Match the following code:
from typing import Callable, Any
TFunc = Callable[..., Any]
def get_authenticated_user(): return "John"
def require_auth() -> Callable[TFunc, TFunc]:
def decorator(func: TFunc) -> TFunc:
def wrapper(*args, **kwargs) -> Any:
user = get_authenticated_user()
if user is None:
raise Exception("Don't!")
return func(*args, **kwargs)
return wrapper
return decorator
@require_auth()
def foo(a: int) -> bool:
return bool(a % 2)
foo(2)
foo("no!")
This piece of code works as intended. Now imagine that I want to extend this, and instead of just executing, func(*args, **kwargs)
I want to enter the username in the arguments. Therefore, I am changing the signature of the function.
from typing import Callable, Any
TFunc = Callable[..., Any]
def get_authenticated_user(): return "John"
def inject_user() -> Callable[TFunc, TFunc]:
def decorator(func: TFunc) -> TFunc:
def wrapper(*args, **kwargs) -> Any:
user = get_authenticated_user()
if user is None:
raise Exception("Don't!")
return func(*args, user, **kwargs)
return wrapper
return decorator
@inject_user()
def foo(a: int, username: str) -> bool:
print(username)
return bool(a % 2)
foo(2)
foo("no!")
I cannot find the right way to introduce this. I know that in this example the decorated function and the returned function must technically have the same signature (but even this was not found).
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