access names as proxies directly

Author: davidism

src/flask/globals.py

@@ -1,59 +1,50 @@
 import typing as t
-from functools import partial
+from contextvars import ContextVar
 
-from werkzeug.local import LocalProxy
 from werkzeug.local import LocalStack
 
 if t.TYPE_CHECKING:  # pragma: no cover
     from .app import Flask
     from .ctx import _AppCtxGlobals
+    from .ctx import AppContext
+    from .ctx import RequestContext
     from .sessions import SessionMixin
     from .wrappers import Request
 
-_request_ctx_err_msg = """\
-Working outside of request context.
-
-This typically means that you attempted to use functionality that needed
-an active HTTP request.  Consult the documentation on testing for
-information about how to avoid this problem.\
-"""
-_app_ctx_err_msg = """\
+_no_app_msg = """\
 Working outside of application context.
 
 This typically means that you attempted to use functionality that needed
-to interface with the current application object in some way. To solve
-this, set up an application context with app.app_context().  See the
-documentation for more information.\
+the current application. To solve this, set up an application context
+with app.app_context(). See the documentation for more information.\
 """
+_cv_app: ContextVar[t.List["AppContext"]] = ContextVar("flask.app_ctx")
+_app_ctx_stack: LocalStack["AppContext"] = LocalStack(_cv_app)
+app_ctx: "AppContext" = _app_ctx_stack(  # type: ignore[assignment]
+    unbound_message=_no_app_msg
+)
+current_app: "Flask" = _app_ctx_stack(  # type: ignore[assignment]
+    "app", unbound_message=_no_app_msg
+)
+g: "_AppCtxGlobals" = _app_ctx_stack(  # type: ignore[assignment]
+    "g", unbound_message=_no_app_msg
+)
 
+_no_req_msg = """\
+Working outside of request context.
 
-def _lookup_req_object(name):
-    top = _request_ctx_stack.top
-    if top is None:
-        raise RuntimeError(_request_ctx_err_msg)
-    return getattr(top, name)
-
-
-def _lookup_app_object(name):
-    top = _app_ctx_stack.top
-    if top is None:
-        raise RuntimeError(_app_ctx_err_msg)
-    return getattr(top, name)
-
-
-def _find_app():
-    top = _app_ctx_stack.top
-    if top is None:
-        raise RuntimeError(_app_ctx_err_msg)
-    return top.app
-
-
-# context locals
-_request_ctx_stack = LocalStack()
-_app_ctx_stack = LocalStack()
-current_app: "Flask" = LocalProxy(_find_app)  # type: ignore
-request: "Request" = LocalProxy(partial(_lookup_req_object, "request"))  # type: ignore
-session: "SessionMixin" = LocalProxy(  # type: ignore
-    partial(_lookup_req_object, "session")
+This typically means that you attempted to use functionality that needed
+an active HTTP request. Consult the documentation on testing for
+information about how to avoid this problem.\
+"""
+_cv_req: ContextVar[t.List["RequestContext"]] = ContextVar("flask.request_ctx")
+_request_ctx_stack: LocalStack["RequestContext"] = LocalStack(_cv_req)
+request_ctx: "RequestContext" = _request_ctx_stack(  # type: ignore[assignment]
+    unbound_message=_no_req_msg
+)
+request: "Request" = _request_ctx_stack(  # type: ignore[assignment]
+    "request", unbound_message=_no_req_msg
+)
+session: "SessionMixin" = _request_ctx_stack(  # type: ignore[assignment]
+    "session", unbound_message=_no_req_msg
 )
-g: "_AppCtxGlobals" = LocalProxy(partial(_lookup_app_object, "g"))  # type: ignore