Fix error on login without email address

Fixes #28

discordoauth2/auth.py

@@ -1,11 +1,15 @@
 from django.contrib.auth.backends import RemoteUserBackend
 from .models import User
+from typing import Union
+
 
 class DiscordAuthenticationBackend(RemoteUserBackend):
-    def authenticate(self, request, user) -> User:
+    def authenticate(self, request, user) -> Union[User, None]:
         found_user = User.objects.filter(id=user['id'])
         if len(found_user) == 0:
             # New user (first time login)
+            if user['email'] is None:
+                return None
             new_user = User.objects.create_discord_user(user)
             return new_user
         # Returning user

discordoauth2/views.py

@@ -1,3 +1,4 @@
+from typing import Union
 from django.http import JsonResponse, HttpRequest
 from django.shortcuts import redirect, render
 from django.contrib.auth import authenticate, login
@@ -36,20 +37,28 @@ def discord_api_login(request: HttpRequest):
 
 def discord_login_redirect(request: HttpRequest):
     user = exchange_code(request.GET.get('code'))
+    if user is None:
+        return redirect('/login-error/')
     discord_user = authenticate(request, user=user)
+    if discord_user is None:
+        return redirect('/login-error/')
     login(request, discord_user)
     return redirect('/')
 
 
 def discord_api_login_redirect(request: HttpRequest):
     user = exchange_code(request.GET.get(
         'code'), redirect_uri=DISCORD_API_REDIRECT_URI)
+    if user is None:
+        return redirect('/login-error/')
     discord_user = authenticate(request, user=user)
+    if discord_user is None:
+        return redirect('/login-error/')
     login(request, discord_user)
     return redirect('/api/highscores/auth/')
 
 
-def exchange_code(code: str, redirect_uri: str = DISCORD_REDIRECT_URI) -> requests.Response:
+def exchange_code(code: str, redirect_uri: str = DISCORD_REDIRECT_URI) -> Union[requests.Response, None]:
     data = {
         'client_id': DISCORD_CLIENT_ID,
         'client_secret': DISCORD_CLIENT_SECRET,
@@ -64,7 +73,8 @@ def exchange_code(code: str, redirect_uri: str = DISCORD_REDIRECT_URI) -> reques
 
     response = requests.post('%s/oauth2/token' %
                              DISCORD_API_ENDPOINT, data=data, headers=headers)
-    response.raise_for_status()
+    if response.status_code != 200:
+        return None
 
     response = requests.get('%s/users/@me' % DISCORD_API_ENDPOINT, headers={
         'Authorization': 'Bearer %s' % response.json()['access_token']

home/templates/home/login_error.html

@@ -0,0 +1,17 @@
+{% extends 'home/base.html' %} {% block content %}
+<div
+    class="
+        position-relative
+        overflow-hidden
+        p-3 p-md-5
+        m-md-3
+        text-center
+        bg-danger
+    "
+>
+    <div class="col-md-5 p-lg-5 mx-auto my-5">
+        <h1 class="display-4 fw-normal">Login error</h1>
+        <p>Ensure there is an email address attached to your discord account, and you select authorize.</p>
+    </div>
+</div>
+{% endblock %}

home/urls.py

@@ -24,4 +24,5 @@
     path("privacy/", views.privacy, name="privacy"),
     path("logopack/", views.logos, name="logos"),
     path("link-success/", views.link_success, name="link success"),
+    path("login-error/", views.login_error, name="login error"),
 ]

home/views.py

@@ -81,6 +81,10 @@ def login_page(request):
         return redirect('/oauth2/login')
 
 
+def login_error(request):
+    return render(request, "home/login_error.html", {})
+
+
 def logout_user(request):
     logout(request)
     return redirect('/')