Add script to ease migration to black (#3038)

[etc/vim.git] / src / black / __init__.py

diff --git a/src/black/__init__.py b/src/black/__init__.py
index 3a1ce24f059e3c0bd57d73770d394d1956306aa7..8872102a6ea8baec5d74094297bb327adaccd8c7 100644 (file)
--- a/src/black/__init__.py
+++ b/src/black/__init__.py
@@ -1,7 +1,6 @@
 import asyncio
 from json.decoder import JSONDecodeError
 import json
-from concurrent.futures import Executor, ThreadPoolExecutor, ProcessPoolExecutor
 from contextlib import contextmanager
 from datetime import datetime
 from enum import Enum
@@ -17,6 +16,7 @@ import sys
 import tokenize
 import traceback
 from typing import (
+    TYPE_CHECKING,
     Any,
     Dict,
     Generator,
@@ -77,6 +77,9 @@ from blib2to3.pgen2 import token
 
 from _black_version import version as __version__
 
+if TYPE_CHECKING:
+    from concurrent.futures import Executor
+
 COMPILED = Path(__file__).suffix in (".pyd", ".so")
 
 # types
@@ -767,6 +770,8 @@ def reformat_many(
     workers: Optional[int],
 ) -> None:
     """Reformat multiple files using a ProcessPoolExecutor."""
+    from concurrent.futures import Executor, ThreadPoolExecutor, ProcessPoolExecutor
+
     executor: Executor
     loop = asyncio.get_event_loop()
     worker_count = workers if workers is not None else DEFAULT_WORKERS
@@ -808,7 +813,7 @@ async def schedule_formatting(
     mode: Mode,
     report: "Report",
     loop: asyncio.AbstractEventLoop,
-    executor: Executor,
+    executor: "Executor",
 ) -> None:
     """Run formatting of `sources` in parallel using the provided `executor`.
 
@@ -1303,6 +1308,18 @@ def get_features_used(  # noqa: C901
         ):
             features.add(Feature.EXCEPT_STAR)
 
+        elif n.type in {syms.subscriptlist, syms.trailer} and any(
+            child.type == syms.star_expr for child in n.children
+        ):
+            features.add(Feature.VARIADIC_GENERICS)
+
+        elif (
+            n.type == syms.tname_star
+            and len(n.children) == 3
+            and n.children[2].type == syms.star_expr
+        ):
+            features.add(Feature.VARIADIC_GENERICS)
+
     return features