refactor: ES6+ modernization + 2 bugfixes

- var→const/let, function→arrow/class across all 13 JS files
- Timer: prototype→class with ES6 getters
- plan days: IIFE→Array.from declarative generation
- storage/plan: unified formatDate via util.js
- Bugfix: getPlanDay now filters by planId (plan switch accuracy)
- Bugfix: getTodayRecord searches all months (cross-month boundary)
- WXML/WXSS unchanged; public API unchanged

pages/index/index.js

@@ -1,7 +1,7 @@
-var storage = require('../../utils/storage')
-var planMod = require('../../utils/plan')
-var util = require('../../utils/util')
-var themeMod = require('../../utils/theme')
+const storage = require('../../utils/storage')
+const planMod = require('../../utils/plan')
+const util = require('../../utils/util')
+const themeMod = require('../../utils/theme')
 
 Page({
   data: {
@@ -22,38 +22,33 @@ Page({
     customInput: ''
   },
 
-  onLoad: function () {
+  onLoad() {
     this.refresh()
   },
 
-  onShow: function () {
+  onShow() {
     themeMod.applyThemeToPage(this)
     try {
-      var tb = this.getTabBar()
+      const tb = this.getTabBar()
       if (tb) tb.setData({ selected: 0 })
     } catch (e) {}
     this.refresh()
   },
 
-  onPullDownRefresh: function () {
+  onPullDownRefresh() {
     this.refresh()
     wx.stopPullDownRefresh()
   },
 
-  refresh: function () {
-    var settings = storage.getSettings()
-    var streak = storage.getStreak()
-    var todayRecord = storage.getTodayRecord()
+  refresh() {
+    const settings = storage.getSettings()
+    const streak = storage.getStreak()
+    const todayRecord = storage.getTodayRecord()
 
-    var records = []
-    var allRecords = storage.getRecords()
-    Object.keys(allRecords).forEach(function (key) {
-      records = records.concat(allRecords[key])
-    })
-
-    var plan = planMod.getPlan(settings.planId)
-    var planDay = planMod.getPlanDay(settings.planId, records)
-    var target = planMod.getTodayTarget(settings.planId, Math.min(planDay, plan.totalDays))
+    const allRecords = Object.values(storage.getRecords()).flat()
+    const plan = planMod.getPlan(settings.planId)
+    const planDay = planMod.getPlanDay(settings.planId, allRecords)
+    const target = planMod.getTodayTarget(settings.planId, Math.min(planDay, plan.totalDays))
 
     this.setData({
       todayTarget: target,
@@ -68,37 +63,37 @@ Page({
     })
   },
 
-  onStartTrain: function () {
+  onStartTrain() {
     wx.navigateTo({ url: '/pages/timer/timer' })
   },
 
-  onFreeTrain: function () {
+  onFreeTrain() {
     this.setData({ showPicker: true, customInput: '', customDuration: 60 })
   },
 
-  onClosePicker: function () {
+  onClosePicker() {
     this.setData({ showPicker: false })
   },
 
-  onSelectPreset: function (e) {
-    var val = e.currentTarget.dataset.value
+  onSelectPreset(e) {
+    const val = e.currentTarget.dataset.value
     this.setData({ customDuration: val, customInput: '' })
   },
 
-  onCustomInput: function (e) {
-    var val = parseInt(e.detail.value) || 0
+  onCustomInput(e) {
+    const val = parseInt(e.detail.value) || 0
     this.setData({ customInput: e.detail.value, customDuration: val })
   },
 
-  onConfirmFree: function () {
-    var dur = this.data.customDuration
+  onConfirmFree() {
+    const dur = this.data.customDuration
     if (!dur || dur <= 0) {
       wx.showToast({ title: '请输入有效时长', icon: 'none' })
       return
     }
     this.setData({ showPicker: false })
-    wx.navigateTo({ url: '/pages/timer/timer?free=' + dur })
+    wx.navigateTo({ url: `/pages/timer/timer?free=${dur}` })
   },
 
-  noop: function () {}
+  noop() {}
 })