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Author SHA1 Message Date
Dhruv Manilawala
376e3ff395
[ty] Limit argument expansion size for overload call evaluation (#20041)
## Summary

This PR limits the argument type expansion size for an overload call
evaluation to 512.

The limit chosen is arbitrary but I've taken the 256 limit from Pyright
into account and bumped it x2 to start with.

Initially, I actually started out by trying to refactor the entire
argument type expansion to be lazy. Currently, expanding a single
argument at any position eagerly creates the combination (argument
lists) and returns that (`Vec<CallArguments>`) but I thought we could
make it lazier by converting the return type of `expand` from
`Iterator<Item = Vec<CallArguments>>` to `Iterator<Item = Iterator<Item
= CallArguments>>` but that's proving to be difficult to implement
mainly because we **need** to maintain the previous expansion to
generate the next expansion which is the main reason to use
`std::iter::successors` in the first place.

Another approach would be to eagerly expand all the argument types and
then use the `combinations` from `itertools` to generate the
combinations but we would need to find the "boundary" between arguments
lists produced from expanding argument at position 1 and position 2
because that's important for the algorithm.

Closes: https://github.com/astral-sh/ty/issues/868

## Test Plan

Add test case to demonstrate the limit along with the diagnostic
snapshot stating that the limit has been reached.
2025-08-25 09:43:04 +00:00
Jelle Zijlstra
ec86a4e960
[ty] Add Top[] and Bottom[] special forms, replacing top_materialization_of() function (#20054)
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Part of astral-sh/ty#994

## Summary

Add new special forms to `ty_extensions`, `Top[T]` and `Bottom[T]`.
Remove `ty_extensions.top_materialization` and
`ty_extensions.bottom_materialization`.

## Test Plan

Converted the existing `materialization.md` mdtest to the new syntax.
Added some tests for invalid use of the new special form.
2025-08-23 11:20:56 -07:00
Andrew Gallant
85931ab594 [ty] Add a TODO for linting on todo! 2025-08-23 12:53:41 -04:00
Ibraheem Ahmed
7abc41727b
[ty] Shrink size of AstNodeRef (#20028)
## Summary

Removes the `module_ptr` field from `AstNodeRef` in release mode, and
change `NodeIndex` to a `NonZeroU32` to reduce the size of
`Option<AstNodeRef<_>>` fields.

I believe CI runs in debug mode, so this won't show up in the memory
report, but this reduces memory by ~2% in release mode.
2025-08-22 17:03:22 -04:00
Alex Waygood
bc6ea68733
[ty] Add precise iteration and unpacking inference for string literals and bytes literals (#20023)
## Summary

Previously we held off from doing this because we weren't sure that it
was worth the added complexity cost. But our code has changed in the
months since we made that initial decision, and I think the structure of
the code is such that it no longer really leads to much added complexity
to add precise inference when unpacking a string literal or a bytes
literal.

The improved inference we gain from this has real benefits to users (see
the mypy_primer report), and this PR doesn't appear to have a
performance impact.

## Test plan

mdtests
2025-08-22 19:33:08 +01:00
Micha Reiser
796819e7a0
[ty] Disallow std::env and io methods in most ty crates (#20046)
## Summary

We use the `System` abstraction in ty to abstract away the host/system
on which ty runs.
This has a few benefits:

* Tests can run in full isolation using a memory system (that uses an
in-memory file system)
* The LSP has a custom implementation where `read_to_string` returns the
content as seen by the editor (e.g. unsaved changes) instead of always
returning the content as it is stored on disk
* We don't require any file system polyfills for wasm in the browser


However, it does require extra care that we don't accidentally use
`std::fs` or `std::env` (etc.) methods in ty's code base (which is very
easy).

This PR sets up Clippy and disallows the most common methods, instead
pointing users towards the corresponding `System` methods.

The setup is a bit awkward because clippy doesn't support inheriting
configurations. That means, a crate can only override the entire
workspace configuration or not at all.
The approach taken in this PR is:

* Configure the disallowed methods at the workspace level
* Allow `disallowed_methods` at the workspace level
* Enable the lint at the crate level using the warn attribute (in code)


The obvious downside is that it won't work if we ever want to disallow
other methods, but we can figure that out once we reach that point.

