TypeVarTuple instantiation with the empty tuple in Generic not being recognized as such

Bug Report

Mypy does not recognize that a TypeVarTuple was instantiated with the empty tuple in a generic.

To Reproduce

from typing import Generic, reveal_type, TypeVarTuple

Ts = TypeVarTuple('Ts')

class A(Generic[*Ts]):

    def args(self) -> tuple[*Ts]:
        raise NotImplementedError

class B(A[int, *Ts]):
    pass

class C(B[*tuple[()]]):
    pass

reveal_type(A.args)
reveal_type(B.args)
reveal_type(C.args)

Expected Behavior

I'd expect that the return type of C.args be tuple[int]. And this, indeed, is what pyright infers:

test.py:18:13 - information: Type of "A.args" is "(self: A[Unknown]) -> tuple[Unknown]"
test.py:19:13 - information: Type of "B.args" is "(self: B[Unknown]) -> tuple[int, Unknown]"
test.py:20:13 - information: Type of "C.args" is "(self: C) -> tuple[int]"

Actual Behavior

Mypy however infers tuple[int, *tuple[Any, ...]]:

test.py:18: note: Revealed type is "def [Ts] (self: test8.A[Unpack[Ts`1]]) -> tuple[Unpack[Ts`1]]"
test.py:19: note: Revealed type is "def [Ts] (self: test8.A[builtins.int, Unpack[Ts`1]]) -> tuple[builtins.int, Unpack[Ts`1]]"
test.py:20: note: Revealed type is "def (self: test8.A[builtins.int, Unpack[builtins.tuple[Any, ...]]]) -> tuple[builtins.int, Unpack[builtins.tuple[Any, ...]]]"

Your Environment

• Mypy version used: 1.17.0 (compiled: yes)
• Mypy command-line flags: (none)
• Mypy configuration options from mypy.ini (and other config files): (none)
• Python version used: 3.13.5

Riprodurre l’esempio in test.py con mypy 1.17.0 e analizzare la gestione di TypeVarTuple coinvolta nell’ereditarietà di Generic e nell’istanza di una tupla vuota. Aggiungere un test di regressione basato sull’esempio, mostrando tramite il completamento che C.args viene rivelato come restituente tuple[int] invece di includere una tupla non vincolata.