diff --git a/client/src/components/AssignmentWithSubmissions.vue b/client/src/components/AssignmentWithSubmissions.vue
index bec42176..05918395 100644
--- a/client/src/components/AssignmentWithSubmissions.vue
+++ b/client/src/components/AssignmentWithSubmissions.vue
@@ -1,4 +1,5 @@
 <template>
+  <!-- eslint-disable vue/no-v-html -->
   <div class="assignment-with-submissions">
     <p class="assignment-with-submissions__text">
       {{ assignment.assignment }}
diff --git a/client/src/components/ColorChooser.vue b/client/src/components/ColorChooser.vue
index 82294c25..3880b7a6 100644
--- a/client/src/components/ColorChooser.vue
+++ b/client/src/components/ColorChooser.vue
@@ -25,7 +25,7 @@
   const Tick = () => import(/* webpackChunkName: "icons" */'@/components/icons/Tick');
 
   export default {
-    props: ['selected-color'],
+    props: ['selectedColor'],
 
     components: {
       Tick
diff --git a/client/src/components/HeaderBar.vue b/client/src/components/HeaderBar.vue
index 82ea6371..a2827a0d 100644
--- a/client/src/components/HeaderBar.vue
+++ b/client/src/components/HeaderBar.vue
@@ -35,7 +35,6 @@
   import openSidebar from '@/mixins/open-sidebar';
   import me from '@/mixins/me';
 
-  const Logo = () => import(/* webpackChunkName: "icons" */'@/components/icons/Logo');
   const Hamburger = () => import(/* webpackChunkName: "icons" */'@/components/icons/Hamburger');
 
   export default {
@@ -44,7 +43,6 @@
     components: {
       ContentNavigation,
       UserWidget,
-      Logo,
       CurrentClass,
       Hamburger,
     },
diff --git a/client/src/components/SectionBlock.vue b/client/src/components/SectionBlock.vue
index a065ee57..61b5c7bd 100644
--- a/client/src/components/SectionBlock.vue
+++ b/client/src/components/SectionBlock.vue
@@ -41,7 +41,7 @@
 
 <script>
   export default {
-    props: ['title', 'subtitle', 'route', 'link-text'],
+    props: ['title', 'subtitle', 'route', 'linkText'],
     methods: {
       navigate() {
         if (this.route) {
diff --git a/client/src/components/book-navigation/BookTopicNavigation.vue b/client/src/components/book-navigation/BookTopicNavigation.vue
index bdb29be3..09a181c3 100644
--- a/client/src/components/book-navigation/BookTopicNavigation.vue
+++ b/client/src/components/book-navigation/BookTopicNavigation.vue
@@ -45,7 +45,7 @@
       topics: {
         query: ALL_TOPICS_QUERY,
         manual: true,
-        result({data, loading, networkStatus}) {
+        result({data, loading}) {
           if (!loading) {
             this.topics = this.$getRidOfEdges(data).topics;
           }
diff --git a/client/src/components/book-navigation/SubNavigationItem.vue b/client/src/components/book-navigation/SubNavigationItem.vue
index ddacfeaa..9a351602 100644
--- a/client/src/components/book-navigation/SubNavigationItem.vue
+++ b/client/src/components/book-navigation/SubNavigationItem.vue
@@ -40,7 +40,7 @@
     },
 
     watch: {
-      $route(to, from) {
+      $route() {
         this.show = false;
       }
     },
diff --git a/client/src/components/content-block-form/ContentsForm.vue b/client/src/components/content-block-form/ContentsForm.vue
index 7b28941f..acf2d669 100644
--- a/client/src/components/content-block-form/ContentsForm.vue
+++ b/client/src/components/content-block-form/ContentsForm.vue
@@ -120,7 +120,7 @@
     },
 
     methods: {
-      setContentBlockType(checked, localContentBlock) {
+      setContentBlockType(checked) {
         this.localContentBlock.isAssignment = checked;
       },
       update(index, element) {
diff --git a/client/src/components/content-blocks/ContentComponent.vue b/client/src/components/content-blocks/ContentComponent.vue
index 2292f2fb..b901e381 100644
--- a/client/src/components/content-blocks/ContentComponent.vue
+++ b/client/src/components/content-blocks/ContentComponent.vue
@@ -93,13 +93,12 @@ export default {
 
   methods: {
     addNote(id) {
-      if (!this.parent.hasOwnProperty('__typename')) {
-        this.parent.__typename = 'ContentBlockNode';
-      }
+      const type = Object.prototype.hasOwnProperty.call(this.parent, '__typename')
+        ? this.parent.__typename : 'ContentBlockNode';
 
