Let user know that he's in demo

src/auth/AuthProvider.tsx

@@ -1,10 +1,13 @@
 import { maybe } from "@saleor/misc";
+import React from "react";
+import { useIntl } from "react-intl";
+
+import useNotifier from "@saleor/hooks/useNotifier";
 import {
   isSupported as isCredentialsManagementAPISupported,
   login as loginWithCredentialsManagementAPI,
   saveCredentials
 } from "@saleor/utils/credentialsManagement";
-import React from "react";
 import { MutationFunction, MutationResult } from "react-apollo";
 
 import { UserContext } from "./";
@@ -30,7 +33,19 @@ interface AuthProviderOperationsProps {
 }
 const AuthProviderOperations: React.FC<AuthProviderOperationsProps> = ({
   children
-}) => (
+}) => {
+  const intl = useIntl();
+  const notify = useNotifier();
+
+  const handleLogin = () =>
+    notify({
+      text: intl.formatMessage({
+        defaultMessage:
+          "Just to let you know... You're in demo mode. You can play around with the dashboard but can't save changes."
+      })
+    });
+
+  return (
     <TypedTokenAuthMutation>
       {(...tokenAuth) => (
         <TypedVerifyTokenMutation>
@@ -41,6 +56,7 @@ const AuthProviderOperations: React.FC<AuthProviderOperationsProps> = ({
                   tokenAuth={tokenAuth}
                   tokenVerify={tokenVerify}
                   tokenRefresh={tokenRefresh}
+                  onLogin={handleLogin}
                 >
                   {children}
                 </AuthProvider>
@@ -50,7 +66,8 @@ const AuthProviderOperations: React.FC<AuthProviderOperationsProps> = ({
         </TypedVerifyTokenMutation>
       )}
     </TypedTokenAuthMutation>
-);
+  );
+};
 
 interface AuthProviderProps {
   children: (props: {
@@ -72,6 +89,7 @@ interface AuthProviderProps {
     MutationFunction<RefreshToken, RefreshTokenVariables>,
     MutationResult<RefreshToken>
   ];
+  onLogin: () => void;
 }
 
 interface AuthProviderState {
@@ -130,11 +148,12 @@ class AuthProvider extends React.Component<
   }
 
   login = async (email: string, password: string) => {
-    const { tokenAuth } = this.props;
+    const { tokenAuth, onLogin } = this.props;
     const [tokenAuthFn] = tokenAuth;
 
     tokenAuthFn({ variables: { email, password } }).then(result => {
       if (result && !result.data.tokenCreate.errors.length) {
+        onLogin();
         saveCredentials(result.data.tokenCreate.user, password);
       }
     });