Cleanup discovery & add tests (#212)

* Cleanup discovery & add tests

* discovered_devices_raw is not anymore available, as that can be accessed directly from the device objects
* test most of the discovery code paths
* some minor cleanups to test handling
* update discovery docs

* Move category check to be after the definitions

* skip a couple of tests requiring asyncmock not available on py37

* Remove return_raw usage from cli.discover

kasa/tests/test_discovery.py

@@ -1,7 +1,10 @@
 # type: ignore
+import sys
+
 import pytest  # type: ignore # https://github.com/pytest-dev/pytest/issues/3342
 
 from kasa import DeviceType, Discover, SmartDevice, SmartDeviceException
+from kasa.discover import _DiscoverProtocol
 
 from .conftest import bulb, dimmer, lightstrip, plug, pytestmark, strip
 
@@ -47,3 +50,57 @@ async def test_type_unknown():
     invalid_info = {"system": {"get_sysinfo": {"type": "nosuchtype"}}}
     with pytest.raises(SmartDeviceException):
         Discover._get_device_class(invalid_info)
+
+
+@pytest.mark.skipif(sys.version_info < (3, 8), reason="3.8 is first one with asyncmock")
+async def test_discover_single(discovery_data: dict, mocker):
+    """Make sure that discover_single returns an initialized SmartDevice instance."""
+    mocker.patch("kasa.TPLinkSmartHomeProtocol.query", return_value=discovery_data)
+    x = await Discover.discover_single("127.0.0.1")
+    assert issubclass(x.__class__, SmartDevice)
+    assert x._sys_info is not None
+
+
+INVALIDS = [
+    ("No 'system' or 'get_sysinfo' in response", {"no": "data"}),
+    (
+        "Unable to find the device type field",
+        {"system": {"get_sysinfo": {"missing_type": 1}}},
+    ),
+    ("Unknown device type: foo", {"system": {"get_sysinfo": {"type": "foo"}}}),
+]
+
+
+@pytest.mark.skipif(sys.version_info < (3, 8), reason="3.8 is first one with asyncmock")
+@pytest.mark.parametrize("msg, data", INVALIDS)
+async def test_discover_invalid_info(msg, data, mocker):
+    """Make sure that invalid discovery information raises an exception."""
+    mocker.patch("kasa.TPLinkSmartHomeProtocol.query", return_value=data)
+    with pytest.raises(SmartDeviceException, match=msg):
+        await Discover.discover_single("127.0.0.1")
+
+
+async def test_discover_send(mocker):
+    """Test discovery parameters."""
+    proto = _DiscoverProtocol()
+    assert proto.discovery_packets == 3
+    assert proto.target == ("255.255.255.255", 9999)
+    sendto = mocker.patch.object(proto, "transport")
+    proto.do_discover()
+    assert sendto.sendto.call_count == proto.discovery_packets
+
+
+async def test_discover_datagram_received(mocker, discovery_data):
+    """Verify that datagram received fills discovered_devices."""
+    proto = _DiscoverProtocol()
+    mocker.patch("json.loads", return_value=discovery_data)
+    mocker.patch.object(proto, "protocol")
+
+    addr = "127.0.0.1"
+    proto.datagram_received("<placeholder data>", (addr, 1234))
+
+    # Check that device in discovered_devices is initialized correctly
+    assert len(proto.discovered_devices) == 1
+    dev = proto.discovered_devices[addr]
+    assert issubclass(dev.__class__, SmartDevice)
+    assert dev.host == addr