       this.$store.dispatch('addNote', {
         content: id,
-        type: this.parent.__typename,
+        type,
         block: this.root
       });
     },
diff --git a/client/src/components/content-blocks/InstrumentWidget.vue b/client/src/components/content-blocks/InstrumentWidget.vue
index 1dd96fca..183df474 100644
--- a/client/src/components/content-blocks/InstrumentWidget.vue
+++ b/client/src/components/content-blocks/InstrumentWidget.vue
@@ -1,4 +1,5 @@
 <template>
+  <!-- eslint-disable vue/no-v-html -->
   <div class="instrument-widget">
     <div
       class="instrument-widget__description"
diff --git a/client/src/components/content-blocks/LinkBlock.vue b/client/src/components/content-blocks/LinkBlock.vue
index c7d9a913..6458235f 100644
--- a/client/src/components/content-blocks/LinkBlock.vue
+++ b/client/src/components/content-blocks/LinkBlock.vue
@@ -18,7 +18,7 @@
   export default {
     props: {
       value: Object,
-      'no-margin': {
+      noMargin: {
         default: false
       }
     },
diff --git a/client/src/components/content-blocks/SectionTitleBlock.vue b/client/src/components/content-blocks/SectionTitleBlock.vue
index 79f10255..fda0706d 100644
--- a/client/src/components/content-blocks/SectionTitleBlock.vue
+++ b/client/src/components/content-blocks/SectionTitleBlock.vue
@@ -1,4 +1,5 @@
 <template>
+  <!-- eslint-disable vue/no-v-html -->
   <h4
     class="section-title"
     v-html="value.text"
diff --git a/client/src/components/content-blocks/SubtitleBlock.vue b/client/src/components/content-blocks/SubtitleBlock.vue
index 1e0e84bd..83e33974 100644
--- a/client/src/components/content-blocks/SubtitleBlock.vue
+++ b/client/src/components/content-blocks/SubtitleBlock.vue
@@ -6,6 +6,7 @@
 </template>
 
 <script>
+  //todo: esacpe value.text
   export default {
     props: ['value']
   };
diff --git a/client/src/components/content-blocks/Task.vue b/client/src/components/content-blocks/Task.vue
index a44989d1..a15749e7 100644
--- a/client/src/components/content-blocks/Task.vue
+++ b/client/src/components/content-blocks/Task.vue
@@ -1,4 +1,5 @@
 <template>
+  <!-- eslint-disable vue/no-v-html -->
   <div class="task">
     <div
       class="task__text"
diff --git a/client/src/components/content-blocks/TextBlock.vue b/client/src/components/content-blocks/TextBlock.vue
index b398baef..6a11ec26 100644
--- a/client/src/components/content-blocks/TextBlock.vue
+++ b/client/src/components/content-blocks/TextBlock.vue
@@ -6,6 +6,7 @@
 </template>
 
 <script>
+  // todo: escape text maybe
   export default {
     props: ['value']
   };
diff --git a/client/src/components/content-blocks/assignment/Assignment.vue b/client/src/components/content-blocks/assignment/Assignment.vue
index 26c07e7f..5573c934 100644
--- a/client/src/components/content-blocks/assignment/Assignment.vue
+++ b/client/src/components/content-blocks/assignment/Assignment.vue
@@ -112,6 +112,7 @@
         return this.assignment.id ? this.assignment.id.replace(/=/g, '') : '';
       },
       feedbackText() {
+        // todo: should we maybe clean up this feedback text?
         let feedback = this.assignment.submission.submissionFeedback;
         return `<span class="inline-title">Feedback von ${feedback.teacher.firstName} ${feedback.teacher.lastName}:</span> ${feedback.text}`;
       },
diff --git a/client/src/components/content-blocks/assignment/SpellCheck.vue b/client/src/components/content-blocks/assignment/SpellCheck.vue
index eea7bf10..c7f3e546 100644
--- a/client/src/components/content-blocks/assignment/SpellCheck.vue
+++ b/client/src/components/content-blocks/assignment/SpellCheck.vue
@@ -1,4 +1,5 @@
 <template>
+  <!-- eslint-disable vue/no-v-html -->
   <p
     class="spellcheck"
     v-if="corrections"
diff --git a/client/src/components/content-blocks/assignment/SubmissionForm.vue b/client/src/components/content-blocks/assignment/SubmissionForm.vue
index da25bdb9..adf6ffae 100644
--- a/client/src/components/content-blocks/assignment/SubmissionForm.vue
+++ b/client/src/components/content-blocks/assignment/SubmissionForm.vue
@@ -52,7 +52,6 @@
   const FinalSubmission = () => import('@/components/content-blocks/assignment/FinalSubmission');
   const FileUpload = () => import('@/components/ui/file-upload/FileUpload');
 