What about false positives: Just add an `allow` and move on with your
life :) This isn't something that we have to enforce strictly; the goal
is to catch accidental misuse.

## Test Plan

Clippy found a place where we incorrectly used `std::fs::read_to_string`
2025-08-22 11:13:47 -07:00
Carl Meyer
8b827c3c6c
[ty] rename BareTypeAliasType to ManualPEP695TypeAliasType (#20037)
## Summary

Rename `TypeAliasType::Bare` to `TypeAliasType::ManualPEP695`, and
`BareTypeAliasType` to `ManualPEP695TypeAliasType`.

Why?

Both existing variants of `TypeAliasType` are specific to features added
in PEP 695 (which introduced both the `type` statement and
`types.TypeAliasType`), so it doesn't make sense to name one with the
name `PEP695` and not the other.

A "bare" type alias, in my mind, is a legacy type alias like `IntOrStr =
int | str`, which is "bare" in that there is nothing at all
distinguishing it as a type alias. I will want to use the "bare" name
for this variant, in a future PR.

The renamed variant here describes a type alias created with `IntOrStr =
types.TypeAliasType("IntOrStr", int | str)`, which is not "bare", it's
just "manually" instantiated instead of using the `type` statement
syntax sugar. (This is useful when using the `typing_extensions`
backport of `TypeAliasType` on older Python versions.)

## Test Plan

Pure rename, existing tests pass.
2025-08-22 07:40:29 -07:00
github-actions[bot]
7a44ea680e
[ty] Sync vendored typeshed stubs (#20031)
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Co-authored-by: typeshedbot <>
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-08-21 21:32:48 +00:00
Alex Waygood
f82025d919
[ty] Improve diagnostics for bad calls to functions (#20022) 2025-08-21 22:00:44 +01:00
Micha Reiser
365f521c37
[ty] Fix incorrect docstring in call signature completion (#20021)
## Summary

This PR fixes https://github.com/astral-sh/ty/issues/1071

The core issue is that `CallableType` is a salsa interned but
`Signature` (which `CallableType` stores) ignores the `Definition` in
its `Eq` and `Hash` implementation.

This PR tries to simplest fix by removing the custom `Eq` and `Hash`
implementation. The main downside of this fix is that it can increase
memory usage because `CallableType`s that are equal except for their
`Definition` are now interned separately.

The alternative is to remove `Definition` from `CallableType` and
instead, call `bindings` directly on the callee (call_expression.func).
However, this would require
addressing the TODO 

here
39ee71c2a5/crates/ty_python_semantic/src/types.rs (L4582-L4586)

This might probably be worth addressing anyway, but is the more involved
fix. That's why I opted for removing the custom `Eq` implementation.

We already "ignore" the definition during normalization, thank's to
Alex's work in https://github.com/astral-sh/ruff/pull/19615

## Test Plan



https://github.com/user-attachments/assets/248d1cb1-12fd-4441-adab-b7e0866d23eb
2025-08-21 16:36:40 -04:00
Douglas Creager
14fe1228e7
[ty] Perform assignability etc checks using new Constraints trait (#19838)
"Why would you do this? This looks like you just replaced `bool` with an
overly complex trait"

Yes that's correct!

This should be a no-op refactoring. It replaces all of the logic in our
assignability, subtyping, equivalence, and disjointness methods to work
over an arbitrary `Constraints` trait instead of only working on `bool`.

The methods that `Constraints` provides looks very much like what we get
from `bool`. But soon we will add a new impl of this trait, and some new
methods, that let us express "fuzzy" constraints that aren't always true
or false. (In particular, a constraint will express the upper and lower
bounds of the allowed specializations of a typevar.)

Even once we have that, most of the operations that we perform on
constraint sets will be the usual boolean operations, just on sets.
(`false` becomes empty/never; `true` becomes universe/always; `or`
becomes union; `and` becomes intersection; `not` becomes negation.) So
it's helpful to have this separate PR to refactor how we invoke those
operations without introducing the new functionality yet.

