Pyright fails if builtins.tuple has a decorator #10836
Description
In python/typeshed#14599, I'm attempting to add the @disjoint_base decorator from PEP 800 to the stdlib where it makes sense. Pyright runs into trouble if I add the decorator to the stub for builtins.tuple.
To reproduce, use a small program like this:
def f(x: tuple[int, int]) -> None:
print(x[0] + x[1])Apply this patch to builtins.pyi:
diff --git a/stdlib/builtins.pyi b/stdlib/builtins.pyi
index c7ab95482..4b5468066 100644
--- a/stdlib/builtins.pyi
+++ b/stdlib/builtins.pyi
@@ -71,6 +71,7 @@ from typing_extensions import ( # noqa: Y023
TypeIs,
TypeVarTuple,
deprecated,
+ disjoint_base,
)
if sys.version_info >= (3, 14):
@@ -1009,6 +1010,7 @@ class slice(Generic[_StartT_co, _StopT_co, _StepT_co]):
def indices(self, len: SupportsIndex, /) -> tuple[int, int, int]: ...
+@disjoint_base
class tuple(Sequence[_T_co]):
def __new__(cls, iterable: Iterable[_T_co] = ..., /) -> Self: ...
def __len__(self) -> int: ...And run pyright on the sample:
/Users/jelle/py/typeshed/basic.py
/Users/jelle/py/typeshed/basic.py:1:10 - error: Type "tuple[_T_co@tuple, ...]" is already specialized (reportInvalidTypeArguments)
/Users/jelle/py/typeshed/basic.py:2:11 - error: Operator "+" not supported for types "_T_co@tuple" and "_T_co@tuple" (reportOperatorIssue)
/Users/jelle/py/typeshed/basic.py:2:11 - error: Argument type is unknown
Argument corresponds to parameter "values" in function "print" (reportUnknownArgumentType)
3 errors, 0 warnings, 0 informations
It seems to lose its knowledge about tuple needing special casing.
It's also reproducible if you just add an identity decorator to the class like this:
diff --git a/stdlib/builtins.pyi b/stdlib/builtins.pyi
index c7ab95482..2333ac0cd 100644
--- a/stdlib/builtins.pyi
+++ b/stdlib/builtins.pyi
@@ -1009,6 +1009,9 @@ class slice(Generic[_StartT_co, _StopT_co, _StepT_co]):
def indices(self, len: SupportsIndex, /) -> tuple[int, int, int]: ...
+def f[T](x: T, /) -> T: ...
+
+@f
class tuple(Sequence[_T_co]):
def __new__(cls, iterable: Iterable[_T_co] = ..., /) -> Self: ...
def __len__(self) -> int: ...