-  const DocumentBlock = () => import(/* webpackChunkName: "content-components" */'@/components/content-blocks/DocumentBlock');
 
   export default {
     props: {
@@ -81,7 +80,6 @@
       FileUpload,
       SubmissionInput,
       FinalSubmission,
-      DocumentBlock,
     },
 
     computed: {
diff --git a/client/src/components/content-forms/ImageForm.vue b/client/src/components/content-forms/ImageForm.vue
index 5fe9c5ae..f1fe337b 100644
--- a/client/src/components/content-forms/ImageForm.vue
+++ b/client/src/components/content-forms/ImageForm.vue
@@ -48,7 +48,7 @@
       this.mountUploadcare();
     },
     methods: {
-      error(e) {
+      error() {
         this.hadError = true;
         delete this.value.url;
 
@@ -84,8 +84,7 @@
 </script>
 
 <style scoped lang="scss">
-  @import "@/styles/_variables.scss";
-  @import "@/styles/_mixins.scss";
+  @import "~styles/helpers";
 
   .image-form {
     &__error {
diff --git a/client/src/components/content-forms/TextForm.vue b/client/src/components/content-forms/TextForm.vue
index b51f261f..e8ec7762 100644
--- a/client/src/components/content-forms/TextForm.vue
+++ b/client/src/components/content-forms/TextForm.vue
@@ -17,7 +17,7 @@
         type: Object,
         default: null,
         validator(value) {
-          return value.hasOwnProperty('text');
+          return Object.prototype.hasOwnProperty.call(value, 'text');
         }
       },
       index: {
diff --git a/client/src/components/instruments/InstrumentFilter.vue b/client/src/components/instruments/InstrumentFilter.vue
index bcf265d4..c5d197eb 100644
--- a/client/src/components/instruments/InstrumentFilter.vue
+++ b/client/src/components/instruments/InstrumentFilter.vue
@@ -31,7 +31,6 @@
 <script>
   import {INTERDISCIPLINARY, LANGUAGE_COMMUNICATION, SOCIETY} from '@/consts/instrument.consts';
 
-  import Checkbox from '@/components/ui/Checkbox';
   import FilterGroup from '@/components/instruments/FilterGroup';
 
   import INSTRUMENT_TYPES_QUERY from 'gql/queries/instrumentTypesQuery';
@@ -40,7 +39,6 @@
 
     components: {
       FilterGroup,
-      Checkbox,
     },
     data() {
       return {
diff --git a/client/src/components/modules/Module.vue b/client/src/components/modules/Module.vue
index bad08b41..5c5c1098 100644
--- a/client/src/components/modules/Module.vue
+++ b/client/src/components/modules/Module.vue
@@ -1,4 +1,5 @@
 <template>
+  <!-- eslint-disable vue/no-v-html -->
   <div
     class="module"
     v-if="module.id"
diff --git a/client/src/components/modules/ModuleNavigation.vue b/client/src/components/modules/ModuleNavigation.vue
index f919cc89..9cfe4c4b 100644
--- a/client/src/components/modules/ModuleNavigation.vue
+++ b/client/src/components/modules/ModuleNavigation.vue
@@ -73,7 +73,6 @@
   import BackLink from '@/components/BackLink';
   import {moduleQuery} from '@/graphql/queries';
 
-  import SubNavigationItem from '@/components/book-navigation/SubNavigationItem';
   import ToggleEditing from '@/components/toggle-menu/ToggleEditing';
   import me from '@/mixins/me';
   import SnapshotMenu from '@/components/modules/SnapshotMenu';
@@ -88,7 +87,6 @@
     components: {
       SnapshotMenu,
       BackLink,
-      SubNavigationItem,
       ToggleEditing,
     },
 