Note that we also have translations of `Option::is_some_and` and
`is_none_or`, and of `Iterator::any` and `all`, and that the `and`,
`or`, `when_any`, and `when_all` methods are meant to short-circuit,
just like the corresponding boolean operations. For constraint sets,
that depends on being able to implement the `is_always` and `is_never`
trait methods.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-08-21 09:30:09 -04:00
Dhruv Manilawala
d43a3d34dd
[ty] Avoid unnecessary argument type expansion (#19999)
## Summary

Part of: https://github.com/astral-sh/ty/issues/868

This PR adds a heuristic to avoid argument type expansion if it's going
to eventually lead to no matching overload.

This is done by checking whether the non-expandable argument types are
assignable to the corresponding annotated parameter type. If one of them
is not assignable to all of the remaining overloads, then argument type
expansion isn't going to help.

## Test Plan

Add mdtest that would otherwise take a long time because of the number
of arguments that it would need to expand (30).
2025-08-21 06:13:11 +00:00
Aria Desires
99111961c0
[ty] Add link for namespaces being partial (#20015)
As requested
2025-08-20 21:28:57 -07:00
Leandro Braga
39ee71c2a5
[ty] correctly ignore field specifiers when not specified (#20002)
This commit corrects the type checker's behavior when handling
`dataclass_transform` decorators that don't explicitly specify
`field_specifiers`. According to [PEP 681 (Data Class
Transforms)](https://peps.python.org/pep-0681/#dataclass-transform-parameters),
when `field_specifiers` is not provided, it defaults to an empty tuple,
meaning no field specifiers are supported and
`dataclasses.field`/`dataclasses.Field` calls should be ignored.

Fixes https://github.com/astral-sh/ty/issues/980
2025-08-20 11:33:23 -07:00
Andrew Gallant
ddd4bab67c [ty] Re-arrange "list modules" implementation for Salsa caching
This basically splits `list_modules` into a higher level "aggregation"
routine and a lower level "get modules for one search path" routine.
This permits Salsa to cache the lower level components, e.g., many
search paths refer to directories that rarely change. This saves us
interaction with the system.

This did require a fair bit of surgery in terms of being careful about
adding file roots. Namely, now that we rely even more on file roots
existing for correct handling of cache invalidation, there were several
spots in our code that needed to be updated to add roots (that we
weren't previously doing). This feels Not Great, and it would be better
if we had some kind of abstraction that handled this for us. But it
isn't clear to me at this time what that looks like.
2025-08-20 10:41:47 -04:00
Andrew Gallant
468eb37d75 [ty] Test "list modules" versus "resolve module" in every mdtest
This ensures there is some level of consistency between the APIs.

This did require exposing a couple more things on `Module` for good
error messages. This also motivated a switch to an interned struct
instead of a tracked struct. This ensures that `list_modules` and
`resolve_modules` reuse the same `Module` values when the inputs are the
same.

Ref https://github.com/astral-sh/ruff/pull/19883#discussion_r2272520194
2025-08-20 10:27:54 -04:00
Andrew Gallant
2e9c241d7e [ty] Wire up "list modules" API to make module completions work
This makes `import <CURSOR>` and `from <CURSOR>` completions work.

This also makes `import os.<CURSOR>` and `from os.<CURSOR>`
completions work. In this case, we are careful to only offer
submodule completions.
2025-08-20 10:27:54 -04:00
Andrew Gallant
4db20f459c [ty] Add "list modules" implementation
The actual implementation wasn't too bad. It's not long
but pretty fiddly. I copied over the tests from the existing
module resolver and adapted them to work with this API. Then
I added a number of my own tests as well.
2025-08-20 10:27:54 -04:00
Andrew Gallant
ec7c2efef9 [ty] Lightly expose FileModule and NamespacePackage fields
This will make it easier to emit this info into snapshots for
testing.
2025-08-20 10:27:54 -04:00
Andrew Gallant
79b2754215 [ty] Add some more helper routines to ModulePath 2025-08-20 10:27:54 -04:00
Andrew Gallant
a0ddf1f7c4 [ty] Fix a bug when converting ModulePath to ModuleName
Previously, if the module was just `foo-stubs`, we'd skip over
stripping the `-stubs` suffix which would lead to us returning
`None`.

