Spaces:
Running
Running
File size: 5,465 Bytes
1d777c4 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 |
import asyncio
import contextvars
import inspect
import warnings
from .case import TestCase
class IsolatedAsyncioTestCase(TestCase):
# Names intentionally have a long prefix
# to reduce a chance of clashing with user-defined attributes
# from inherited test case
#
# The class doesn't call loop.run_until_complete(self.setUp()) and family
# but uses a different approach:
# 1. create a long-running task that reads self.setUp()
# awaitable from queue along with a future
# 2. await the awaitable object passing in and set the result
# into the future object
# 3. Outer code puts the awaitable and the future object into a queue
# with waiting for the future
# The trick is necessary because every run_until_complete() call
# creates a new task with embedded ContextVar context.
# To share contextvars between setUp(), test and tearDown() we need to execute
# them inside the same task.
# Note: the test case modifies event loop policy if the policy was not instantiated
# yet.
# asyncio.get_event_loop_policy() creates a default policy on demand but never
# returns None
# I believe this is not an issue in user level tests but python itself for testing
# should reset a policy in every test module
# by calling asyncio.set_event_loop_policy(None) in tearDownModule()
def __init__(self, methodName='runTest'):
super().__init__(methodName)
self._asyncioRunner = None
self._asyncioTestContext = contextvars.copy_context()
async def asyncSetUp(self):
pass
async def asyncTearDown(self):
pass
def addAsyncCleanup(self, func, /, *args, **kwargs):
# A trivial trampoline to addCleanup()
# the function exists because it has a different semantics
# and signature:
# addCleanup() accepts regular functions
# but addAsyncCleanup() accepts coroutines
#
# We intentionally don't add inspect.iscoroutinefunction() check
# for func argument because there is no way
# to check for async function reliably:
# 1. It can be "async def func()" itself
# 2. Class can implement "async def __call__()" method
# 3. Regular "def func()" that returns awaitable object
self.addCleanup(*(func, *args), **kwargs)
async def enterAsyncContext(self, cm):
"""Enters the supplied asynchronous context manager.
If successful, also adds its __aexit__ method as a cleanup
function and returns the result of the __aenter__ method.
"""
# We look up the special methods on the type to match the with
# statement.
cls = type(cm)
try:
enter = cls.__aenter__
exit = cls.__aexit__
except AttributeError:
raise TypeError(f"'{cls.__module__}.{cls.__qualname__}' object does "
f"not support the asynchronous context manager protocol"
) from None
result = await enter(cm)
self.addAsyncCleanup(exit, cm, None, None, None)
return result
def _callSetUp(self):
# Force loop to be initialized and set as the current loop
# so that setUp functions can use get_event_loop() and get the
# correct loop instance.
self._asyncioRunner.get_loop()
self._asyncioTestContext.run(self.setUp)
self._callAsync(self.asyncSetUp)
def _callTestMethod(self, method):
if self._callMaybeAsync(method) is not None:
warnings.warn(f'It is deprecated to return a value that is not None from a '
f'test case ({method})', DeprecationWarning, stacklevel=4)
def _callTearDown(self):
self._callAsync(self.asyncTearDown)
self._asyncioTestContext.run(self.tearDown)
def _callCleanup(self, function, *args, **kwargs):
self._callMaybeAsync(function, *args, **kwargs)
def _callAsync(self, func, /, *args, **kwargs):
assert self._asyncioRunner is not None, 'asyncio runner is not initialized'
assert inspect.iscoroutinefunction(func), f'{func!r} is not an async function'
return self._asyncioRunner.run(
func(*args, **kwargs),
context=self._asyncioTestContext
)
def _callMaybeAsync(self, func, /, *args, **kwargs):
assert self._asyncioRunner is not None, 'asyncio runner is not initialized'
if inspect.iscoroutinefunction(func):
return self._asyncioRunner.run(
func(*args, **kwargs),
context=self._asyncioTestContext,
)
else:
return self._asyncioTestContext.run(func, *args, **kwargs)
def _setupAsyncioRunner(self):
assert self._asyncioRunner is None, 'asyncio runner is already initialized'
runner = asyncio.Runner(debug=True)
self._asyncioRunner = runner
def _tearDownAsyncioRunner(self):
runner = self._asyncioRunner
runner.close()
def run(self, result=None):
self._setupAsyncioRunner()
try:
return super().run(result)
finally:
self._tearDownAsyncioRunner()
def debug(self):
self._setupAsyncioRunner()
super().debug()
self._tearDownAsyncioRunner()
def __del__(self):
if self._asyncioRunner is not None:
self._tearDownAsyncioRunner()
|