Commit Graph

1330 Commits

Author SHA1 Message Date
Alex Waygood
28bfcf82b8 [ty] Make ModuleType and object attributes available on namespace packages (#22606)
## Summary

Currently we don't think that namespace packages (e.g. `google` after
you've pip-installed `google-cloud-ndb`) have attributes such as
`__file__`, `__name__`, etc. This PR fixes that.

## Test Plan

Mdtests and snapshots.
2026-01-16 08:42:58 +00:00
Ibraheem Ahmed
78d1343583 [ty] Infer implicit type of cls in __new__ methods (#22584)
## Summary

Resolves https://github.com/astral-sh/ty/issues/2489.
2026-01-15 15:42:16 -05:00
Charlie Marsh
b4b8299d6c [ty] Make NamedTuple(...) and namedtuple(...) calls stricter (#22601)
## Summary

Closes https://github.com/astral-sh/ty/issues/2513.
2026-01-15 18:24:25 +00:00
Rob Hand
eca58ca1d3 [ty] Override __file__ to str when applicable on imported modules (#22333) 2026-01-15 17:08:50 +00:00
Bhuminjay Soni
b2d57ddaa5 [ty]: consolidate type[] types in a union when displaying them in diagnostics (#22592) 2026-01-15 15:20:58 +00:00
Charlie Marsh
de954b6fa4 [ty] Support starred unpacking in class bases (#22591)
## Summary

Closes https://github.com/astral-sh/ty/issues/2492.
2026-01-15 10:17:11 -05:00
Charlie Marsh
fd7cc1f9c9 [ty] Validate field names for typing.NamedTuple(...) (#22599)
## Summary

Closes https://github.com/astral-sh/ty/issues/2511.
2026-01-15 09:15:45 -05:00
github-actions[bot]
1f9b44f7ce [ty] Sync vendored typeshed stubs (#22590)
Co-authored-by: typeshedbot <>
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2026-01-15 12:37:30 +00:00
Carl Meyer
87110c2892 [ty] Fix PEP 695 type aliases not expanding in overload resolution (#22589)
Fixes https://github.com/astral-sh/ty/issues/2488

When a type alias is defined using PEP 695's `type` statement syntax
(e.g., `type Array = Eager | Lazy`), overload resolution was failing
because the type alias was not being expanded into its underlying union
type.

This fix updates both `expand_type` and `is_expandable_type` in
`arguments.rs` to handle `Type::TypeAlias` by recursively checking and
expanding the alias's value type.
2026-01-15 06:25:08 +00:00
Alex Waygood
5a18e93d65 [ty] Make special cases for subscript inference exhaustive (#22035)
## Summary

Fixes https://github.com/astral-sh/ty/issues/2015. We weren't recursing
into the value of a type alias when we should have been.

There are situations where we should also be recursing into the
bounds/constraints of a typevar. I initially tried to do that as well in
this PR, but that seems... trickier. For now I'm cutting scope; this PR
does, however, add several failing tests for those cases.

## Test Plan

added mdtests
2026-01-15 00:18:54 +00:00
Alex Waygood
b79e9bac14 [ty] Use let-chains more (#22580)
## Summary

just a little refactor.

Edit: okay, I removed a period at the end of a diagnostic message, which
I guess changes a _lot_ of diagnostic messages.
2026-01-14 19:56:07 +00:00
Charlie Marsh
b07a53ab68 [ty] Emit diagnostics for invalid dynamic namedtuple fields (#22575)
## Summary

Removes some TODOs from the dynamic namedtuple implementation.
2026-01-14 18:42:35 +00:00
Charlie Marsh
87eec9bb51 [ty] Show dynamic NamedTuple defaults in signature (#22574)
## Summary

Follow-up from https://github.com/astral-sh/ruff/pull/22327.
2026-01-14 18:28:23 +00:00
Charlie Marsh
eb96456e1e [ty] Synthesize an empty __slots__ for named tuples (#22573)
## Summary

Closes https://github.com/astral-sh/ty/issues/2490.
2026-01-14 18:22:27 +00:00
Charlie Marsh
3e0299488e [ty] Add support for functional namedtuple creation (#22327)
## Summary

This PR is intended to demonstrate how the pattern established in
https://github.com/astral-sh/ruff/pull/22291 generalizes to other class
"kinds".

Closes https://github.com/astral-sh/ty/issues/1049.

