diff --git a/webapp/components/CommentList/CommentList.vue b/webapp/components/CommentList/CommentList.vue
index ef6e3b096..b700b8452 100644
--- a/webapp/components/CommentList/CommentList.vue
+++ b/webapp/components/CommentList/CommentList.vue
@@ -1,13 +1,13 @@
 <template>
   <div id="comments" class="comment-list">
     <h3 class="title">
-      <counter-icon icon="comments" :count="post.comments.length" />
+      <counter-icon icon="comments" :count="postComments.length" />
       {{ $t('common.comment', null, 0) }}
     </h3>
     <ds-space margin-bottom="large" />
-    <div v-if="post.comments && post.comments.length" id="comments" class="comments">
+    <div id="comments" class="comments">
       <comment
-        v-for="comment in post.comments"
+        v-for="comment in postComments"
         :key="comment.id"
         :comment="comment"
         :post="post"
@@ -36,6 +36,11 @@ export default {
     routeHash: { type: String, default: () => '' },
     post: { type: Object, default: () => {} },
   },
+  computed: {
+    postComments() {
+      return (this.post && this.post.comments) || []
+    },
+  },
   methods: {
     reply(message) {
       this.$emit('reply', message)
@@ -44,7 +49,7 @@ export default {
       return anchor === '#comments'
     },
     updateCommentList(updatedComment) {
-      this.post.comments = this.post.comments.map(comment => {
+      this.postComments = this.postComments.map(comment => {
         return comment.id === updatedComment.id ? updatedComment : comment
       })
     },
diff --git a/webapp/pages/post/_id/_slug/index.spec.js b/webapp/pages/post/_id/_slug/index.spec.js
index 6c5cb5259..a516334ad 100644
--- a/webapp/pages/post/_id/_slug/index.spec.js
+++ b/webapp/pages/post/_id/_slug/index.spec.js
@@ -1,5 +1,6 @@
 import { config, mount } from '@vue/test-utils'
 import Vuex from 'vuex'
+import Vue from 'vue'
 import PostSlug from './index.vue'
 import CommentList from '~/components/CommentList/CommentList'
 
@@ -11,85 +12,103 @@ const localVue = global.localVue
 localVue.directive('scrollTo', jest.fn())
 
 describe('PostSlug', () => {
-  let store, propsData, mocks, stubs, wrapper, Wrapper
+  let wrapper, Wrapper, backendData, mocks, stubs
 
   beforeEach(() => {
-    store = new Vuex.Store({
-      getters: {
-        'auth/user': () => {
-          return { id: '1stUser' }
-        },
-        'auth/isModerator': () => false,
-      },
-    })
-    propsData = {}
-    mocks = {
-      $t: jest.fn(),
-      $filters: {
-        truncate: a => a,
-        removeHtml: a => a,
-      },
-      $route: {
-        hash: '',
-      },
-      // If you are mocking the router, then don't use VueRouter with localVue: https://vue-test-utils.vuejs.org/guides/using-with-vue-router.html
-      $router: {
-        history: {
-          push: jest.fn(),
-        },
-      },
-      $toast: {
-        success: jest.fn(),
-        error: jest.fn(),
-      },
-      $apollo: {
-        mutate: jest.fn().mockResolvedValue(),
-        query: jest.fn().mockResolvedValue({ data: { PostEmotionsCountByEmotion: {} } }),
-      },
-      $scrollTo: jest.fn(),
-    }
-    stubs = {
-      HcEditor: { render: () => {}, methods: { insertReply: jest.fn(() => null) } },
-      ContentViewer: true,
-    }
-    jest.useFakeTimers()
-    wrapper = Wrapper()
-    wrapper.setData({
+    const author = { id: '1stUser', slug: '1st-user' }
+    backendData = {
       post: {
         id: '1',
-        author: {
-          id: '1stUser',
-        },
+        author,
         comments: [
           {
             id: 'comment134',
             contentExcerpt: 'this is a comment',
             content: 'this is a comment',
-            author: {
-              id: '1stUser',
-              slug: '1st-user',
-            },
+            author,
           },
         ],
       },
       ready: true,
-    })
+    }
   })
 
