Commit Graph

738 Commits

Author SHA1 Message Date
Dhruv Manilawala 902b0b4ce9
[ty] Add support for `**kwargs` (#20430)
## Summary

This PR adds support for unpacking `**kwargs` argument.

This can be matched against any standard (positional or keyword),
keyword-only, or keyword variadic parameter that haven't been matched
yet.

This PR also takes care of special casing `TypedDict` because the key
names and the corresponding value type is known, so we can be more
precise in our matching and type checking step. In the future, this
special casing would be extended to include `ParamSpec` as well.

Part of astral-sh/ty#247

## Test Plan

Add test cases for various scenarios.
2025-09-19 05:00:30 +00:00
Eric Mark Martin 2502ff7638
[ty] Make TypeIs invariant in its type argument (#20428)
## Summary

What it says on the tin. See the [typing
spec](https://docs.python.org/3/library/typing.html#typing.TypeIs) for
justification.

## Test Plan

Add more tests to PEP 695 `variance.md` suite.
2025-09-18 07:53:13 -07:00
David Peter 50bd3943da
[ty] Faster iteration on mdtests (#20465)
## Summary

This change reduces MD test compilation time from 6s to 3s on my laptop.
We don't need to build the unit tests and the corpus tests when we're
only interested in Markdown-based tests.

## Test Plan

local benchmarks
2025-09-18 10:48:52 +00:00
Ibraheem Ahmed e84d523bcf
[ty] Infer more precise types for collection literals (#20360)
## Summary

Part of https://github.com/astral-sh/ty/issues/168. Infer more precise types for collection literals (currently, only `list` and `set`). For example,

```py
x = [1, 2, 3] # revealed: list[Unknown | int]
y: list[int] = [1, 2, 3] # revealed: list[int]
```

This could easily be extended to `dict` literals, but I am intentionally limiting scope for now.
2025-09-17 18:51:50 -04:00
Shaygan Hooshyari 05622ae757
[ty] Bind Self typevar to method context (#20366)
Fixes: https://github.com/astral-sh/ty/issues/1173

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## Summary

This PR will change the logic of binding Self type variables to bind
self to the immediate function that it's used on.
Since we are binding `self` to methods and not the class itself we need
to ensure that we bind self consistently.

The fix is to traverse scopes containing the self and find the first
function inside a class and use that function to bind the typevar for
self.

If no such scope is found we fallback to the normal behavior. Using Self
outside of a class scope is not legal anyway.

## Test Plan

Added a new mdtest.

Checked the diagnostics that are not emitted anymore in [primer
results](https://github.com/astral-sh/ruff/pull/20366#issuecomment-3289411424).
It looks good altough I don't completely understand what was wrong
before.

---------

Co-authored-by: Douglas Creager <dcreager@dcreager.net>
2025-09-17 14:58:54 -04:00
Andrew Gallant 3fcbe8bde6 [ty] Remove TODO about using a non-panicking lookup method
Ref https://github.com/astral-sh/ruff/pull/20439#discussion_r2355082049

Ref https://github.com/astral-sh/ruff/pull/18455#discussion_r2126833137
2025-09-17 13:59:28 -04:00
Andrew Gallant b6a29592e7 [ty] Add a new abstraction for adding imports to a module
This is somewhat inspired by a similar abstraction in
`ruff_linter`. The main idea is to create an importer once
for a module that you want to add imports to. And then call
`import` to generate an edit for each symbol you want to
add.

I haven't done any performance profiling here yet. I don't
know if it will be a bottleneck. In particular, I do expect
`Importer::import` (but not `Importer::new`) to get called
many times for a single completion request when auto-import
is enabled. Particularly in projects with a lot of unimported
symbols. Because I don't know the perf impact, I didn't do
any premature optimization here. But there are surely some
low hanging fruit if this does prove to be a problem.

New tests make up a big portion of the diff here. I tried to
think of a bunch of different cases, although I'm sure there
are more.
2025-09-17 13:59:28 -04:00
Andrew Gallant 0a2325c5fe [ty] Move `CompletionKind` to `ty_ide`
I think this is a better home for it. This way, `ty_ide`
more clearly owns how the "kind" of a completion is computed.
In particular, it is computed differently for things where
we know its type versus unimported symbols.
2025-09-17 13:59:28 -04:00
Andrew Gallant 6c3c963f8a [ty] Include definition site for "members of" API
In the course of writing the "add an import" implementation,
I realized that we needed to know which symbols were in scope
and how they were defined. This was necessary to be able to
determine how to add a new import in a way that (minimally)
does not conflict with existing symbols.

