astral-sh/ty 0.0.1-alpha.26

on GitHub

Release Notes

Released on 2025-11-10.

Bug fixes

• Language server: For semantic tokens, fix range filtering for tokens starting at the end of the requested range (#21193)
• Fix panic due to simplifying Divergent types out of intersections types (#21253)
• Fix merging of --exclude CLI flag and src.exclude config-file setting (#21341)

Type inference

• Infer type of self for decorated methods and properties (#21123)
• Add support for properties that return Self (#21335)
• Understand legacy and PEP 695 ParamSpec (#21139)
• Type inference for comprehensions (#20962)
• Reachability and narrowing for enum methods (#21130)
• Implicit type aliases: Support for PEP 604 unions, Literals, Optional, and Annotated (#21195, #21296, #21321)
• dict is not assignable to TypedDict (#21238)
• Allow values of type None in type expressions (#21263)
• Add narrowing for isinstance() and issubclass() checks that use PEP-604 unions (#21334)
• Do not promote Literal types when solving type variables in contravariant positions (#21164, astral-sh/ruff#21171))
• Fix lookup of __new__ methods on instances (#21147)
• Fix narrowing of generic classes in class patterns for match statements (#21150)
• Improve understanding of disjointness for @final classes (#21167)
• Fix the inferred signature of the synthesized __init__ method of a non-dataclass inheriting from a generic dataclass (#21159)
• Improve exhaustiveness analysis for type variables with bounds or constraints (#21172)
• Prefer exact matches when solving constrained type variables (#21165)
• Simplify unions containing multiple type variables during inference (#21275)
• Use the declared attribute type when inferring union attribute assignments (#21170)
• Sync vendored typeshed stubs (#21178). Typeshed diff
• Use declared attribute types as type context when solving type variables (#21143)
• Don't union in the inferred type of a parameter's default value when inferring the type of an annotated parameter (#21208)
• Support subscripting typing.Literal with a type alias (#21207)

LSP server

• Don't provide completions when in a class or function definition (#21146)
• For autocompletions, favor symbols defined in the current file over auto-imported symbols (#21194) and builtin symbols (#21285)

Diagnostics

• Add diagnostics for isinstance() and issubclass() calls that use invalid PEP-604 unions for their second argument (#21343)
• Don't assume in diagnostic messages that a TypedDict key error is about subscript access (#21166)

Other changes

• Consistently wrap tokens in parser diagnostics in backticks instead of 'quotes' (#21163)
• Discover the site-packages directory from the environment that ty is installed in (#21286), improving the ergonomics of uvx ty check
• Support implicit imports of submodules in __init__.pyi (#20855)
• Use "cannot" consistently over "can not" in diagnostics (#21255)
• Resolve from foo import bar to the foo.bar submodule rather than using the __getattr__ function in foo/__init__.py (in situations where they both exist)(#21260)

Contributors

• @MatthewMckee4
• @dhruvmanila
• @sharkdp
• @Gankra
• @saada
• @zanieb
• @MichaReiser
• @ibraheemdev
• @AlexWaygood
• @lucach
• @mtshiba
• @carljm

Install ty 0.0.1-alpha.26

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ty/releases/download/0.0.1-alpha.26/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ty/releases/download/0.0.1-alpha.26/ty-installer.ps1 | iex"

Download ty 0.0.1-alpha.26