generics_syntax_declarations.py

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True Positive
False Positive
False Negative
Optional (detected)
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TP: 10
FP: 0
FN: 0
Optional: 0 / 0
"""
Validates the type parameter syntax introduced in PEP 695.
"""

# Specification: https://peps.python.org/pep-0695/#type-parameter-declarations

# This generic class is parameterized by a TypeVar T, a
# TypeVarTuple Ts, and a ParamSpec P.
from typing import Generic, Protocol

class ChildClass[T, *Ts, **P]:
    pass

class ClassA[T](Generic[T]):  # E: Runtime error
[invalid-generic-class] Cannot both inherit from `typing.Generic` and use PEP 695 type variables
    ...

class ClassB[S, T](Protocol):  # OK
    ...

class ClassC[S, T](Protocol[S, T]):  # E
[invalid-generic-class] Cannot both inherit from subscripted `Protocol` and use PEP 695 type variables
    ...

class ClassD[T: str]:
    def method1(self, x: T):
        x.capitalize()  # OK
        x.is_integer()  # E
[unresolved-attribute] Object of type `T@ClassD` has no attribute `is_integer`

class ClassE[T: dict[str, int]]:  # OK
    pass

class ClassF[S: ForwardReference[int], T: "ForwardReference[str]"]:  # OK
    ...

class ClassG[V]:
    class ClassD[T: dict[str, V]]:  # E: generic type not allowed
[invalid-type-variable-bound] TypeVar upper bound cannot be generic
        ...

class ClassH[T: [str, int]]:  # E: illegal expression form
[invalid-type-form] List literals are not allowed in this context in a type expression: Did you mean `tuple[str, int]`?
    ...

class ClassI[AnyStr: (str, bytes)]:  # OK
    ...

class ClassJ[T: (ForwardReference[int], "ForwardReference[str]", bytes)]:  # OK
    ...

class ClassK[T: ()]:  # E: two or more types required
[invalid-type-variable-constraints] TypeVar must have at least two constrained types
    ...

class ClassL[T: (str,)]:  # E: two or more types required
[invalid-type-variable-constraints] TypeVar must have at least two constrained types
    ...

t1 = (bytes, str)

class ClassM[T: t1]:  # E: literal tuple expression required
[invalid-type-form] Variable of type `tuple[<class 'bytes'>, <class 'str'>]` is not allowed in a type expression
    ...

class ClassN[T: (3, bytes)]:  # E: invalid expression form
[invalid-type-form] Int literals are not allowed in this context in a type expression
    ...

class ClassO[T: (list[S], str)]:  # E: generic type
[unresolved-reference] Name `S` used when not defined
    ...

class ForwardReference[T]: ...