litellm/tests/test_litellm_rust/ocr/test_callbacks.py
yucheng-berri dd511a2b22
fix(logging)!: fire one CustomLogger failure hook per async call outside the async flag list (#47124)
* fix(logging): fire one CustomLogger hook per async call outside the async flag list

aspeech, atranscription, aimage_generation, aimage_edit, aocr and asearch are
missing from is_sync_litellm_request's flag list, so the sync success and
failure handlers called a CustomLogger's sync hook on top of the async hook the
async handler had already called for the same request.

The sync handlers now skip a CustomLogger's log_success_event and
log_failure_event when that run is paired with an async handler run
(for_async_request) and the async handler gives the logger its own async hook.
The async client wrapper, dispatch_failure_handlers, the proxy-only failure
dispatch and the native bridge's sync failure step for an async call mark their
sync failure run as paired.

Resolves LIT-9486

* fix(logging): keep the sync CustomLogger hook when no async success runs

The async client wrapper skips async success logging for calls carrying a
fallbacks kwarg, and the native bridge skips it for internal and fallbacks
calls, yet the paired sync success run still dropped a both-hooks logger's
sync hook, so that logger got no success event at all.

The sync success run now suppresses the sync hook only when the async success
handler was actually scheduled for the call: the client wrapper passes
async_handler_runs=not is_completion_with_fallbacks, and the native host
records per call whether it enqueued or deferred the async success.

Tests that pinned the doubled failure hook on native aocr, messages and
responses calls and on proxy-rejected requests now expect the async hook
alone. The integration test adds /v1/messages and /v1/responses cells and
runs the key-auth rejection on every route.

* fix(logging): type dispatch_success_handlers kwargs

The new async_handler_runs keyword on success_handler made the untyped
**kwargs that dispatch_success_handlers forwards an unknown argument for it,
which grew the reportUnknownArgumentType count past its merge-base ceiling.
Typing the forwarded kwargs as Any, as _success_handler_body already does,
removes those diagnostics without changing what is forwarded.

* test(integration): cover CustomLogger hook counts across modes, chaos and router strategies

Moves the hook count rig into tests/integration/_support/hook_counts.py and
extends the cells it drives:

- streamed chat, Messages and Responses requests, success and failure
- loggers the async handler never reaches (sync-only overrides, sync event
  lists only) keep one sync hook per request on every surface outside the
  async flag list, key-auth rejections included
- a concurrent burst while the logger's destination stalls and then fails,
  and a burst while a worker is killed, never give a request two hooks
- least-busy keeps counting a request in flight while async speech requests
  finish around it, and usage-based routing v2 counts an async image
  request's tokens once

* test(integration): Datadog and LangSmith deliver one record per async request

Points the built-in Datadog, LangSmith and OpenTelemetry loggers at a local
sink and checks every async surface outside the flag list: one Datadog log
entry and one LangSmith run per request (two on the merge base), and never two
OpenTelemetry spans, which its own emit-once guard already ensured.

* fix(logging): give a both-hooks logger its sync hook when the async run never reaches it

The sync hook was skipped whenever the logger sat in the async callback list, so a
logger the async run never reached got no hook at all: a sibling stalled past the
logging worker timeout, a batch poll that skips default logging, or an async
failure run cut off. The sync run now holds the hook and the async run hands it
back unless it reached the logger

* fix(logging): run the held sync success hooks when the proxy drops a blocked response's success

A post-call guardrail block drops the parked async success, which left the sync
success hook held for it unrun. Base gave a both-hooks logger that hook on these
call types, so the drop now ends the pairing and the held hook runs as before

* fix(logging): run held sync hooks only after every sync run of the request has closed

A held hook released by the async run could run on another thread while the sync
run was still walking its other callbacks. The pairing now waits until the async
run has ended and every sync run has closed, and the last sync run to close runs
the held hooks itself

* fix(logging): end the async run when its coroutine is dropped before it starts

A logging queue that drops the async success coroutine, or a deferred success
that fails to schedule, left the sync hooks held for it unrun. The enqueued async
run now ends when its coroutine is discarded, and the proxy ends it when firing
the deferred success raises

