use pre-commit/ruff to enforce a basic coding style

.pre-commit-config.yaml

@@ -0,0 +1,17 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v4.4.0
+  hooks:
+    - id: trailing-whitespace
+    - id: end-of-file-fixer
+    - id: debug-statements
+
+- repo: https://github.com/charliermarsh/ruff-pre-commit
+  # Ruff version.
+  rev: 'v0.0.291'
+  hooks:
+    - id: ruff
+      # args: [--fix, --exit-non-zero-on-fix]
+      exclude: ^schwarz/mailqueue/lib/smtplib_py37.py

MANIFEST.in

@@ -1,4 +1,2 @@
 include *.txt
 include *.ini
-
-

README.md

@@ -243,5 +243,3 @@ a Windows machine should be fine.
 The code is licensed unter the MIT license with only few exceptions: It
 contains a custom (slightly modified) version of Python's smtplib which is
 licensed under the [Python License 2.0](https://spdx.org/licenses/Python-2.0.html).
-
-

pyproject.toml

@@ -0,0 +1,34 @@
+[tool.ruff]
+line-length = 100
+src = ["schwarz", "tests"]
+
+ignore = [
+    # F405 "… may be undefined, or defined from star imports: …"
+    #    Sometimes star imports are perfectly fine IMHO.
+    "F403",
+    "F405",
+    # E731: "Do not assign a `lambda` expression, use a `def`"
+    #    I think assigning to lambda expressions is ok.
+    "E731",
+]
+
+select = [
+    # Pyflakes
+    "F",
+    # Pycodestyle
+    "E",
+    "W",
+    # isort
+    "I001",
+
+    # Special rule code to enforce that your noqa directives are "valid", in that
+    # the violations they say they ignore are actually being triggered on that line
+    # (and thus suppressed).
+    # replaces basically "yesqa"
+    "RUF100",
+]
+
+[tool.ruff.isort]
+lines-after-imports = 2
+known-first-party = ["schwarz.mailqueue"]
+combine-as-imports = true

schwarz/mailqueue/app_helpers.py

@@ -8,9 +8,9 @@
 import os
 import sys
 
-from schwarz.puzzle_plugins import parse_list_str, PluginLoader
+from schwarz.puzzle_plugins import PluginLoader, parse_list_str
 
-from .compat import configparser, SafeConfigParser
+from .compat import SafeConfigParser, configparser
 from .mailer import SMTPMailer
 from .plugins import registry
 
@@ -163,4 +163,3 @@ def configure_logging(settings, options):
     # the root logger (this might lead to duplicate lines shown to the user,
     # e.g. in case of errors).
     mq_logger.propagate = False
-

schwarz/mailqueue/cli.py

@@ -62,4 +62,3 @@ def send_test_message_main(argv=sys.argv, return_rc_code=False):
     if return_rc_code:
         return exit_code
     sys.exit(exit_code)
-

schwarz/mailqueue/compat.py

@@ -36,6 +36,7 @@ def os_makedirs(name, mode, exist_ok=False):
 
 try:
     import configparser
+
     # in Python 3.2 "SafeConfigParser" was renamed to "ConfigParser"
     from configparser import ConfigParser as SafeConfigParser
 except ImportError:
@@ -98,4 +99,3 @@ def make_msgid(domain=None):
     msg_id_str = email.utils.make_msgid('@'+domain)
     msg_id = msg_id_str.rsplit('@', 1)[0] + '>'
     return msg_id
-

schwarz/mailqueue/lib/result.py

@@ -60,7 +60,7 @@ def __setattr__(self, key, value):
             self.__dict__[key] = value
             return
         if key not in self.data:
-            raise AttributeError("'%s' object has no attribute '%s'" % (self.__class__.__name__, key))
+            class_name = self.__class__.__name__, key
+            raise AttributeError("'%s' object has no attribute '%s'" % class_name)
         setter = getattr(self, 'set_'+key)
         setter(value)
-

schwarz/mailqueue/maildir_utils.py

@@ -5,10 +5,10 @@
 
 import os
 
-from boltons.fileutils import atomic_rename, atomic_save
 import portalocker
+from boltons.fileutils import atomic_rename, atomic_save
 