---------

Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2026-01-14 17:41:04 +00:00
Alex Waygood
7f0ce3e88d [ty] Infer type[Unknown] for calls to type() when overload evaluation is ambiguous (#22569)
Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>
2026-01-14 14:23:07 +00:00
Charlie Marsh
ba0736385d [ty] Add a diagnostic for non-decorator uses of final (#22555)
## Summary

See:
https://github.com/astral-sh/ruff/pull/22499#discussion_r2687263390.
2026-01-14 09:14:59 -05:00
Charlie Marsh
e41f045ec5 [ty] Emit diagnostics for invalid base classes in type(...) (#22499)
## Summary

Tackles a few TODOs from https://github.com/astral-sh/ruff/pull/22291.
2026-01-14 08:56:04 -05:00
Charlie Marsh
b24afb643c [ty] Support 'dangling' type(...) constructors (#22537)
## Summary

This PR adds support for 'dangling' `type(...)` constructors, e.g.:

```python
class Foo(type("Bar", ...)):
   ...
```

As opposed to:

```python
Bar = type("Bar", ...)
```

The former doesn't have a `Definition` since it doesn't get bound to a
place, so we instead need to store the `NodeIndex`. Per @MichaReiser's
suggestion, we can use a Salsa tracked struct for this.
2026-01-14 08:48:53 -05:00
Charlie Marsh
b5814b91c1 [ty] Add diagnostics to validate TypeIs and TypeGuard definitions (#22300)
## Summary

Closes https://github.com/astral-sh/ty/issues/2267.
2026-01-13 20:24:05 -05:00
Charlie Marsh
ea46426157 [ty] Apply narrowing to walrus targets (#22369)
## Summary

Closes https://github.com/astral-sh/ty/issues/2300.
2026-01-14 00:56:47 +00:00
Alex Waygood
ddd2fc7a90 [ty] Use "typeguard constraints" for two kinds of tuple narrowing (#22348)
## Summary

Since we've already filtered the union in these locations, it seems like
needless overhead to then intersect the previous union with the filtered
union. We know what that intersection will simplify to: it will simplify
to the filtered union. So rather than using a regular intersection-based
constraint, we can use a "typeguard constraint", which will just
directly replace the previous type with the new type instead of creating
an intersection.

## Test Plan

- Existing tests all pass
- The primer report should be clean
2026-01-13 23:37:09 +00:00
Charlie Marsh
9a676bbeb7 [ty] Add diagnostic to catch generic enums (#22482)
## Summary

Closes https://github.com/astral-sh/ty/issues/2416.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2026-01-13 16:55:46 -05:00
Alex Waygood
56077ee9a9 [ty] Fix @Todo type for starred expressions (#22503) 2026-01-13 21:09:29 +00:00
Alex Waygood
20c01d2553 [ty] Use the top materialization of classes for if type(x) is y narrowing (#22553) 2026-01-13 20:53:52 +00:00
Carl Meyer
a697050a83 [ty] Fix stack overflow with recursive type aliases containing tuple … (#22543)
This fixes issue #2470 where recursive type aliases like `type
RecursiveT = int | tuple[RecursiveT, ...]` caused a stack overflow when
used in return type checking with constructors like `list()`.

The fix moves all type mapping processing for `UniqueSpecialization`
(and other non-EagerExpansion mappings) inside the `visitor.visit()`
closure. This ensures that if we encounter the same TypeAlias
recursively during type mapping, the cycle detector will properly detect
it and return the fallback value instead of recursing infinitely.

The key insight is that the previous code called
`apply_function_specialization` followed by another
`apply_type_mapping_impl` AFTER the visitor closure returned. At that
point, the TypeAlias was no longer in the visitor's `seen` set, so
recursive references would not be detected as cycles.
2026-01-13 11:25:01 -08:00
Dex Devlon
2f64ef9c72 [ty] Include type parameters in generic callable display (#22435) 2026-01-13 17:29:08 +00:00
RasmusNygren
fde7d72fbb [ty] Add diagnostics for __init_subclass__ argument mismatch (#22185) 2026-01-13 16:15:51 +00:00
drbh
d13b5db066 [ty] narrow the right-hand side of ==, !=, is and is not conditions when the left-hand side is not narrowable (#22511)
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2026-01-13 16:01:54 +00:00
Alex Waygood
c7b41060f4 [ty] Improve disambiguation of types (#22547) 2026-01-13 14:56:56 +00:00
Charlie Marsh
3878701265 [ty] Support own instance members for type(...) classes (#22480)
## Summary

Addresses
https://github.com/astral-sh/ruff/pull/22291#discussion_r2674467950.
2026-01-13 09:36:03 -05:00
Enric Calabuig
6e89e0abff [ty] Fix classmethod + contextmanager + Self (#22407)
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## Summary

The test I've added illustrates the fix. Copying it here too:

```python
from contextlib import contextmanager
from typing import Iterator
from typing_extensions import Self

class Base:
    @classmethod
    @contextmanager
    def create(cls) -> Iterator[Self]:
        yield cls()

class Child(Base): ...

with Base.create() as base:
    reveal_type(base)  # revealed: Base (after the fix, None before)

with Child.create() as child:
    reveal_type(child)  # revealed: Child (after the fix, None before)
```

Full disclosure: I've used LLMs for this PR, but the result is
thoroughly reviewed by me before submitting. I'm excited about my first
Rust contribution to Astral tools and will address feedback quickly.

