Web exceptions refactoring

aiohttp/web_exceptions.py

@@ -1,6 +1,11 @@
 import warnings
-from typing import Any, Dict, Iterable, List, Optional, Set  # noqa
+from http import HTTPStatus
+from typing import Any, Dict, Iterable, List, Optional, Set, Type, cast  # noqa
 
+from multidict import CIMultiDict
+from yarl import URL
+
+from . import hdrs
 from .typedefs import LooseHeaders, StrOrURL
 from .web_response import Response
 
@@ -70,36 +75,80 @@
 # HTTP Exceptions
 ############################################################
 
-class HTTPException(Response, Exception):
+class HTTPException(Exception):
 
     # You should set in subclasses:
     # status = 200
 
     status_code = -1
     empty_body = False
+    default_reason = ""  # Initialized at the end of the module
 
     __http_exception__ = True
 
     def __init__(self, *,
                  headers: Optional[LooseHeaders]=None,
                  reason: Optional[str]=None,
-                 body: Any=None,
                  text: Optional[str]=None,
                  content_type: Optional[str]=None) -> None:
-        if body is not None:
-            warnings.warn(
-                "body argument is deprecated for http web exceptions",
-                DeprecationWarning)
-        Response.__init__(self, status=self.status_code,
-                          headers=headers, reason=reason,
-                          body=body, text=text, content_type=content_type)
-        Exception.__init__(self, self.reason)
-        if self.body is None and not self.empty_body:
-            self.text = "{}: {}".format(self.status, self.reason)
+        if reason is None:
+            reason = self.default_reason
+
+        if text is None:
+            if not self.empty_body:
+                text = "{}: {}".format(self.status_code, reason)
+        else:
+            if self.empty_body:
+                warnings.warn(
+                    "text argument is deprecated for HTTP status {} ,"
+                    "the response should be provided without a body".format(
+                        self.status_code),
+                    DeprecationWarning,
+                    stacklevel=2)
+
+        if headers is not None:
+            real_headers = CIMultiDict(headers)
+        else:
+            real_headers = CIMultiDict()
+        if content_type is not None:
+            if text:
+                warnings.warn("content_type without text is deprecated",
+                              DeprecationWarning,
+                              stacklevel=2)
+            real_headers[hdrs.CONTENT_TYPE] = content_type
+        elif hdrs.CONTENT_TYPE not in real_headers and text:
+            real_headers[hdrs.CONTENT_TYPE] = 'text/plain'
+
+        super().__init__(reason)
+
+        self._text = text
+        self._headers = real_headers
 
     def __bool__(self) -> bool:
         return True
 
+    @property
+    def status(self) -> int:
+        return self.status_code
+
+    @property
+    def reason(self) -> str:
+        return self.args[0]
+
+    @property
+    def text(self) -> Optional[str]:
+        return self._text
+
+    @property
+    def headers(self) -> 'CIMultiDict[str]':
+        return self._headers
+
+    def make_response(self) -> Response:
+        return Response(status=self.status_code,
+                        reason=self.reason,
+                        text=self._text,
+                        headers=self._headers)
+
 
 class HTTPError(HTTPException):
     """Base class for exceptions with status codes in the 400s and 500s."""
@@ -155,15 +204,18 @@ def __init__(self,
                  *,
                  headers: Optional[LooseHeaders]=None,
                  reason: Optional[str]=None,
-                 body: Any=None,
                  text: Optional[str]=None,
                  content_type: Optional[str]=None) -> None:
         if not location:
             raise ValueError("HTTP redirects need a location to redirect to.")
         super().__init__(headers=headers, reason=reason,
-                         body=body, text=text, content_type=content_type)
+                         text=text, content_type=content_type)
         self.headers['Location'] = str(location)
-        self.location = location
+        self._location = URL(location)
+
+    @property
+    def location(self) -> URL:
+        return self._location
 
 
 class HTTPMultipleChoices(_HTTPMove):
@@ -241,15 +293,22 @@ def __init__(self,
                  *,
                  headers: Optional[LooseHeaders]=None,
                  reason: Optional[str]=None,
-                 body: Any=None,
                  text: Optional[str]=None,
                  content_type: Optional[str]=None) -> None:
         allow = ','.join(sorted(allowed_methods))
         super().__init__(headers=headers, reason=reason,
-                         body=body, text=text, content_type=content_type)
+                         text=text, content_type=content_type)
         self.headers['Allow'] = allow
-        self.allowed_methods = set(allowed_methods)  # type: Set[str]
-        self.method = method.upper()
+        self._allowed = set(allowed_methods)  # type: Set[str]
+        self._method = method.upper()
+
+    @property
+    def allowed_methods(self) -> Set[str]:
+        return self._allowed
+
+    @property
+    def method(self) -> str:
+        return self._method
 
 
 class HTTPNotAcceptable(HTTPClientError):
@@ -347,11 +406,10 @@ def __init__(self,
                  *,
                  headers: Optional[LooseHeaders]=None,
                  reason: Optional[str]=None,
-                 body: Any=None,
                  text: Optional[str]=None,
                  content_type: Optional[str]=None) -> None:
         super().__init__(headers=headers, reason=reason,
-                         body=body, text=text, content_type=content_type)
+                         text=text, content_type=content_type)
         self.headers['Link'] = '<%s>; rel="blocked-by"' % link
         self.link = link
 
@@ -410,3 +468,19 @@ class HTTPNotExtended(HTTPServerError):
 
 class HTTPNetworkAuthenticationRequired(HTTPServerError):
     status_code = 511
+
+
+def _initialize_default_reason() -> None:
+    for obj in globals().values():
+        if isinstance(obj, type) and issubclass(obj, HTTPException):
+            exc = cast(Type[HTTPException], obj)
+            if exc.status_code >= 0:
+                try:
+                    status = HTTPStatus(exc.status_code)
+                    exc.default_reason = status.phrase
+                except ValueError:
+                    pass
+
+
+_initialize_default_reason()
+del _initialize_default_reason

aiohttp/web_protocol.py

@@ -405,7 +405,7 @@ async def start(self) -> None:
                         self._request_handler(request))
                     resp = await task
                 except HTTPException as exc:
-                    resp = exc
+                    resp = exc.make_response()
                 except asyncio.CancelledError:
                     self.log_debug('Ignored premature client disconnection')
                     break