[IMPR] Add ClientError for http status 4XX

- add ClientError for http status 400-451
- rename Server414Error to Client414Error
- raise ClientError with site_detect.check_response()
  in addition to ServerError
- raise Client414Error with http.error_handling_callback()
- check for Client414Error with Request._http_request()

Change-Id: Ie125730837db50d4143d9b4f656b2bd4d9f01430
---
M pywikibot/exceptions.py
M pywikibot/comms/http.py
M pywikibot/site_detect.py
M pywikibot/data/api/_requests.py
4 files changed, 81 insertions(+), 37 deletions(-)

diff --git a/pywikibot/comms/http.py b/pywikibot/comms/http.py
index 77128be..319f512 100644
--- a/pywikibot/comms/http.py
+++ b/pywikibot/comms/http.py
@@ -48,8 +48,8 @@
 from pywikibot import config, tools
 from pywikibot.backports import Tuple
 from pywikibot.exceptions import (
+    Client414Error,
     FatalServerError,
-    Server414Error,
     Server504Error,
     ServerError,
 )
@@ -333,7 +333,7 @@
         raise response from None
 
     if response.status_code == HTTPStatus.REQUEST_URI_TOO_LONG:
-        raise Server414Error('Too long GET request')
+        raise Client414Error(HTTPStatus(response.status_code).description)
 
     if response.status_code == HTTPStatus.GATEWAY_TIMEOUT:
         raise Server504Error('Server {} timed out'
diff --git a/pywikibot/data/api/_requests.py b/pywikibot/data/api/_requests.py
index 9d4dc8e..ebdbe9e 100644
--- a/pywikibot/data/api/_requests.py
+++ b/pywikibot/data/api/_requests.py
@@ -25,11 +25,11 @@
 from pywikibot.backports import Callable, Dict, Match, Tuple, removeprefix
 from pywikibot.comms import http
 from pywikibot.exceptions import (
+    Client414Error,
     Error,
     FatalServerError,
     MaxlagTimeoutError,
     NoUsernameError,
-    Server414Error,
     Server504Error,
     SiteDefinitionError,
     TimeoutError,
@@ -687,13 +687,13 @@
                                     data=data, headers=headers)
         except Server504Error:
             pywikibot.log('Caught HTTP 504 error; retrying')
-        except Server414Error:
+        except Client414Error:
             if use_get:
                 pywikibot.log('Caught HTTP 414 error; retrying')
                 use_get = False
             else:
-                pywikibot.warning('Caught HTTP 414 error, although not '
-                                  'using GET.')
+                pywikibot.warning(
+                    'Caught HTTP 414 error, although not using GET.')
                 raise
         except (ConnectionError, FatalServerError):
             # This error is not going to be fixed by just waiting
diff --git a/pywikibot/exceptions.py b/pywikibot/exceptions.py
index 654e579..36da84e 100644
--- a/pywikibot/exceptions.py
+++ b/pywikibot/exceptions.py
@@ -10,6 +10,8 @@
           |    +-- UploadError
           +-- AutoblockUserError
           +-- CaptchaError
+          +-- ClientError
+          |    +-- Client414Error
           +-- InvalidTitleError
           +-- NoUsernameError
           +-- PageInUseError
@@ -41,7 +43,6 @@
           +-- SectionError
           +-- ServerError
           |    +-- FatalServerError
-          |    +-- Server414Error
           |    +-- Server504Error
           +-- SiteDefinitionError
           |    +-- UnknownFamilyError
@@ -68,17 +69,18 @@
 
 Error: Base class, all exceptions should the subclass of this class.
 
-  - NoUsernameError: Username is not in user config file, or it is invalid.
-  - AutoblockUserError: requested action on a virtual autoblock user not valid
-  - TranslationError: no language translation found
-  - UserRightsError: insufficient rights for requested action
-  - InvalidTitleError: Invalid page title
   - CaptchaError: Captcha is asked and config.solve_captcha == False
-  - i18n.TranslationError: i18n/l10n message not available
+  - ClientError: A problem with the client request
+  - AutoblockUserError: requested action on a virtual autoblock user not valid
+  - InvalidTitleError: Invalid page title
+  - NoUsernameError: Username is not in user config file, or it is invalid.
   - PageInUseError: Page cannot be reserved due to a lock
-  - UnknownExtensionError: Extension is not defined for this site
-  - VersionParseError: failed to parse version information
   - SectionError: The section specified by # does not exist
+  - TranslationError: no language translation found
+  - UnknownExtensionError: Extension is not defined for this site
+  - UserRightsError: insufficient rights for requested action
+  - VersionParseError: failed to parse version information
+  - i18n.TranslationError: i18n/l10n message not available
 
