fix(vuepress-theme-reco): fix eslint errors

Author: reco_luan

packages/vuepress-theme-reco/components/SidebarLinks.vue

@@ -53,60 +53,62 @@ export default {
     }
   },
 
-  mounted() {
+  mounted () {
     this.activationLink()
     this.isInViewPortOfOne()
   },
-  
+
   updated: function () {
     this.isInViewPortOfOne()
   },
 
   methods: {
     activationLink () {
-      let subtitleName = decodeURIComponent(this.$route.fullPath)
-      if (!subtitleName || subtitleName=='') return
+      const subtitleName = decodeURIComponent(this.$route.fullPath)
+      if (!subtitleName || subtitleName == '') return
+      // eslint-disable-next-line no-undef
       const subtitles = [].slice.call(document.querySelectorAll(AHL_SIDEBAR_LINK_SELECTOR))
-      for(let i = 0; i < subtitles.length; i++) {
-        if(decodeURIComponent(subtitles[i].getAttribute('href')).indexOf(subtitleName) != -1){
+      for (let i = 0; i < subtitles.length; i++) {
+        if (decodeURIComponent(subtitles[i].getAttribute('href')).indexOf(subtitleName) != -1) {
           subtitles[i].click()
           this.activationAnchor()
           return
         }
       }
     },
-    
-    activationAnchor() {
-      let anchors = [].slice.call(document.querySelectorAll(AHL_HEADER_ANCHOR_SELECTOR))
-                    .filter(anchor => decodeURIComponent(this.$route.fullPath).indexOf(decodeURIComponent(anchor.hash)) != -1)
-      if(anchors == null || anchors.length<1 || anchors[0].offsetTop == undefined) return
-      setTimeout(function(){
+
+    activationAnchor () {
+      // eslint-disable-next-line no-undef
+      const anchors = [].slice.call(document.querySelectorAll(AHL_HEADER_ANCHOR_SELECTOR))
+        .filter(anchor => decodeURIComponent(this.$route.fullPath).indexOf(decodeURIComponent(anchor.hash)) != -1)
+      if (anchors == null || anchors.length < 1 || anchors[0].offsetTop == undefined) return
+      setTimeout(function () {
         window.scrollTo(0, anchors[0].offsetTop + 160)
-      },100)
+      }, 100)
     },
-    
+
     isInViewPortOfOne () {
-      let siderbarScroll = document.getElementsByClassName("sidebar")[0]
-      let el = document.getElementsByClassName("active sidebar-link")[1]
-      if (el ==null || el == undefined || el.offsetTop == undefined) {
-        el = document.getElementsByClassName("active sidebar-link")[0]
+      const siderbarScroll = document.getElementsByClassName('sidebar')[0]
+      let el = document.getElementsByClassName('active sidebar-link')[1]
+      if (el == null || el == undefined || el.offsetTop == undefined) {
+        el = document.getElementsByClassName('active sidebar-link')[0]
       }
-      if (el ==null || el == undefined || el.offsetTop == undefined) return
-      
+      if (el == null || el == undefined || el.offsetTop == undefined) return
+
       const viewPortHeight = siderbarScroll.clientHeight || window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight
-      let offsetTop = el.offsetTop
-      let offsetBottom = el.offsetTop + el.offsetHeight
-      let scrollTop = siderbarScroll.scrollTop
-      let bottomVisible = (offsetBottom <= viewPortHeight + scrollTop)
+      const offsetTop = el.offsetTop
+      const offsetBottom = el.offsetTop + el.offsetHeight
+      const scrollTop = siderbarScroll.scrollTop
+      const bottomVisible = (offsetBottom <= viewPortHeight + scrollTop)
       if (!bottomVisible) {
         siderbarScroll.scrollTop = (offsetBottom + 5 - viewPortHeight)
       }
-      let topVisible = (offsetTop >= scrollTop)
+      const topVisible = (offsetTop >= scrollTop)
       if (!topVisible) {
         siderbarScroll.scrollTop = (offsetTop - 5)
       }
     },
-    
+
     refreshIndex () {
       const index = resolveOpenGroupIndex(
         this.$route,