feat: strengthen typing and remove suppressions (#451)

- Replaced '# type: ignore' suppressions in discovery transport with 'assert isinstance' guards

- Removed hasattr defensive checks in node.py (Checkpoint.root is Bytes32, always provides .hex())

- Narrowed Coroutine[Any, Any, None] to Coroutine[None, None, None] in sync service and removed typing.Any import

- Updated unit test mocks to provide spec matching assertions

Author: morelucks

src/lean_spec/subspecs/networking/discovery/transport.py

@@ -135,7 +135,8 @@ def __init__(self, transport_handler: DiscoveryTransport) -> None:
 
     def connection_made(self, transport: asyncio.transports.BaseTransport) -> None:
         """Called when UDP socket is ready."""
-        self._transport = transport  # type: ignore[assignment]
+        assert isinstance(transport, asyncio.DatagramTransport)
+        self._transport = transport
 
     def datagram_received(self, data: bytes, addr: tuple[str, int]) -> None:
         """Called when a UDP packet is received."""
@@ -219,8 +220,10 @@ async def start(self, host: str = "0.0.0.0", port: int = 9000) -> None:
             lambda: DiscoveryProtocol(self),
             local_addr=(host, port),
         )
-        self._transport = transport  # type: ignore[assignment]
-        self._protocol = protocol  # type: ignore[assignment]
+        assert isinstance(transport, asyncio.DatagramTransport)
+        assert isinstance(protocol, DiscoveryProtocol)
+        self._transport = transport
+        self._protocol = protocol
 
         self._running = True
         logger.info("Discovery transport started on %s:%d", host, port)

src/lean_spec/subspecs/node/node.py

@@ -484,8 +484,8 @@ async def _log_justified_finalized_periodically(self) -> None:
             metrics.lean_validators_count.set(count)
             j = store.latest_justified
             f = store.latest_finalized
-            j_root = j.root.hex() if hasattr(j.root, "hex") else str(j.root)
-            f_root = f.root.hex() if hasattr(f.root, "hex") else str(f.root)
+            j_root = j.root.hex()
+            f_root = f.root.hex()
             logger.info("=" * 64)
             logger.info(
                 "Peers=%s | Justified slot=%s root=%s | Finalized slot=%s root=%s",

src/lean_spec/subspecs/sync/service.py

@@ -41,7 +41,7 @@
 import time
 from collections.abc import Callable, Coroutine
 from dataclasses import dataclass, field
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING
 
 from lean_spec.subspecs.chain.clock import SlotClock
 from lean_spec.subspecs.containers import (
@@ -164,7 +164,7 @@ class SyncService:
     )
     """Block processor function. Defaults to the store's block processing."""
 
-    _publish_agg_fn: Callable[[SignedAggregatedAttestation], Coroutine[Any, Any, None]] = field(
+    _publish_agg_fn: Callable[[SignedAggregatedAttestation], Coroutine[None, None, None]] = field(
         default=_noop_publish_agg
     )
     """Callback for publishing aggregated attestations to the network."""
@@ -204,7 +204,7 @@ class SyncService:
     """
 
     def set_publish_agg_fn(
-        self, fn: Callable[[SignedAggregatedAttestation], Coroutine[Any, Any, None]]
+        self, fn: Callable[[SignedAggregatedAttestation], Coroutine[None, None, None]]
     ) -> None:
         """Wire the aggregated attestation publisher after construction.
 

tests/lean_spec/subspecs/networking/discovery/test_transport.py

@@ -42,7 +42,7 @@ def test_connection_made_stores_transport(self):
         mock_handler = MagicMock()
         protocol = DiscoveryProtocol(mock_handler)
 
-        mock_transport = MagicMock()
+        mock_transport = MagicMock(spec=asyncio.DatagramTransport)
         protocol.connection_made(mock_transport)
 
         assert protocol._transport is mock_transport
@@ -189,8 +189,8 @@ async def test_start_creates_udp_endpoint(self, local_node_id, local_private_key
         )
 
