TaskiqState.copy mutates the source and overwrites the data key #720

Taskiq version

Current main at f08a54a

Python version

Python 3.12.15

OS

Linux

What happened?

Calling the inherited copy() method adds a self-referencing data entry to the original state. An existing user entry with that name is overwritten.

from taskiq.state import TaskiqState

state = TaskiqState()
state.value = 1
copied = state.copy()
print(list(state))  # ['value', 'data']
print(state["data"] is state.data)  # True

Expected the original mapping to remain {"value": 1} and the result to have an independent shallow copy of it.

UserDict.copy() temporarily assigns self.data, which TaskiqState routes through its attribute setter into the mapping. Its inherited __copy__() already avoids that setter and copies the backing dictionary directly.