add retry interceptor impl

Author: dimaanj

media-store/app-src/.eslintrc.json

@@ -36,6 +36,8 @@
       }
     ],
     "react/jsx-props-no-spreading": "off", // props spreading,
-    "no-console": "off"
+    "no-console": "off",
+    "consistent-return": "off",
+    "prefer-destructuring": "off"
   }
 }

media-store/app-src/package.json

@@ -5,7 +5,8 @@
   "scripts": {
     "start": "./node_modules/.bin/webpack-dev-server --config ./webpack/webpack-dev-server.js",
     "watch": "./node_modules/.bin/webpack -w --config ./webpack/webpack.dev.js",
-    "build": "./node_modules/.bin/webpack --config ./webpack/webpack.prod.js",
+    "build:dev": "./node_modules/.bin/webpack --config ./webpack/webpack.dev.js",
+    "build:prod": "./node_modules/.bin/webpack --config ./webpack/webpack.prod.js",
     "lint": "./node_modules/.bin/eslint"
   },
   "dependencies": {

media-store/app-src/src/api/axiosInstance.js

@@ -2,12 +2,17 @@ import axios from 'axios';
 import { getUserFromLS, getLocaleFromLS } from '../util/localStorageService';
 import { emitter } from '../util/EventEmitter';
 
+const TIMEOUT = 2000;
+const RETRY_COUNT = 1;
+
 /**
  * This is axios instance
  */
 const axiosInstance = axios.create({
   baseURL: process.env.SERVICE_URL,
-  timeout: 2000,
+  timeout: TIMEOUT,
+  retryDelay: TIMEOUT,
+  retry: RETRY_COUNT,
 });
 
 /**
@@ -41,15 +46,51 @@ function changeLocaleDefaults(locale) {
 }
 
 /**
- * Initializing initial data
+ * Init axios defaults
  */
 const user = getUserFromLS();
 const locale = getLocaleFromLS();
 changeUserDefaults(user);
 changeLocaleDefaults(locale);
 
 /**
- * Error interceptor for refresh tokens mechanism
+ * Retry request if response time is too long
+ * See link below
+ * {@link https://github.com/axios/axios/issues/164#issuecomment-327837467 GitHub}
+ * @param {*} err response error object
+ */
+function axiosRetryInterceptor(err) {
+  const config = err.config;
+  // If config does not exist or the retry option is not set, reject
+  if (config && config.retry) {
+    // Set the variable for keeping track of the retry count
+    config.retryCount = config.retryCount || 0;
+
+    // Check if we've maxed out the total number of retries
+    if (config.retryCount >= config.retry) {
+      // Reject with the error
+      return Promise.reject(err);
+    }
+
+    // Increase the retry count
+    config.retryCount += 1;
+
+    // Create new promise to handle exponential backoff
+    const backoff = new Promise((resolve) => {
+      setTimeout(() => {
+        resolve();
+      }, config.retryDelay || 1);
+    });
+
+    // Return the promise in which recalls axios to retry the request
+    return backoff.then(() => {
+      return axios(config);
+    });
+  }
+}
+
+/**
+ * Things below needed for refresh tokens mechanism implementation
  */
 let isRefreshing = false;
 let subscribers = [];
@@ -62,7 +103,14 @@ const refreshTokens = (refreshToken) => {
     }
   );
 };
-axiosInstance.interceptors.response.use(null, (error) => {
+
+/**
+ * Refresh tokens interceptor
+ * See link below
+ * {@link https://gist.github.com/mkjiau/650013a99c341c9f23ca00ccb213db1c#gistcomment-3536511 GitHub}
+ * @param {*} error error response object
+ */
+function axiosRefreshTokensInterceptor(error) {
   const originalRequest = error.config;
   const user = getUserFromLS();
 
@@ -109,8 +157,12 @@ axiosInstance.interceptors.response.use(null, (error) => {
       });
     });
   }
+}
 
-  return Promise.reject(error);
+axiosInstance.interceptors.response.use(null, (error) => {
+  return (
+    axiosRefreshTokensInterceptor(error) || axiosRetryInterceptor(error) || Promise.reject(error)
+  );
 });
 
 export { axiosInstance, changeLocaleDefaults, changeUserDefaults };

media-store/app-src/src/components/Header.jsx

@@ -1,5 +1,5 @@
 import React from 'react';
-import { Menu, Badge, Spin } from 'antd';
+import { Menu, Badge, Spin, message } from 'antd';
 import { isEmpty } from 'lodash';
 import {
   CreditCardOutlined,
@@ -13,7 +13,7 @@ import { setLocaleToLS } from '../util/localStorageService';
 import { changeLocaleDefaults } from '../api/axiosInstance';
 import { emitter } from '../util/EventEmitter';
 import './Header.css';
-import { requireEmployee, requireCustomer } from '../util/constants';
+import { requireEmployee, requireCustomer, MESSAGE_TIMEOUT } from '../util/constants';
 
 const { SubMenu } = Menu;
 
@@ -24,7 +24,7 @@ const RELOAD_LOCATION_NUMBER = 0;
 const Header = () => {
   const history = useHistory();
   const location = useLocation();
-  const { user, invoicedItems, setInvoicedItems, locale, setLocale, loading } = useAppState();
+  const { user, invoicedItems, locale, setLocale, loading } = useAppState();
   const currentKey = [keys.find((key) => key === location.pathname)];
   const haveInvoicedItems = !isEmpty(invoicedItems);
   const invoicedItemsLength = invoicedItems.length;
@@ -45,7 +45,11 @@ const Header = () => {
 
   const onUserLogout = () => {
     emitter.emit('UPDATE_USER', undefined);
-    history.go(0);
+    message.warn(
+      'Now you are not authenticated. Log in to use full functionality',
+      MESSAGE_TIMEOUT
+    );
+    history.push('/');
   };
 
   return (

media-store/app/.gitignore

@@ -10,9 +10,9 @@
   "private": true,
   "dependencies": {
     "@sap/cds": "^4.2.8",
-    "@sap/hana-client": "^2.6.61",
     "bcryptjs": "^2.4.3",
     "express": "^4",
+    "hdb": "^0.18.2",
     "jsonwebtoken": "^8.5.1",
     "moment": "^2.29.1",
     "passport": "^0.4.1"