-from .compat import os_makedirs, FileNotFoundError, IS_WINDOWS
+from .compat import IS_WINDOWS, FileNotFoundError, os_makedirs
 
 
 __all__ = ['create_maildir_directories', 'lock_file', 'move_message']
@@ -63,7 +63,7 @@ def create_maildir_directories(basedir, is_folder=False):
         maildirfolder_path = os.path.join(basedir, 'maildirfolder')
         # never overwrite an existing "maildirfolder" file (just being overcautious)
         # in Python 3 we could also use "open(..., 'xb')" and catch FileExistsError
-        with atomic_save(maildirfolder_path, overwrite=False) as fp:
+        with atomic_save(maildirfolder_path, overwrite=False):
             pass
     return new_path
 
@@ -183,4 +183,3 @@ def move_message(file_, target_folder, open_file=True):
     except (IOError, OSError):
         pass
     return None
-

schwarz/mailqueue/mailer.py

@@ -3,9 +3,9 @@
 
 from __future__ import absolute_import, print_function, unicode_literals
 
+import socket
 from io import BytesIO
 from smtplib import SMTPException
-import socket
 
 from .message_utils import MsgInfo, SendResult
 from .smtpclient import SMTPClient
@@ -16,7 +16,7 @@
 class SMTPMailer(object):
     def __init__(self, hostname=None, **kwargs):
         if (hostname is None) and ('client' not in kwargs):
-            raise TypeError('not enough parameters for __init__(): please specify at least "hostname" or "client"')
+            raise TypeError('not enough parameters for __init__(): please specify at least "hostname" or "client"')  # noqa: E501 (line too long)
         self.hostname = hostname
         # ensure "port" is numeric as "socket.connect()" in Python 2 only
         # accepts ints (in Python 3 '25' works as well).
@@ -31,7 +31,12 @@ def __init__(self, hostname=None, **kwargs):
             raise TypeError("__init__() got an unexpected keyword argument '%s'" % extra_name)
 
     def init_smtp_client(self):
-        smtp_client = SMTPClient(self.hostname, self.port, timeout=self.connect_timeout, smtp_log=self.smtp_log)
+        smtp_client = SMTPClient(
+            self.hostname,
+            self.port,
+            timeout=self.connect_timeout,
+            smtp_log=self.smtp_log,
+        )
         return smtp_client
 
     def send(self, fromaddr, toaddrs, message):
@@ -80,4 +85,3 @@ def send(self, fromaddr, toaddrs, message):
             msg_info = MsgInfo(fromaddr, toaddrs, BytesIO(message))
             self.sent_mails.append(msg_info)
         return was_sent
-

schwarz/mailqueue/mailflow_check.py

@@ -47,4 +47,3 @@ def send_test_message(config_path, options):
     mh = MessageHandler(transports=(mailer,))
     was_sent = mh.send_message(msg)
     return was_sent
-

schwarz/mailqueue/message_handler.py

@@ -3,10 +3,10 @@
 
 from __future__ import absolute_import, print_function, unicode_literals
 
-from io import BytesIO
 import logging
+from io import BytesIO
 
-from .message_utils import dt_now, msg_as_bytes, MsgInfo, SendResult
+from .message_utils import MsgInfo, SendResult, dt_now, msg_as_bytes
 from .plugins import MQAction, MQSignal
 
