Implement very basic server version check (#70)

implement very basic server version check

Author: marcelveldt

requirements.txt

@@ -1 +1,2 @@
-aiohttp==3.7.3
+aiohttp==3.7.3
+packaging==20.8

zwave_js_server/client.py

@@ -7,10 +7,12 @@
 from typing import Any, Awaitable, Callable, Dict, List, Optional, cast
 
 from aiohttp import ClientSession, ClientWebSocketResponse, WSMsgType, client_exceptions
+from packaging.version import parse as parse_version
 
+from .const import MIN_SERVER_VERSION
 from .event import Event
-from .model.version import VersionInfo
 from .model.driver import Driver
+from .model.version import VersionInfo
 
 STATE_CONNECTING = "connecting"
 STATE_CONNECTED = "connected"
@@ -39,6 +41,10 @@ class InvalidState(Exception):
     """Exception raised when data gets in invalid state."""
 
 
+class InvalidServerVersion(Exception):
+    """Exception raised when connected to server with incompatible version."""
+
+
 class FailedCommand(Exception):
     """When a command has failed."""
 
@@ -265,6 +271,9 @@ async def _handle_connection(  # pylint: disable=too-many-branches, too-many-sta
                 await client.receive_json()
             )
 
+            # basic check for server version compatability
+            self._check_server_version(self.version.server_version)
+
             self._logger.info(
                 "Connected to Home %s (Server %s, Driver %s)",
                 version.home_id,
@@ -365,3 +374,17 @@ async def _start_listening(self) -> None:
             self._logger.warning(
                 "Re-connected and don't know how to handle new state yet"
             )
+
+    def _check_server_version(self, server_version: str) -> None:
+        """Perform a basic check on the server version compatability."""
+        cur_version = parse_version(server_version)
+        min_version = parse_version(MIN_SERVER_VERSION)
+        if (cur_version.major != min_version.major) or (
+            cur_version.minor < min_version.minor
+        ):
+            raise InvalidServerVersion
+        if cur_version.minor > min_version:
+            self._logger.warning(
+                "Connected to a Zwave JS Server with an untested version, \
+                    you may run into compatibility issues!"
+            )

zwave_js_server/const.py

@@ -2,6 +2,8 @@
 from enum import Enum, IntEnum
 from typing import Dict, List
 
+MIN_SERVER_VERSION = "1.0.0-beta.1"
+
 
 class CommandClass(IntEnum):
     """Enum with all known CommandClasses."""