synapse/tests/test_utils/__init__.py

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# -*- coding: utf-8 -*-
# Copyright 2019 New Vector Ltd
# Copyright 2020 The Matrix.org Foundation C.I.C
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Utilities for running the unit tests
"""
import sys
import warnings
from asyncio import Future
from typing import Any, Awaitable, Callable, TypeVar
TV = TypeVar("TV")
def get_awaitable_result(awaitable: Awaitable[TV]) -> TV:
"""Get the result from an Awaitable which should have completed
Asserts that the given awaitable has a result ready, and returns its value
"""
i = awaitable.__await__()
try:
next(i)
except StopIteration as e:
# awaitable returned a result
return e.value
# if next didn't raise, the awaitable hasn't completed.
raise Exception("awaitable has not yet completed")
def make_awaitable(result: Any) -> Awaitable[Any]:
"""
Makes an awaitable, suitable for mocking an `async` function.
This uses Futures as they can be awaited multiple times so can be returned
to multiple callers.
"""
future = Future() # type: ignore
future.set_result(result)
return future
def setup_awaitable_errors() -> Callable[[], None]:
"""
Convert warnings from a non-awaited coroutines into errors.
"""
warnings.simplefilter("error", RuntimeWarning)
# unraisablehook was added in Python 3.8.
if not hasattr(sys, "unraisablehook"):
return lambda: None
# State shared between unraisablehook and check_for_unraisable_exceptions.
unraisable_exceptions = []
orig_unraisablehook = sys.unraisablehook # type: ignore
def unraisablehook(unraisable):
unraisable_exceptions.append(unraisable.exc_value)
def cleanup():
"""
A method to be used as a clean-up that fails a test-case if there are any new unraisable exceptions.
"""
sys.unraisablehook = orig_unraisablehook # type: ignore
if unraisable_exceptions:
raise unraisable_exceptions.pop()
sys.unraisablehook = unraisablehook # type: ignore
return cleanup