458 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			458 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| import asyncio
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| from contextlib import asynccontextmanager, AbstractAsyncContextManager, AsyncExitStack
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| import functools
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| from test import support
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| import unittest
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| 
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| from test.test_contextlib import TestBaseExitStack
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| 
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| 
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| def _async_test(func):
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|     """Decorator to turn an async function into a test case."""
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|     @functools.wraps(func)
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|     def wrapper(*args, **kwargs):
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|         coro = func(*args, **kwargs)
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|         loop = asyncio.new_event_loop()
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|         asyncio.set_event_loop(loop)
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|         try:
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|             return loop.run_until_complete(coro)
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|         finally:
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|             loop.close()
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|             asyncio.set_event_loop_policy(None)
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|     return wrapper
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| 
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| 
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| class TestAbstractAsyncContextManager(unittest.TestCase):
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| 
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|     @_async_test
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|     async def test_enter(self):
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|         class DefaultEnter(AbstractAsyncContextManager):
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|             async def __aexit__(self, *args):
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|                 await super().__aexit__(*args)
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| 
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|         manager = DefaultEnter()
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|         self.assertIs(await manager.__aenter__(), manager)
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| 
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|         async with manager as context:
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|             self.assertIs(manager, context)
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| 
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|     @_async_test
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|     async def test_async_gen_propagates_generator_exit(self):
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|         # A regression test for https://bugs.python.org/issue33786.
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| 
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|         @asynccontextmanager
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|         async def ctx():
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|             yield
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| 
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|         async def gen():
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|             async with ctx():
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|                 yield 11
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| 
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|         ret = []
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|         exc = ValueError(22)
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|         with self.assertRaises(ValueError):
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|             async with ctx():
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|                 async for val in gen():
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|                     ret.append(val)
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|                     raise exc
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| 
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|         self.assertEqual(ret, [11])
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| 
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|     def test_exit_is_abstract(self):
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|         class MissingAexit(AbstractAsyncContextManager):
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|             pass
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| 
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|         with self.assertRaises(TypeError):
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|             MissingAexit()
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| 
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|     def test_structural_subclassing(self):
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|         class ManagerFromScratch:
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|             async def __aenter__(self):
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|                 return self
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|             async def __aexit__(self, exc_type, exc_value, traceback):
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|                 return None
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| 
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|         self.assertTrue(issubclass(ManagerFromScratch, AbstractAsyncContextManager))
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| 
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|         class DefaultEnter(AbstractAsyncContextManager):
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|             async def __aexit__(self, *args):
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|                 await super().__aexit__(*args)
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| 
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|         self.assertTrue(issubclass(DefaultEnter, AbstractAsyncContextManager))
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| 
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|         class NoneAenter(ManagerFromScratch):
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|             __aenter__ = None
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| 
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|         self.assertFalse(issubclass(NoneAenter, AbstractAsyncContextManager))
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| 
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|         class NoneAexit(ManagerFromScratch):
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|             __aexit__ = None
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| 
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|         self.assertFalse(issubclass(NoneAexit, AbstractAsyncContextManager))
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| 
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| 
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| class AsyncContextManagerTestCase(unittest.TestCase):
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| 
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|     @_async_test
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|     async def test_contextmanager_plain(self):
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|         state = []
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|         @asynccontextmanager
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|         async def woohoo():
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|             state.append(1)
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|             yield 42
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|             state.append(999)
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|         async with woohoo() as x:
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|             self.assertEqual(state, [1])
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|             self.assertEqual(x, 42)
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|             state.append(x)
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|         self.assertEqual(state, [1, 42, 999])
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| 
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|     @_async_test
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|     async def test_contextmanager_finally(self):
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|         state = []
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|         @asynccontextmanager
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|         async def woohoo():
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|             state.append(1)
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|             try:
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|                 yield 42
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|             finally:
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|                 state.append(999)
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|         with self.assertRaises(ZeroDivisionError):
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|             async with woohoo() as x:
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|                 self.assertEqual(state, [1])
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|                 self.assertEqual(x, 42)
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|                 state.append(x)
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|                 raise ZeroDivisionError()
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|         self.assertEqual(state, [1, 42, 999])
