generics_typevartuple_callable.py

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True Positive

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TP: 0

FP: 3

FN: 1

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"""
Tests the use of TypeVarTuple within a Callable.
"""

# Specification: https://typing.readthedocs.io/en/latest/spec/generics.html#type-variable-tuples-with-callable

# > Type variable tuples can also be used in the arguments section of a Callable.


from typing import Callable, TypeVar, TypeVarTuple, assert_type

Ts = TypeVarTuple("Ts")
T = TypeVar("T")


class Process:
    def __init__(self, target: Callable[[*Ts], None], args: tuple[*Ts]) -> None:
        ...


def func1(arg1: int, arg2: str) -> None:
    ...


Process(target=func1, args=(0, ""))  # OK
Process(target=func1, args=("", 0))  # E
Expected a ty diagnostic for this line


def func2(f: Callable[[int, *Ts, T], tuple[T, *Ts]]) -> tuple[*Ts, T]:
    raise NotImplementedError


def callback1(a: int, b: str, c: int, d: complex) -> tuple[complex, str, int]:
    raise NotImplementedError


def callback2(a: int, d: str) -> tuple[str]:
    raise NotImplementedError


assert_type(func2(callback1), tuple[str, int, complex])
Unexpected error
[type-assertion-failure] Type `tuple[@Todo(TypeVarTuple), ...]` does not match asserted type `tuple[str, int, int | float | complex]`
assert_type(func2(callback2), tuple[str])
Unexpected error
[type-assertion-failure] Type `tuple[@Todo(TypeVarTuple), ...]` does not match asserted type `tuple[str]`


def func3(*args: *tuple[int, *Ts, T]) -> tuple[T, *Ts]:
    raise NotImplementedError


def has_int_and_str(a: int, b: str, c: float, d: complex):
    assert_type(func3(a, b, c, d), tuple[complex, str, float])
Unexpected error
[type-assertion-failure] Type `tuple[@Todo(TypeVarTuple), ...]` does not match asserted type `tuple[int | float | complex, str, int | float]`