wrong encoding for decorator objects

[RRRajput]

Hi,

jsonpickle is not able to correctly decode decorated functions that return an object.

Here's the minimal reproducible example:

import jsonpickle

class FuncNested:
    def __init__(self, func) -> None:
        self.func = func

    def __call__(self, *args, **kwargs):
        return self.func(*args, **kwargs)

def nester(func):
    return FuncNested(func)


@nester
def bro():
    return "Mate"

# Check that original object is a FuncNested object
assert type(bro) is FuncNested

# Check that the `.func` member variable of the original object is NOT a FuncNested object. 
assert type(bro.func) is not FuncNested

encoded_bro_str = jsonpickle.encode(bro)

print(encoded_bro_str)
>> {"py/object": "__main__.FuncNested", "func": {"py/function": "__main__.bro"}}
decoded_bro = jsonpickle.decode(encoded_bro_str)

# Check that decoded object is also a FuncNested object
assert type(decoded_bro) is FuncNested

# Check that the `.func` member variable of decoded object is NOT a FuncNested object. 
assert type(decoded_bro.func) is not FuncNested # <-- This fails
>> ---------------------------------------------------------------------------
>> AssertionError                            Traceback (most recent call last)
>> Cell In[29], line 26
>>      24 assert type(decoded_bro) is FuncNested
>>      25 # Check that the `.func` member variable is NOT a FuncNested object. 
>> ---> 26 assert type(decoded_bro.func) is not FuncNested # <-- This fails
>> 
>> AssertionError: 

[Theelx]

That's really interesting, thanks for reporting! I did a bit of further digging, and it seems that before bro gets encoded, bro.func is of type function, and after it is of type FuncNested (the latter being obvious). I think it could be fixed by going back in FuncNested's mro once before it's returned to the user, but I'll need to check later because I'm supposed to be paying attention in class instead of doing unrelated stuff 😅