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| 
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|     @_async_test
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|     async def test_contextmanager_no_reraise(self):
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|         @asynccontextmanager
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|         async def whee():
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|             yield
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|         ctx = whee()
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|         await ctx.__aenter__()
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|         # Calling __aexit__ should not result in an exception
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|         self.assertFalse(await ctx.__aexit__(TypeError, TypeError("foo"), None))
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| 
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|     @_async_test
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|     async def test_contextmanager_trap_yield_after_throw(self):
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|         @asynccontextmanager
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|         async def whoo():
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|             try:
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|                 yield
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|             except:
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|                 yield
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|         ctx = whoo()
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|         await ctx.__aenter__()
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|         with self.assertRaises(RuntimeError):
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|             await ctx.__aexit__(TypeError, TypeError('foo'), None)
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| 
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|     @_async_test
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|     async def test_contextmanager_trap_no_yield(self):
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|         @asynccontextmanager
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|         async def whoo():
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|             if False:
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|                 yield
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|         ctx = whoo()
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|         with self.assertRaises(RuntimeError):
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|             await ctx.__aenter__()
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| 
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|     @_async_test
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|     async def test_contextmanager_trap_second_yield(self):
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|         @asynccontextmanager
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|         async def whoo():
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|             yield
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|             yield
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|         ctx = whoo()
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|         await ctx.__aenter__()
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|         with self.assertRaises(RuntimeError):
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|             await ctx.__aexit__(None, None, None)
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| 
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|     @_async_test
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|     async def test_contextmanager_non_normalised(self):
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|         @asynccontextmanager
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|         async def whoo():
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|             try:
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|                 yield
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|             except RuntimeError:
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|                 raise SyntaxError
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| 
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|         ctx = whoo()
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|         await ctx.__aenter__()
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|         with self.assertRaises(SyntaxError):
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|             await ctx.__aexit__(RuntimeError, None, None)
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| 
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|     @_async_test
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|     async def test_contextmanager_except(self):
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|         state = []
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|         @asynccontextmanager
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|         async def woohoo():
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|             state.append(1)
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|             try:
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|                 yield 42
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|             except ZeroDivisionError as e:
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|                 state.append(e.args[0])
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|                 self.assertEqual(state, [1, 42, 999])
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|         async with woohoo() as x:
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|             self.assertEqual(state, [1])
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|             self.assertEqual(x, 42)
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|             state.append(x)
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|             raise ZeroDivisionError(999)
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|         self.assertEqual(state, [1, 42, 999])
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| 
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|     @_async_test
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|     async def test_contextmanager_except_stopiter(self):
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|         @asynccontextmanager
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|         async def woohoo():
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|             yield
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| 
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|         for stop_exc in (StopIteration('spam'), StopAsyncIteration('ham')):
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|             with self.subTest(type=type(stop_exc)):
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|                 try:
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|                     async with woohoo():
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|                         raise stop_exc
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|                 except Exception as ex:
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|                     self.assertIs(ex, stop_exc)
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|                 else:
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|                     self.fail(f'{stop_exc} was suppressed')
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| 
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|     @_async_test
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|     async def test_contextmanager_wrap_runtimeerror(self):
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|         @asynccontextmanager
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|         async def woohoo():
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|             try:
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|                 yield
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|             except Exception as exc:
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|                 raise RuntimeError(f'caught {exc}') from exc
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| 
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|         with self.assertRaises(RuntimeError):
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|             async with woohoo():
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|                 1 / 0
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| 
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|         # If the context manager wrapped StopAsyncIteration in a RuntimeError,
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|         # we also unwrap it, because we can't tell whether the wrapping was
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|         # done by the generator machinery or by the generator itself.
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|         with self.assertRaises(StopAsyncIteration):
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|             async with woohoo():
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|                 raise StopAsyncIteration
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| 
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|     def _create_contextmanager_attribs(self):
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|         def attribs(**kw):
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|             def decorate(func):
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|                 for k,v in kw.items():
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|                     setattr(func,k,v)
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|                 return func
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|             return decorate
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|         @asynccontextmanager
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|         @attribs(foo='bar')
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|         async def baz(spam):
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|             """Whee!"""