I'm not sure that this is fully correct (especially for
symbol bindings) and it's unclear to me in which cases a
definition site will be missing. But this seems to work for
some of the basic cases that I tried.
2025-09-17 13:59:28 -04:00
Andrew Gallant 6ec52991cb [ty] Fix a bug with "all_submodule_names_for_package" API
The names of the submodules returned should be *complete*. This
is the contract of `Module::name`. However, we were previously
only returning the basename of the submodule.
2025-09-17 13:59:28 -04:00
Andrew Gallant cf16fc4aa4 [ty] Export some stuff from `ty_python_semantic`
We're going to want to use this outside of `ty_python_semantic`.
Specifically, in `ty_ide`.
2025-09-17 13:59:28 -04:00
Carl Meyer 7e464b8150
[ty] move graphql-core to good.txt (#20447)
## Summary

With https://github.com/astral-sh/ruff/pull/20446, graphql-core now
checks without error; we can move it to `good.txt`.

## Test Plan

CI
2025-09-17 10:09:32 +02:00
David Peter ffd650e5fd
[ty] Update mypy_primer (#20433)
## Summary

Revert the materialize-changes, see
https://github.com/hauntsaninja/mypy_primer/pull/208

## Test Plan

CI
2025-09-17 09:51:48 +02:00
Carl Meyer 99ec4d2c69
[ty] detect cycles in binary comparison inference (#20446)
## Summary

Catch infinite recursion in binary-compare inference.

Fixes the stack overflow in `graphql-core` in mypy-primer.

## Test Plan

Added two tests that stack-overflowed before this PR.
2025-09-17 09:45:25 +02:00
justin 9f0b942b9e
[ty] infer `name` and `value` for enum members (#20311)
## summary
- this pr implements the following attributes for `Enum` members:
  - `name`
  - `_name_`
  - `value`
  - `_value_`
- adds a TODO test for `my_enum_class_instance.name`
- only implements if the instance is a subclass of `Enum` re: this
[comment](https://github.com/astral-sh/ruff/pull/19481#issuecomment-3103460307)
and existing
[test](c34449ed7c/crates/ty_python_semantic/resources/mdtest/enums.md?plain=1#L625)

### pointers
- https://github.com/astral-sh/ty/issues/876
- https://typing.python.org/en/latest/spec/enums.html#enum-definition
- https://github.com/astral-sh/ruff/pull/19481#issuecomment-3103460307

## test plan
- mdtests
- triaged conformance diffs here:
https://diffswarm.dev/d-01k531ag4nee3xmdeq4f3j66pb
- triaged mypy primer diffs here for django-stubs:
https://diffswarm.dev/d-01k5331n13k9yx8tvnxnkeawp3
  - added a TODO test for overriding `.value`
- discord diff seems reasonable

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-09-17 09:36:27 +02:00
Carl Meyer c2fa449954
[ty] support type aliases in binary compares (#20445)
## Summary

Add missing `Type::TypeAlias` clauses to `infer_binary_type_comparison`.

## Test Plan

Added mdtests that failed before.
2025-09-17 09:33:26 +02:00
Carl Meyer 681ad2fd92
[ty] move primer projects to good.txt (#20444)
## Summary

After https://github.com/astral-sh/ruff/pull/20359 we can move all but
three remaining projects over to `good.txt`.

## Test Plan

CI
2025-09-17 09:31:27 +02:00
Carl Meyer d121a76aef
[ty] no more diverging query cycles in type expressions (#20359)
## Summary

Use `Type::Divergent` to short-circuit diverging types in type
expressions. This avoids panicking in a wide variety of cases of
recursive type expressions.

Avoids many panics (but not yet all -- I'll be tracking down the rest)
from https://github.com/astral-sh/ty/issues/256 by falling back to
Divergent. For many of these recursive type aliases, we'd like to
support them properly (i.e. really understand the recursive nature of
the type, not just fall back to Divergent) but that will be future work.

This switches `Type::has_divergent_type` from using `any_over_type` to a
custom set of visit methods, because `any_over_type` visits more than we
need to visit, and exercises some lazy attributes of type, causing
significantly more work. This change means this diff doesn't regress
perf; it even reclaims some of the perf regression from
https://github.com/astral-sh/ruff/pull/20333.

## Test Plan

Added mdtest for recursive type alias that panics on main.

