diff --git a/src/newsreader/js/pages/homepage/actions/categories.js b/src/newsreader/js/pages/homepage/actions/categories.js
index f30424f..0fc63a6 100644
--- a/src/newsreader/js/pages/homepage/actions/categories.js
+++ b/src/newsreader/js/pages/homepage/actions/categories.js
@@ -28,49 +28,6 @@ export const receiveCategories = categories => ({
 export const requestCategory = () => ({ type: REQUEST_CATEGORY });
 export const requestCategories = () => ({ type: REQUEST_CATEGORIES });
 
-export const fetchCategories = () => {
-  return dispatch => {
-    dispatch(requestCategories());
-
-    return fetch('/api/categories/')
-      .then(response => response.json())
-      .then(json => {
-        const categories = {};
-
-        json.forEach(category => {
-          categories[category.id] = { ...category };
-        });
-
-        dispatch(receiveCategories(categories));
-        return json;
-      })
-      .then(json => {
-        const promises = json.map(category => {
-          return fetch(`/api/categories/${category.id}/rules/`);
-        });
-
-        dispatch(requestRules());
-        return Promise.all(promises);
-      })
-      .then(responses => {
-        return Promise.all(responses.map(response => response.json()));
-      })
-      .then(responseData => {
-        let rules = {};
-
-        responseData.forEach(json => {
-          const data = Object.values(json);
-
-          data.forEach(item => {
-            rules = { ...rules, [item.id]: item };
-          });
-        });
-
-        dispatch(receiveRules(rules));
-      });
-  };
-};
-
 export const fetchCategory = category => {
   return (dispatch, getState) => {
     const { selected } = getState();
@@ -93,3 +50,28 @@ export const fetchCategory = category => {
       });
   };
 };
+
+export const fetchCategories = () => {
+  return dispatch => {
+    dispatch(requestCategories());
+
+    return fetch('/api/categories/')
+      .then(response => response.json())
+      .then(categories => {
+        dispatch(receiveCategories(categories));
+
+        return categories;
+      })
+      .then(categories => {
+        dispatch(requestRules());
+
+        const promises = categories.map(category => {
+          return fetch(`/api/categories/${category.id}/rules/`);
+        });
+
+        return Promise.all(promises);
+      })
+      .then(responses => Promise.all(responses.map(response => response.json())))
+      .then(nestedRules => dispatch(receiveRules(nestedRules.flat())));
+  };
+};
diff --git a/src/newsreader/js/pages/homepage/actions/posts.js b/src/newsreader/js/pages/homepage/actions/posts.js
index 598dde1..d1fc79b 100644
--- a/src/newsreader/js/pages/homepage/actions/posts.js
+++ b/src/newsreader/js/pages/homepage/actions/posts.js
@@ -75,15 +75,7 @@ export const fetchPostsBySection = (section, page = false) => {
 
     return fetch(url)
       .then(response => response.json())
-      .then(json => {
-        const posts = {};
-
-        json.results.forEach(post => {
-          posts[post.id] = post;
-        });
-
-        dispatch(receivePosts(posts, json.next));
-      })
+      .then(posts => dispatch(receivePosts(posts.results, posts.next)))
       .catch(error => {
         if (error instanceof TypeError) {
           console.log(`Unable to parse posts from request: ${error}`);
diff --git a/src/newsreader/js/pages/homepage/actions/rules.js b/src/newsreader/js/pages/homepage/actions/rules.js
index 41e2e06..0f45f1d 100644
--- a/src/newsreader/js/pages/homepage/actions/rules.js
+++ b/src/newsreader/js/pages/homepage/actions/rules.js
@@ -61,14 +61,6 @@ export const fetchRulesByCategory = category => {
 
     return fetch(`/api/categories/${category.id}/rules/`)
       .then(response => response.json())
-      .then(responseData => {
-        const rules = {};
-
-        responseData.forEach(rule => {
-          rules[rule.id] = { ...rule };
-        });
-
-        dispatch(receiveRules(rules));
-      });
+      .then(rules => dispatch(receiveRules(rules)));
   };
 };
diff --git a/src/newsreader/js/pages/homepage/reducers/categories.js b/src/newsreader/js/pages/homepage/reducers/categories.js
index a1f8961..612b98f 100644
--- a/src/newsreader/js/pages/homepage/reducers/categories.js
+++ b/src/newsreader/js/pages/homepage/reducers/categories.js
@@ -2,6 +2,8 @@ import { isEqual } from 'lodash';
 
 import { CATEGORY_TYPE, RULE_TYPE } from '../constants.js';
 
