Change payload type to enum

catfish/worker/server.py

@@ -4,6 +4,7 @@ import os
 import shlex
 import socket
 import subprocess
+from enum import Enum, auto
 from pathlib import Path
 
 import click
@@ -22,10 +23,17 @@ from catfish.utils.sockets import (
 WORKER_SERVER_SOCKET = BASE_SOCKET_DIR.joinpath("catfish.sock")
 
 
-def send_to_server(payload):
+class PayloadType(Enum):
+    PING = auto()
+    PROCESS = auto()
+
+
+def send_to_server(type: PayloadType, payload):
     with socket.socket(socket.AF_UNIX, type=socket.SOCK_STREAM) as sock:
         sock.connect(str(WORKER_SERVER_SOCKET))
-        sock.sendall(ujson.dumps(payload).encode() + NEW_LINE)
+        sock.sendall(
+            ujson.dumps({"type": type.value, "payload": payload}).encode() + NEW_LINE
+        )
         return read_all_from_socket(sock)
 
 
@@ -59,9 +67,14 @@ async def publish_stdout(process):
     await aio.remove_file(socket_path)
 
 
+async def parse_payload(payload):
+    data = ujson.loads(payload)
+    return PayloadType(data["type"]), data["payload"]
+
+
 async def client_connected(reader, writer):
-    data = ujson.loads(await reader.readline())
+    payload_type, data = await parse_payload(await reader.readline())
-    if data["type"] == "process":
+    if payload_type == PayloadType.PROCESS:
         command = shlex.split(data["command"])
         proc = await asyncio.create_subprocess_exec(
             *command,
@@ -71,7 +84,7 @@ async def client_connected(reader, writer):
         )
         asyncio.ensure_future(publish_stdout(proc))
         write_data(writer, {"pid": proc.pid})
-    elif data["type"] == "ping":
+    elif payload_type == PayloadType.PING:
         write_data(writer, {"ping": "pong"})
     else:
         write_data(writer, {"error": "Invalid command"})

tests/test_worker/test_server.py

@@ -1,31 +1,27 @@
 from catfish.utils.processes import is_process_running
 from catfish.utils.sockets import stdout_socket_for_pid
-from catfish.worker.server import read_from_stdout_socket, send_to_server
+from catfish.worker.server import PayloadType, read_from_stdout_socket, send_to_server
 from tests import BaseWorkerTestCase
 
 
 class WorkerServerTestCase(BaseWorkerTestCase):
     def test_server_creates_process(self):
-        response = send_to_server({"type": "process", "command": str(self.DUMMY_EXE)})
+        response = send_to_server(PayloadType.PROCESS, {"command": str(self.DUMMY_EXE)})
         self.assertTrue(is_process_running(response["pid"]))
 
-    def test_unknown_command_type(self):
-        response = send_to_server({"type": "nothing"})
-        self.assertEqual(response, {"error": "Invalid command"})
-
     def test_ping(self):
-        response = send_to_server({"type": "ping"})
+        response = send_to_server(PayloadType.PING, {})
         self.assertEqual(response, {"ping": "pong"})
 
 
 class ProcessLogsTestCase(BaseWorkerTestCase):
     def test_creates_socket(self):
-        response = send_to_server({"type": "process", "command": str(self.DUMMY_EXE)})
+        response = send_to_server(PayloadType.PROCESS, {"command": str(self.DUMMY_EXE)})
         stdout_socket = stdout_socket_for_pid(response["pid"])
         self.assertTrue(stdout_socket.exists())
 
     def test_gets_logs(self):
-        response = send_to_server({"type": "process", "command": str(self.DUMMY_EXE)})
+        response = send_to_server(PayloadType.PROCESS, {"command": str(self.DUMMY_EXE)})
         stdout_socket = stdout_socket_for_pid(response["pid"])
         stdout_iter = read_from_stdout_socket(stdout_socket)
         for i in range(3):