tests: add test_websocket.py

- tests.conftest: alter WEBSOCKET_URL as well

tests/conftest.py

@@ -17,6 +17,7 @@ def _test_app(unused_tcp_port, event_loop):
     # reassign an unused tcp port for websockets
     # since the config might give a used one.
     main_app.config['WS_PORT'] = unused_tcp_port
+    main_app.config['WEBSOCKET_URL'] = f'localhost:{unused_tcp_port}'
 
     # make sure we're calling the before_serving hooks
     event_loop.run_until_complete(main_app.startup())

tests/test_websocket.py

@@ -0,0 +1,39 @@
+import pytest
+import websockets
+import json
+
+from tests.common import login
+from litecord.gateway.opcodes import OP
+
+
+async def _json(conn):
+    frame = await conn.recv()
+    return json.loads(frame)
+
+
+async def get_gw(test_cli) -> str:
+    """Get the Gateway URL."""
+    gw_resp = await test_cli.get('/api/v6/gateway')
+    gw_json = await gw_resp.json
+    return gw_json['url']
+
+
+async def gw_start(test_cli):
+    gw_url = await get_gw(test_cli)
+    return websockets.connect(gw_url)
+
+
+@pytest.mark.asyncio
+async def test_gw(test_cli):
+    """Test if the gateway connects and sends a proper
+    HELLO payload."""
+    conn = await gw_start(test_cli)
+
+    hello = await _json(conn)
+    assert hello['op'] == OP.HELLO
+
+    assert isinstance(hello['d'], dict)
+    assert isinstance(hello['d']['heartbeat_interval'], int)
+    assert isinstance(hello['d']['_trace'], list)
+
+    await conn.close(1000, 'test end')