Verified that we can now type-check `packaging` (and projects depending
on it) without panic; this will allow moving a number of mypy-primer
projects from `bad.txt` to `good.txt` in a subsequent PR.
2025-09-16 16:44:11 -07:00
Bhuminjay Soni c3f2187fda
[syntax-errors]: import from * only allowed at module scope (F406) (#20166)
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## Summary

This PR implements F406
https://docs.astral.sh/ruff/rules/undefined-local-with-nested-import-star-usage/
as a semantic syntax error

## Test Plan

I have written inline tests as directed in #17412

---------

Signed-off-by: 11happy <soni5happy@gmail.com>
2025-09-16 15:53:28 -04:00
Douglas Creager 1f46c18921
[ty] More constraint set simplifications via simpler constraint representation (#20423)
Previously, we used a very fine-grained representation for individual
constraints: each constraint was _either_ a range constraint, a
not-equivalent constraint, or an incomparable constraint. These three
pieces are enough to represent all of the "real" constraints we need to
create — range constraints and their negation.

However, it meant that we weren't picking up as many chances to simplify
constraint sets as we could. Our simplification logic depends on being
able to look at _pairs_ of constraints or clauses to see if they
simplify relative to each other. With our fine-grained representation,
we could easily encounter situations that we should have been able to
simplify, but that would require looking at three or more individual
constraints.

For instance, negating a range constraint would produce:

```
¬(Base ≤ T ≤ Super) = ((T ≤ Base) ∧ (T ≠ Base)) ∨ (T ≁ Base) ∨
                      ((Super ≤ T) ∧ (T ≠ Super)) ∨ (T ≁ Super)
```

That is, `T` must be (strictly) less than `Base`, (strictly) greater
than `Super`, or incomparable to either.

If we tried to union those back together, we should get `always`, since
`x ∨ ¬x` should always be true, no matter what `x` is. But instead we
would get:

```
(Base ≤ T ≤ Super) ∨ ((T ≤ Base) ∧ (T ≠ Base)) ∨ (T ≁ Base) ∨ ((Super ≤ T) ∧ (T ≠
 Super)) ∨ (T ≁ Super)
```

Nothing would simplify relative to each other, because we'd have to look
at all five union elements to see that together they do in fact combine
to `always`.

The fine-grained representation was nice, because it made it easier to
[work out the math](https://dcreager.net/theory/constraints/) for
intersections and unions of each kind of constraint. But being able to
simplify is more important, since the example above comes up immediately
in #20093 when trying to handle constrained typevars.

The fix in this PR is to go back to a more coarse-grained
representation, where each individual constraint consists of a positive
range (which might be `always` / `Never ≤ T ≤ object`), and zero or more
negative ranges. The intuition is to think of a constraint as a region
of the type space (representable as a range) with zero or more "holes"
removed from it.

With this representation, negating a range constraint produces:

```
¬(Base ≤ T ≤ Super) = (always ∧ ¬(Base ≤ T ≤ Super))
```

(That looks trivial, because it is! We just move the positive range to
the negative side.)

The math is not that much harder than before, because there are only
three combinations to consider (each for intersection and union) —
though the fact that there can be multiple holes in a constraint does
require some nested loops. But the mdtest suite gives me confidence that
this is not introducing any new issues, and it definitely removes a
troublesome TODO.

(As an aside, this change also means that we are back to having each
clause contain no more than one individual constraint for any typevar.
This turned out to be important, because part of our simplification
logic was also depending on that!)

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-09-16 10:05:01 -04:00
David Peter 2a6dde4acb
[ty] Remove `Self` from generic context when binding `Self` (#20364)
## Summary

This mainly removes an internal inconsistency, where we didn't remove
the `Self` type variable when eagerly binding `Self` to an instance
type. It has no observable effect, apparently.

builds on top of https://github.com/astral-sh/ruff/pull/20328

## Test Plan

None
2025-09-15 17:40:10 +02:00
David Peter 25cbf38a47
[ty] Patch `Self` for fallback-methods on `NamedTuple`s and `TypedDict`s (#20328)
## Summary

We use classes like
[`_typeshed._type_checker_internals.NamedTupleFallback`](d9c76e1d9f/stdlib/_typeshed/_type_checker_internals.pyi (L54-L75))
to tack on additional attributes/methods to instances of user-defined
`NamedTuple`s (or `TypedDict`s), even though these classes are not
present in the MRO of those types.

