From 0f65f9289db0627b6c5ee756929dc7adadd5b9c9 Mon Sep 17 00:00:00 2001
From: Tyler Goodlet <jgbt@protonmail.com>
Date: Tue, 21 Jul 2020 10:32:37 -0400
Subject: [PATCH] Attempt to make mypy happy..

---
 tractor/to_asyncio.py | 58 +++++++++++++++++++++++++++----------------
 1 file changed, 36 insertions(+), 22 deletions(-)

diff --git a/tractor/to_asyncio.py b/tractor/to_asyncio.py
index fb8f4cd..0f22300 100644
--- a/tractor/to_asyncio.py
+++ b/tractor/to_asyncio.py
@@ -4,6 +4,7 @@ Infection apis for ``asyncio`` loops running ``trio`` using guest mode.
 import asyncio
 import inspect
 from typing import (
+    Any,
     Callable,
     AsyncGenerator,
     Awaitable,
@@ -21,21 +22,26 @@ log = get_logger(__name__)
 __all__ = ['run_task', 'run_as_asyncio_guest']
 
 
-async def _invoke(
-    from_trio: trio.abc.ReceiveChannel,
-    to_trio: asyncio.Queue,
+async def run_coro(
+    to_trio: trio.MemorySendChannel,
     coro: Awaitable,
 ) -> None:
-    """Await or stream awaiable object based on ``coro`` type into
-    ``trio`` memory channel.
-
-    ``from_trio`` might eventually be used here for bidirectional streaming.
+    """Await ``coro`` and relay result back to ``trio``.
     """
-    if inspect.isasyncgen(coro):
-        async for item in coro:
-            to_trio.send_nowait(item)
-    elif inspect.iscoroutine(coro):
-        to_trio.send_nowait(await coro)
+    to_trio.send_nowait(await coro)
+
+
+async def consume_asyncgen(
+    to_trio: trio.MemorySendChannel,
+    coro: AsyncGenerator,
+) -> None:
+    """Stream async generator results back to ``trio``.
+
+    ``from_trio`` might eventually be used here for
+    bidirectional streaming.
+    """
+    async for item in coro:
+        to_trio.send_nowait(item)
 
 
 async def run_task(
@@ -44,15 +50,15 @@ async def run_task(
     qsize: int = 2**10,
     _treat_as_stream: bool = False,
     **kwargs,
-) -> Union[AsyncGenerator, Awaitable]:
+) -> Union[AsyncGenerator, Any]:
     """Run an ``asyncio`` async function or generator in a task, return
     or stream the result back to ``trio``.
     """
     assert current_actor().is_infected_aio()
 
     # ITC (inter task comms)
-    from_trio = asyncio.Queue(qsize)
-    to_trio, from_aio = trio.open_memory_channel(qsize)
+    from_trio = asyncio.Queue(qsize)  # type: ignore
+    to_trio, from_aio = trio.open_memory_channel(qsize)  # type: ignore
 
     args = tuple(inspect.getfullargspec(func).args)
 
@@ -66,7 +72,7 @@ async def run_task(
     if 'to_trio' in args:
         kwargs['to_trio'] = to_trio
     if 'from_trio' in args:
-        kwargs['from_trio'] = to_trio
+        kwargs['from_trio'] = from_trio
 
     coro = func(**kwargs)
 
@@ -74,7 +80,13 @@ async def run_task(
 
     # start the asyncio task we submitted from trio
     # TODO: try out ``anyio`` asyncio based tg here
-    task = asyncio.create_task(_invoke(from_trio, to_trio, coro))
+    if inspect.isawaitable(coro):
+        task = asyncio.create_task(run_coro(to_trio, coro))
+    elif inspect.isasyncgen(coro):
+        task = asyncio.create_task(consume_asyncgen(to_trio, coro))
+    else:
+        raise TypeError(f"No support for {coro}")
+
     err = None
 
     def cancel_trio(task):
@@ -88,27 +100,29 @@ async def run_task(
 
     # asycn gen
     if inspect.isasyncgen(coro) or _treat_as_stream:
-        async def result():
+
+        async def stream_results():
             with cancel_scope:
+                # stream values upward
                 async with from_aio:
                     async for item in from_aio:
                         yield item
             if cancel_scope.cancelled_caught and err:
                 raise err
 
-        return result()
+        return stream_results()
 
     # simple async func
     elif inspect.iscoroutine(coro):
         with cancel_scope:
-            result = await from_aio.receive()
-            return result
+            # return single value
+            return await from_aio.receive()
         if cancel_scope.cancelled_caught and err:
             raise err
 
 
 def run_as_asyncio_guest(
-    trio_main: Awaitable,
+    trio_main: Callable,
 ) -> None:
     """Entry for an "infected ``asyncio`` actor".