Web: add superfeedr_subscribed prop, populate it in maybe_superfeedr_subscribe

for #550

tests/test_web.py

@@ -1771,8 +1771,9 @@ class WebTest(TestCase):
         self.assertEqual(400, got.status_code)
 
     @patch('oauth_dropins.webutil.appengine_info.LOCAL_SERVER', False)
-    def test_superfeedr_subscribe(self, mock_get, mock_post):
-        web.superfeedr_subscribe(self.user)
+    def test_maybe_superfeedr_subscribe(self, mock_get, mock_post):
+        self.assertFalse(self.user.superfeedr_subscribed)
+        web.maybe_superfeedr_subscribe(self.user)
         self.assert_req(mock_post, SUPERFEEDR_PUSH_API, data={
             'hub.mode': 'subscribe',
             'hub.topic': 'https://user.com/feed',
@@ -1780,6 +1781,13 @@ class WebTest(TestCase):
             'format': 'atom',
             'retrieve': 'true',
         }, auth=ANY)
+        self.assertTrue(self.user.key.get().superfeedr_subscribed)
+
+    def test_maybe_superfeedr_subscribe_already_subscribed(self, mock_get, mock_post):
+        self.user.superfeedr_subscribed = True
+        self.user.put()
+        web.maybe_superfeedr_subscribe(self.user)
+        # should be a noop
 
     def _test_verify(self, redirects, hcard, actor, redirects_error=None):
         self.user.has_redirects = False

web.py

@@ -95,6 +95,7 @@ class Web(User, Protocol):
     redirects_error = ndb.TextProperty()
     has_hcard = ndb.BooleanProperty()
     last_webmention_in = ndb.DateTimeProperty(tzinfo=timezone.utc)
+    superfeedr_subscribed = ndb.BooleanProperty(default=False)
 
     # Originally, BF served Web users' AP actor ids on fed.brid.gy, eg
     # https://fed.brid.gy/snarfed.org . When we started adding new protocols, we
@@ -591,12 +592,16 @@ def webmention_interactive():
         return redirect('/', code=302)
 
 
-def superfeedr_subscribe(user):
+def maybe_superfeedr_subscribe(user):
     """Subscribes to a user's Atom or RSS feed in Superfeedr.
 
     Args:
       user (Web)
     """
+    if user.superfeedr_subscribed:
+        logger.info('Already subscribed via Superfeedr')
+        return
+
     logger.info(f'Subscribing to {user.key.id()} via Superfeedr')
     if appengine_info.LOCAL_SERVER:
         logger.info(f"Skipping since we're local")
@@ -613,7 +618,9 @@ def superfeedr_subscribe(user):
         'retrieve': 'true',
     })
     resp.raise_for_status()
-    return resp
+
+    user.superfeedr_subscribed = True
+    user.put()
 
 
 # generate/check per-user token for auth?