This function is now a little convoluted and could be simpler
if we did an intermediate allocation. But I kept the iterative
approach and added a special case to handle `foo-stubs`.
2025-08-20 10:27:54 -04:00
Andrew Gallant
5b00ec981b [ty] Split out another constructor for ModuleName
This makes it a little more flexible to call. For example,
we might have a `StmtImport` and not a `StmtImportFrom`.
2025-08-20 10:27:54 -04:00
Andrew Gallant
306ef3bb02 [ty] Add stub-file tests to existing module resolver
These tests capture existing behavior.

I added these when I stumbled upon what I thought was an
oddity: we prioritize `foo.pyi` over `foo.py`, but
prioritize `foo/__init__.py` over `foo.pyi`.

(I plan to investigate this more closely in follow-up
work. Particularly, to look at other type checkers. It
seems like we may want to change this to always prioritize
stubs.)
2025-08-20 10:27:54 -04:00
Andrew Gallant
a4cd13c6e2 [ty] Expose some routines in the module resolver
We'll want to use these when implementing the
"list modules" API.
2025-08-20 10:27:54 -04:00
Andrew Gallant
e0c98874e2 [ty] Add more path helper functions
This makes it easier to do exhaustive case analysis
on a `SearchPath` depending on whether it is a vendored
or system path.
2025-08-20 10:27:54 -04:00
Aria Desires
1d2128f918
[ty] distinguish base conda from child conda (#19990)
This is a port of the logic in https://github.com/astral-sh/uv/pull/7691

The basic idea is we use CONDA_DEFAULT_ENV as a signal for whether
CONDA_PREFIX is just the ambient system conda install, or the user has
explicitly activated a custom one. If the former, then the conda is
treated like a system install (having lowest priority). If the latter,
the conda is treated like an activated venv (having priority over
everything but an Actual activated venv).

Fixes https://github.com/astral-sh/ty/issues/611
2025-08-20 09:07:42 -04:00
Dhruv Manilawala
f019cfd15f
[ty] Use specialized parameter type for overload filter (#19964)
## Summary

Closes: https://github.com/astral-sh/ty/issues/669

(This turned out to be simpler that I thought :))

## Test Plan

Update existing test cases.

### Ecosystem report

Most of them are basically because ty has now started inferring more
precise types for the return type to an overloaded call and a lot of the
types are defined using type aliases, here's some examples:

<details><summary>Details</summary>
<p>

> attrs (https://github.com/python-attrs/attrs)
> + tests/test_make.py:146:14: error[unresolved-attribute] Type
`Literal[42]` has no attribute `default`
> - Found 555 diagnostics
> + Found 556 diagnostics

This is accurate now that we infer the type as `Literal[42]` instead of
`Unknown` (Pyright infers it as `int`)

> optuna (https://github.com/optuna/optuna)
> + optuna/_gp/search_space.py:181:53: error[invalid-argument-type]
Argument to function `_round_one_normalized_param` is incorrect:
Expected `tuple[int | float, int | float]`, found `tuple[Unknown |
ndarray[Unknown, <class 'float'>], Unknown | ndarray[Unknown, <class
'float'>]]`
> + optuna/_gp/search_space.py:181:83: error[invalid-argument-type]
Argument to function `_round_one_normalized_param` is incorrect:
Expected `int | float`, found `Unknown | ndarray[Unknown, <class
'float'>]`
> + tests/gp_tests/test_search_space.py:109:13:
error[invalid-argument-type] Argument to function
`_unnormalize_one_param` is incorrect: Expected `tuple[int | float, int
| float]`, found `Unknown | ndarray[Unknown, <class 'float'>]`
> + tests/gp_tests/test_search_space.py:110:13:
error[invalid-argument-type] Argument to function
`_unnormalize_one_param` is incorrect: Expected `int | float`, found
`Unknown | ndarray[Unknown, <class 'float'>]`
> - Found 559 diagnostics
> + Found 563 diagnostics

Same as above where ty is now inferring a more precise type like
`Unknown | ndarray[tuple[int, int], <class 'float'>]` instead of just
`Unknown` as before

> jinja (https://github.com/pallets/jinja)
> + src/jinja2/bccache.py:298:39: error[invalid-argument-type] Argument
to bound method `write_bytecode` is incorrect: Expected `IO[bytes]`,
found `_TemporaryFileWrapper[str]`
> - Found 186 diagnostics
> + Found 187 diagnostics

This requires support for type aliases to match the correct overload.

