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import pytest
from .._events import (
ConnectionClosed,
Data,
EndOfMessage,
Event,
InformationalResponse,
Request,
Response,
)
from .._state import (
_SWITCH_CONNECT,
_SWITCH_UPGRADE,
CLIENT,
CLOSED,
ConnectionState,
DONE,
IDLE,
MIGHT_SWITCH_PROTOCOL,
MUST_CLOSE,
SEND_BODY,
SEND_RESPONSE,
SERVER,
SWITCHED_PROTOCOL,
)
from .._util import LocalProtocolError
def test_ConnectionState() -> None:
cs = ConnectionState()
# Basic event-triggered transitions
assert cs.states == {CLIENT: IDLE, SERVER: IDLE}
cs.process_event(CLIENT, Request)
# The SERVER-Request special case:
assert cs.states == {CLIENT: SEND_BODY, SERVER: SEND_RESPONSE}
# Illegal transitions raise an error and nothing happens
with pytest.raises(LocalProtocolError):
cs.process_event(CLIENT, Request)
assert cs.states == {CLIENT: SEND_BODY, SERVER: SEND_RESPONSE}
cs.process_event(SERVER, InformationalResponse)
assert cs.states == {CLIENT: SEND_BODY, SERVER: SEND_RESPONSE}
cs.process_event(SERVER, Response)
assert cs.states == {CLIENT: SEND_BODY, SERVER: SEND_BODY}
cs.process_event(CLIENT, EndOfMessage)
cs.process_event(SERVER, EndOfMessage)
assert cs.states == {CLIENT: DONE, SERVER: DONE}
# State-triggered transition
cs.process_event(SERVER, ConnectionClosed)
assert cs.states == {CLIENT: MUST_CLOSE, SERVER: CLOSED}
def test_ConnectionState_keep_alive() -> None:
# keep_alive = False
cs = ConnectionState()
cs.process_event(CLIENT, Request)
cs.process_keep_alive_disabled()
cs.process_event(CLIENT, EndOfMessage)
assert cs.states == {CLIENT: MUST_CLOSE, SERVER: SEND_RESPONSE}
cs.process_event(SERVER, Response)
cs.process_event(SERVER, EndOfMessage)
assert cs.states == {CLIENT: MUST_CLOSE, SERVER: MUST_CLOSE}
def test_ConnectionState_keep_alive_in_DONE() -> None:
# Check that if keep_alive is disabled when the CLIENT is already in DONE,
# then this is sufficient to immediately trigger the DONE -> MUST_CLOSE
# transition
cs = ConnectionState()
cs.process_event(CLIENT, Request)
cs.process_event(CLIENT, EndOfMessage)
assert cs.states[CLIENT] is DONE
cs.process_keep_alive_disabled()
assert cs.states[CLIENT] is MUST_CLOSE
def test_ConnectionState_switch_denied() -> None:
for switch_type in (_SWITCH_CONNECT, _SWITCH_UPGRADE):
for deny_early in (True, False):
cs = ConnectionState()
cs.process_client_switch_proposal(switch_type)
cs.process_event(CLIENT, Request)
cs.process_event(CLIENT, Data)
assert cs.states == {CLIENT: SEND_BODY, SERVER: SEND_RESPONSE}
assert switch_type in cs.pending_switch_proposals
if deny_early:
# before client reaches DONE
cs.process_event(SERVER, Response)
assert not cs.pending_switch_proposals
cs.process_event(CLIENT, EndOfMessage)
if deny_early:
assert cs.states == {CLIENT: DONE, SERVER: SEND_BODY}
else:
assert cs.states == {
CLIENT: MIGHT_SWITCH_PROTOCOL,
SERVER: SEND_RESPONSE,
}
cs.process_event(SERVER, InformationalResponse)
assert cs.states == {
CLIENT: MIGHT_SWITCH_PROTOCOL,
SERVER: SEND_RESPONSE,
}
cs.process_event(SERVER, Response)
assert cs.states == {CLIENT: DONE, SERVER: SEND_BODY}
assert not cs.pending_switch_proposals
_response_type_for_switch = {
_SWITCH_UPGRADE: InformationalResponse,
_SWITCH_CONNECT: Response,
None: Response,
}
def test_ConnectionState_protocol_switch_accepted() -> None:
for switch_event in [_SWITCH_UPGRADE, _SWITCH_CONNECT]:
cs = ConnectionState()
cs.process_client_switch_proposal(switch_event)
cs.process_event(CLIENT, Request)
cs.process_event(CLIENT, Data)
assert cs.states == {CLIENT: SEND_BODY, SERVER: SEND_RESPONSE}
cs.process_event(CLIENT, EndOfMessage)
assert cs.states == {CLIENT: MIGHT_SWITCH_PROTOCOL, SERVER: SEND_RESPONSE}
cs.process_event(SERVER, InformationalResponse)
assert cs.states == {CLIENT: MIGHT_SWITCH_PROTOCOL, SERVER: SEND_RESPONSE}
cs.process_event(SERVER, _response_type_for_switch[switch_event], switch_event)
assert cs.states == {CLIENT: SWITCHED_PROTOCOL, SERVER: SWITCHED_PROTOCOL}
def test_ConnectionState_double_protocol_switch() -> None:
