Wrong class seen from asyncio.create_datagram_endpoint #2292
Description
Summary
When using protocol instances returned from asyncio.create_datagram_endpoint, it seems like ty is guessing the wrong (parent's parent) class instead of the actual one being used
Here is a minimal example, (almost) copied from python documentation
import asyncio
from time import time
from typing import reveal_type
class EchoServerProtocol(asyncio.DatagramProtocol):
start: float
def connection_made(self, transport):
self.transport = transport
def datagram_received(self, data, addr):
message = data.decode()
print('Received %r from %s' % (message, addr))
print('Send %r to %s' % (message, addr))
self.transport.sendto(data, addr)
def __init__(self):
super().__init__()
self.start = time()
async def main():
print("Starting UDP server")
loop = asyncio.get_event_loop()
transport, protocol = await loop.create_datagram_endpoint(
EchoServerProtocol,
local_addr=('127.0.0.1', 9999))
reveal_type(protocol) # BaseProtocol instead of EchoServerProtocol
print(protocol.start)
try:
await asyncio.sleep(3600)
finally:
transport.close()
if __name__ == '__main__':
asyncio.run(main())When analysed, ty guesses the type of protocol as BaseProtocol (the parent class of DatagramProtocol), the error is error[unresolved-attribute]: Object of type BaseProtocolhas no attributestart``
The actual MRO at runtime is:
<class '__main__.EchoServerProtocol'>,
<class 'asyncio.protocols.DatagramProtocol'>,
<class 'asyncio.protocols.BaseProtocol'>,
<class 'object'>
Note that not inheriting from asyncio.DatagramProtocol will not raise an issue but the type will then be Unknown
Version
0.0.8