> hydra-zen (https://github.com/mit-ll-responsible-ai/hydra-zen)
> + src/hydra_zen/wrapper/_implementations.py:945:16:
error[invalid-return-type] Return type does not match returned value:
expected `DataClass_ | type[@Todo(type[T] for protocols)] | ListConfig |
DictConfig`, found `@Todo(unsupported type[X] special form) | (((...) ->
Any) & dict[Unknown, Unknown]) | (DataClass_ & dict[Unknown, Unknown]) |
dict[Any, Any] | (ListConfig & dict[Unknown, Unknown]) | (DictConfig &
dict[Unknown, Unknown]) | (((...) -> Any) & list[Unknown]) | (DataClass_
& list[Unknown]) | list[Any] | (ListConfig & list[Unknown]) |
(DictConfig & list[Unknown])`
> + tests/annotations/behaviors.py:60:28: error[call-non-callable]
Object of type `Path` is not callable
> + tests/annotations/behaviors.py:64:21: error[call-non-callable]
Object of type `Path` is not callable
> + tests/annotations/declarations.py:167:17: error[call-non-callable]
Object of type `Path` is not callable
> + tests/annotations/declarations.py:524:17:
error[unresolved-attribute] Type `<class 'int'>` has no attribute
`_target_`
> - Found 561 diagnostics
> + Found 566 diagnostics

Same as above, this requires support for type aliases to match the
correct overload.

> paasta (https://github.com/yelp/paasta)
> + paasta_tools/utils.py:4188:19: warning[redundant-cast] Value is
already of type `list[str]`
> - Found 888 diagnostics
> + Found 889 diagnostics

This is correct.

> colour (https://github.com/colour-science/colour)
> + colour/plotting/diagrams.py:448:13: error[invalid-argument-type]
Argument to bound method `__init__` is incorrect: Expected
`Sequence[@Todo(Support for `typing.TypeAlias`)]`, found
`ndarray[tuple[int, int, int], dtype[Unknown]]`
> + colour/plotting/diagrams.py:462:13: error[invalid-argument-type]
Argument to bound method `__init__` is incorrect: Expected
`Sequence[@Todo(Support for `typing.TypeAlias`)]`, found
`ndarray[tuple[int, int, int], dtype[Unknown]]`
> + colour/plotting/models.py:419:13: error[invalid-argument-type]
Argument to bound method `__init__` is incorrect: Expected
`Sequence[@Todo(Support for `typing.TypeAlias`)]`, found
`ndarray[tuple[int, int, int], dtype[Unknown]]`
> + colour/plotting/temperature.py:230:9: error[invalid-argument-type]
Argument to bound method `__init__` is incorrect: Expected
`Sequence[@Todo(Support for `typing.TypeAlias`)]`, found
`ndarray[tuple[int, int, int], dtype[Unknown]]`
> + colour/plotting/temperature.py:474:13: error[invalid-argument-type]
Argument to bound method `__init__` is incorrect: Expected
`Sequence[@Todo(Support for `typing.TypeAlias`)]`, found
`ndarray[tuple[int, int, int], dtype[Unknown]]`
> + colour/plotting/temperature.py:495:17: error[invalid-argument-type]
Argument to bound method `__init__` is incorrect: Expected
`Sequence[@Todo(Support for `typing.TypeAlias`)]`, found
`ndarray[tuple[int, int, int], dtype[Unknown]]`
> + colour/plotting/temperature.py:513:13: error[invalid-argument-type]
Argument to bound method `text` is incorrect: Expected `int | float`,
found `ndarray[@Todo(Support for `typing.TypeAlias`), dtype[Unknown]]`
> + colour/plotting/temperature.py:514:13: error[invalid-argument-type]
Argument to bound method `text` is incorrect: Expected `int | float`,
found `ndarray[@Todo(Support for `typing.TypeAlias`), dtype[Unknown]]`
> - Found 480 diagnostics
> + Found 488 diagnostics

Most of them are correct except for the last two diagnostics which I'm
not sure
what's happening, it's trying to index into an `np.ndarray` type (which
is
inferred correctly) but I think it might be picking up an incorrect
overload
for the `__getitem__` method.