Related to https://github.com/astral-sh/ty/issues/2030, I am working on
a fix for the TypeVar case also reported in that issue (by me)

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

## Test Plan

<!-- How was it tested? -->

Updated mdtests

---------

Co-authored-by: Douglas Creager <dcreager@dcreager.net>
2026-01-13 09:29:58 -05:00
Charlie Marsh
6d8f2864c3 [ty] Rename MRO structs to match static nomenclature (#22549)
## Summary

I didn't want to make the "dynamic" `type(...)` PR any larger, but it
probably makes sense to rename these now that we have `Dynamic`
variants.
2026-01-13 08:53:49 -05:00
Carl Meyer
99beabdde8 [ty] Fix false positive for bounded type parameters with NewType (#22542)
Fixes https://github.com/astral-sh/ty/issues/2467

When calling a method on an instance of a generic class with bounded
type parameters (e.g., `C[T: K]` where `K` is a NewType), ty was
incorrectly reporting: "Argument type `C[K]` does not satisfy upper
bound `C[T@C]` of type variable `Self`"

The issue was introduced by PR #22105, which moved the catch-all case
for NewType assignments that falls back to the concrete base type. This
case was moved before the TypeVar handling cases, so when checking `K <:
T@C` (where K is a NewType and T@C is a TypeVar with upper bound K):

1. The NewType fallback matched first
2. It delegated to `int` (K's concrete base type)
3. Then checked `int <: T@C`, which checks if `int` satisfies bound `K`
4. But `int` is not assignable to `K` (NewTypes are distinct from their
bases)

The fix moves the NewType fallback case after the TypeVar cases, so
TypeVar handling takes precedence. Now when checking `K <: T@C`, we use
the TypeVar case at line 828 which returns `false` for non-inferable
typevars - but this is correct because the *other* direction (`T@C <:
K`) passes, and for the overall specialization comparison both
directions are checked.
2026-01-12 17:23:31 -08:00
Ibraheem Ahmed
3ae4db3ccd [ty] Support assignment to unions of TypedDicts (#22294)
## Summary

Resolves https://github.com/astral-sh/ty/issues/2265.
2026-01-12 16:10:58 -05:00
Ibraheem Ahmed
8ac5f9d8bc [ty] Use key and value parameter types as type context for __setitem__ dunder calls (#22148)
## Summary

Resolves https://github.com/astral-sh/ty/issues/2136.
2026-01-12 16:05:05 -05:00
Charlie Marsh
4abc5fe2f1 [ty] Add support for dynamic type() classes (#22291)
## Summary

This PR adds support for dynamic classes created via `type()`. The core
of the change is that `ClassLiteral` is now an enum:

```rust
pub enum ClassLiteral<'db> {
    /// A class defined via a `class` statement.
    Stmt(StmtClassLiteral<'db>),
    /// A class created via the functional form `type(name, bases, dict)`.
    Functional(FunctionalClassLiteral<'db>),
}
```

And, in turn, various methods on `ClassLiteral` like `body_scope` now
return `Option` or similar (and callers must adjust to that change in
signature).

Over time, we can expand the enum to include functional namedtuples,
etc. (I already have this working in a separate branch, and I believe it
slots in well.)

(I'd love help with the names -- I think `StmtClassLiteral` is kind of
lame. Maybe `DeclarativeClassLiteral`?)

Closes https://github.com/astral-sh/ty/issues/740.

---------

Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2026-01-12 15:20:42 -05:00
Charlie Marsh
e4ba29392b [ty] Fix __file__ type in completions to show str instead of str | None (#22510)
## Summary

The type inference system already correctly special-cases `__file__` to
return `str` for the current module (since the code is executing from an
existing file). However, the completion system was bypassing this logic
and pulling `__file__: str | None` directly from `types.ModuleType` in
typeshed.

This PR adds implicit module globals (like `__file__`, `__name__`, etc.)
with their correctly-typed values to completions, reusing the existing
`module_type_implicit_global_symbol` function that already handles the
special-casing.

