add User context

src/core/App.tsx

-import React from 'react';
+import React, { useEffect, useState } from 'react';
 import { BrowserRouter as Router } from 'react-router-dom';
 import styled from 'styled-components';
 import Footer from './components/Footer';
 import Header from './components/Header';
 import MainRouting from './components/MainRouting';
+import UserContext from './components/UserContext';
 
 const Container = styled.div`
   height: 100%;
@@ -17,16 +18,30 @@ const MainContent = styled.div`
 `;
 
 function App() {
+  const [user, setUser] = useState({ loggedIn: false, name: '' });
+
+  useEffect(() => {
+    fetch('/api/v1/users/me')
+      .then((response) => response.json())
+      .then((profile) => {
+        if (profile.loggedIn) {
+          setUser({ loggedIn: true, name: profile.name });
+        }
+      });
+  }, []);
+
   return (
-    <Router>
-      <Container>
-        <Header />
-        <MainContent>
-          <MainRouting />
-        </MainContent>
-        <Footer />
-      </Container>
-    </Router>
+    <UserContext.Provider value={user}>
+      <Router>
+        <Container>
+          <Header />
+          <MainContent>
+            <MainRouting />
+          </MainContent>
+          <Footer />
+        </Container>
+      </Router>
+    </UserContext.Provider>
   );
 }
 

src/core/components/ContextTest.tsx

+import React, { useContext } from 'react';
+import UserContext from './UserContext';
+
+const ContextTest = () => {
+  const user = useContext(UserContext);
+
+  return <div>{user.loggedIn ? user.name : 'Not logged in!'}</div>;
+};
+
+export default ContextTest;

src/core/components/MainRouting.tsx

 import React from 'react';
 import { Route, Switch } from 'react-router';
+import ContextTest from './ContextTest';
 
 const Main = () => (
   <Switch>
     <Route path="/" exact>
       Hello
+      <ContextTest />
     </Route>
     <Route path="/news">News</Route>
   </Switch>

src/core/components/UserContext.tsx

+import { createContext } from 'react';
+
+const UserContext = createContext({ loggedIn: false, name: '' });
+
+export default UserContext;