forked from public/pyceo
53 lines
1.4 KiB
Python
53 lines
1.4 KiB
Python
import inspect
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import re
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from typing import Callable
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class InvalidUsernameException(Exception):
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pass
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class InvalidForwardingAddressException(Exception):
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pass
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valid_username_re = re.compile(r'^[a-z][\w-]+$')
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# Only allow usernames and email addresses to be set in ~/.forward
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valid_forwarding_address_re = re.compile(r'^[\w-]+|[\w.+-]+@[\w-]+(\.[\w-]+)*$')
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def is_valid_username(username: str) -> bool:
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"""Returns True if the username has a valid format."""
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return valid_username_re.match(username) is not None
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def check_valid_username(f: Callable) -> Callable:
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"""
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A decorator which raises an Exception if the username passed
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to f is invalid.
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f must accept `username` as a regular argument.
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"""
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argspec = inspect.getfullargspec(f)
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try:
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arg_idx = argspec.args.index('username')
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except ValueError:
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return f
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def wrapper(*args, **kwargs):
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username = None
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if arg_idx < len(args):
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username = args[arg_idx]
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elif 'username' in kwargs:
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username = kwargs['username']
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if username is not None and not is_valid_username(username):
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raise InvalidUsernameException(username)
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return f(*args, **kwargs)
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return wrapper
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def is_valid_forwarding_address(address: str) -> bool:
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"""Returns True if the address is a valid forwarding address."""
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return valid_forwarding_address_re.match(address) is not None
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