Address mypy errors on 3.10 w/ asyncio loop parameter (#2580)

CHANGES.md

@@ -8,6 +8,8 @@
 - Add new `--workers` parameter (#2514)
 - Fixed feature detection for positional-only arguments in lambdas (#2532)
 - Bumped typed-ast version minimum to 1.4.3 for 3.10 compatiblity (#2519)
+- Fixed a Python 3.10 compatibility issue where the loop argument was still being passed
+  even though it has been removed (#2580)
 
 ### _Blackd_
 

src/black/__init__.py

@@ -763,6 +763,9 @@ async def schedule_formatting(
                     sources_to_cache.append(src)
                 report.done(src, changed)
     if cancelled:
+        if sys.version_info >= (3, 7):
+            await asyncio.gather(*cancelled, return_exceptions=True)
+        else:
             await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
     if sources_to_cache:
         write_cache(cache, sources_to_cache, mode)

src/black/concurrency.py

@@ -42,6 +42,9 @@ def shutdown(loop: asyncio.AbstractEventLoop) -> None:
 
         for task in to_cancel:
             task.cancel()
+        if sys.version_info >= (3, 7):
+            loop.run_until_complete(asyncio.gather(*to_cancel, return_exceptions=True))
+        else:
             loop.run_until_complete(
                 asyncio.gather(*to_cancel, loop=loop, return_exceptions=True)
             )