Return specific error code when email / phone not supported

Implements matrix-org/matrix-spec-proposals#4178

synapse/api/errors.py

@@ -70,6 +70,7 @@ class Codes(str, Enum):
     THREEPID_NOT_FOUND = "M_THREEPID_NOT_FOUND"
     THREEPID_DENIED = "M_THREEPID_DENIED"
     INVALID_USERNAME = "M_INVALID_USERNAME"
+    THREEPID_MEDIUM_NOT_SUPPORTED = "M_THREEPID_MEDIUM_NOT_SUPPORTED"
     SERVER_NOT_TRUSTED = "M_SERVER_NOT_TRUSTED"
     CONSENT_NOT_GIVEN = "M_CONSENT_NOT_GIVEN"
     CANNOT_LEAVE_SERVER_NOTICE_ROOM = "M_CANNOT_LEAVE_SERVER_NOTICE_ROOM"

synapse/rest/client/account.py

@@ -357,6 +357,7 @@ async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
             raise SynapseError(
                 400,
                 "Adding an email to your account is disabled on this server",
+                Codes.THREEPID_MEDIUM_NOT_SUPPORTED
             )
 
         body = parse_and_validate_json_object_from_request(
@@ -463,6 +464,7 @@ async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
             raise SynapseError(
                 400,
                 "Adding phone numbers to user account is not supported by this homeserver",
+                Codes.THREEPID_MEDIUM_NOT_SUPPORTED
             )
 
         ret = await self.identity_handler.requestMsisdnToken(
@@ -505,7 +507,8 @@ async def on_GET(self, request: Request) -> None:
                 "Adding emails have been disabled due to lack of an email config"
             )
             raise SynapseError(
-                400, "Adding an email to your account is disabled on this server"
+                400, "Adding an email to your account is disabled on this server",
+                Codes.THREEPID_MEDIUM_NOT_SUPPORTED
             )
 
         sid = parse_string(request, "sid", required=True)