Add type annotations.

demo/dictionary_auth/authz.py

@@ -1,20 +1,25 @@
+from enum import Enum
+from typing import Dict, Optional, Union
+
 from aiohttp_security.abc import AbstractAuthorizationPolicy
 
+from .users import User
+
 
 class DictionaryAuthorizationPolicy(AbstractAuthorizationPolicy):
-    def __init__(self, user_map):
+    def __init__(self, user_map: Dict[str, User]):
         super().__init__()
         self.user_map = user_map
 
-    async def authorized_userid(self, identity):
+    async def authorized_userid(self, identity: str) -> Optional[str]:
         """Retrieve authorized user id.
         Return the user_id of the user identified by the identity
         or 'None' if no user exists related to the identity.
         """
-        if identity in self.user_map:
-            return identity
+        return identity if identity in self.user_map else None
 
-    async def permits(self, identity, permission, context=None):
+    async def permits(self, identity: str, permission: Union[str, Enum],
+                      context: None = None) -> bool:
         """Check user permissions.
         Return True if the identity is allowed the permission in the
         current context, else return False.
@@ -26,7 +31,7 @@ class DictionaryAuthorizationPolicy(AbstractAuthorizationPolicy):
         return permission in user.permissions
 
 
-async def check_credentials(user_map, username, password):
+async def check_credentials(user_map: Dict[str, User], username: str, password: str) -> bool:
     user = user_map.get(username)
     if not user:
         return False

demo/dictionary_auth/handlers.py

@@ -1,4 +1,5 @@
 from textwrap import dedent
+from typing import Dict, NoReturn
 
 from aiohttp import web
 
@@ -8,6 +9,7 @@ from aiohttp_security import (
 )
 
 from .authz import check_credentials
+from .users import User
 
 
 index_template = dedent("""
@@ -27,7 +29,7 @@ index_template = dedent("""
 """)
 
 
-async def index(request):
+async def index(request: web.Request) -> web.Response:
     username = await authorized_userid(request)
     if username:
         template = index_template.format(
@@ -40,22 +42,26 @@ async def index(request):
     )
 
 
-async def login(request):
-    response = web.HTTPFound('/')
+async def login(request: web.Request) -> NoReturn:
+    user_map: Dict[str, User] = request.app['user_map']
+    invalid_response = web.HTTPUnauthorized(body='Invalid username / password combination')
     form = await request.post()
     username = form.get('username')
     password = form.get('password')
 
-    verified = await check_credentials(
-        request.app.user_map, username, password)
+    if not (isinstance(username, str) and isinstance(password, str)):
+        raise invalid_response
+
+    verified = await check_credentials(user_map, username, password)
     if verified:
+        response = web.HTTPFound('/')
         await remember(request, response, username)
-        return response
+        raise response
 
-    return web.HTTPUnauthorized(body='Invalid username / password combination')
+    raise invalid_response
 
 
-async def logout(request):
+async def logout(request: web.Request) -> web.Response:
     await check_authorized(request)
     response = web.Response(
         text='You have been logged out',
@@ -65,7 +71,7 @@ async def logout(request):
     return response
 
 
-async def internal_page(request):
+async def internal_page(request: web.Request) -> web.Response:
     await check_permission(request, 'public')
     response = web.Response(
         text='This page is visible for all registered users',
@@ -74,7 +80,7 @@ async def internal_page(request):
     return response
 
 
-async def protected_page(request):
+async def protected_page(request: web.Request) -> web.Response:
     await check_permission(request, 'protected')
     response = web.Response(
         text='You are on protected page',
@@ -83,7 +89,7 @@ async def protected_page(request):
     return response
 
 
-def configure_handlers(app):
+def configure_handlers(app: web.Application) -> None:
     router = app.router
     router.add_get('/', index, name='index')
     router.add_post('/login', login, name='login')

demo/dictionary_auth/main.py

@@ -11,9 +11,9 @@ from demo.dictionary_auth.handlers import configure_handlers
 from demo.dictionary_auth.users import user_map
 
 
-def make_app():
+def make_app() -> web.Application:
     app = web.Application()
-    app.user_map = user_map
+    app['user_map'] = user_map
     configure_handlers(app)
 
     # secret_key must be 32 url-safe base64-encoded bytes

demo/dictionary_auth/users.py

@@ -1,6 +1,11 @@
-from collections import namedtuple
+from typing import NamedTuple, Tuple
+
+
+class User(NamedTuple):
+    username: str
+    password: str
+    permissions: Tuple[str, ...]
 
-User = namedtuple('User', ['username', 'password', 'permissions'])
 
 user_map = {
     user.username: user for user in [