         # Mock the event loop's create_datagram_endpoint.
-        mock_transport_obj = MagicMock()
-        mock_protocol_obj = MagicMock()
+        mock_transport_obj = MagicMock(spec=asyncio.DatagramTransport)
+        mock_protocol_obj = MagicMock(spec=DiscoveryProtocol)
 
         with patch.object(
             asyncio.get_event_loop(),
@@ -213,8 +213,8 @@ async def test_start_is_idempotent(self, local_node_id, local_private_key, local
             local_enr=local_enr,
         )
 
-        mock_transport_obj = MagicMock()
-        mock_protocol_obj = MagicMock()
+        mock_transport_obj = MagicMock(spec=asyncio.DatagramTransport)
+        mock_protocol_obj = MagicMock(spec=DiscoveryProtocol)
 
         with patch.object(
             asyncio.get_event_loop(),
@@ -238,8 +238,8 @@ async def test_stop_closes_transport(self, local_node_id, local_private_key, loc
             local_enr=local_enr,
         )
 
-        mock_transport_obj = MagicMock()
-        mock_protocol_obj = MagicMock()
+        mock_transport_obj = MagicMock(spec=asyncio.DatagramTransport)
+        mock_protocol_obj = MagicMock(spec=DiscoveryProtocol)
 
         with patch.object(
             asyncio.get_event_loop(),
@@ -262,8 +262,8 @@ async def test_stop_cancels_pending_requests(self, local_node_id, local_private_
             local_enr=local_enr,
         )
 
-        mock_transport_obj = MagicMock()
-        mock_protocol_obj = MagicMock()
+        mock_transport_obj = MagicMock(spec=asyncio.DatagramTransport)
+        mock_protocol_obj = MagicMock(spec=DiscoveryProtocol)
 
         with patch.object(
             asyncio.get_event_loop(),
@@ -347,8 +347,8 @@ async def test_send_response_without_session_returns_false(
             local_enr=local_enr,
         )
 
-        mock_transport_obj = MagicMock()
-        mock_protocol_obj = MagicMock()
+        mock_transport_obj = MagicMock(spec=asyncio.DatagramTransport)
+        mock_protocol_obj = MagicMock(spec=DiscoveryProtocol)
 
         with patch.object(
             asyncio.get_event_loop(),
@@ -767,8 +767,8 @@ async def test_pending_requests_cleared_on_stop(
             local_enr=local_enr,
         )
 
-        mock_transport_obj = MagicMock()
-        mock_protocol_obj = MagicMock()
+        mock_transport_obj = MagicMock(spec=asyncio.DatagramTransport)
+        mock_protocol_obj = MagicMock(spec=DiscoveryProtocol)
 
         with patch.object(
             asyncio.get_event_loop(),
@@ -809,8 +809,8 @@ async def test_pending_request_futures_cancelled_on_stop(
             local_enr=local_enr,
         )
 
-        mock_transport_obj = MagicMock()
-        mock_protocol_obj = MagicMock()
+        mock_transport_obj = MagicMock(spec=asyncio.DatagramTransport)
+        mock_protocol_obj = MagicMock(spec=DiscoveryProtocol)
 
         with patch.object(
             asyncio.get_event_loop(),
@@ -871,11 +871,11 @@ async def test_send_ping_returns_none_on_timeout(
             config=config,
         )
 
-        mock_udp = MagicMock()
+        mock_udp = MagicMock(spec=asyncio.DatagramTransport)
         with patch.object(
             asyncio.get_event_loop(),
             "create_datagram_endpoint",
-            new=AsyncMock(return_value=(mock_udp, MagicMock())),
+            new=AsyncMock(return_value=(mock_udp, MagicMock(spec=DiscoveryProtocol))),
         ):
             await transport.start("127.0.0.1", 9000)
 
@@ -899,11 +899,11 @@ async def test_send_ping_sends_packet_to_correct_address(
             config=config,
         )
 