diff --git a/client/src/components/modules/SnapshotListItem.vue b/client/src/components/modules/SnapshotListItem.vue
index 54193b09..aa76c87a 100644
--- a/client/src/components/modules/SnapshotListItem.vue
+++ b/client/src/components/modules/SnapshotListItem.vue
@@ -1,4 +1,5 @@
 <template>
+  <!-- eslint-disable vue/no-v-html -->
   <div class="snapshot-list-item">
     <router-link
       :to="snapshotRoute"
diff --git a/client/src/components/objective-groups/ObjectiveGroups.vue b/client/src/components/objective-groups/ObjectiveGroups.vue
index 740becb5..59ced210 100644
--- a/client/src/components/objective-groups/ObjectiveGroups.vue
+++ b/client/src/components/objective-groups/ObjectiveGroups.vue
@@ -2,8 +2,7 @@
   <div class="objective-groups">
     <objective-group
       :group="group"
-      v-for="group in objectiveGroups"
-      v-if="!group.hidden"
+      v-for="group in filteredObjectiveGroups"
       :key="group.id"
     />
   </div>
@@ -39,6 +38,9 @@
     },
 
     computed: {
+      filteredObjectiveGroups() {
+        return this.objectiveGroups.filter(g => !g.hidden);
+      },
       objectiveGroups() {
         /*
          a teacher should get multiple blocks, so he can manage the visibility for his students.
diff --git a/client/src/components/ui/file-upload/SimpleFileUploadWithIcon.vue b/client/src/components/ui/file-upload/SimpleFileUploadWithIcon.vue
index 65668bcf..4d3463bb 100644
--- a/client/src/components/ui/file-upload/SimpleFileUploadWithIcon.vue
+++ b/client/src/components/ui/file-upload/SimpleFileUploadWithIcon.vue
@@ -14,7 +14,6 @@
 <script>
   const SimpleFileUploadHiddenInput = () => import('@/components/ui/file-upload/SimpleFileUploadHiddenInput');
   const ButtonWithIconAndText = () => import('@/components/ui/ButtonWithIconAndText');
-  const DocumentIcon = () => import(/* webpackChunkName: "icons" */'@/components/icons/DocumentIcon');
 
   export default {
     props: ['value'],
@@ -22,7 +21,6 @@
     components: {
       ButtonWithIconAndText,
       SimpleFileUploadHiddenInput,
-      DocumentIcon,
     },
 
     methods: {
diff --git a/client/src/filters/date-filter.js b/client/src/filters/date-filter.js
index b69ff14e..f4cb60bf 100644
--- a/client/src/filters/date-filter.js
+++ b/client/src/filters/date-filter.js
@@ -1,5 +1,5 @@
 import dayjs from 'dayjs';
-require('dayjs/locale/de');
+import 'dayjs/locale/de';
 
 dayjs.locale('de');
 
diff --git a/client/src/helpers/sorting.js b/client/src/helpers/sorting.js
index 9e3db38e..079c2eb0 100644
--- a/client/src/helpers/sorting.js
+++ b/client/src/helpers/sorting.js
@@ -1 +1 @@
-export const withoutOwnerFirst = (a, b) => a.owner ? 1 : -1;
+export const withoutOwnerFirst = (a) => a.owner ? 1 : -1;
diff --git a/client/src/helpers/teaser.js b/client/src/helpers/teaser.js
index 0bf547c1..5ffa3e92 100644
--- a/client/src/helpers/teaser.js
+++ b/client/src/helpers/teaser.js
@@ -2,6 +2,7 @@ export default (contents) => {
   if (contents && contents.length) {
     let first = contents.find(content => content.type !== 'image_url_block');
     if (first && first.type) {
+      let parts;
       switch (first.type) {
         case 'text_block':
           return first.value.text.replace(/<p>/g, '').replace(/<\/p>/g, '<br>').slice(0, 75) + '...';
@@ -9,7 +10,7 @@ export default (contents) => {
         case 'link_block':
           return first.value.url;
         case 'document_block':
-          const parts = first.value.url.split('/');
+          parts = first.value.url.split('/');
           return parts[parts.length - 1];
         default:
           return '';
diff --git a/client/src/helpers/update-content-bookmark-mutation.js b/client/src/helpers/update-content-bookmark-mutation.js
index d46f93d1..76592747 100644
--- a/client/src/helpers/update-content-bookmark-mutation.js
+++ b/client/src/helpers/update-content-bookmark-mutation.js
@@ -67,7 +67,7 @@ export const constructContentComponentBookmarkMutation = (uuid, bookmarked, pare
           bookmarked
         }
       },
-      update: (store, response) => {
+      update: (store) => {
         const query = CONTENT_BLOCK_QUERY;
         const variables = {id: root};
         const data = store.readQuery({
diff --git a/client/src/main.js b/client/src/main.js
index 24f46f59..bcf7f828 100644
--- a/client/src/main.js
+++ b/client/src/main.js
@@ -68,14 +68,14 @@ function getCookieValue(cookieName) {
 
 function loginRequired(to) {
   // public pages have the meta.public property set to true
-  return !to.hasOwnProperty('meta') || !to.meta.hasOwnProperty('public') || !to.meta.public;
+  return !Object.prototype.hasOwnProperty.call(to, 'meta') || !Object.prototype.hasOwnProperty.call(to.meta ,'public') || !to.meta.public;
 }
 
 function unauthorizedAccess(to) {
   return loginRequired(to) && getCookieValue('loginStatus') !== 'true';
 }
 