+import { objectsFromArray } from '../../../utils.js';
+
 import {
   RECEIVE_CATEGORY,
   RECEIVE_CATEGORIES,
@@ -26,13 +28,7 @@ export const categories = (state = { ...defaultState }, action) => {
         isFetching: false,
       };
     case RECEIVE_CATEGORIES:
-      const receivedCategories = {};
-
-      Object.values({ ...action.categories }).forEach(category => {
-        receivedCategories[category.id] = {
-          ...category,
-        };
-      });
+      const receivedCategories = objectsFromArray(action.categories, 'id');
 
       return {
         ...state,
@@ -41,10 +37,7 @@ export const categories = (state = { ...defaultState }, action) => {
       };
     case REQUEST_CATEGORIES:
     case REQUEST_CATEGORY:
-      return {
-        ...state,
-        isFetching: true,
-      };
+      return { ...state, isFetching: true };
     case MARK_POST_READ:
       let category = {};
 
diff --git a/src/newsreader/js/pages/homepage/reducers/posts.js b/src/newsreader/js/pages/homepage/reducers/posts.js
index 4e7cb8c..220c59b 100644
--- a/src/newsreader/js/pages/homepage/reducers/posts.js
+++ b/src/newsreader/js/pages/homepage/reducers/posts.js
@@ -1,4 +1,6 @@
 import { isEqual } from 'lodash';
+
+import { objectsFromArray } from '../../../utils.js';
 import { CATEGORY_TYPE, RULE_TYPE } from '../constants.js';
 
 import {
@@ -15,12 +17,6 @@ const defaultState = { items: {}, isFetching: false };
 
 export const posts = (state = { ...defaultState }, action) => {
   switch (action.type) {
-    case RECEIVE_POSTS:
-      return {
-        ...state,
-        isFetching: false,
-        items: { ...state.items, ...action.posts },
-      };
     case REQUEST_POSTS:
       return { ...state, isFetching: true };
     case RECEIVE_POST:
@@ -28,6 +24,14 @@ export const posts = (state = { ...defaultState }, action) => {
         ...state,
         items: { ...state.items, [action.post.id]: { ...action.post } },
       };
+    case RECEIVE_POSTS:
+      const receivedItems = objectsFromArray(action.posts, 'id');
+
+      return {
+        ...state,
+        isFetching: false,
+        items: { ...state.items, ...receivedItems },
+      };
     case MARK_SECTION_READ:
       const updatedPosts = {};
       let relatedPosts = [];
diff --git a/src/newsreader/js/pages/homepage/reducers/rules.js b/src/newsreader/js/pages/homepage/reducers/rules.js
index 0802576..ea3480c 100644
--- a/src/newsreader/js/pages/homepage/reducers/rules.js
+++ b/src/newsreader/js/pages/homepage/reducers/rules.js
@@ -1,5 +1,7 @@
 import { isEqual } from 'lodash';
 
+import { objectsFromArray } from '../../../utils.js';
+
 import { CATEGORY_TYPE, RULE_TYPE } from '../constants.js';
 
 import {
@@ -17,14 +19,13 @@ export const rules = (state = { ...defaultState }, action) => {
   switch (action.type) {
     case REQUEST_RULE:
     case REQUEST_RULES:
-      return {
-        ...state,
-        isFetching: true,
-      };
+      return { ...state, isFetching: true };
     case RECEIVE_RULES:
+      const receivedItems = objectsFromArray(action.rules, 'id');
+
       return {
         ...state,
-        items: { ...state.items, ...action.rules },
+        items: { ...state.items, ...receivedItems },
         isFetching: false,
       };
     case RECEIVE_RULE:
diff --git a/src/newsreader/js/pages/homepage/reducers/selected.js b/src/newsreader/js/pages/homepage/reducers/selected.js
index 632654d..babcb82 100644
--- a/src/newsreader/js/pages/homepage/reducers/selected.js
+++ b/src/newsreader/js/pages/homepage/reducers/selected.js
@@ -67,15 +67,9 @@ export const selected = (state = { ...defaultState }, action) => {
         ...state,
       };
     case SELECT_POST:
-      return {
-        ...state,
-        post: action.post,
-      };
+      return { ...state, post: action.post };
     case UNSELECT_POST:
-      return {
-        ...state,
-        post: {},
-      };
+      return { ...state, post: {} };
     case MARK_POST_READ:
       return {
         ...state,
diff --git a/src/newsreader/js/tests/homepage/actions/category.test.js b/src/newsreader/js/tests/homepage/actions/category.test.js
index 235de76..a6be5ad 100644
--- a/src/newsreader/js/tests/homepage/actions/category.test.js
+++ b/src/newsreader/js/tests/homepage/actions/category.test.js
@@ -96,22 +96,13 @@ describe('category actions', () => {
   });
 
