make remote follow handle non-web users

for #1640. thanks for reporting @mistrk7!

follow.py

@@ -32,10 +32,10 @@ def remote_follow():
     if not cls:
         error(f'Unknown protocol {request.values["protocol"]}')
 
-    domain = request.values['domain']
-    user = cls.get_by_id(domain)
+    id = request.values['id']
+    user = cls.get_by_id(id)
     if not user:
-        error(f'No web user found for domain {domain}')
+        error(f'No {cls.LABEL} user found for {id}')
 
     addr = request.values['address']
     resp = webfinger.fetch(addr)

pages.py

@@ -204,6 +204,9 @@ def update_profile(protocol, id):
 @canonicalize_request_domain(common.PROTOCOL_DOMAINS, common.PRIMARY_DOMAIN)
 def followers_or_following(protocol, id, collection):
     user = load_user(protocol, id)
+    id = user.key.id()
+    handle = user.handle
+
     followers, before, after = Follower.fetch_page(collection, user)
     num_followers, num_following = user.count_followers()
     return render_template(

templates/followers.html

@@ -6,11 +6,11 @@
 <div class="row">
     <form method="post" action="/remote-follow">
     <nobr>
-     <label for="follow-address">Follow @{{ id }} with your fediverse address:</label>
+     <label for="follow-address">Follow @{{ handle }} with your fediverse address:</label>
      <input id="follow-address" name="address" type="text" required
             placeholder="@[email protected]" alt="fediverse address"
             value="{{ follow_url or '' }}"></input>
-     <input name="domain" type="hidden" value="{{ id }}"></input>
+     <input name="id" type="hidden" value="{{ id }}"></input>
      <input name="protocol" type="hidden" value="{{ user.LABEL }}"></input>
      <button type="submit" class="btn btn-default">Follow</button>
     </nobr>

tests/test_follow.py

@@ -70,29 +70,29 @@ def setUp(self):
         super().setUp()
         self.make_user('user.com', cls=Web, has_redirects=True)
 
-    def test_no_domain(self, _):
+    def test_no_id(self, _):
         got = self.client.post('/remote-follow?address=@[email protected]&protocol=web')
         self.assertEqual(400, got.status_code)
 
     def test_no_address(self, _):
-        got = self.client.post('/remote-follow?domain=baz.com&protocol=web')
+        got = self.client.post('/remote-follow?id=baz.com&protocol=web')
         self.assertEqual(400, got.status_code)
 
     def test_no_protocol(self, _):
-        got = self.client.post('/remote-follow?address=@[email protected]&domain=user.com')
+        got = self.client.post('/remote-follow?address=@[email protected]&id=user.com')
         self.assertEqual(400, got.status_code)
 
     def test_unknown_protocol(self, _):
-        got = self.client.post('/remote-follow?address=@[email protected]&domain=user.com&protocol=foo')
+        got = self.client.post('/remote-follow?address=@[email protected]&id=user.com&protocol=foo')
         self.assertEqual(400, got.status_code)
 
     def test_no_user(self, _):
-        got = self.client.post('/remote-follow?address=@[email protected]&domain=baz.com')
+        got = self.client.post('/remote-follow?address=@[email protected]&id=baz.com')
         self.assertEqual(400, got.status_code)
 
     def test_addr(self, mock_get):
         mock_get.return_value = WEBFINGER
-        got = self.client.post('/remote-follow?address=@[email protected]&domain=user.com&protocol=web')
+        got = self.client.post('/remote-follow?address=@[email protected]&id=user.com&protocol=web')
         self.assertEqual(302, got.status_code)
         self.assertEqual('https://ba.r/[email protected]@user.com',
                          got.headers['Location'])
@@ -103,35 +103,48 @@ def test_addr(self, mock_get):
 
     def test_url(self, mock_get):
         mock_get.return_value = WEBFINGER
-        got = self.client.post('/remote-follow?address=https://ba.r/foo&domain=user.com&protocol=web')
+        got = self.client.post('/remote-follow?address=https://ba.r/foo&id=user.com&protocol=web')
         self.assertEqual(302, got.status_code)
         self.assertEqual('https://ba.r/[email protected]@user.com', got.headers['Location'])
 
         mock_get.assert_has_calls((
             self.req('https://ba.r/.well-known/webfinger?resource=https://ba.r/foo'),
         ))
 
+    def test_non_web_user(self, mock_get):
+        user = self.make_user('fake:user', cls=Fake)
+
+        mock_get.return_value = WEBFINGER
+        got = self.client.post('/remote-follow?address=@[email protected]&id=fake:user&protocol=fake')
+        self.assertEqual(302, got.status_code)
+        self.assertEqual('https://ba.r/follow?uri=@fake:handle:[email protected]',
+                         got.headers['Location'])
+
+        mock_get.assert_has_calls((
+            self.req('https://ba.r/.well-known/webfinger?resource=acct:[email protected]'),
+        ))
+
     def test_no_webfinger_subscribe_link(self, mock_get):
         mock_get.return_value = requests_response({
             'subject': 'acct:[email protected]',
             'links': [{'rel': 'other', 'template': 'meh'}],
         })
 
-        got = self.client.post('/remote-follow?address=https://ba.r/foo&domain=user.com&protocol=web')
+        got = self.client.post('/remote-follow?address=https://ba.r/foo&id=user.com&protocol=web')
         self.assertEqual(302, got.status_code)
         self.assertEqual('/web/user.com', got.headers['Location'])
 
     def test_webfinger_error(self, mock_get):
         mock_get.return_value = requests_response(status=500)
 
-        got = self.client.post('/remote-follow?address=https://ba.r/foo&domain=user.com&protocol=web')
+        got = self.client.post('/remote-follow?address=https://ba.r/foo&id=user.com&protocol=web')
         self.assertEqual(302, got.status_code)
         self.assertEqual('/web/user.com', got.headers['Location'])
 
     def test_webfinger_returns_not_json(self, mock_get):
         mock_get.return_value = requests_response('<html>not json</html>')
 
-        got = self.client.post('/remote-follow?address=https://ba.r/foo&domain=user.com&protocol=web')
+        got = self.client.post('/remote-follow?address=https://ba.r/foo&id=user.com&protocol=web')
         self.assertEqual(302, got.status_code)
         self.assertEqual('/web/user.com', got.headers['Location'])