   describe('mount', () => {
-    Wrapper = () => {
-      return mount(PostSlug, {
+    Wrapper = async (opts = {}) => {
+      jest.useFakeTimers()
+      const store = new Vuex.Store({
+        getters: {
+          'auth/user': () => {
+            return { id: '1stUser' }
+          },
+          'auth/isModerator': () => false,
+        },
+      })
+      const propsData = {}
+      mocks = {
+        $t: jest.fn(),
+        $filters: {
+          truncate: a => a,
+          removeHtml: a => a,
+        },
+        $route: {
+          hash: '',
+        },
+        // If you are mocking the router, then don't use VueRouter with localVue: https://vue-test-utils.vuejs.org/guides/using-with-vue-router.html
+        $router: {
+          history: {
+            push: jest.fn(),
+          },
+        },
+        $toast: {
+          success: jest.fn(),
+          error: jest.fn(),
+        },
+        $apollo: {
+          mutate: jest.fn().mockResolvedValue(),
+          query: jest.fn().mockResolvedValue({ data: { PostEmotionsCountByEmotion: {} } }),
+        },
+        $scrollTo: jest.fn(),
+      }
+      stubs = {
+        HcEditor: { render: () => {}, methods: { insertReply: jest.fn(() => null) } },
+        ContentViewer: true,
+      }
+      const defaults = {
         store,
         mocks,
         localVue,
         propsData,
         stubs,
+      }
+      const wrapper = mount(PostSlug, {
+        ...defaults,
+        ...opts,
       })
+      wrapper.setData(backendData)
+      await Vue.nextTick()
+      return wrapper
     }
 
+    describe('given author is `null`', () => {
+      it('does not crash', async () => {
+        backendData = {
+          post: {
+            id: '1',
+            author: null,
+            comments: [],
+          },
+          ready: true,
+        }
+        wrapper = await Wrapper()
+        expect(wrapper.find('.info.anonymous').exists()).toBe(true)
+      })
+    })
+
     describe('test Post callbacks', () => {
       describe('deletion of Post from Page by invoking "deletePostCallback()"', () => {
         beforeEach(async () => {
+          wrapper = await Wrapper()
           await wrapper.vm.deletePostCallback()
         })
 
@@ -113,6 +132,7 @@ describe('PostSlug', () => {
 
     describe('reply method called when emitted reply received', () => {
       it('CommentList', async () => {
+        wrapper = await Wrapper()
         wrapper.find(CommentList).vm.$emit('reply', {
           id: 'commentAuthorId',
           slug: 'ogerly',
diff --git a/webapp/pages/post/_id/_slug/index.vue b/webapp/pages/post/_id/_slug/index.vue
index 8115294c5..ed418d2b3 100644
--- a/webapp/pages/post/_id/_slug/index.vue
+++ b/webapp/pages/post/_id/_slug/index.vue
@@ -30,7 +30,7 @@
           resource-type="contribution"
           :resource="post"
           :modalsData="menuModalsData"
-          :is-owner="isAuthor(post.author ? post.author.id : null)"
+          :is-owner="isAuthor"
           @pinPost="pinPost"
           @unpinPost="unpinPost"
         />
@@ -74,7 +74,7 @@
           >
             <hc-shout-button
               v-if="post.author"
-              :disabled="isAuthor(post.author.id)"
+              :disabled="isAuthor"
               :count="post.shoutedCount"
               :is-shouted="post.shoutedByCurrentUser"
               :post-id="post.id"
@@ -92,12 +92,12 @@
         />
         <ds-space margin-bottom="large" />
         <comment-form
-          v-if="showNewCommentForm && !post.author.blocked"
+          v-if="showNewCommentForm && !isBlocked"
           ref="commentForm"
           :post="post"
           @createComment="createComment"
         />
-        <ds-placeholder v-if="post.author.blocked">
+        <ds-placeholder v-if="isBlocked">
           {{ $t('settings.blocked-users.explanation.commenting-disabled') }}
           <br />
           {{ $t('settings.blocked-users.explanation.commenting-explanation') }}
@@ -170,14 +170,21 @@ export default {
         this.deletePostCallback,
       )
     },
+    isBlocked() {
+      const { author } = this.post
+      if (!author) return false
+      return author.blocked
+    },
+    isAuthor() {
+      const { author } = this.post
+      if (!author) return false
+      return this.$store.getters['auth/user'].id === author.id
+    },
   },
   methods: {
     reply(message) {
       this.$refs.commentForm && this.$refs.commentForm.reply(message)
     },
-    isAuthor(id) {
-      return this.$store.getters['auth/user'].id === id
-    },
     async deletePostCallback() {
       try {
         await this.$apollo.mutate(deletePostMutation(this.post.id))