Fix instability due to trailing comma logic (#2572)

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

diff --git a/src/blackd/__init__.py b/src/blackd/__init__.py
index d79bfe75bc2f8c7b419668e8cf10f28e432362c9..0463f169e196518eb7b9d611a321ea4abc9a9216 100644 (file)
--- a/src/blackd/__init__.py
+++ b/src/blackd/__init__.py
@@ -1,14 +1,23 @@
 import asyncio
+import logging
 from concurrent.futures import Executor, ProcessPoolExecutor
 from datetime import datetime
 from functools import partial
-import logging
 from multiprocessing import freeze_support
 from typing import Set, Tuple
 
-from aiohttp import web
-import aiohttp_cors
+try:
+    from aiohttp import web
+    from .middlewares import cors
+except ImportError as ie:
+    raise ImportError(
+        f"aiohttp dependency is not installed: {ie}. "
+        + "Please re-install black with the '[d]' extra install "
+        + "to obtain aiohttp_cors: `pip install black[d]`"
+    ) from None
+
 import black
+from black.concurrency import maybe_install_uvloop
 import click
 
 from _black_version import version as __version__
@@ -21,6 +30,7 @@ PROTOCOL_VERSION_HEADER = "X-Protocol-Version"
 LINE_LENGTH_HEADER = "X-Line-Length"
 PYTHON_VARIANT_HEADER = "X-Python-Variant"
 SKIP_STRING_NORMALIZATION_HEADER = "X-Skip-String-Normalization"
+SKIP_MAGIC_TRAILING_COMMA = "X-Skip-Magic-Trailing-Comma"
 FAST_OR_SAFE_HEADER = "X-Fast-Or-Safe"
 DIFF_HEADER = "X-Diff"
 
@@ -29,6 +39,7 @@ BLACK_HEADERS = [
     LINE_LENGTH_HEADER,
     PYTHON_VARIANT_HEADER,
     SKIP_STRING_NORMALIZATION_HEADER,
+    SKIP_MAGIC_TRAILING_COMMA,
     FAST_OR_SAFE_HEADER,
     DIFF_HEADER,
 ]
@@ -56,20 +67,11 @@ def main(bind_host: str, bind_port: int) -> None:
 
 
 def make_app() -> web.Application:
-    app = web.Application()
-    executor = ProcessPoolExecutor()
-
-    cors = aiohttp_cors.setup(app)
-    resource = cors.add(app.router.add_resource("/"))
-    cors.add(
-        resource.add_route("POST", partial(handle, executor=executor)),
-        {
-            "*": aiohttp_cors.ResourceOptions(
-                allow_headers=(*BLACK_HEADERS, "Content-Type"), expose_headers="*"
-            )
-        },
+    app = web.Application(
+        middlewares=[cors(allow_headers=(*BLACK_HEADERS, "Content-Type"))]
     )
-
+    executor = ProcessPoolExecutor()
+    app.add_routes([web.post("/", partial(handle, executor=executor))])
     return app
 
 
@@ -103,6 +105,9 @@ async def handle(request: web.Request, executor: Executor) -> web.Response:
         skip_string_normalization = bool(
             request.headers.get(SKIP_STRING_NORMALIZATION_HEADER, False)
         )
+        skip_magic_trailing_comma = bool(
+            request.headers.get(SKIP_MAGIC_TRAILING_COMMA, False)
+        )
         fast = False
         if request.headers.get(FAST_OR_SAFE_HEADER, "safe") == "fast":
             fast = True
@@ -111,6 +116,7 @@ async def handle(request: web.Request, executor: Executor) -> web.Response:
             is_pyi=pyi,
             line_length=line_length,
             string_normalization=not skip_string_normalization,
+            magic_trailing_comma=not skip_magic_trailing_comma,
         )
         req_bytes = await request.content.read()
         charset = request.charset if request.charset is not None else "utf8"
@@ -168,10 +174,8 @@ def parse_python_variant_header(value: str) -> Tuple[bool, Set[black.TargetVersi
                     raise InvalidVariantHeader("major version must be 2 or 3")
                 if len(rest) > 0:
                     minor = int(rest[0])
-                    if major == 2 and minor != 7:
-                        raise InvalidVariantHeader(
-                            "minor version must be 7 for Python 2"
-                        )
+                    if major == 2:
+                        raise InvalidVariantHeader("Python 2 is not supported")
                 else:
                     # Default to lowest supported minor version.
                     minor = 7 if major == 2 else 3
@@ -180,11 +184,12 @@ def parse_python_variant_header(value: str) -> Tuple[bool, Set[black.TargetVersi
                     raise InvalidVariantHeader(f"3.{minor} is not supported")
                 versions.add(black.TargetVersion[version_str])
             except (KeyError, ValueError):
-                raise InvalidVariantHeader("expected e.g. '3.7', 'py3.5'")
+                raise InvalidVariantHeader("expected e.g. '3.7', 'py3.5'") from None
         return False, versions
 
 
 def patched_main() -> None:
+    maybe_install_uvloop()
     freeze_support()
     black.patch_click()
     main()