astral-sh/ty 0.0.12

on GitHub

Release Notes

Released on 2026-01-14.

Bug fixes

• Avoid panic that could occur when casting an object to a TypedDict or union of TypedDicts (#22509)
• Fix incorrect narrowing for if type(x) == y (#22531)
• Fix stack overflow with recursive type aliases containing tuple types (#22543)
• functools.total_ordering: ensure the signatures of generated methods reflect the signature of the user-provided method (#22496)
• Support dataclass_transform as a function call (#22378)
• Use the top materialization of classes for if type(x) is y narrowing. For example, if type(x) is tuple will cause the type of x to be intersected with tuple[object, ...] rather than tuple[Unknown, ...]. (#22553)
• Avoid emitting Liskov violations with respect to a grandparent class if such violations could not be fixed without introducing Liskov violations with respect to a parent class (#22484)
• Fix interaction between classmethod, contextmanager, and Self (#22407)
• Check contravariant type variable bounds contravariantly in specialization inference (#22488)
• Fix false positive for bounded type parameters with NewType (#22542)

Type checking

• Add support for dynamic type() classes (#22291, #22499, #22537, #22480)
• Add support for functional namedtuple creation (#22327, #22573, #22575, #22574)
• Add a diagnostic for non-decorator uses of final (#22555)
• Add diagnostic to catch generic enums (#22482)
• Add diagnostics for __init_subclass__ argument mismatch (#22185)
• Add diagnostics to validate TypeIs and TypeGuard definitions (#22300)
• Apply type narrowing to walrus targets (#22369)
• Detect invalid @total_ordering applications in non-decorator contexts (#22486)
• Fix @Todo type for starred expressions (#22503)
• Improve disambiguation of types in diagnostics (#22547)
• Include type parameters in the display for generic Callable types (#22435)
• Infer type[Unknown] for calls to type() when overload evaluation is ambiguous (#22569)
• Support assignment to unions of TypedDicts (#22294)
• Use the key and value parameter types as type context for __setitem__ dunder calls (#22148)
• Narrow the right-hand side of ==, !=, is and is not conditions when the left-hand side is not narrowable (#22511)

LSP server

• Fix __file__ type in completions to show str instead of str | None when the inferred type is str (#22510)
• Improve rendering of ReST directives in docstrings (#22512)

Contributors

• @eclbg
• @RasmusNygren
• @carljm
• @drbh
• @AryanBagade
• @bxff
• @ibraheemdev
• @charliermarsh
• @AlexWaygood

Install ty 0.0.12

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ty/releases/download/0.0.12/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ty/releases/download/0.0.12/ty-installer.ps1 | iex"

Download ty 0.0.12