-function redirectUsersWithoutValidLicense(to) {
+function redirectUsersWithoutValidLicense() {
   return privateApolloClient.query({
     query: ME_QUERY,
   }).then(({data}) => data.me.expiryDate == null);
@@ -87,7 +87,7 @@ function redirectStudentsWithoutClass() {
   }).then(({data}) => data.me.schoolClasses.edges.length === 0 && !data.me.isTeacher);
 }
 
-function redirectUsersToOnboarding(to) {
+function redirectUsersToOnboarding() {
   return privateApolloClient.query({
     query: ME_QUERY,
   }).then(({data}) => !data.me.onboardingVisited);
diff --git a/client/src/mixins/update-selected-class.js b/client/src/mixins/update-selected-class.js
index cc9637de..db2c6a33 100644
--- a/client/src/mixins/update-selected-class.js
+++ b/client/src/mixins/update-selected-class.js
@@ -15,7 +15,7 @@ export default {
             id: selectedClass.id
           }
         },
-        update(store, data) {
+        update(store) {
           let meData = store.readQuery({query: ME_QUERY});
 
           meData.me.selectedClass = selectedClass;
diff --git a/client/src/pages/createContentBlock.vue b/client/src/pages/createContentBlock.vue
index ea2c1ca1..c7028ab6 100644
--- a/client/src/pages/createContentBlock.vue
+++ b/client/src/pages/createContentBlock.vue
@@ -92,7 +92,6 @@
   import NEW_CONTENT_BLOCK_MUTATION from '@/graphql/gql/mutations/addContentBlock.gql';
   import {setUserBlockType} from '@/helpers/content-block';
   import MODULE_DETAILS_QUERY from '@/graphql/gql/queries/modules/moduleDetailsQuery.gql';
-  import {MODULE_PAGE} from '@/router/module.names';
 
   export default Vue.extend({
     props: {
diff --git a/client/src/pages/index.vue b/client/src/pages/index.vue
index 6df67989..42778bef 100644
--- a/client/src/pages/index.vue
+++ b/client/src/pages/index.vue
@@ -41,7 +41,7 @@
         query: ALL_MODULES,
         // prefetch: true,
         manual: true,
-        result({data, loading, networkStatus}) {
+        result({data, loading}) {
           if (!loading) {
             this.modules = this.$getRidOfEdges(data).modules;
           }
diff --git a/client/src/plugins/edges.js b/client/src/plugins/edges.js
index 50b7df7c..1981bd17 100644
--- a/client/src/plugins/edges.js
+++ b/client/src/plugins/edges.js
@@ -2,7 +2,7 @@ const getRidOfEdges = (collection) => {
   if (typeof collection === 'object' && collection && !Array.isArray(collection)) {
     let newObj = {};
     for (const k in collection) {
-      if (collection.hasOwnProperty(k)) {
+      if (Object.prototype.hasOwnProperty.call(collection, k)) {
         if (k === 'edges') {
           return collection.edges.map(edge => getRidOfEdges(edge.node));
         } else {
@@ -20,7 +20,7 @@ const getRidOfEdges = (collection) => {
 };
 
 const EdgesPlugin = {
-  install(Vue, options) {
+  install(Vue) {
     Vue.prototype.$getRidOfEdges = getRidOfEdges;
   }
 };
diff --git a/client/src/plugins/modal.js b/client/src/plugins/modal.js
index b11072a5..355b22f5 100644
--- a/client/src/plugins/modal.js
+++ b/client/src/plugins/modal.js
@@ -3,7 +3,7 @@
 import Vue from 'vue';
 
 class ModalStore {
-  constructor(data = {}) {
+  constructor() {
     this.vm = new Vue({
       data: () => ({
         component: '',
@@ -18,7 +18,7 @@ class ModalStore {
 }
 
 const ModalPlugin = {
-  install(Vue, options) {
+  install(Vue) {
     const store = new ModalStore({});
 
     const reset = () => {