   it('should create multiple actions when fetching categories', () => {
-    const categories = {
-      1: { id: 1, name: 'Tech', unread: 29 },
-      2: { id: 2, name: 'World news', unread: 956 },
-    };
+    const categories = [
+      { id: 1, name: 'Tech', unread: 29 },
+      { id: 2, name: 'World news', unread: 956 },
+    ];
 
-    const rules = {
-      4: {
-        id: 4,
-        name: 'BBC',
-        url: 'http://feeds.bbci.co.uk/news/world/rss.xml',
-        favicon:
-          'https://m.files.bbci.co.uk/modules/bbc-morph-news-waf-page-meta/2.5.2/apple-touch-icon-57x57-precomposed.png',
-        category: 2,
-        unread: 345,
-      },
-      5: {
+    const rules = [
+      {
         id: 5,
         name: 'Ars Technica',
         url: 'http://feeds.arstechnica.com/arstechnica/index?fmt=xml',
@@ -119,19 +110,28 @@ describe('category actions', () => {
         category: 1,
         unread: 7,
       },
-    };
+      {
+        id: 6,
+        name: 'BBC',
+        url: 'http://feeds.bbci.co.uk/news/world/rss.xml',
+        favicon:
+          'https://m.files.bbci.co.uk/modules/bbc-morph-news-waf-page-meta/2.5.2/apple-touch-icon-57x57-precomposed.png',
+        category: 2,
+        unread: 345,
+      },
+    ];
 
     fetchMock
       .get('/api/categories/', {
-        body: Object.values({ ...categories }),
+        body: categories,
         headers: { 'content-type': 'application/json' },
       })
       .get('/api/categories/1/rules/', {
-        body: [{ ...rules[5] }],
+        body: [{ ...rules[0] }],
         headers: { 'content-type': 'application/json' },
       })
       .get('/api/categories/2/rules/', {
-        body: [{ ...rules[4] }],
+        body: [{ ...rules[1] }],
         headers: { 'content-type': 'application/json' },
       });
 
@@ -161,8 +161,8 @@ describe('category actions', () => {
       unread: 0,
     };
 
-    const rules = {
-      1: {
+    const rules = [
+      {
         id: 1,
         name: 'Ars Technica',
         url: 'http://feeds.arstechnica.com/arstechnica/index?fmt=xml',
@@ -170,7 +170,7 @@ describe('category actions', () => {
         category: 1,
         unread: 200,
       },
-      2: {
+      {
         id: 2,
         name: 'Hacker News',
         url: 'https://news.ycombinator.com/rss',
@@ -178,7 +178,7 @@ describe('category actions', () => {
         category: 1,
         unread: 350,
       },
-    };
+    ];
 
     fetchMock
       .get('/api/categories/1', {
@@ -186,7 +186,7 @@ describe('category actions', () => {
         headers: { 'content-type': 'application/json' },
       })
       .get('/api/categories/1/rules/', {
-        body: Object.values({ ...rules }),
+        body: rules,
         headers: { 'content-type': 'application/json' },
       });
 
@@ -197,7 +197,7 @@ describe('category actions', () => {
         category: { ...category, unread: 500 },
       },
       { type: ruleActions.REQUEST_RULES },
-      { type: ruleActions.RECEIVE_RULES, rules: { ...rules } },
+      { type: ruleActions.RECEIVE_RULES, rules },
     ];
 
     const store = mockStore({
diff --git a/src/newsreader/js/tests/homepage/actions/post.test.js b/src/newsreader/js/tests/homepage/actions/post.test.js
index 31bb666..65967b4 100644
--- a/src/newsreader/js/tests/homepage/actions/post.test.js
+++ b/src/newsreader/js/tests/homepage/actions/post.test.js
@@ -163,8 +163,8 @@ describe('rule actions', () => {
   });
 