* fix(logging): leave a still-queued async run to the exit flush

The discard finalizer ran at interpreter exit before the logging worker's exit
flush, so a queued request could get its held sync hook and then its async hook

* test: keep the router and file-stream tests in step with main

Main gives each owned proxy a private Redis by default, so the router cells
share the worker's Redis to read its counters, and the file-stream stub takes
the hook pairing the stream now passes

* fix(logging): run held sync hooks when a during_call guardrail raises or the exit flush gives up

A during_call guardrail that raised after the LLM call parked its deferred
success skipped the proxy's flush, and async runs the exit flush never started
were never ended, so a both-hooks logger lost its sync hook in both cases

* fix(logging): skip the sync failure hook when the async failure run logs to the logger

An async call outside is_sync_litellm_request's flag list ran both failure
handlers, so a CustomLogger with both failure hooks got both. The sync run
of an async request now skips log_failure_event for a logger that overrides
async_log_failure_event and is registered for async failures. The four sync
runs of async failures (dispatch_failure_handlers, the @client async wrapper,
the proxy-only failure thread and the Rust host) pass for_async_request=True.

Drops the HookPairing fallback. Successes are left to #47192, which already
gives such a logger only async_log_success_event.

---------

Co-authored-by: yucheng-berri <293926326+yucheng-berri@users.noreply.github.com>
2026-10-20 15:19:14 -07:00

