Update 2025-04-13_16:25:39

venv/lib/python3.11/site-packages/h11/tests/test_state.py

@@ -0,0 +1,271 @@
+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)