Scipy's diagnostics also requires support for type alises to pick the
correct overload.

</p>
</details>
2025-08-20 09:39:05 +05:30
Eric Mark Martin
33030b34cd
[ty] linear variance inference for PEP-695 type parameters (#18713)
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## Summary

Implement linear-time variance inference for type variables
(https://github.com/astral-sh/ty/issues/488).

Inspired by Martin Huschenbett's [PyCon 2025
Talk](https://www.youtube.com/watch?v=7uixlNTOY4s&t=9705s).

## Test Plan

update tests, add new tests, including for mutually recursive classes

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-08-19 17:54:09 -07:00
Alex Waygood
656fc335f2
[ty] Strict validation of protocol members (#17750) 2025-08-19 22:45:41 +00:00
Alex Waygood
662d18bd05
[ty] Add precise inference for unpacking a TypeVar if the TypeVar has an upper bound with a precise tuple spec (#19985) 2025-08-19 22:11:30 +01:00
Aria Desires
c82e255ca8
[ty] Fix namespace packages that behave like partial stubs (#19994)
In implementing partial stubs I had observed that this continue in the
namespace package code seemed erroneous since the same continue for
partial stubs didn't work. Unfortunately I wasn't confident enough to
push on that hunch. Fortunately I remembered that hunch to make this an
easy fix.

The issue with the continue is that it bails out of the current
search-path without testing any .py files. This breaks when for example
`google` and `google-stubs`/`types-google` are both in the same
site-packages dir -- failing to find a module in `types-google` has us
completely skip over `google`!

Fixes https://github.com/astral-sh/ty/issues/520
2025-08-19 16:34:39 -04:00
Eric Jolibois
58efd19f11
[ty] apply KW_ONLY sentinel only to local fields (#19986)
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fix https://github.com/astral-sh/ty/issues/1047

## Summary

This PR fixes how `KW_ONLY` is applied in dataclasses. Previously, the
sentinel leaked into subclasses and incorrectly marked their fields as
keyword-only; now it only affects fields declared in the same class.

```py
from dataclasses import dataclass, KW_ONLY

@dataclass
class D:
    x: int
    _: KW_ONLY
    y: str

@dataclass
class E(D):
    z: bytes

# This should work: x=1 (positional), z=b"foo" (positional), y="foo" (keyword-only)
E(1, b"foo", y="foo")

reveal_type(E.__init__)  # revealed: (self: E, x: int, z: bytes, *, y: str) -> None
```

<!-- What's the purpose of the change? What does it do, and why? -->

## Test Plan

<!-- How was it tested? -->
mdtests
2025-08-19 11:01:35 -07:00
Aria Desires
c6dcfe36d0
[ty] introduce multiline pretty printer (#19979)
Requires some iteration, but this includes the most tedious part --
threading a new concept of DisplaySettings through every type display
impl. Currently it only holds a boolean for multiline, but in the future
it could also take other things like "render to markdown" or "here's
your base indent if you make a newline".

For types which have exposed display functions I've left the old
signature as a compatibility polyfill to avoid having to audit
everywhere that prints types right off the bat (notably I originally
tried doing multiline functions unconditionally and a ton of things
churned that clearly weren't ready for multi-line (diagnostics).

The only real use of this API in this PR is to multiline render function
types in hovers, which is the highest impact (see snapshot changes).

Fixes https://github.com/astral-sh/ty/issues/1000
2025-08-19 17:31:44 +00:00
Alex Waygood
600245478c
[ty] Look for site-packages directories in <sys.prefix>/lib64/ as well as <sys.prefix>/lib/ on non-Windows systems (#19978) 2025-08-19 11:53:06 +00:00
Alex Waygood
e5c091b850
[ty] Fix protocol interface inference for stub protocols and subprotocols (#19950) 2025-08-19 10:31:11 +00:00
Alex Waygood
4242905b36
[ty] Detect NamedTuple classes where fields without default values follow fields with default values (#19945) 2025-08-19 08:56:08 +00:00
Aria Desires
c20d906503
[ty] improve goto/hover for definitions (#19976)
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By computing the actual Definition for, well, definitions, we unlock a
bunch of richer machinery in the goto/hover subsystems for free.

