[skip ci] code review comments

app/assets/javascripts/sidebar/components/assignees/sidebar_assignees.js

@@ -48,8 +48,7 @@ export default {
     eventHub.$on('sidebar.saveUsers', this.saveUsers);
   },
   beforeMount() {
-    const element = this.$el;
-    this.field = element.dataset.field;
+    this.field = this.$el.dataset.field;
   },
   template: `
     <div>

app/assets/javascripts/sidebar/components/time_tracking/collapsed_state.js

@@ -24,10 +24,12 @@ export default {
     timeSpentHumanReadable: {
       type: String,
       required: false,
+      default: '',
     },
     timeEstimateHumanReadable: {
       type: String,
       required: false,
+      default: '',
     },
   },
   methods: {

app/assets/javascripts/sidebar/components/time_tracking/time_tracker.js

@@ -13,24 +13,25 @@ export default {
     time_estimate: {
       type: Number,
       required: true,
-      default: 0,
     },
     time_spent: {
       type: Number,
       required: true,
-      default: 0,
     },
     human_time_estimate: {
       type: String,
       required: false,
+      default: '',
     },
     human_time_spent: {
       type: String,
       required: false,
+      default: '',
     },
     rootPath: {
       type: String,
       required: true,
+      default: '',
     },
   },
   data() {

app/assets/javascripts/sidebar/services/sidebar_service.js

 import Vue from 'vue';
 import VueResource from 'vue-resource';
-import '../../vue_shared/vue_resource_interceptor';
 
 Vue.use(VueResource);