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Recognize quoted types in typing.TypeForm - #28507
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Summary -- `typing.TypeForm` was introduced in Python 3.15 and [PEP 747](https://peps.python.org/pep-0747/) as a way to annotate the passing of type objects like `int | str`, `list[int]`, or `MyTypeAlias`. It can be used either as a subscripted generic, as in this example from the PEP: ```py from typing import TypeForm def trycast[T](typx: TypeForm[T], value: object) -> T | None: ... ``` or as a callable, which returns its argument unchanged: ```py from typing import TypeForm TypeForm("list[int]") ``` This PR recognizes `typing.TypeForm` as a standard-library generic and as a known `typing` callable and visits its argument or subscript as a type definition. While I was reading the [typing docs], I realized that a couple of nearby types were also not listed, so I've attempted to sneak them in here but could split them off if needed. We already had coverage for `typing.TypeGuard` but not `typing_extensions.TypeGuard` (added in 3.10), and we were missing both variants of `TypeIs` (added in 3.13). These are only valid in the subscript form, so they don't need new `Callable` entries. [typing docs]: https://docs.python.org/3.15/library/typing.html#typing.TypeForm Test Plan -- New mdtests, using `unused-import` (`F401`) to demonstrate that visiting these arguments as type definitions marks them as used.
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| | "Type" | ||
| | "TypeForm" | ||
| | "TypeGuard" | ||
| | "TypeIs" |
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Should we also add some tests for the other newly added generic types?
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…aliases * origin/main: (30 commits) [ty] Respect instance dictionary storage for slotted classes (#27749) Add a GitHub repository threat model for Ruff (#28395) [ty] Preserve wrapped signatures in nominal descriptor checks (#28466) [ty] Avoid rebinding extracted method calls (#28469) Recognize quoted types in `typing.TypeForm` (#28507) Support conditional assignment to `__lazy_modules__` (#28491) Add support for `__lazy_modules__` (#28459) [`pyupgrade`] Stop recommending deprecated `ByteString` aliases (`UP035`) (#28498) [ty] Anchor default exclude patterns at the project root (#28463) [ty] Add playground command to toggle inlay hints (#28517) [ty] Ignore divergent markers when detecting descriptors (#28514) [ty] Reuse rendered union elements when displaying types (#28494) [ty] Fix assignability of bounded typevars to intersection types (#28479) [ty] Retain package listings between resolution steps (#28278) Add accessors for comparison expressions (#28485) [ty] Refactor module resolution to use a `ModuleDirectory` abstraction. (#28418) [ty] Reduce retained AST memory by shrinking expressions (#28335) Bump version to 0.16.7 (#28496) Install rustfmt before linting releases (#28495) ensure prepare release changes pass prek (#28488) ... # Conflicts: # crates/ty_python_semantic/src/types/bool.rs
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Summary
typing.TypeFormwas introduced in Python 3.15 and PEP 747 asa way to annotate the passing of type objects like
int | str,list[int], orMyTypeAlias. Itcan be used either as a subscripted generic, as in this example from the PEP:
or as a callable, which returns its argument unchanged:
This PR recognizes
typing.TypeFormas a standard-library generic and as a knowntypingcallableand visits its argument or subscript as a type definition.
While I was reading the typing docs, I realized that a couple of nearby types were also not
listed, so I've attempted to sneak them in here but could split them off if needed. We already had
coverage for
typing.TypeGuardbut nottyping_extensions.TypeGuard(added in 3.10), and we weremissing both variants of
TypeIs(added in 3.13). These are only valid in the subscript form, sothey don't need new
Callableentries.Test Plan
New mdtests, using
unused-import(F401) to demonstrate that visiting these arguments as typedefinitions marks them as used, but other rules will be affected as well.