Fix discovery cli to print devices not printed during discovery timeout (#670)

* Fix discovery cli to print devices not printed during discovery

* Fix tests

* Fix print exceptions not being propagated

* Fix tests

* Reduce test discover_send time

* Simplify wait logic

* Add tests

* Remove sleep loop and make auth failed a list

kasa/discover.py

@@ -4,7 +4,7 @@ import binascii
 import ipaddress
 import logging
 import socket
-from typing import Awaitable, Callable, Dict, Optional, Set, Type, cast
+from typing import Awaitable, Callable, Dict, List, Optional, Set, Type, cast
 
 # When support for cpython older than 3.11 is dropped
 # async_timeout can be replaced with asyncio.timeout
@@ -46,6 +46,8 @@ class _DiscoverProtocol(asyncio.DatagramProtocol):
     This is internal class, use :func:`Discover.discover`: instead.
     """
 
+    DISCOVERY_START_TIMEOUT = 1
+
     discovered_devices: DeviceDict
 
     def __init__(
@@ -60,7 +62,6 @@ class _DiscoverProtocol(asyncio.DatagramProtocol):
             Callable[[UnsupportedDeviceException], Awaitable[None]]
         ] = None,
         port: Optional[int] = None,
-        discovered_event: Optional[asyncio.Event] = None,
         credentials: Optional[Credentials] = None,
         timeout: Optional[int] = None,
     ) -> None:
@@ -79,12 +80,32 @@ class _DiscoverProtocol(asyncio.DatagramProtocol):
         self.unsupported_device_exceptions: Dict = {}
         self.invalid_device_exceptions: Dict = {}
         self.on_unsupported = on_unsupported
-        self.discovered_event = discovered_event
         self.credentials = credentials
         self.timeout = timeout
         self.discovery_timeout = discovery_timeout
         self.seen_hosts: Set[str] = set()
         self.discover_task: Optional[asyncio.Task] = None
+        self.callback_tasks: List[asyncio.Task] = []
+        self.target_discovered: bool = False
+        self._started_event = asyncio.Event()
+
+    def _run_callback_task(self, coro):
+        task = asyncio.create_task(coro)
+        self.callback_tasks.append(task)
+
+    async def wait_for_discovery_to_complete(self):
+        """Wait for the discovery task to complete."""
+        # Give some time for connection_made event to be received
+        async with asyncio_timeout(self.DISCOVERY_START_TIMEOUT):
+            await self._started_event.wait()
+        try:
+            await self.discover_task
+        except asyncio.CancelledError:
+            # if target_discovered then cancel was called internally
+            if not self.target_discovered:
+                raise
+        # Wait for any pending callbacks to complete
+        await asyncio.gather(*self.callback_tasks)
 
     def connection_made(self, transport) -> None:
         """Set socket options for broadcasting."""
@@ -103,6 +124,7 @@ class _DiscoverProtocol(asyncio.DatagramProtocol):
             )
 
         self.discover_task = asyncio.create_task(self.do_discover())
+        self._started_event.set()
 
     async def do_discover(self) -> None:
         """Send number of discovery datagrams."""
@@ -110,13 +132,12 @@ class _DiscoverProtocol(asyncio.DatagramProtocol):
         _LOGGER.debug("[DISCOVERY] %s >> %s", self.target, Discover.DISCOVERY_QUERY)
         encrypted_req = XorEncryption.encrypt(req)
         sleep_between_packets = self.discovery_timeout / self.discovery_packets
-        for i in range(self.discovery_packets):
+        for _ in range(self.discovery_packets):
             if self.target in self.seen_hosts:  # Stop sending for discover_single
                 break
             self.transport.sendto(encrypted_req[4:], self.target_1)  # type: ignore
             self.transport.sendto(Discover.DISCOVERY_QUERY_2, self.target_2)  # type: ignore
-            if i < self.discovery_packets - 1:
-                await asyncio.sleep(sleep_between_packets)
+            await asyncio.sleep(sleep_between_packets)
 
     def datagram_received(self, data, addr) -> None:
         """Handle discovery responses."""
@@ -145,7 +166,7 @@ class _DiscoverProtocol(asyncio.DatagramProtocol):
             _LOGGER.debug("Unsupported device found at %s << %s", ip, udex)
             self.unsupported_device_exceptions[ip] = udex
             if self.on_unsupported is not None:
-                asyncio.ensure_future(self.on_unsupported(udex))
+                self._run_callback_task(self.on_unsupported(udex))
             self._handle_discovered_event()
             return
         except SmartDeviceException as ex:
@@ -157,16 +178,16 @@ class _DiscoverProtocol(asyncio.DatagramProtocol):
         self.discovered_devices[ip] = device
 
         if self.on_discovered is not None:
-            asyncio.ensure_future(self.on_discovered(device))
+            self._run_callback_task(self.on_discovered(device))
 
         self._handle_discovered_event()
 
     def _handle_discovered_event(self):
-        """If discovered_event is available set it and cancel discover_task."""
-        if self.discovered_event is not None:
+        """If target is in seen_hosts cancel discover_task."""
+        if self.target in self.seen_hosts:
+            self.target_discovered = True
             if self.discover_task:
                 self.discover_task.cancel()
-            self.discovered_event.set()
 
     def error_received(self, ex):
         """Handle asyncio.Protocol errors."""
@@ -289,7 +310,11 @@ class Discover:
 
         try:
             _LOGGER.debug("Waiting %s seconds for responses...", discovery_timeout)
-            await asyncio.sleep(discovery_timeout)
+            await protocol.wait_for_discovery_to_complete()
+        except SmartDeviceException as ex:
+            for device in protocol.discovered_devices.values():
+                await device.protocol.close()
+            raise ex
         finally:
             transport.close()
 
@@ -322,7 +347,6 @@ class Discover:
         :return: Object for querying/controlling found device.
         """
         loop = asyncio.get_event_loop()
-        event = asyncio.Event()
 
         try:
             ipaddress.ip_address(host)
@@ -352,7 +376,6 @@ class Discover:
             lambda: _DiscoverProtocol(
                 target=ip,
                 port=port,
-                discovered_event=event,
                 credentials=credentials,
                 timeout=timeout,
                 discovery_timeout=discovery_timeout,
@@ -365,13 +388,7 @@ class Discover:
             _LOGGER.debug(
                 "Waiting a total of %s seconds for responses...", discovery_timeout
             )
-
-            async with asyncio_timeout(discovery_timeout):
-                await event.wait()
-        except asyncio.TimeoutError as ex:
-            raise TimeoutException(
-                f"Timed out getting discovery response for {host}"
-            ) from ex
+            await protocol.wait_for_discovery_to_complete()
         finally:
             transport.close()
 
@@ -384,7 +401,7 @@ class Discover:
         elif ip in protocol.invalid_device_exceptions:
             raise protocol.invalid_device_exceptions[ip]
         else:
-            raise SmartDeviceException(f"Unable to get discovery response for {host}")
+            raise TimeoutException(f"Timed out getting discovery response for {host}")
 
     @staticmethod
     def _get_device_class(info: dict) -> Type[Device]: