Method test_compile_top_level_await

Lib/test/test_builtin.py:477–559

Test whether code with top level await can be compiled. Make sure it compiles only with the PyCF_ALLOW_TOP_LEVEL_AWAIT flag set, and make sure the generated code object has the CO_COROUTINE flag set in order to execute it with `await eval(.....)` instead of exec, or

(self)

    def test_compile_top_level_await(self):
        """Test whether code with top level await can be compiled.

        Make sure it compiles only with the PyCF_ALLOW_TOP_LEVEL_AWAIT flag
        set, and make sure the generated code object has the CO_COROUTINE flag
        set in order to execute it with  `await eval(.....)` instead of exec,
        or via a FunctionType.
        """

        # helper function just to check we can run top=level async-for
        async def arange(n):
            for i in range(n):
                yield i

        class Lock:
            async def __aenter__(self):
                return self

            async def __aexit__(self, *exc_info):
                pass

        async def sleep(delay, result=None):
            assert delay == 0
            await async_yield(None)
            return result

        modes = ('single', 'exec')
        optimizations = (-1, 0, 1, 2)
        code_samples = [
            '''a = await sleep(0, result=1)''',
            '''async for i in arange(1):
                   a = 1''',
            '''async with Lock() as l:
                   a = 1''',
            '''a = [x async for x in arange(2)][1]''',
            '''a = 1 in {x async for x in arange(2)}''',
            '''a = {x:1 async for x in arange(1)}[0]''',
            '''a = [x async for x in arange(2) async for x in arange(2)][1]''',
            '''a = [x async for x in (x async for x in arange(5))][1]''',
            '''a, = [1 for x in {x async for x in arange(1)}]''',
            '''a = [await sleep(0, x) async for x in arange(2)][1]''',
            # gh-121637: Make sure we correctly handle the case where the
            # async code is optimized away
            '''assert not await sleep(0); a = 1''',
            '''assert [x async for x in arange(1)]; a = 1''',
            '''assert {x async for x in arange(1)}; a = 1''',
            '''assert {x: x async for x in arange(1)}; a = 1''',
            '''
            if (a := 1) and __debug__:
                async with Lock() as l:
                    pass
            ''',
            '''
            if (a := 1) and __debug__:
                async for x in arange(2):
                    pass
            ''',
        ]