 APIError: wiki API returned an error
 
@@ -160,9 +162,13 @@
    All Pywikibot Error exceptions must be imported from
    ``pywikibot.exceptions``. Deprecated exceptions identifiers were
    removed.
+
+.. versionchanged:: 8.1
+   ``Server414Error`` class is deprecated; use :class:`Client414Error`
+   instead.
 """
 #
-# (C) Pywikibot team, 2008-2022
+# (C) Pywikibot team, 2008-2023
 #
 # Distributed under the terms of the MIT license.
 #
@@ -170,7 +176,7 @@
 from typing import Any, Optional, Union
 
 import pywikibot
-from pywikibot.tools import issue_deprecation_warning
+from pywikibot.tools import ModuleDeprecationWrapper, issue_deprecation_warning
 from pywikibot.tools._deprecate import _NotImplementedWarning
 
 
@@ -576,6 +582,22 @@
     message = 'Page {} is title-blacklisted.'
 
 
+class ClientError(Error):
+
+    """Got unexpected server response due to client issue.
+
+    .. versionadded:: 8.1
+    """
+
+
+class Client414Error(ClientError):
+
+    """Server returned with HTTP 414 code.
+
+    .. versionadded:: 8.1
+    """
+
+
 class ServerError(Error):
 
     """Got unexpected server response."""
@@ -591,11 +613,6 @@
     """Server timed out with HTTP 504 code."""
 
 
-class Server414Error(ServerError):
-
-    """Server returned with HTTP 414 code."""
-
-
 class CaptchaError(Error):
 
     """Captcha is asked and config.solve_captcha == False."""
@@ -681,3 +698,8 @@
 class MaxlagTimeoutError(TimeoutError):
 
     """Request failed with a maxlag timeout error."""
+
+
+wrapper = ModuleDeprecationWrapper(__name__)
+wrapper.add_deprecated_attr(
+    'Server414Error', Client414Error, since='8.1.0')
diff --git a/pywikibot/site_detect.py b/pywikibot/site_detect.py
index 8a266d2..5dde965 100644
--- a/pywikibot/site_detect.py
+++ b/pywikibot/site_detect.py
@@ -17,7 +17,7 @@
 import pywikibot
 from pywikibot.backports import removesuffix
 from pywikibot.comms.http import fetch
-from pywikibot.exceptions import ServerError
+from pywikibot.exceptions import ClientError, ServerError
 from pywikibot.tools import MediaWikiVersion
 
 
@@ -280,25 +280,31 @@
 
 
 def check_response(response):
-    """Raise ServerError if the response indicates a server error.
+    """Raise ClientError or ServerError depending on http status.
 
     .. versionadded:: 3.0
     .. versionchanged:: 7.0
-       Raise a generic ServerError if http status code is not
-       IANA-registered but unofficial code
-
-
+       Raise a generic :class:`exceptions.ServerError` if http status
+       code is not IANA-registered but unofficial code
+    .. versionchanged:: 8.1
+       Raise a :class:`exceptions.ClientError` if status code is 4XX
     """
-    if response.status_code >= HTTPStatus.INTERNAL_SERVER_ERROR:
-        try:
-            msg = HTTPStatus(response.status_code).phrase
-        except ValueError as err:
-            m = re.search(r'\d{3}', err.args[0], flags=re.ASCII)
-            if not m:
-                raise err
-            msg = f'Generic Server Error ({m.group()})'
+    for status_code, err_class, err_type in [
+        (HTTPStatus.INTERNAL_SERVER_ERROR, ServerError, 'Server'),
+        (HTTPStatus.BAD_REQUEST, ClientError, 'Client')
+    ]:  # highest http status code first
+        if response.status_code >= status_code:
+            try:
+                status = HTTPStatus(response.status_code).description
+            except ValueError as err:
+                m = re.search(r'\d{3}', err.args[0], flags=re.ASCII)
+                if not m:
+                    raise err
+                msg = f'Generic {err_type} Error ({m.group()})'
+            else:
+                msg = f'({status}) {status.description}'
 
-        raise ServerError(msg)
+            raise err_class(msg)
 
     if response.status_code == HTTPStatus.OK \
        and SERVER_DB_ERROR_MSG in response.text:

