Fixed small bug of reducer

src/reducers/articleList.js

@@ -13,6 +13,7 @@ import {
 } from '../constants/actionTypes';
 
 export default (state = {}, action) => {
+  if (!action.payload) return state;
   switch (action.type) {
     case ARTICLE_FAVORITED:
     case ARTICLE_UNFAVORITED:
@@ -32,15 +33,15 @@ export default (state = {}, action) => {
     case SET_PAGE:
       return {
         ...state,
-        articles: action.payload.articles,
+        articles: action.payload.articles || [],
         articlesCount: action.payload.articlesCount,
         currentPage: action.page
       };
     case APPLY_TAG_FILTER:
       return {
         ...state,
         pager: action.pager,
-        articles: action.payload.articles,
+        articles: action.payload.articles || [],
         articlesCount: action.payload.articlesCount,
         tab: null,
         tag: action.tag,
@@ -50,9 +51,9 @@ export default (state = {}, action) => {
       return {
         ...state,
         pager: action.pager,
-        tags: action.payload[0].tags,
-        articles: action.payload[1].articles,
-        articlesCount: action.payload[1].articlesCount,
+        tags: (!!action.payload[0] && action.payload[0].tags) || [],
+        articles: (!!action.payload[1] && action.payload[1].articles) || [],
+        articlesCount: !!action.payload[1] && action.payload[1].articlesCount,
         currentPage: 0,
         tab: action.tab
       };
@@ -62,7 +63,7 @@ export default (state = {}, action) => {
       return {
         ...state,
         pager: action.pager,
-        articles: action.payload.articles,
+        articles: action.payload.articles || [],
         articlesCount: action.payload.articlesCount,
         tab: action.tab,
         currentPage: 0,
@@ -73,8 +74,8 @@ export default (state = {}, action) => {
       return {
         ...state,
         pager: action.pager,
-        articles: action.payload[1].articles,
-        articlesCount: action.payload[1].articlesCount,
+        articles: (!!action.payload[1] && action.payload[1].articles) || [],
+        articlesCount: !!action.payload[1] && action.payload[1].articlesCount,
         currentPage: 0
       };
     case PROFILE_PAGE_UNLOADED:

src/reducers/auth.js

@@ -11,6 +11,7 @@ export default (state = {}, action) => {
   switch (action.type) {
     case LOGIN:
     case REGISTER:
+      if (!action.payload) return state;
       return {
         ...state,
         inProgress: false,

src/reducers/home.js

@@ -1,11 +1,12 @@
 import { HOME_PAGE_LOADED, HOME_PAGE_UNLOADED } from '../constants/actionTypes';
 
 export default (state = {}, action) => {
+  if (!action.payload) return state;
   switch (action.type) {
     case HOME_PAGE_LOADED:
       return {
         ...state,
-        tags: action.payload[0].tags
+        tags: (!!action.payload[0] && action.payload[0].tags) || []
       };
     case HOME_PAGE_UNLOADED:
       return {};