596 lines
21 KiB
Python

import asyncio
import copy
import gc
import queue
import threading
from collections.abc import Mapping
from types import MappingProxyType
from typing import Final
import pytest
from hypothesis import HealthCheck, given, settings
from hypothesis import strategies as st
import litellm
from litellm.integrations.custom_guardrail import CustomGuardrail
from litellm.integrations.custom_logger import CustomLogger
from litellm.llms.base_llm.ocr.transformation import OCRResponse
from tests.test_litellm_rust.ocr.data import (
OCR_DOCUMENT,
OCR_RESPONSE,
call,
call_aocr,
call_ocr,
)
from tests.test_litellm_rust.support.callback_recorder import (
RecordingLogger,
drain_logging,
request_body,
request_headers,
)
from tests.test_litellm_rust.support.isolation import isolated_callback_registries, rebound
from tests.test_litellm_rust.support.recording_server import RecordingServer, ResponseSpec
pytestmark = pytest.mark.requires_rust_extension
def test_native_ocr_pre_call_callback_receives_transformed_provider_request(server: RecordingServer) -> None:
observations: Final = []
class Observe(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
observations.append((model, copy.deepcopy(kwargs["additional_args"])))
call_ocr(server, callbacks=[Observe()], pages=[0])
assert len(observations) == 1
model, additional_args = observations[0]
assert model == "mistral-ocr-latest"
assert additional_args["api_base"] == f"{server.base_url}/v1/ocr"
assert additional_args["complete_input_dict"] == {
"model": "mistral-ocr-latest",
"document": OCR_DOCUMENT,
"pages": [0],
}
@pytest.mark.asyncio
async def test_native_ocr_does_not_restore_keywords_deleted_by_a_pre_call_hook(server: RecordingServer) -> None:
class DropKeywords(CustomLogger):
async def async_pre_call_deployment_hook(
self, kwargs: dict[str, object], call_type: object
) -> dict[str, object]:
return {name: value for name, value in kwargs.items() if name not in ("pages", "extra_headers")}
with rebound(litellm, "callbacks", [DropKeywords()]):
await call_aocr(server, pages=[0], extra_headers={"x-deleted": "remove this header"})
assert len(server.requests) == 1
sent: Final = server.requests[0]
assert sent.body == {"model": "mistral-ocr-latest", "document": OCR_DOCUMENT}
assert sent.headers.get("x-deleted") is None
@pytest.mark.parametrize("raise_after_edit", [False, True], ids=["callback-returns", "callback-raises"])
def test_native_ocr_pre_call_body_edit_reaches_next_callback_and_provider(
server: RecordingServer, raise_after_edit: bool
) -> None:
observed: Final = []
class Edit(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
request_body(kwargs)["include_image_base64"] = True
if raise_after_edit:
raise RuntimeError("pre-call callback failed")
class Observe(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
observed.append(copy.deepcopy(request_body(kwargs)))
call_ocr(server, callbacks=[Edit(), Observe()], include_image_base64=False)
assert observed[0]["include_image_base64"] is True
assert server.requests[0].body["include_image_base64"] is True
def test_native_ocr_pre_call_header_edit_reaches_next_callback_and_provider(server: RecordingServer) -> None:
observed: Final = []
class Edit(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
request_headers(kwargs)["x-audit-tag"] = "reviewed"
class Observe(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
observed.append(dict(request_headers(kwargs)))
call_ocr(server, callbacks=[Edit(), Observe()])
assert observed[0]["x-audit-tag"] == "reviewed"
assert server.requests[0].headers["x-audit-tag"] == "reviewed"
@pytest.mark.asyncio
@pytest.mark.parametrize("asynchronous", [False, True], ids=["sync", "async"])
async def test_native_ocr_pre_call_nested_document_edit_updates_caller_callback_and_provider_references(
server: RecordingServer, asynchronous: bool
) -> None:
original: Final = dict(OCR_DOCUMENT)
replacement_url: Final = "data:application/pdf;base64,ZGVm"
retained: Final = []
aliases: Final = []
class Retain(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
aliases.append(request_body(kwargs)["document"] is original)
retained.append(request_body(kwargs)["document"])
class Edit(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
original["document_url"] = replacement_url
arguments: Final = {
"model": "mistral/mistral-ocr-latest",
"document": original,
"api_key": "test-key",
"api_base": server.base_url,
"callbacks": [Retain(), Edit()],
}
response: Final = await call_aocr(server, **arguments) if asynchronous else call_ocr(server, **arguments)
assert aliases == [True]
assert retained[0]["document_url"] == replacement_url
assert original["document_url"] == replacement_url
assert server.requests[0].body["document"]["document_url"] == replacement_url
