return _c(
         'div',
         [
@@ -261,9 +261,9 @@ describe('Options functional', () => {
         2
       )
     }
-    var staticRenderFns = [
+    const staticRenderFns = [
       function (_h, _vm) {
-        var _c = _vm._c
+        const _c = _vm._c
         return _c('div', [_vm._v('Some '), _c('span', [_vm._v('text')])])
       }
     ]

test/unit/features/options/watch.spec.js

@@ -106,9 +106,9 @@ describe('Options watch', () => {
   })
 
   it('correctly merges multiple extends', done => {
-    var spy2 = jasmine.createSpy('A')
-    var spy3 = jasmine.createSpy('B')
-    var A = Vue.extend({
+    const spy2 = jasmine.createSpy('A')
+    const spy3 = jasmine.createSpy('B')
+    const A = Vue.extend({
       data: function () {
         return {
           a: 0,
@@ -120,21 +120,21 @@ describe('Options watch', () => {
       }
     })
 
-    var B = Vue.extend({
+    const B = Vue.extend({
       extends: A,
       watch: {
         a: spy2
       }
     })
 
-    var C = Vue.extend({
+    const C = Vue.extend({
       extends: B,
       watch: {
         a: spy3
       }
     })
 
-    var vm = new C()
+    const vm = new C()
     vm.a = 1
 
     waitForUpdate(() => {

test/unit/features/transition/inject-styles.js

@@ -1,5 +1,5 @@
 function insertCSS (text) {
-  var cssEl = document.createElement('style')
+  const cssEl = document.createElement('style')
   cssEl.textContent = text.trim()
   document.head.appendChild(cssEl)
 }

test/unit/karma.base.config.js

@@ -1,7 +1,7 @@
-var alias = require('../../scripts/alias')
-var webpack = require('webpack')
+const alias = require('../../scripts/alias')
+const webpack = require('webpack')
 
-var webpackConfig = {
+const webpackConfig = {
   mode: 'development',
   resolve: {
     alias: alias

test/unit/karma.cover.config.js

@@ -1,7 +1,7 @@
-var base = require('./karma.base.config.js')
+const base = require('./karma.base.config.js')
 
 module.exports = function (config) {
-  var options = Object.assign(base, {
+  const options = Object.assign(base, {
     browsers: ['PhantomJS'],
     reporters: ['mocha', 'coverage'],
     coverageReporter: {

test/unit/karma.dev.config.js

@@ -1,4 +1,4 @@
-var base = require('./karma.base.config.js')
+const base = require('./karma.base.config.js')
 
 module.exports = function (config) {
   config.set(Object.assign(base, {

test/unit/karma.sauce.config.js

@@ -1,5 +1,5 @@
-var webpack = require('webpack')
-var base = require('./karma.base.config.js')
+const webpack = require('webpack')
+const base = require('./karma.base.config.js')
 
 base.webpack.plugins = [
   new webpack.DefinePlugin({
@@ -19,7 +19,7 @@ base.webpack.plugins = [
  * smaller batches.
  */
 
-var batches = [
+const batches = [
   // the cool kids
   {
     sl_chrome: {
@@ -79,7 +79,7 @@ var batches = [
 ]
 
 module.exports = function (config) {
-  var batch = batches[process.argv[4] || 0]
+  const batch = batches[process.argv[4] || 0]
 
   config.set(Object.assign(base, {
     singleRun: true,

test/unit/karma.unit.config.js

@@ -1,4 +1,4 @@
-var base = require('./karma.base.config.js')
+const base = require('./karma.base.config.js')
 
 module.exports = function (config) {
   config.set(Object.assign(base, {