Dataclasses: `No overload variant of "asdict" matches argument type "Self" [call-overload]` when deciding decorator conditionally

Chạy ví dụ Python 3.12 được cung cấp với mypy 1.10.0 và --show-error-context --strict để tái hiện các lỗi đối với dataclasses.asdict và dataclasses.replace. Trước tiên, hãy lần theo cách xử lý trình trang trí dataclass có điều kiện, Self và các kiểm tra overload và type-variable được báo cáo. Công việc được xem là hoàn tất khi ví dụ vượt qua kiểm tra kiểu mà không có các dương tính giả này, đồng thời vẫn giữ nguyên hành vi khi chạy.

Bug Report

Mypy raises a false positive for dataclass.asdict (No overload variant of "asdict" matches argument type "Self" [call-overload]) on the very specific circumstances:

1. The specific decorator for dataclass is decided based on a condition (e.g. Python version)
2. The datalcasses.asdict method is called from a method that uses PEP 673's Self Type.

I also noted a similar problem occurs for dataclasses.replace: Value of type variable "_DataclassT" of "replace" cannot be "Self" [type-var].

To Reproduce

import sys
import dataclasses
import json
from typing import Self

if sys.version_info >= (3, 10):
    dataclass = dataclasses.dataclass(kw_only=True)
else:
    dataclass = dataclasses.dataclass


@dataclass
class HelloWorld:
    a: int = 1
    b: int = 2
    c: int = 3

    def double(self) -> Self:
        fields = dataclasses.asdict(self)
        return self.__class__(**{k: v*2 for k, v in fields.items()})

    def json_overwrite(self, text: str) -> Self:
        new = json.loads(text)
        return dataclasses.replace(self, **new)

x = HelloWorld().double()
y = HelloWorld().json_overwrite('{"c": 42}')
assert x.b == 4
assert y.c == 42
print(f"{x=}")
print(f"{y=}")

Gist URL: https://gist.github.com/mypy-play/70b801fbe15391f0750be8f6c403fdf4
Playground URL: https://mypy-play.net/?mypy=latest&python=3.12&flags=show-error-context%2Cstrict&gist=70b801fbe15391f0750be8f6c403fdf4

Expected Behavior

There should be no false negative.
The program works fine in runtime:

$ python3.12 main.py
x=HelloWorld(a=2, b=4, c=6)
y=HelloWorld(a=1, b=2, c=42)

Actual Behavior

main.py: note: In member "double" of class "HelloWorld":
main.py:19: error: No overload variant of "asdict" matches argument type "Self"  [call-overload]
main.py:19: note: Possible overload variants:
main.py:19: note:     def asdict(obj: DataclassInstance) -> dict[str, Any]
main.py:19: note:     def [_T] asdict(obj: DataclassInstance, *, dict_factory: Callable[[list[tuple[str, Any]]], _T]) -> _T
main.py: note: In member "json_overwrite" of class "HelloWorld":
main.py:24: error: Value of type variable "_DataclassT" of "replace" cannot be "Self"  [type-var]
Found 2 errors in 1 file (checked 1 source file)

Your Environment

• Mypy version used: 1.10.0
• Mypy command-line flags: --show-error-context, --strict
• Mypy configuration options from mypy.ini (and other config files):
• Python version used: 3.12