Update discover single to handle hostnames (#539)

kasa/tests/test_discovery.py

@@ -1,5 +1,6 @@
 # type: ignore
 import re
+import socket
 import sys
 
 import pytest  # type: ignore # https://github.com/pytest-dev/pytest/issues/3342
@@ -74,6 +75,31 @@ async def test_discover_single(discovery_data: dict, mocker, custom_port):
     assert x.port == custom_port or x.port == 9999
 
 
+async def test_discover_single_hostname(discovery_data: dict, mocker):
+    """Make sure that discover_single returns an initialized SmartDevice instance."""
+    host = "foobar"
+    ip = "127.0.0.1"
+
+    def mock_discover(self):
+        self.datagram_received(
+            protocol.TPLinkSmartHomeProtocol.encrypt(json_dumps(discovery_data))[4:],
+            (ip, 9999),
+        )
+
+    mocker.patch.object(_DiscoverProtocol, "do_discover", mock_discover)
+    mocker.patch("kasa.TPLinkSmartHomeProtocol.query", return_value=discovery_data)
+    mocker.patch("socket.getaddrinfo", return_value=[(None, None, None, None, (ip, 0))])
+
+    x = await Discover.discover_single(host)
+    assert issubclass(x.__class__, SmartDevice)
+    assert x._sys_info is not None
+    assert x.host == host
+
+    mocker.patch("socket.getaddrinfo", side_effect=socket.gaierror())
+    with pytest.raises(SmartDeviceException):
+        x = await Discover.discover_single(host)
+
+
 @pytest.mark.parametrize("custom_port", [123, None])
 async def test_connect_single(discovery_data: dict, mocker, custom_port):
     """Make sure that connect_single returns an initialized SmartDevice instance."""