-        mock_udp = MagicMock()
+        mock_udp = MagicMock(spec=asyncio.DatagramTransport)
         with patch.object(
             asyncio.get_event_loop(),
             "create_datagram_endpoint",
-            new=AsyncMock(return_value=(mock_udp, MagicMock())),
+            new=AsyncMock(return_value=(mock_udp, MagicMock(spec=DiscoveryProtocol))),
         ):
             await transport.start("127.0.0.1", 9000)
 
@@ -929,11 +929,11 @@ async def test_send_ping_registers_node_address(
             config=config,
         )
 
-        mock_udp = MagicMock()
+        mock_udp = MagicMock(spec=asyncio.DatagramTransport)
         with patch.object(
             asyncio.get_event_loop(),
             "create_datagram_endpoint",
-            new=AsyncMock(return_value=(mock_udp, MagicMock())),
+            new=AsyncMock(return_value=(mock_udp, MagicMock(spec=DiscoveryProtocol))),
         ):
             await transport.start("127.0.0.1", 9000)
 
@@ -975,11 +975,11 @@ async def test_send_findnode_returns_empty_on_timeout(
             config=config,
         )
 
-        mock_udp = MagicMock()
+        mock_udp = MagicMock(spec=asyncio.DatagramTransport)
         with patch.object(
             asyncio.get_event_loop(),
             "create_datagram_endpoint",
-            new=AsyncMock(return_value=(mock_udp, MagicMock())),
+            new=AsyncMock(return_value=(mock_udp, MagicMock(spec=DiscoveryProtocol))),
         ):
             await transport.start("127.0.0.1", 9000)
 
@@ -1003,11 +1003,11 @@ async def test_send_findnode_sends_packet_to_correct_address(
             config=config,
         )
 
-        mock_udp = MagicMock()
+        mock_udp = MagicMock(spec=asyncio.DatagramTransport)
         with patch.object(
             asyncio.get_event_loop(),
             "create_datagram_endpoint",
-            new=AsyncMock(return_value=(mock_udp, MagicMock())),
+            new=AsyncMock(return_value=(mock_udp, MagicMock(spec=DiscoveryProtocol))),
         ):
             await transport.start("127.0.0.1", 9000)
 
@@ -1052,11 +1052,11 @@ async def test_send_talkreq_returns_none_on_timeout(
             config=config,
         )
 
-        mock_udp = MagicMock()
+        mock_udp = MagicMock(spec=asyncio.DatagramTransport)
         with patch.object(
             asyncio.get_event_loop(),
             "create_datagram_endpoint",
-            new=AsyncMock(return_value=(mock_udp, MagicMock())),
+            new=AsyncMock(return_value=(mock_udp, MagicMock(spec=DiscoveryProtocol))),
         ):
             await transport.start("127.0.0.1", 9000)
 
@@ -1303,11 +1303,11 @@ async def test_send_whoareyou_sends_packet(
             local_enr=local_enr,
         )
 
-        mock_udp = MagicMock()
+        mock_udp = MagicMock(spec=asyncio.DatagramTransport)
         with patch.object(
             asyncio.get_event_loop(),
             "create_datagram_endpoint",
-            new=AsyncMock(return_value=(mock_udp, MagicMock())),
+            new=AsyncMock(return_value=(mock_udp, MagicMock(spec=DiscoveryProtocol))),
         ):
             await transport.start("127.0.0.1", 9000)
 
@@ -1338,11 +1338,11 @@ async def test_send_whoareyou_uses_cached_enr_seq(
         )
         transport.register_enr(remote_node_id, remote_enr)
 
-        mock_udp = MagicMock()
+        mock_udp = MagicMock(spec=asyncio.DatagramTransport)
         with patch.object(
             asyncio.get_event_loop(),
             "create_datagram_endpoint",
-            new=AsyncMock(return_value=(mock_udp, MagicMock())),
+            new=AsyncMock(return_value=(mock_udp, MagicMock(spec=DiscoveryProtocol))),
         ):
             await transport.start("127.0.0.1", 9000)