   it('should create multiple actions to fetch posts by rule', () => {
-    const posts = {
-      2067: {
+    const posts = [
+      {
         id: 2067,
         remoteIdentifier: 'https://arstechnica.com/?p=1648607',
         title:
@@ -177,7 +177,7 @@ describe('rule actions', () => {
         rule: 4,
         read: false,
       },
-      2141: {
+      {
         id: 2141,
         remoteIdentifier: 'https://arstechnica.com/?p=1648757',
         title: 'The most complete brain map ever is here: A fly’s “connectome”',
@@ -189,7 +189,7 @@ describe('rule actions', () => {
         rule: 4,
         read: false,
       },
-    };
+    ];
 
     const rule = {
       id: 4,
@@ -206,7 +206,7 @@ describe('rule actions', () => {
         count: 2,
         next: 'https://durp.com/api/rules/4/posts/?page=2&read=false',
         previous: null,
-        results: Object.values({ ...posts }),
+        results: posts,
       },
       headers: { 'content-type': 'application/json' },
     });
@@ -233,8 +233,8 @@ describe('rule actions', () => {
   });
 
   it('should create multiple actions to fetch posts by category', () => {
-    const posts = {
-      2067: {
+    const posts = [
+      {
         id: 2067,
         remoteIdentifier: 'https://arstechnica.com/?p=1648607',
         title:
@@ -247,7 +247,7 @@ describe('rule actions', () => {
         rule: 4,
         read: false,
       },
-      2141: {
+      {
         id: 2141,
         remoteIdentifier: 'https://arstechnica.com/?p=1648757',
         title: 'The most complete brain map ever is here: A fly’s “connectome”',
@@ -259,7 +259,7 @@ describe('rule actions', () => {
         rule: 4,
         read: false,
       },
-    };
+    ];
 
     const category = {
       id: 1,
@@ -273,7 +273,7 @@ describe('rule actions', () => {
         count: 2,
         next: 'https://durp.com/api/categories/4/posts/?page=2&read=false',
         previous: null,
-        results: Object.values({ ...posts }),
+        results: posts,
       },
       headers: { 'content-type': 'application/json' },
     });
diff --git a/src/newsreader/js/tests/homepage/actions/rule.test.js b/src/newsreader/js/tests/homepage/actions/rule.test.js
index 509938d..70a3a89 100644
--- a/src/newsreader/js/tests/homepage/actions/rule.test.js
+++ b/src/newsreader/js/tests/homepage/actions/rule.test.js
@@ -2,6 +2,8 @@ import configureMockStore from 'redux-mock-store';
 import thunk from 'redux-thunk';
 import fetchMock from 'fetch-mock';
 
+import { objectsFromArray } from '../../../utils.js';
+
 import * as actions from '../../../pages/homepage/actions/rules.js';
 import * as constants from '../../../pages/homepage/constants.js';
 import * as categoryActions from '../../../pages/homepage/actions/categories.js';
@@ -63,8 +65,8 @@ describe('rule actions', () => {
   });
 
   it('should create an action to receive multiple rules', () => {
-    const rules = {
-      1: {
+    const rules = [
+      {
         id: 1,
         name: 'Test rule',
         unread: 100,
@@ -72,7 +74,7 @@ describe('rule actions', () => {
         url: 'http://feeds.arstechnica.com/arstechnica/index?fmt=xml',
         favicon: 'https://cdn.arstechnica.net/favicon.ico',
       },
-      2: {
+      {
         id: 2,
         name: 'Test rule 2',
         unread: 50,
@@ -80,7 +82,7 @@ describe('rule actions', () => {
         url: 'https://xkcd.com/atom.xml',
         favicon: null,
       },
-    };
+    ];
 
     const expectedAction = {
       type: actions.RECEIVE_RULES,
@@ -211,8 +213,8 @@ describe('rule actions', () => {
       unread: 0,
     };
 
-    const rules = {
-      1: {
+    const rules = [
+      {
         id: 1,
         name: 'Ars Technica',
         url: 'http://feeds.arstechnica.com/arstechnica/index?fmt=xml',
@@ -220,7 +222,7 @@ describe('rule actions', () => {
         category: 1,
         unread: 200,
       },
-      2: {
+      {
         id: 2,
         name: 'Hacker News',
         url: 'https://news.ycombinator.com/rss',
@@ -228,10 +230,10 @@ describe('rule actions', () => {
         category: 1,
         unread: 350,
       },
-    };
+    ];
 
     fetchMock.getOnce('/api/categories/1/rules/', {
-      body: Object.values({ ...rules }),
+      body: rules,
       headers: { 'content-type': 'application/json' },
     });
 
diff --git a/src/newsreader/js/tests/homepage/reducers/category.test.js b/src/newsreader/js/tests/homepage/reducers/category.test.js
index 2eeed65..f5c27ae 100644
--- a/src/newsreader/js/tests/homepage/reducers/category.test.js
+++ b/src/newsreader/js/tests/homepage/reducers/category.test.js
@@ -1,5 +1,7 @@
 import { categories as reducer } from '../../../pages/homepage/reducers/categories.js';
 