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|             yield
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|         return baz
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| 
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|     def test_contextmanager_attribs(self):
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|         baz = self._create_contextmanager_attribs()
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|         self.assertEqual(baz.__name__,'baz')
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|         self.assertEqual(baz.foo, 'bar')
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| 
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|     @support.requires_docstrings
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|     def test_contextmanager_doc_attrib(self):
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|         baz = self._create_contextmanager_attribs()
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|         self.assertEqual(baz.__doc__, "Whee!")
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| 
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|     @support.requires_docstrings
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|     @_async_test
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|     async def test_instance_docstring_given_cm_docstring(self):
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|         baz = self._create_contextmanager_attribs()(None)
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|         self.assertEqual(baz.__doc__, "Whee!")
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|         async with baz:
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|             pass  # suppress warning
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| 
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|     @_async_test
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|     async def test_keywords(self):
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|         # Ensure no keyword arguments are inhibited
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|         @asynccontextmanager
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|         async def woohoo(self, func, args, kwds):
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|             yield (self, func, args, kwds)
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|         async with woohoo(self=11, func=22, args=33, kwds=44) as target:
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|             self.assertEqual(target, (11, 22, 33, 44))
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| 
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| 
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| class TestAsyncExitStack(TestBaseExitStack, unittest.TestCase):
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|     class SyncAsyncExitStack(AsyncExitStack):
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|         @staticmethod
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|         def run_coroutine(coro):
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|             loop = asyncio.get_event_loop()
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| 
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|             f = asyncio.ensure_future(coro)
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|             f.add_done_callback(lambda f: loop.stop())
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|             loop.run_forever()
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| 
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|             exc = f.exception()
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| 
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|             if not exc:
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|                 return f.result()
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|             else:
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|                 context = exc.__context__
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| 
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|                 try:
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|                     raise exc
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|                 except:
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|                     exc.__context__ = context
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|                     raise exc
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| 
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|         def close(self):
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|             return self.run_coroutine(self.aclose())
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| 
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|         def __enter__(self):
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|             return self.run_coroutine(self.__aenter__())
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| 
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|         def __exit__(self, *exc_details):
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|             return self.run_coroutine(self.__aexit__(*exc_details))
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| 
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|     exit_stack = SyncAsyncExitStack
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| 
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|     def setUp(self):
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|         self.loop = asyncio.new_event_loop()
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|         asyncio.set_event_loop(self.loop)
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|         self.addCleanup(self.loop.close)
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|         self.addCleanup(asyncio.set_event_loop_policy, None)
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| 
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|     @_async_test
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|     async def test_async_callback(self):
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|         expected = [
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|             ((), {}),
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|             ((1,), {}),
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|             ((1,2), {}),
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|             ((), dict(example=1)),
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|             ((1,), dict(example=1)),
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|             ((1,2), dict(example=1)),
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|         ]
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|         result = []
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|         async def _exit(*args, **kwds):
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|             """Test metadata propagation"""
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|             result.append((args, kwds))
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| 
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|         async with AsyncExitStack() as stack:
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|             for args, kwds in reversed(expected):
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|                 if args and kwds:
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|                     f = stack.push_async_callback(_exit, *args, **kwds)
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|                 elif args:
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|                     f = stack.push_async_callback(_exit, *args)
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|                 elif kwds:
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|                     f = stack.push_async_callback(_exit, **kwds)
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|                 else:
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|                     f = stack.push_async_callback(_exit)
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|                 self.assertIs(f, _exit)
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|             for wrapper in stack._exit_callbacks:
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|                 self.assertIs(wrapper[1].__wrapped__, _exit)
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|                 self.assertNotEqual(wrapper[1].__name__, _exit.__name__)
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|                 self.assertIsNone(wrapper[1].__doc__, _exit.__doc__)
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| 
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|         self.assertEqual(result, expected)
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| 
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|         result = []
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|         async with AsyncExitStack() as stack:
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|             with self.assertRaises(TypeError):
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|                 stack.push_async_callback(arg=1)
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|             with self.assertRaises(TypeError):
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|                 self.exit_stack.push_async_callback(arg=2)
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|             with self.assertRaises(TypeError):
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|                 stack.push_async_callback(callback=_exit, arg=3)
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|         self.assertEqual(result, [])
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| 
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|     @_async_test
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|     async def test_async_push(self):
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|         exc_raised = ZeroDivisionError
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|         async def _expect_exc(exc_type, exc, exc_tb):
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|             self.assertIs(exc_type, exc_raised)
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|         async def _suppress_exc(*exc_details):
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|             return True
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|         async def _expect_ok(exc_type, exc, exc_tb):
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|             self.assertIsNone(exc_type)
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|             self.assertIsNone(exc)
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|             self.assertIsNone(exc_tb)
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|         class ExitCM(object):
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|             def __init__(self, check_exc):
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|                 self.check_exc = check_exc
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|             async def __aenter__(self):
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|                 self.fail("Should not be called!")
