Remove WSGI layer entirely

Delete WSGIHandler, WSGIRequest, and the plain.wsgi entry point.
Remove dead WSGI helpers (base_environ, default_environ, create,
WSGIErrorsWrapper, headers_to_wsgi_environ, unquote_to_wsgi_str).
Rename server/http/wsgi.py to server/http/response.py. Server now
loads BaseHandler directly.

Author: davegaeddert

plain/plain/cli/server.py

@@ -120,7 +120,7 @@ def server(
     max_requests: int,
     pidfile: str | None,
 ) -> None:
-    """Production-ready WSGI server"""
+    """Production-ready HTTP server"""
     from plain.runtime import settings
 
     # Show settings loaded from environment

plain/plain/http/__init__.py

@@ -18,7 +18,6 @@
     Request,
     RequestHeaders,
     UnreadablePostError,
-    headers_to_wsgi_environ,
 )
 from .response import (
     BadHeaderError,
@@ -64,6 +63,4 @@
     "TooManyFieldsSentError400",
     "TooManyFilesSentError400",
     "RequestDataTooBigError400",
-    # WSGI helpers (used by test client)
-    "headers_to_wsgi_environ",
 ]

plain/plain/http/request.py

@@ -466,7 +466,7 @@ def close(self) -> None:
     # File-like and iterator interface.
     #
     # Expects self._stream to be set to an appropriate source of bytes by
-    # a corresponding request subclass (e.g. WSGIRequest).
+    # a corresponding request creator (e.g. server or test client).
     # Also when request data has already been read by request.json_data,
     # request.form_data, or request.body, self._stream points to a BytesIO
     # instance containing that data.
@@ -525,26 +525,6 @@ def __getitem__(self, key: str) -> str:
         return super().__getitem__(key.replace("_", "-"))
 
 
-# WSGI environ conversion helpers (used by test client and WSGIRequest)
-_WSGI_UNPREFIXED_HEADERS = {"CONTENT_TYPE", "CONTENT_LENGTH"}
-
-
-def headers_to_wsgi_environ(headers: dict[str, str]) -> dict[str, str]:
-    """Convert standard HTTP header names to WSGI environ keys.
-
-    Example: {"Content-Type": "text/html"} -> {"CONTENT_TYPE": "text/html"}
-             {"Accept": "text/html"} -> {"HTTP_ACCEPT": "text/html"}
-    """
-    result: dict[str, str] = {}
-    for name, value in headers.items():
-        key = name.replace("-", "_").upper()
-        if key in _WSGI_UNPREFIXED_HEADERS:
-            result[key] = value
-        else:
-            result[f"HTTP_{key}"] = value
-    return result
-
-
 class QueryDict(MultiValueDict):
     """
     A specialized MultiValueDict which represents a query string.

plain/plain/http/response.py

@@ -305,7 +305,7 @@ def make_bytes(self, value: str | bytes) -> bytes:
         # Handle non-string types.
         return str(value).encode(self.charset)
 
-    # The WSGI server must call this method upon completion of the request.
+    # The server must call this method upon completion of the request.
     # See http://blog.dscpl.com.au/2012/10/obligations-for-calling-close-on.html
     def close(self) -> None:
         for closer in self._resource_closers:

plain/plain/internal/handlers/base.py

@@ -82,11 +82,10 @@ def get_response(self, request: Request) -> ResponseBase:
             url_attributes.URL_SCHEME: request.scheme,
         }
 
-        # Add full URL if we can build it (requires proper WSGI environment)
+        # Add full URL if we can build it
         try:
             span_attributes[url_attributes.URL_FULL] = request.build_absolute_uri()
-        except KeyError:
-            # Missing required WSGI environment variables (e.g. in tests)
+        except (KeyError, AttributeError):
             pass
 
         # Add query string if present

plain/plain/internal/handlers/wsgi.py

@@ -58,7 +58,7 @@ def populate(
             return
 
         # populate() might be called by two threads in parallel on servers
-        # that create threads before initializing the WSGI callable.
+        # that create threads before initializing the request handler.
         with self._lock:
             if self.ready:
                 return

plain/plain/packages/registry.py

@@ -26,10 +26,12 @@ def __init__(self, cfg: Config) -> None:
     def load(self) -> Any:
         """Load the request handler."""
         import plain.runtime
-        from plain.internal.handlers.wsgi import WSGIHandler
+        from plain.internal.handlers.base import BaseHandler
 
         plain.runtime.setup()
-        return WSGIHandler()
+        handler = BaseHandler()
+        handler.load_middleware()
+        return handler
 
     def handler(self) -> Any:
         """Get the request handler."""

plain/plain/server/app.py

@@ -160,7 +160,7 @@ def parse_headers(
             # X-Forwarded-For: 2001:db8::ha:cc:ed
             # X_Forwarded_For: 127.0.0.1,::1
             # HTTP_X_FORWARDED_FOR = 2001:db8::ha:cc:ed,127.0.0.1,::1
-            # Only modify after fixing *ALL* header transformations; network to wsgi env
+            # Only modify after fixing *ALL* header transformations
             if "_" in name:
                 if name in forwarder_headers or "*" in forwarder_headers:
                     # This forwarder may override our environment