+import { objectsFromArray } from '../../../utils.js';
+
 import * as actions from '../../../pages/homepage/actions/categories.js';
 import * as postActions from '../../../pages/homepage/actions/posts.js';
 import * as selectedActions from '../../../pages/homepage/actions/selected.js';
@@ -25,19 +27,15 @@ describe('category reducer', () => {
   });
 
   it('should return state after receiving multiple categories', () => {
-    const receivedCategories = {
-      0: { id: 9, name: 'Tech', unread: 291 },
-      1: { id: 2, name: 'World news', unread: 444 },
-    };
+    const receivedCategories = [
+      { id: 9, name: 'Tech', unread: 291 },
+      { id: 2, name: 'World news', unread: 444 },
+    ];
+
     const action = { type: actions.RECEIVE_CATEGORIES, categories: receivedCategories };
 
-    const items = {};
-
-    Object.values({ ...receivedCategories }).forEach(category => {
-      items[category.id] = category;
-    });
-
-    const expectedState = { ...defaultState, items };
+    const expectedCategories = objectsFromArray(receivedCategories, 'id');
+    const expectedState = { ...defaultState, items: expectedCategories };
 
     expect(reducer(undefined, action)).toEqual(expectedState);
   });
diff --git a/src/newsreader/js/tests/homepage/reducers/post.test.js b/src/newsreader/js/tests/homepage/reducers/post.test.js
index b54c3a1..ef4234a 100644
--- a/src/newsreader/js/tests/homepage/reducers/post.test.js
+++ b/src/newsreader/js/tests/homepage/reducers/post.test.js
@@ -1,5 +1,7 @@
 import { posts as reducer } from '../../../pages/homepage/reducers/posts.js';
 
+import { objectsFromArray } from '../../../utils.js';
+
 import * as actions from '../../../pages/homepage/actions/posts.js';
 import * as selectedActions from '../../../pages/homepage/actions/selected.js';
 import * as constants from '../../../pages/homepage/constants.js';
@@ -45,8 +47,8 @@ describe('post actions', () => {
   });
 
   it('should return state after receiving posts', () => {
-    const posts = {
-      2067: {
+    const posts = [
+      {
         id: 2067,
         remoteIdentifier: 'https://arstechnica.com/?p=1648607',
         title:
@@ -59,7 +61,7 @@ describe('post actions', () => {
         rule: 4,
         read: false,
       },
-      2141: {
+      {
         id: 2141,
         remoteIdentifier: 'https://arstechnica.com/?p=1648757',
         title: 'The most complete brain map ever is here: A fly’s “connectome”',
@@ -71,7 +73,7 @@ describe('post actions', () => {
         rule: 4,
         read: false,
       },
-    };
+    ];
 
     const action = {
       type: actions.RECEIVE_POSTS,
@@ -79,10 +81,11 @@ describe('post actions', () => {
       posts,
     };
 
+    const expectedPosts = objectsFromArray(posts, 'id');
     const expectedState = {
       ...defaultState,
       isFetching: false,
-      items: posts,
+      items: expectedPosts,
     };
 
     expect(reducer(undefined, action)).toEqual(expectedState);
diff --git a/src/newsreader/js/tests/homepage/reducers/rule.test.js b/src/newsreader/js/tests/homepage/reducers/rule.test.js
index 67e1f4c..171c301 100644
--- a/src/newsreader/js/tests/homepage/reducers/rule.test.js
+++ b/src/newsreader/js/tests/homepage/reducers/rule.test.js
@@ -1,5 +1,7 @@
 import { rules as reducer } from '../../../pages/homepage/reducers/rules.js';
 
