Add command to dump the state of a server (#57)

* Add command to dump the state of a server

* Always clean up client

* remove unused param

* Types

* Apply suggestions from code review

Co-authored-by: Martin Hjelmare <[email protected]>

* Fix import

Co-authored-by: Martin Hjelmare <[email protected]>

Author: balloob

README.md

@@ -5,7 +5,19 @@ Python library for communicating with zwave-js-server. Goal for this library is
 ## Trying it out
 
 ```shell
-python3 -m zwave_js_server ws://localhost:3000/zjs
+python3 -m zwave_js_server ws://localhost:3000
+```
+
+Or get the version of the server
+
+```shell
+python3 -m zwave_js_server ws://localhost:3000 --server-version
+```
+
+Or dump the state. Optionally add `--event-timeout 5` if you want to listen 5 seconds extra for events.
+
+```shell
+python3 -m zwave_js_server ws://localhost:3000 --dump-state
 ```
 
 ## Sending commands

zwave_js_server/__main__.py

@@ -7,6 +7,7 @@
 
 from .client import Client
 from .version import get_server_version
+from .dump import dump_msgs
 
 logging.basicConfig(level=logging.INFO)
 logger = logging.getLogger(__package__)
@@ -19,6 +20,13 @@ def get_arguments() -> argparse.Namespace:
     parser.add_argument(
         "--server-version", action="store_true", help="Print the version of the server"
     )
+    parser.add_argument(
+        "--dump-state", action="store_true", help="Dump the driver state"
+    )
+    parser.add_argument(
+        "--event-timeout",
+        help="How long to listen for events when dumping state",
+    )
     parser.add_argument(
         "url",
         type=str,
@@ -36,6 +44,8 @@ async def main() -> None:
     async with aiohttp.ClientSession() as session:
         if args.server_version:
             await print_version(args, session)
+        elif args.dump_state:
+            await handle_dump_state(args, session)
         else:
             await connect(args, session)
 
@@ -50,6 +60,16 @@ async def print_version(
     print("Home ID:", version.home_id)
 
 
+async def handle_dump_state(
+    args: argparse.Namespace, session: aiohttp.ClientSession
+) -> None:
+    """Dump the state of the server."""
+    timeout = None if args.event_timeout is None else float(args.event_timeout)
+    msgs = await dump_msgs(args.url, session, timeout=timeout)
+    for msg in msgs:
+        print(msg)
+
+
 async def connect(args: argparse.Namespace, session: aiohttp.ClientSession) -> None:
     """Connect to the server."""
     client = Client(args.url, session)

zwave_js_server/dump.py

@@ -0,0 +1,37 @@
+"""Dump helper."""
+import asyncio
+from typing import List, Optional
+
+import aiohttp
+
+
+async def dump_msgs(
+    url: str, session: aiohttp.ClientSession, timeout: Optional[float] = None
+) -> List[dict]:
+    """Dump server state."""
+    client = await session.ws_connect(url)
+    msgs = []
+
+    version = await client.receive_json()
+    msgs.append(version)
+
+    await client.send_json({"command": "start_listening"})
+    state = await client.receive_json()
+    msgs.append(state)
+
+    if timeout is None:
+        await client.close()
+        return msgs
+
+    current_task = asyncio.current_task()
+    assert current_task is not None
+    asyncio.get_running_loop().call_later(timeout, current_task.cancel)
+
+    try:
+        event = await client.receive_json()
+        msgs.append(event)
+    except asyncio.CancelledError:
+        pass
+
+    await client.close()
+    return msgs