 
@@ -46,7 +46,7 @@ def send_message(self, msg, **kwargs):
         if not send_result:
             msg_wrapper.retries += 1
             msg_wrapper.last_delivery_attempt = dt_now()
-            discard_message = self._notify_plugins(MQSignal.delivery_failed, msg_wrapper, send_result)
+            discard_message = self._notify_plugins(MQSignal.delivery_failed, msg_wrapper, send_result)  # noqa: E501 (line too long)
             msg_wrapper.delivery_failed(discard=discard_message)
             send_result.discarded = discard_message
         return send_result
@@ -61,7 +61,8 @@ def _log_successful_delivery(self, msg, sender, recipients):
     def _notify_plugins(self, signal, msg, send_result):
         if self.plugins is None:
             return
-        results = self.plugins.call_plugins(signal, signal_kwargs={'msg': msg, 'send_result': send_result})
+        signal_kwargs = {'msg': msg, 'send_result': send_result}
+        results = self.plugins.call_plugins(signal, signal_kwargs=signal_kwargs)
 
         if not results:
             return None
@@ -86,7 +87,7 @@ def _msg_metadata(self, msg, **kwargs):
         recipient = kwargs.pop('recipient', None)
         recipients = kwargs.pop('recipients', None)
         if recipient and recipients:
-            raise ValueError('__init__() got conflicting parameters: recipient=%r, recipients=%r' % (recipient, recipients))
+            raise ValueError('__init__() got conflicting parameters: recipient=%r, recipients=%r' % (recipient, recipients))  # noqa: E501 (line too long)
         if recipient:
             recipients = (recipient,)
         if not recipients:
@@ -166,4 +167,3 @@ def __init__(self, from_addr, to_addrs, msg_bytes):
 
     def start_delivery(self):
         return True
-

schwarz/mailqueue/message_utils.py

@@ -4,13 +4,13 @@
 from __future__ import absolute_import, print_function, unicode_literals
 
 import calendar
+import email.utils
+import re
 from collections import namedtuple
 from datetime import datetime as DateTime, timedelta as TimeDelta
 from email.header import decode_header
 from email.parser import FeedParser, HeaderParser
-import email.utils
 from io import BytesIO, TextIOWrapper
-import re
 
 from boltons.timeutils import ConstantTZInfo, LocalTZ
 
@@ -69,7 +69,7 @@ def dt_now():
     return DateTime.now(tz=LocalTZ)
 
 
-_MsgInfo = namedtuple('_MsgInfo', ('from_addr', 'to_addrs', 'msg_fp', 'queue_date', 'last', 'retries'))
+_MsgInfo = namedtuple('_MsgInfo', ('from_addr', 'to_addrs', 'msg_fp', 'queue_date', 'last', 'retries'))  # noqa: E501 (line too long)
 
 class MsgInfo(_MsgInfo):
     def __new__(cls, from_addr, to_addrs, msg_fp, queue_date=None, last=None, retries=None):
@@ -138,7 +138,10 @@ def decode_header_value(encoded_str):
 def strip_brackets(value):
     if value is None:
         return None
-    angle_regex = _re_angle_brackets if isinstance(value, bytes) else _re_angle_brackets_str
+    if isinstance(value, bytes):
+        angle_regex = _re_angle_brackets
+    else:
+        angle_regex = _re_angle_brackets_str
     match = angle_regex.search(value)
     return match.group(1)
 
@@ -161,7 +164,7 @@ def parse_datetime(dt_str):
 def parse_number(number_str):
     if number_str is None:
         return None
-    return int(re.search('^(\d+)$', number_str).group(1))
+    return int(re.search(r'^(\d+)$', number_str).group(1))
 
 def msg_as_bytes(msg):
     if hasattr(msg, 'as_bytes'):
@@ -174,4 +177,3 @@ def msg_as_bytes(msg):
     else:
         msg_bytes = msg
     return msg_bytes
-

schwarz/mailqueue/plugins.py

@@ -16,4 +16,3 @@ class MQSignal(object):
 