+import { objectsFromArray } from '../../../utils.js';
+
 import * as actions from '../../../pages/homepage/actions/rules.js';
 import * as postActions from '../../../pages/homepage/actions/posts.js';
 import * as selectedActions from '../../../pages/homepage/actions/selected.js';
@@ -49,8 +51,8 @@ describe('category reducer', () => {
   });
 
   it('should return state after receiving multiple rules', () => {
-    const rules = {
-      1: {
+    const rules = [
+      {
         id: 1,
         name: 'Test rule',
         unread: 100,
@@ -58,7 +60,7 @@ describe('category reducer', () => {
         url: 'http://feeds.arstechnica.com/arstechnica/index?fmt=xml',
         favicon: 'https://cdn.arstechnica.net/favicon.ico',
       },
-      2: {
+      {
         id: 2,
         name: 'Another Test rule',
         unread: 444,
@@ -66,11 +68,12 @@ describe('category reducer', () => {
         url: 'http://feeds.arstechnica.com/arstechnica/index?fmt=xml',
         favicon: 'https://cdn.arstechnica.net/favicon.ico',
       },
-    };
+    ];
 
     const action = { type: actions.RECEIVE_RULES, rules };
 
-    const expectedState = { ...defaultState, items: { ...rules } };
+    const mappedRules = objectsFromArray(rules, 'id');
+    const expectedState = { ...defaultState, items: { ...mappedRules } };
 
     expect(reducer(undefined, action)).toEqual(expectedState);
   });
diff --git a/src/newsreader/js/tests/homepage/reducers/selected.test.js b/src/newsreader/js/tests/homepage/reducers/selected.test.js
index 22a5e7e..215c6e1 100644
--- a/src/newsreader/js/tests/homepage/reducers/selected.test.js
+++ b/src/newsreader/js/tests/homepage/reducers/selected.test.js
@@ -211,8 +211,8 @@ describe('selected reducer', () => {
   });
 
   it('should return state after receiving posts', () => {
-    const posts = {
-      2067: {
+    const posts = [
+      {
         id: 2067,
         remoteIdentifier: 'https://arstechnica.com/?p=1648607',
         title:
@@ -225,7 +225,7 @@ describe('selected reducer', () => {
         rule: 4,
         read: false,
       },
-      2141: {
+      {
         id: 2141,
         remoteIdentifier: 'https://arstechnica.com/?p=1648757',
         title: 'The most complete brain map ever is here: A fly’s “connectome”',
@@ -237,7 +237,7 @@ describe('selected reducer', () => {
         rule: 4,
         read: false,
       },
-    };
+    ];
 
     const action = {
       type: postActions.RECEIVE_POSTS,
@@ -254,7 +254,7 @@ describe('selected reducer', () => {
     expect(reducer(undefined, action)).toEqual(expectedState);
   });
 
-  it('should return state after receiving a post', () => {
+  it('should return state after receiving a post which is selected', () => {
     const post = {
       id: 2067,
       remoteIdentifier: 'https://arstechnica.com/?p=1648607',
@@ -280,6 +280,32 @@ describe('selected reducer', () => {
     expect(reducer(state, action)).toEqual(expectedState);
   });
 
+  it('should return state after receiving a post with none selected', () => {
+    const post = {
+      id: 2067,
+      remoteIdentifier: 'https://arstechnica.com/?p=1648607',
+      title:
+        'This amazing glitch puts Star Fox 64 ships in an unmodified Zelda cartridge',
+      body:
+        '"Stale-reference manipulation," 300-character file names, and a clash between worlds.',
+      author: 'Kyle Orland',
+      publicationDate: '2020-01-24T19:50:12Z',
+      url: 'https://arstechnica.com/?p=1648607',
+      rule: 4,
+      read: false,
+    };
+
+    const action = {
+      type: postActions.RECEIVE_POST,
+      post: { ...post, rule: 6 },
+    };
+
+    const state = { ...defaultState, post: {} };
+    const expectedState = { ...defaultState, post: {} };
+
+    expect(reducer(state, action)).toEqual(expectedState);
+  });
+
   it('should return state after selecting a post', () => {
     const post = {
       id: 2067,
diff --git a/src/newsreader/js/utils.js b/src/newsreader/js/utils.js
index 0794a1a..9db723e 100644
--- a/src/newsreader/js/utils.js
+++ b/src/newsreader/js/utils.js
@@ -12,3 +12,13 @@ export const formatDatetime = dateString => {
 
   return date.toLocaleDateString(locale, dateOptions);
 };
+
+export const objectsFromArray = (array, key) => {
+  const arrayEntries = array
+    .filter(object => key in object)
+    .map(object => {
+      return [object[key], { ...object }];
+    });
+
+  return Object.fromEntries(arrayEntries);
+};