Factor out add_user from accept_invite and join_group

synapse/groups/groups_server.py

@@ -677,6 +677,40 @@ class GroupsServerHandler(object):
         else:
             raise SynapseError(502, "Unknown state returned by HS")
 
+    @defer.inlineCallbacks
+    def add_user(self, group_id, user_id, content):
+        """Add a user to a group based on a content dict.
+
+        See accept_invite, join_group.
+        """
+        if not self.hs.is_mine_id(user_id):
+            local_attestation = self.attestations.create_attestation(
+                group_id, user_id,
+            )
+
+            remote_attestation = content["attestation"]
+
+            yield self.attestations.verify_attestation(
+                remote_attestation,
+                user_id=user_id,
+                group_id=group_id,
+            )
+        else:
+            local_attestation = None
+            remote_attestation = None
+
+        is_public = _parse_visibility_from_contents(content)
+
+        yield self.store.add_user_to_group(
+            group_id, user_id,
+            is_admin=False,
+            is_public=is_public,
+            local_attestation=local_attestation,
+            remote_attestation=remote_attestation,
+        )
+
+        defer.returnValue(local_attestation)
+
     @defer.inlineCallbacks
     def accept_invite(self, group_id, requester_user_id, content):
         """User tries to accept an invite to the group.
@@ -693,30 +727,7 @@ class GroupsServerHandler(object):
         if not is_invited:
             raise SynapseError(403, "User not invited to group")
 
-        if not self.hs.is_mine_id(requester_user_id):
+        local_attestation = yield self.add_user(group_id, requester_user_id, content)
-            local_attestation = self.attestations.create_attestation(
-                group_id, requester_user_id,
-            )
-            remote_attestation = content["attestation"]
-
-            yield self.attestations.verify_attestation(
-                remote_attestation,
-                user_id=requester_user_id,
-                group_id=group_id,
-            )
-        else:
-            local_attestation = None
-            remote_attestation = None
-
-        is_public = _parse_visibility_from_contents(content)
-
-        yield self.store.add_user_to_group(
-            group_id, requester_user_id,
-            is_admin=False,
-            is_public=is_public,
-            local_attestation=local_attestation,
-            remote_attestation=remote_attestation,
-        )
 
         defer.returnValue({
             "state": "join",
@@ -738,30 +749,7 @@ class GroupsServerHandler(object):
         if not group_info['is_joinable']:
             raise SynapseError(403, "Group is not publicly joinable")
 
-        if not self.hs.is_mine_id(requester_user_id):
+        local_attestation = yield self.add_user(group_id, requester_user_id, content)
-            local_attestation = self.attestations.create_attestation(
-                group_id, requester_user_id,
-            )
-            remote_attestation = content["attestation"]
-
-            yield self.attestations.verify_attestation(
-                remote_attestation,
-                user_id=requester_user_id,
-                group_id=group_id,
-            )
-        else:
-            local_attestation = None
-            remote_attestation = None
-
-        is_public = _parse_visibility_from_contents(content)
-
-        yield self.store.add_user_to_group(
-            group_id, requester_user_id,
-            is_admin=False,
-            is_public=is_public,
-            local_attestation=local_attestation,
-            remote_attestation=remote_attestation,
-        )
 
         defer.returnValue({
             "state": "join",