Fix #20

* Logout on invalid token stored in cache

src/actions/auth.ts

@@ -46,6 +46,15 @@ export const logout = () => (dispatch: Dispatch) => {
     });
 };
 
+/** Redux action creator. Performs a logout locally without making an API call.
+ * */
+export const localLogout = () => {
+    resetToken();
+    return {
+        type: Actions.LoggedOut,
+    } as AuthAction;
+};
+
 /**
  * Signup function. Performs an HTTP POST request, calls the provided functions
  * on success/fail.

src/main.tsx

@@ -2,14 +2,18 @@ import React from "react";
 import { connect } from "react-redux";
 import { BrowserRouter as Router, Switch, Route } from "react-router-dom";
 
+import req from "./axios";
+
 import { Store } from "./typings/store";
+import { Dispatch } from "./typings/react";
+import { HTTPSuccessCode } from "./typings/api";
 
 import LoginForm from "./views/loginForm";
 import SignupForm from "./views/signupForm";
 import MainView from "./views/mainView";
 import EditorView from "./views/editorView";
 
-import { setToken, resetToken } from "./actions/auth";
+import { setToken, resetToken, localLogout } from "./actions/auth";
 
 import "./views/styles/common.scss";
 
@@ -18,7 +22,11 @@ const mapStateToProps = (state: Store) => ({
     username: state.auth.username,
 });
 
-interface Props {
+const mapDispatchToProps = (dispatch: Dispatch) => ({
+    logout: () => dispatch(localLogout()),
+});
+
+interface Props extends ReturnType<typeof mapDispatchToProps> {
     token?: string;
     username?: string;
 }
@@ -47,6 +55,13 @@ class App extends React.Component<Props, Props> {
             });
         }
     };
+    componentDidMount = () => {
+        req.head("/session").then((res) => {
+            if (res.status !== HTTPSuccessCode) {
+                this.props.logout();
+            }
+        });
+    };
     render = () => {
         const token = this.state.token as string;
         const loggedIn = token.length !== 0;
@@ -69,4 +84,4 @@ class App extends React.Component<Props, Props> {
     };
 }
 
-export default connect(mapStateToProps)(App);
+export default connect(mapStateToProps, mapDispatchToProps)(App);

src/typings/api.ts

@@ -12,3 +12,5 @@ export type VersionData = {
     version: string;
     signup: boolean;
 };
+
+export const HTTPSuccessCode = 200;