Use and pin black 20 (#1042)

requirements.txt

@@ -10,7 +10,7 @@ ujson
 
 # Testing
 autoflake
-black
+black==20.8b1
 databases[sqlite]
 isort==5.*
 mypy

starlette/applications.py

@@ -76,11 +76,11 @@ def build_middleware_stack(self) -> ASGIApp:
                 exception_handlers[key] = value
 
         middleware = (
-            [Middleware(ServerErrorMiddleware, handler=error_handler, debug=debug,)]
+            [Middleware(ServerErrorMiddleware, handler=error_handler, debug=debug)]
             + self.user_middleware
             + [
                 Middleware(
-                    ExceptionMiddleware, handlers=exception_handlers, debug=debug,
+                    ExceptionMiddleware, handlers=exception_handlers, debug=debug
                 )
             ]
         )

starlette/config.py

@@ -57,12 +57,12 @@ def __init__(
             self.file_values = self._read_file(env_file)
 
     def __call__(
-        self, key: str, cast: typing.Callable = None, default: typing.Any = undefined,
+        self, key: str, cast: typing.Callable = None, default: typing.Any = undefined
     ) -> typing.Any:
         return self.get(key, cast, default)
 
     def get(
-        self, key: str, cast: typing.Callable = None, default: typing.Any = undefined,
+        self, key: str, cast: typing.Callable = None, default: typing.Any = undefined
     ) -> typing.Any:
         if key in self.environ:
             value = self.environ[key]
@@ -87,7 +87,7 @@ def _read_file(self, file_name: typing.Union[str, Path]) -> typing.Dict[str, str
         return file_values
 
     def _perform_cast(
-        self, key: str, value: typing.Any, cast: typing.Callable = None,
+        self, key: str, value: typing.Any, cast: typing.Callable = None
     ) -> typing.Any:
         if cast is None or value is None:
             return value

tests/middleware/test_lifespan.py

@@ -24,7 +24,7 @@ def run_shutdown():
     app = Router(
         on_startup=[run_startup],
         on_shutdown=[run_shutdown],
-        routes=[Route("/", hello_world),],
+        routes=[Route("/", hello_world)],
     )
 
     assert not startup_complete

tests/test_graphql.py

@@ -155,7 +155,7 @@ def test_graphql_async():
 @pytest.fixture
 def old_style_async_app(event_loop) -> GraphQLApp:
     old_style_async_app = GraphQLApp(
-        schema=async_schema, executor=AsyncioExecutor(loop=event_loop),
+        schema=async_schema, executor=AsyncioExecutor(loop=event_loop)
     )
     return old_style_async_app
 

tests/test_routing.py

@@ -443,7 +443,7 @@ def test_url_for_with_root_path():
 
 
 double_mount_routes = [
-    Mount("/mount", name="mount", routes=[Mount("/static", ..., name="static")],),
+    Mount("/mount", name="mount", routes=[Mount("/static", ..., name="static")]),
 ]