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|             async def __aexit__(self, *exc_details):
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|                 await self.check_exc(*exc_details)
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| 
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|         async with self.exit_stack() as stack:
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|             stack.push_async_exit(_expect_ok)
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|             self.assertIs(stack._exit_callbacks[-1][1], _expect_ok)
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|             cm = ExitCM(_expect_ok)
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|             stack.push_async_exit(cm)
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|             self.assertIs(stack._exit_callbacks[-1][1].__self__, cm)
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|             stack.push_async_exit(_suppress_exc)
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|             self.assertIs(stack._exit_callbacks[-1][1], _suppress_exc)
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|             cm = ExitCM(_expect_exc)
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|             stack.push_async_exit(cm)
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|             self.assertIs(stack._exit_callbacks[-1][1].__self__, cm)
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|             stack.push_async_exit(_expect_exc)
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|             self.assertIs(stack._exit_callbacks[-1][1], _expect_exc)
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|             stack.push_async_exit(_expect_exc)
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|             self.assertIs(stack._exit_callbacks[-1][1], _expect_exc)
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|             1/0
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| 
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|     @_async_test
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|     async def test_async_enter_context(self):
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|         class TestCM(object):
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|             async def __aenter__(self):
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|                 result.append(1)
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|             async def __aexit__(self, *exc_details):
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|                 result.append(3)
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| 
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|         result = []
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|         cm = TestCM()
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| 
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|         async with AsyncExitStack() as stack:
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|             @stack.push_async_callback  # Registered first => cleaned up last
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|             async def _exit():
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|                 result.append(4)
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|             self.assertIsNotNone(_exit)
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|             await stack.enter_async_context(cm)
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|             self.assertIs(stack._exit_callbacks[-1][1].__self__, cm)
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|             result.append(2)
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| 
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|         self.assertEqual(result, [1, 2, 3, 4])
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| 
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|     @_async_test
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|     async def test_async_exit_exception_chaining(self):
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|         # Ensure exception chaining matches the reference behaviour
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|         async def raise_exc(exc):
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|             raise exc
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| 
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|         saved_details = None
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|         async def suppress_exc(*exc_details):
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|             nonlocal saved_details
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|             saved_details = exc_details
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|             return True
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| 
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|         try:
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|             async with self.exit_stack() as stack:
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|                 stack.push_async_callback(raise_exc, IndexError)
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|                 stack.push_async_callback(raise_exc, KeyError)
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|                 stack.push_async_callback(raise_exc, AttributeError)
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|                 stack.push_async_exit(suppress_exc)
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|                 stack.push_async_callback(raise_exc, ValueError)
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|                 1 / 0
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|         except IndexError as exc:
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|             self.assertIsInstance(exc.__context__, KeyError)
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|             self.assertIsInstance(exc.__context__.__context__, AttributeError)
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|             # Inner exceptions were suppressed
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|             self.assertIsNone(exc.__context__.__context__.__context__)
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|         else:
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|             self.fail("Expected IndexError, but no exception was raised")
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|         # Check the inner exceptions
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|         inner_exc = saved_details[1]
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|         self.assertIsInstance(inner_exc, ValueError)
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|         self.assertIsInstance(inner_exc.__context__, ZeroDivisionError)
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| 
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| 
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| if __name__ == '__main__':
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|     unittest.main()
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