Closes https://github.com/astral-sh/ty/issues/2445.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2026-01-12 14:20:32 +00:00
Charlie Marsh
f1db842821 [ty] Avoid panic for comparison on synthesized variants (#22509)
## Summary

Like `ProtocolInstance`, we now use `left.cmp(right)` by deriving
`PartialOrd` and `Ord`. IIUC, this uses Salsa ID for Salsa-interned
types, but avoids `None.cmp(None)` for synthesized variants.

Closes https://github.com/astral-sh/ty/issues/2451.
2026-01-12 13:35:56 +00:00
Alex Waygood
5a3deee353 [ty] Fix incorrect narrowing for if type(x) == y (#22531) 2026-01-12 12:26:47 +00:00
Dex Devlon
e15f88ff21 [ty] Fix contravariant type variable bound checking in specialization inference (#22488)
## Summary

Correctly handle upper bounds for contravariant type variables during
specialization inference. Previously, the type checker incorrectly
applied covariant subtyping rules, requiring the actual type to directly
satisfy the bound rather than checking for a valid intersection.

In contravariant positions, subtyping relationships are inverted. The
bug caused valid code like `f(x: Contra[str])` where `f` expects
`Contra[T: int]` to be incorrectly rejected, when it should solve `T` to
`Never` (the intersection of `int` and `str`).

Closes https://github.com/astral-sh/ty/issues/2427

## Details

- Added `is_contravariant()` helper to `TypeVarVariance` in
`variance.rs`
- Updated `SpecializationBuilder::infer_map_impl` in `generics.rs` to
treat bounds and constraints differently based on variance:
  * Skip immediate `ty <: bound` check for contravariant upper bounds
* Flip constraint check to `constraint <: ty` for contravariant
positions
- Added test case for bounded contravariant type variables in
`variance.md`
- All 308 mdtest cases pass & 150 ty_python_semantic unit tests pass

---------

Co-authored-by: Douglas Creager <dcreager@dcreager.net>
2026-01-12 05:00:35 -05:00
Charlie Marsh
2c68057c4b [ty] Preserve argument signature in @total_ordering (#22496)
## Summary

Closes https://github.com/astral-sh/ty/issues/2435.
2026-01-10 14:35:58 -05:00
Charlie Marsh
046c5a46d8 [ty] Support dataclass_transform as a function call (#22378)
## Summary

Instead of just as a decorator.

Closes https://github.com/astral-sh/ty/issues/2319.
2026-01-10 08:45:45 -05:00
Micha Reiser
cfed34334c Update mypy primer pin (#22490) 2026-01-10 14:00:00 +01:00
Charlie Marsh
11cc324449 [ty] Detect invalid @total_ordering applications in non-decorator contexts (#22486)
## Summary

E.g., `ValidOrderedClass = total_ordering(HasOrderingMethod)`.
2026-01-09 19:37:58 -05:00
Charlie Marsh
c88e1a0663 [ty] Avoid emitting Liskov repeated violations from grandparent to child (#22484)
## Summary

If parent violates LSP against grandparent, and child has the same
violation (but matches parent), we no longer flag the LSP violation on
child, since it can't be fixed without violating parent.

If parent violates LSP against grandparent, and child violates LSP
against both parent and grandparent, we emit two diagnostics (one for
each violation).

If parent violates LSP against grandparent, and child violates LSP
against parent (but not grandparent), we flag it.

Closes https://github.com/astral-sh/ty/issues/2000.
2026-01-09 19:27:57 -05:00
Alex Waygood
dc61104726 [ty] Derive Default in a few more places in place.rs (#22481) 2026-01-09 18:37:36 +00:00
Andrew Gallant
e9cc2f6f42 [ty] Refactor completion construction to use a builder
I want to be able to attach extra data to each `Completion`, but not
burden callers with the need to construct it. This commit helps get us
to that point by requiring callers to use a `CompletionBuilder` for
construction instead of a `Completion` itself.

I think this will also help in the future if it proves to be the case
that we can improve performance by delaying work until we actually build
a `Completion`, which might only happen if we know we won't throw it
out. But we aren't quite there yet.

This also lets us tighten things up a little bit and makes completion
construction less noisy. The downside is that callers no longer need to
consider "every" completion field.

There should not be any behavior changes here.
2026-01-09 09:55:32 -05:00
Micha Reiser
e61657ff3c [ty] Enable unused-type-ignore-comment by default (#22474) 2026-01-09 10:58:43 +00:00
Micha Reiser
ba5dd5837c [ty] Pass slice to specialize (#22421) 2026-01-09 09:45:39 +01:00