Better handle large amounts of data being sent over WS (#23842)

* Better handle large amounts of data being sent over WS

* Lint

tests/components/websocket_api/test_connection.py

@@ -0,0 +1,30 @@
+"""Test WebSocket Connection class."""
+from homeassistant.components import websocket_api
+from homeassistant.components.websocket_api import const
+
+
+async def test_send_big_result(hass, websocket_client):
+    """Test sending big results over the WS."""
+    @websocket_api.websocket_command({
+        'type': 'big_result'
+    })
+    @websocket_api.async_response
+    async def send_big_result(hass, connection, msg):
+        await connection.send_big_result(
+            msg['id'], {'big': 'result'}
+        )
+
+    hass.components.websocket_api.async_register_command(
+        send_big_result
+    )
+
+    await websocket_client.send_json({
+        'id': 5,
+        'type': 'big_result',
+    })
+
+    msg = await websocket_client.receive_json()
+    assert msg['id'] == 5
+    assert msg['type'] == const.TYPE_RESULT
+    assert msg['success']
+    assert msg['result'] == {'big': 'result'}