Remove `yield from` usage from asyncio tests

[kumaraditya303]

Support for yield from was deprecated and removed so it should be removed.

See

cpython/Lib/test/test_asyncio/test_tasks.py

Lines 2093 to 2100 in cd67c1b

	# The indirection fut->child_coro is needed since otherwise the
	# gathering task is done at the same time as the child future
	def child_coro():
	return (yield from fut)
	gather_future = asyncio.gather(child_coro())
	return asyncio.ensure_future(gather_future)
	gather_task = loop.run_until_complete(create())

Linked PRs

• GH-100113: remove remaining yield from usage from asyncio tests  #100114

[vstinner]

There are a few yield from in asyncio tests (Lib/test/test_asyncio/):

test_futures.py:296:            x = yield from f
test_futures.py:298:            y = yield from f
test_futures.py:303:        self.assertEqual(next(g), f)  # First yield from f.
test_futures.py:306:        # The second "yield from f" does not yield f.
test_futures.py:408:            yield from fut
test_pep492.py:152:            yield from ()
test_sslproto.py:99:        # yield from waiter hang if lost_connection was called.
test_tasks.py:2096:                return (yield from fut)
utils.py:271:            yield from _run_test_server(address=path, use_ssl=use_ssl,
utils.py:278:    yield from _run_test_server(address=(host, port), use_ssl=use_ssl,

[kumaraditya303]

There are a few yield from in asyncio tests (Lib/test/test_asyncio/):

I think those are testing the internal implementation of futures and they are not used with asyncio APIs. I don't think they should be changed to await.

[gvanrossum]

There's a comment referencing yield from on line 66 of asyncio/futures.py that probably should be updated, if indeed we are dropping (or have dropped) yield from support. Similar on line 292 (seems to refer to the same thing).

Next, in asyncio/tasks.py, line 316 there's an error message complaining about yield instead of yield from. Should that be await too? Again on line 327. The same error messages also occur in _asynciomodule.c.

Then there's _wrap_awaitable(), also in tasks.py, which on line 687 has a yield from.

But maybe I'm not understanding how yield from is used here???

[kumaraditya303]

Then there's _wrap_awaitable(), also in tasks.py, which on line 687 has a yield from.

This has been removed now.

Next, in asyncio/tasks.py, line 316 there's an error message complaining about yield instead of yield from. Should that be await too? Again on line 327. The same error messages also occur in _asynciomodule.c.

That's debugging aid for people who are writing their own awaitables with custom __await__ method.

[kumaraditya303]

Closing this, anything left can be handled in #102748