# CONNECT + Upgrade is legal! Very silly, but legal. So we support
# it. Because sometimes doing the silly thing is easier than not.
for server_switch in [None, _SWITCH_UPGRADE, _SWITCH_CONNECT]:
cs = ConnectionState()
cs.process_client_switch_proposal(_SWITCH_UPGRADE)
cs.process_client_switch_proposal(_SWITCH_CONNECT)
cs.process_event(CLIENT, Request)
cs.process_event(CLIENT, EndOfMessage)
assert cs.states == {CLIENT: MIGHT_SWITCH_PROTOCOL, SERVER: SEND_RESPONSE}
cs.process_event(
SERVER, _response_type_for_switch[server_switch], server_switch
)
if server_switch is None:
assert cs.states == {CLIENT: DONE, SERVER: SEND_BODY}
else:
assert cs.states == {CLIENT: SWITCHED_PROTOCOL, SERVER: SWITCHED_PROTOCOL}
def test_ConnectionState_inconsistent_protocol_switch() -> None:
for client_switches, server_switch in [
([], _SWITCH_CONNECT),
([], _SWITCH_UPGRADE),
([_SWITCH_UPGRADE], _SWITCH_CONNECT),
([_SWITCH_CONNECT], _SWITCH_UPGRADE),
]:
cs = ConnectionState()
for client_switch in client_switches: # type: ignore[attr-defined]
cs.process_client_switch_proposal(client_switch)
cs.process_event(CLIENT, Request)
with pytest.raises(LocalProtocolError):
cs.process_event(SERVER, Response, server_switch)
def test_ConnectionState_keepalive_protocol_switch_interaction() -> None:
# keep_alive=False + pending_switch_proposals
cs = ConnectionState()
cs.process_client_switch_proposal(_SWITCH_UPGRADE)
cs.process_event(CLIENT, Request)
cs.process_keep_alive_disabled()
cs.process_event(CLIENT, Data)
assert cs.states == {CLIENT: SEND_BODY, SERVER: SEND_RESPONSE}
# the protocol switch "wins"
cs.process_event(CLIENT, EndOfMessage)
assert cs.states == {CLIENT: MIGHT_SWITCH_PROTOCOL, SERVER: SEND_RESPONSE}
# but when the server denies the request, keep_alive comes back into play
cs.process_event(SERVER, Response)
assert cs.states == {CLIENT: MUST_CLOSE, SERVER: SEND_BODY}
def test_ConnectionState_reuse() -> None:
cs = ConnectionState()
with pytest.raises(LocalProtocolError):
cs.start_next_cycle()
cs.process_event(CLIENT, Request)
cs.process_event(CLIENT, EndOfMessage)
with pytest.raises(LocalProtocolError):
cs.start_next_cycle()
cs.process_event(SERVER, Response)
cs.process_event(SERVER, EndOfMessage)
cs.start_next_cycle()
assert cs.states == {CLIENT: IDLE, SERVER: IDLE}
# No keepalive
cs.process_event(CLIENT, Request)
cs.process_keep_alive_disabled()
cs.process_event(CLIENT, EndOfMessage)
cs.process_event(SERVER, Response)
cs.process_event(SERVER, EndOfMessage)
with pytest.raises(LocalProtocolError):
cs.start_next_cycle()
# One side closed
cs = ConnectionState()
cs.process_event(CLIENT, Request)
cs.process_event(CLIENT, EndOfMessage)
cs.process_event(CLIENT, ConnectionClosed)
cs.process_event(SERVER, Response)
cs.process_event(SERVER, EndOfMessage)
with pytest.raises(LocalProtocolError):
cs.start_next_cycle()
# Succesful protocol switch
cs = ConnectionState()
cs.process_client_switch_proposal(_SWITCH_UPGRADE)
cs.process_event(CLIENT, Request)
cs.process_event(CLIENT, EndOfMessage)
cs.process_event(SERVER, InformationalResponse, _SWITCH_UPGRADE)
with pytest.raises(LocalProtocolError):
cs.start_next_cycle()
# Failed protocol switch
cs = ConnectionState()
cs.process_client_switch_proposal(_SWITCH_UPGRADE)
cs.process_event(CLIENT, Request)
cs.process_event(CLIENT, EndOfMessage)
cs.process_event(SERVER, Response)
cs.process_event(SERVER, EndOfMessage)
cs.start_next_cycle()
assert cs.states == {CLIENT: IDLE, SERVER: IDLE}
def test_server_request_is_illegal() -> None:
# There used to be a bug in how we handled the Request special case that
# made this allowed...
cs = ConnectionState()
with pytest.raises(LocalProtocolError):
cs.process_event(SERVER, Request)
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