assert response.pages[0].markdown == "native OCR response"
def test_native_ocr_pre_call_body_rebinding_is_visible_to_callbacks_but_not_provider(
server: RecordingServer,
) -> None:
observed: Final = []
class Rebind(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
kwargs["additional_args"]["complete_input_dict"] = {"replacement": True}
class Observe(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
observed.append(request_body(kwargs))
call_ocr(server, callbacks=[Rebind(), Observe()])
assert observed == [{"replacement": True}]
assert server.requests[0].body == {"model": "mistral-ocr-latest", "document": OCR_DOCUMENT}
def test_native_ocr_callback_retained_body_observes_later_callback_mutation(server: RecordingServer) -> None:
queued: Final = []
class QueuePayload(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
queued.append(request_body(kwargs))
class Edit(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
request_body(kwargs)["queued-edit"] = True
call_ocr(server, callbacks=[QueuePayload(), Edit()])
assert queued[0]["queued-edit"] is True
def test_native_ocr_success_callback_receives_state_added_by_pre_call_callback(server: RecordingServer) -> None:
token: Final = object()
terminal_tokens: queue.SimpleQueue[object] = queue.SimpleQueue()
finished: Final = threading.Event()
class Stash(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
kwargs["test-token"] = token
def log_success_event(self, kwargs, response_obj, start_time, end_time):
terminal_tokens.put(kwargs["test-token"])
finished.set()
call_ocr(server, callbacks=[Stash()])
assert finished.wait(10)
assert terminal_tokens.get_nowait() is token
@pytest.mark.asyncio
async def test_native_aocr_success_callback_receives_call_id_metadata_and_response(
server: RecordingServer,
) -> None:
recorder: Final = RecordingLogger()
await call_aocr(
server,
callbacks=[recorder],
litellm_call_id="ocr-success",
metadata={"source": "callback-test"},
)
events: Final = await recorder.wait_for_async("async_log_success_event")
assert len(events) == 1
assert events[0].call_type == "aocr"
assert events[0].kwargs["litellm_call_id"] == "ocr-success"
assert events[0].kwargs["litellm_params"]["metadata"]["source"] == "callback-test"
assert events[0].response.pages[0].markdown == "native OCR response"
@pytest.mark.asyncio
async def test_native_aocr_failure_callbacks_receive_call_type_error_and_no_response(
server: RecordingServer,
) -> None:
server.enqueue(ResponseSpec(body={"message": "provider unavailable"}, status=500))
observations: Final = []
class Observe(CustomLogger):
def log_failure_event(self, kwargs, response_obj, start_time, end_time):
observations.append(("sync", kwargs["call_type"], kwargs["exception"], response_obj))
async def async_log_failure_event(self, kwargs, response_obj, start_time, end_time):
observations.append(("async", kwargs["call_type"], kwargs["exception"], response_obj))
with pytest.raises(litellm.InternalServerError):
await call_aocr(server, callbacks=[Observe()])
assert [observation[0] for observation in observations] == ["async"]
assert all(observation[1] == "aocr" for observation in observations)
assert all(isinstance(observation[2], litellm.InternalServerError) for observation in observations)
assert all(observation[3] is None for observation in observations)
@pytest.mark.asyncio
async def test_native_aocr_pre_call_callback_runs_on_caller_loop_and_thread(server: RecordingServer) -> None:
caller_loop: Final = asyncio.get_running_loop()
caller_thread: Final = threading.current_thread()
recorder: Final = RecordingLogger()
await call_aocr(server, callbacks=[recorder])
events: Final = await recorder.wait_for_async("log_pre_api_call")
assert len(events) == 1
assert events[0].loop is caller_loop
assert events[0].thread is caller_thread
@pytest.mark.asyncio
async def test_native_aocr_failure_callbacks_receive_state_added_by_pre_call_callback(
server: RecordingServer,
) -> None:
server.enqueue(ResponseSpec(body={"message": "provider unavailable"}, status=500))
token: Final = object()
observed: Final = []
class TrackInFlightRequest(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
kwargs["request-token"] = token
def log_failure_event(self, kwargs, response_obj, start_time, end_time):
observed.append(("sync", kwargs["request-token"]))
async def async_log_failure_event(self, kwargs, response_obj, start_time, end_time):
observed.append(("async", kwargs["request-token"]))
with pytest.raises(litellm.InternalServerError):
await call_aocr(server, callbacks=[TrackInFlightRequest()])
assert [event for event, _ in observed] == ["async"]
assert all(observed_token is token for _, observed_token in observed)
