Move get_or_create_user to test code (#5628)

This is only used in tests, so...

synapse/handlers/register.py

@@ -505,57 +505,6 @@ class RegistrationHandler(BaseHandler):
         )
         defer.returnValue(data)
 
-    @defer.inlineCallbacks
-    def get_or_create_user(self, requester, localpart, displayname, password_hash=None):
-        """Creates a new user if the user does not exist,
-        else revokes all previous access tokens and generates a new one.
-
-        Args:
-            localpart : The local part of the user ID to register. If None,
-              one will be randomly generated.
-        Returns:
-            A tuple of (user_id, access_token).
-        Raises:
-            RegistrationError if there was a problem registering.
-
-        NB this is only used in tests. TODO: move it to the test package!
-        """
-        if localpart is None:
-            raise SynapseError(400, "Request must include user id")
-        yield self.auth.check_auth_blocking()
-        need_register = True
-
-        try:
-            yield self.check_username(localpart)
-        except SynapseError as e:
-            if e.errcode == Codes.USER_IN_USE:
-                need_register = False
-            else:
-                raise
-
-        user = UserID(localpart, self.hs.hostname)
-        user_id = user.to_string()
-        token = self.macaroon_gen.generate_access_token(user_id)
-
-        if need_register:
-            yield self.register_with_store(
-                user_id=user_id,
-                token=token,
-                password_hash=password_hash,
-                create_profile_with_displayname=user.localpart,
-            )
-        else:
-            yield self._auth_handler.delete_access_tokens_for_user(user_id)
-            yield self.store.add_access_token_to_user(user_id=user_id, token=token)
-
-        if displayname is not None:
-            logger.info("setting user display name: %s -> %s", user_id, displayname)
-            yield self.profile_handler.set_displayname(
-                user, requester, displayname, by_admin=True
-            )
-
-        defer.returnValue((user_id, token))
-
     @defer.inlineCallbacks
     def _join_user_to_room(self, requester, room_identifier):
         room_id = None