 class MQAction(object):
     DISCARD = 'discard'
-

schwarz/mailqueue/queue_runner.py

@@ -5,17 +5,17 @@
 
 import email.utils
 import logging
-from mailbox import _sync_close, Maildir
 import os
 import time
+from mailbox import Maildir, _sync_close
 
 from boltons.timeutils import dt_to_timestamp
 
 from .app_helpers import init_app, init_smtp_mailer
-from .compat import queue, IS_WINDOWS
+from .compat import IS_WINDOWS, queue
 from .maildir_utils import create_maildir_directories, find_messages, move_message
 from .message_handler import BaseMsg, MessageHandler
-from .message_utils import dt_now, msg_as_bytes, parse_message_envelope, SendResult
+from .message_utils import SendResult, dt_now, msg_as_bytes, parse_message_envelope
 from .plugins import registry
 
 
@@ -26,13 +26,25 @@
     'MaildirBackend',
 ]
 
-def enqueue_message(msg, queue_path, sender, recipients, return_msg=False, in_progress=False, **queue_args):
-    msg_bytes = serialize_message_with_queue_data(msg, sender=sender, recipients=recipients, **queue_args)
+def enqueue_message(msg, queue_path, sender, recipients, return_msg=False,
+                    in_progress=False, **queue_args):
+    msg_bytes = serialize_message_with_queue_data(
+        msg,
+        sender=sender,
+        recipients=recipients,
+        **queue_args
+    )
     create_maildir_directories(queue_path)
 
     mailbox = Maildir(queue_path)
     sub_dir = 'cur' if in_progress else 'new'
-    return inject_message_into_maildir(msg_bytes, mailbox, sub_dir=sub_dir, return_msg=return_msg)
+    msg = inject_message_into_maildir(
+        msg_bytes,
+        mailbox,
+        sub_dir=sub_dir,
+        return_msg=return_msg,
+    )
+    return msg
 
 
 def inject_message_into_maildir(msg_bytes, maildir, sub_dir='new', return_msg=False):
@@ -51,7 +63,8 @@ def inject_message_into_maildir(msg_bytes, maildir, sub_dir='new', return_msg=Fa
     return MaildirBackedMsg(target_.name, fp=target_)
 
 
-def serialize_message_with_queue_data(msg, sender, recipients, queue_date=None, last=None, retries=None):
+def serialize_message_with_queue_data(msg, sender, recipients, queue_date=None,
+                                      last=None, retries=None):
     sender_bytes = _email_address_as_bytes(sender)
     b_recipients = [_email_address_as_bytes(recipient) for recipient in recipients]
     queue_lines = [
@@ -297,4 +310,3 @@ def one_shot_queue_run(queue_dir, config_path=None, options=None, settings=None)
     plugin_loader = settings['plugin_loader']
     send_all_queued_messages(queue_dir, mailer, plugins=registry, mh=mh)
     plugin_loader.terminate_all_activated_plugins()
-

schwarz/mailqueue/smtpclient.py

@@ -6,20 +6,21 @@
 
 from __future__ import absolute_import, print_function, unicode_literals
 
-from contextlib import contextmanager
 import logging
 import re
-import six
 import socket
+from contextlib import contextmanager
+
+import six
 
 from .lib.smtplib_py37 import (
-    _fix_eols,
-    bCRLF,
     CRLF,
     SMTP,
     SMTPDataError,
     SMTPResponseException,
-    SMTPSenderRefused
+    SMTPSenderRefused,
+    _fix_eols,
+    bCRLF,
 )
 
 
@@ -88,7 +89,8 @@ def connect(self, host='localhost', port=0, source_address=None):
         # gets all the interesting info anyway so we can just disable all
         # logging here.
         with disable_debug(self):
-            return super(SMTPClient, self).connect(host=host, port=port, source_address=source_address)
+            _super_instance = super(SMTPClient, self)
+            return _super_instance.connect(host=host, port=port, source_address=source_address)
 
     def _get_socket(self, host, port, timeout):
         # This wrapper method is big because it contains superior logging which