def test_native_ocr_dispatches_each_callback_phase_once_when_logger_is_registered_multiple_times(
server: RecordingServer,
) -> None:
recorder: Final = RecordingLogger()
call_ocr(
server,
callbacks=[recorder, recorder],
success_callback=[recorder],
failure_callback=[recorder],
)
recorder.wait_for("log_success_event")
assert recorder.names.count("log_pre_api_call") == 1
assert recorder.names.count("logging_hook") == 1
assert recorder.names.count("log_success_event") == 1
assert "log_failure_event" not in recorder.names
JSON_SCALARS: Final = (
st.none()
| st.booleans()
| st.integers(min_value=-(2**63), max_value=2**63 - 1)
| st.floats(allow_nan=False, allow_infinity=False)
| st.text(max_size=8)
)
JSON_VALUES: Final = st.recursive(
JSON_SCALARS,
lambda children: st.lists(children, max_size=3) | st.dictionaries(st.text(max_size=6), children, max_size=3),
max_leaves=8,
)
class ApplyEdits(CustomLogger):
def __init__(self, edits: Mapping[str, object]) -> None:
super().__init__()
self.edits: Final = edits
def log_pre_api_call(self, model, messages, kwargs):
request_body(kwargs).update(copy.deepcopy(dict(self.edits)))
@settings(max_examples=25, deadline=None, suppress_health_check=[HealthCheck.function_scoped_fixture])
@given(edits=st.dictionaries(st.from_regex(r"x_[a-z]{1,6}", fullmatch=True), JSON_VALUES, max_size=3))
def test_native_ocr_provider_receives_the_body_exactly_as_pre_call_callbacks_left_it(
server: RecordingServer, edits: dict[str, object]
) -> None:
server.expected_requests = None
with isolated_callback_registries():
call_ocr(server, callbacks=[ApplyEdits(MappingProxyType(edits))])
assert server.requests[-1].body == {"model": "mistral-ocr-latest", "document": OCR_DOCUMENT, **edits}
@pytest.mark.parametrize("hook", ["log_pre_api_call", "logging_hook", "log_success_event"])
def test_native_ocr_sync_hooks_see_no_running_event_loop(server: RecordingServer, hook: str) -> None:
recorder: Final = RecordingLogger()
call_ocr(server, callbacks=[recorder])
[event] = recorder.wait_for(hook)
assert event.loop is None
assert (event.thread is threading.current_thread()) == (hook == "log_pre_api_call")
@pytest.mark.asyncio
@pytest.mark.parametrize("asynchronous", [False, True], ids=["sync", "async"])
async def test_native_ocr_payload_a_callback_retains_outlives_the_call_intact(
server: RecordingServer, asynchronous: bool
) -> None:
retained: Final = []
class Retain(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
retained.append((kwargs, request_body(kwargs), request_headers(kwargs)))
await call(server, asynchronous, callbacks=[Retain()])
await drain_logging()
gc.collect()
[(details, body, headers)] = retained
assert body == server.requests[0].body
assert headers
assert all(server.requests[0].headers[name.lower()] == value for name, value in headers.items())
assert details["additional_args"]["complete_input_dict"] is body
assert details["additional_args"]["headers"] is headers
@pytest.mark.asyncio
@pytest.mark.parametrize("family", ["sync", "async"])
async def test_native_ocr_success_callbacks_share_one_logging_payload(server: RecordingServer, family: str) -> None:
queued: Final = []
finished: Final = threading.Event()
def queue_payload(kwargs: dict[str, object]) -> None:
queued.append(kwargs["standard_logging_object"])
def strip_payload(kwargs: dict[str, object]) -> None:
payload: Final = kwargs["standard_logging_object"]
assert isinstance(payload, dict)
payload["stripped-by-a-later-callback"] = True
finished.set()
class QueuePayload(CustomLogger):
if family == "sync":
def log_success_event(self, kwargs, response_obj, start_time, end_time):
queue_payload(kwargs)
else:
async def async_log_success_event(self, kwargs, response_obj, start_time, end_time):
queue_payload(kwargs)
class StripPayload(CustomLogger):
if family == "sync":
def log_success_event(self, kwargs, response_obj, start_time, end_time):
strip_payload(kwargs)
else:
async def async_log_success_event(self, kwargs, response_obj, start_time, end_time):
strip_payload(kwargs)
await call(server, family == "async", callbacks=[QueuePayload(), StripPayload()])
await drain_logging()
assert await asyncio.to_thread(finished.wait, 10)
assert [payload["stripped-by-a-later-callback"] for payload in queued] == [True]
@pytest.mark.asyncio
async def test_native_aocr_state_stashed_before_a_blocking_hook_raises_reaches_failure_callbacks(
server: RecordingServer,
) -> None:
token: Final = object()
observed: Final = []
class Blocked(Exception):
pass
class Block(CustomGuardrail):
async def async_post_call_success_deployment_hook(self, request_data, response, call_type):
request_data["litellm_logging_obj"].model_call_details["blocked-by"] = token
raise Blocked("blocked after the provider answered")
def log_success_event(self, kwargs, response_obj, start_time, end_time):