Fixes https://github.com/astral-sh/ty/issues/1001
Fixes https://github.com/astral-sh/ty/issues/1004
2025-08-18 21:42:53 -04:00
Carl Meyer
a04375173c
[ty] fix unpacking a type alias with detailed tuple spec (#19981)
## Summary

Fixes https://github.com/astral-sh/ty/issues/1046

We special-case iteration of certain types because they may have a more
detailed tuple-spec. Now that type aliases are a distinct type variant,
we need to handle them as well.

I don't love that `Type::TypeAlias` means we have to remember to add a
case for it basically anywhere we are special-casing a certain kind of
type, but at the moment I don't have a better plan. It's another
argument for avoiding fallback cases in `Type` matches, which we usually
prefer; I've updated this match statement to be comprehensive.

## Test Plan

Added mdtest.
2025-08-18 17:54:05 -07:00
Alex Waygood
e6dcdd29f2
[ty] Add a Todo-type branch for type[P] where P is a protocol class (#19947) 2025-08-18 20:38:19 +00:00
Matthew Mckee
24f6d2dc13
[ty] Infer the correct type of Enum __eq__ and __ne__ comparisions (#19666)
## Summary

Resolves https://github.com/astral-sh/ty/issues/920

## Test Plan

Update `enums.md`

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-08-18 19:45:44 +02:00
Alex Waygood
3314cf90ed
[ty] Add more regression tests for tuple (#19974)
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2025-08-18 18:30:05 +01:00
Aria Desires
0cb1abc1fc
[ty] Implement partial stubs (#19931)
Fixes https://github.com/astral-sh/ty/issues/184
2025-08-18 13:14:13 -04:00
Alex Waygood
fbf24be8ae
[ty] Detect illegal multiple inheritance with NamedTuple (#19943) 2025-08-18 12:03:01 +00:00
Alex Waygood
4ac2b2c222
[ty] Have SemanticIndex::place_table() and SemanticIndex::use_def_map return references (#19944) 2025-08-18 11:30:52 +01:00
Alex Waygood
ec3163781c
[ty] Remove unused code (#19949) 2025-08-17 18:54:24 +01:00
Douglas Creager
b892e4548e
[ty] Track when type variables are inferable or not (#19786)
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`Type::TypeVar` now distinguishes whether the typevar in question is
inferable or not.

A typevar is _not inferable_ inside the body of the generic class or
function that binds it:

```py
def f[T](t: T) -> T:
    return t
```

The infered type of `t` in the function body is `TypeVar(T,
NotInferable)`. This represents how e.g. assignability checks need to be
valid for all possible specializations of the typevar. Most of the
existing assignability/etc logic only applies to non-inferable typevars.

Outside of the function body, the typevar is _inferable_:

```py
f(4)
```

Here, the parameter type of `f` is `TypeVar(T, Inferable)`. This
represents how e.g. assignability doesn't need to hold for _all_
specializations; instead, we need to find the constraints under which
this specific assignability check holds.

This is in support of starting to perform specialization inference _as
part of_ performing the assignability check at the call site.

In the [[POPL2015][]] paper, this concept is called _monomorphic_ /
_polymorphic_, but I thought _non-inferable_ / _inferable_ would be
clearer for us.

Depends on #19784 

[POPL2015]: https://doi.org/10.1145/2676726.2676991

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-08-16 18:25:03 -04:00
Alex Waygood
9ac39cee98
[ty] Ban protocols from inheriting from non-protocol generic classes (#19941) 2025-08-16 19:38:43 +01:00
Alex Waygood
f4d8826428
[ty] Fix error message for invalidly providing type arguments to NamedTuple when it occurs in a type expression (#19940) 2025-08-16 17:45:15 +00:00
Alex Waygood
26d6c3831f
[ty] Represent NamedTuple as an opaque special form, not a class (#19915) 2025-08-15 18:20:14 +01:00
Alex Waygood
9ced219ffc
[ty] Remove incorrect type narrowing for if type(x) is C[int] (#19926) 2025-08-15 17:52:14 +01:00