observed.append(("success", None, None))
def log_failure_event(self, kwargs, response_obj, start_time, end_time):
observed.append(("sync", kwargs.get("blocked-by"), kwargs["exception"]))
async def async_log_failure_event(self, kwargs, response_obj, start_time, end_time):
observed.append(("async", kwargs.get("blocked-by"), kwargs["exception"]))
litellm.callbacks.append(Block())
with pytest.raises(Blocked) as raised:
await call_aocr(server)
await drain_logging()
assert observed == [("async", token, raised.value)]
@pytest.mark.asyncio
@pytest.mark.parametrize("asynchronous", [False, True], ids=["sync", "async"])
async def test_native_azure_ocr_resolves_token_before_pre_call_on_caller_context(
server: RecordingServer,
isolated_azure_auth: None,
asynchronous: bool,
) -> None:
from contextvars import ContextVar
context: Final = ContextVar("azure-token-context", default="missing")
context.set("caller")
caller_thread: Final = threading.current_thread()
caller_loop: Final = asyncio.get_running_loop()
observations: Final = []
class Provider:
def __call__(self) -> str:
assert context.get() == "caller"
assert threading.current_thread() is caller_thread
assert asyncio.get_running_loop() is caller_loop
observations.append("token")
return "caller-token"
class Edit(CustomLogger):
def log_pre_api_call(self, model, messages, kwargs):
assert request_headers(kwargs)["Authorization"] == "Bearer caller-token"
observations.append("pre_call")
request_headers(kwargs)["Authorization"] = "Bearer edited"
provider: Final = Provider()
arguments: Final = {
"model": "azure_ai/mistral-ocr-latest",
"api_key": None,
"azure_ad_token_provider": provider,
"callbacks": [Edit()],
}
response: Final = await call_aocr(server, **arguments) if asynchronous else call_ocr(server, **arguments)
assert response.pages[0].markdown == "native OCR response"
assert observations == ["token", "pre_call"]
assert server.requests[0].headers["authorization"] == "Bearer edited"
@pytest.mark.asyncio
@pytest.mark.parametrize("asynchronous", [False, True], ids=["sync", "async"])
async def test_native_azure_ocr_token_provider_can_make_nested_native_ocr_call(
server: RecordingServer,
isolated_azure_auth: None,
asynchronous: bool,
) -> None:
server.expected_requests = 2
calls: Final = []
def provider() -> str:
calls.append("token")
nested: Final = call_ocr(server)
assert nested.pages[0].markdown == "native OCR response"
return "outer-token"
arguments: Final = {
"model": "azure_ai/mistral-ocr-latest",
"api_key": None,
"azure_ad_token_provider": provider,
}
response: Final = await call_aocr(server, **arguments) if asynchronous else call_ocr(server, **arguments)
assert response.pages[0].markdown == "native OCR response"
assert calls == ["token"]
assert [request.headers["authorization"] for request in server.requests] == [
"Bearer test-key",
"Bearer outer-token",
]
@pytest.mark.asyncio
async def test_concurrent_native_azure_ocr_calls_isolate_token_results_and_error(
server: RecordingServer,
isolated_azure_auth: None,
) -> None:
server.expected_requests = 2
async def request(token: str, fail: bool) -> object:
def provider() -> str:
if fail:
raise ValueError(token)
return token
return await call_aocr(
server,
model="azure_ai/mistral-ocr-latest",
api_key=None,
azure_ad_token_provider=provider,
)
responses: Final = await asyncio.gather(
request("first", False),
request("failed", True),
request("second", False),
return_exceptions=True,
)
assert isinstance(responses[0], OCRResponse)
assert isinstance(responses[1], litellm.APIConnectionError)
assert "Failed to get Azure AD token: failed" in str(responses[1])
assert isinstance(responses[2], OCRResponse)
assert sorted(request.headers["authorization"] for request in server.requests) == [
"Bearer first",
"Bearer second",
]
@pytest.mark.asyncio
async def test_native_azure_ocr_releases_token_provider_after_cancellation(
server: RecordingServer,
isolated_azure_auth: None,
) -> None:
import gc
import weakref
from tests.test_litellm_rust.support.callback_recorder import drain_logging
class Provider:
def __call__(self) -> str:
return "caller-token"
async def invoke() -> weakref.ReferenceType[Provider]:
provider: Final = Provider()
reference: Final = weakref.ref(provider)
server.enqueue(ResponseSpec(body=OCR_RESPONSE, delay=0.1))
task: Final = asyncio.create_task(
call_aocr(
server,
model="azure_ai/mistral-ocr-latest",
api_key=None,
azure_ad_token_provider=provider,
)
)
await server.wait_for_requests(1)
assert reference() is provider
task.cancel()
with pytest.raises(asyncio.CancelledError):
await task
return reference
reference: Final = await invoke()
await drain_logging()
await asyncio.sleep(0)
gc.collect()
assert reference() is None