The problem is that those classes use implicit and explicit `Self`
annotations which refer to `NamedTupleFallback` itself, instead of to
the actual type that we're adding those methods to:
```py
class NamedTupleFallback(tuple[Any, ...]):
    # […]
    def _replace(self, **kwargs: Any) -> typing_extensions.Self: ...
```

In effect, when we access `_replace` on an instance of a custom
`NamedTuple` instance, its `self` parameter and return type refer to the
wrong `Self`. This leads to incorrect *"Argument to bound method
`_replace` is incorrect: Argument type `Person` does not satisfy upper
bound `NamedTupleFallback` of type variable `Self`"* errors on #18007.
It would also lead to similar errors on `TypedDict`s, if they would
already implement assignability properly.


## Test Plan

I applied the following patch to typeshed and verified that no errors
appear anymore.

<details>

```diff
diff --git a/crates/ty_vendored/vendor/typeshed/stdlib/_typeshed/_type_checker_internals.pyi b/crates/ty_vendored/vendor/typeshed/stdlib/_typeshed/_type_checker_internals.pyi
index feb22aae00..8e41034f19 100644
--- a/crates/ty_vendored/vendor/typeshed/stdlib/_typeshed/_type_checker_internals.pyi
+++ b/crates/ty_vendored/vendor/typeshed/stdlib/_typeshed/_type_checker_internals.pyi
@@ -29,27 +29,27 @@ class TypedDictFallback(Mapping[str, object], metaclass=ABCMeta):
         __readonly_keys__: ClassVar[frozenset[str]]
         __mutable_keys__: ClassVar[frozenset[str]]
 
-    def copy(self) -> typing_extensions.Self: ...
+    def copy(self: typing_extensions.Self) -> typing_extensions.Self: ...
     # Using Never so that only calls using mypy plugin hook that specialize the signature
     # can go through.
-    def setdefault(self, k: Never, default: object) -> object: ...
+    def setdefault(self: typing_extensions.Self, k: Never, default: object) -> object: ...
     # Mypy plugin hook for 'pop' expects that 'default' has a type variable type.
-    def pop(self, k: Never, default: _T = ...) -> object: ...  # pyright: ignore[reportInvalidTypeVarUse]
-    def update(self, m: typing_extensions.Self, /) -> None: ...
-    def __delitem__(self, k: Never) -> None: ...
-    def items(self) -> dict_items[str, object]: ...
-    def keys(self) -> dict_keys[str, object]: ...
-    def values(self) -> dict_values[str, object]: ...
+    def pop(self: typing_extensions.Self, k: Never, default: _T = ...) -> object: ...  # pyright: ignore[reportInvalidTypeVarUse]
+    def update(self: typing_extensions.Self, m: typing_extensions.Self, /) -> None: ...
+    def __delitem__(self: typing_extensions.Self, k: Never) -> None: ...
+    def items(self: typing_extensions.Self) -> dict_items[str, object]: ...
+    def keys(self: typing_extensions.Self) -> dict_keys[str, object]: ...
+    def values(self: typing_extensions.Self) -> dict_values[str, object]: ...
     @overload
-    def __or__(self, value: typing_extensions.Self, /) -> typing_extensions.Self: ...
+    def __or__(self: typing_extensions.Self, value: typing_extensions.Self, /) -> typing_extensions.Self: ...
     @overload
-    def __or__(self, value: dict[str, Any], /) -> dict[str, object]: ...
+    def __or__(self: typing_extensions.Self, value: dict[str, Any], /) -> dict[str, object]: ...
     @overload
-    def __ror__(self, value: typing_extensions.Self, /) -> typing_extensions.Self: ...
+    def __ror__(self: typing_extensions.Self, value: typing_extensions.Self, /) -> typing_extensions.Self: ...
     @overload
-    def __ror__(self, value: dict[str, Any], /) -> dict[str, object]: ...
+    def __ror__(self: typing_extensions.Self, value: dict[str, Any], /) -> dict[str, object]: ...
     # supposedly incompatible definitions of __or__ and __ior__
-    def __ior__(self, value: typing_extensions.Self, /) -> typing_extensions.Self: ...  # type: ignore[misc]
+    def __ior__(self: typing_extensions.Self, value: typing_extensions.Self, /) -> typing_extensions.Self: ...  # type: ignore[misc]
 
 # Fallback type providing methods and attributes that appear on all `NamedTuple` types.
 class NamedTupleFallback(tuple[Any, ...]):
@@ -61,18 +61,18 @@ class NamedTupleFallback(tuple[Any, ...]):
         __orig_bases__: ClassVar[tuple[Any, ...]]
 
     @overload
-    def __init__(self, typename: str, fields: Iterable[tuple[str, Any]], /) -> None: ...
+    def __init__(self: typing_extensions.Self, typename: str, fields: Iterable[tuple[str, Any]], /) -> None: ...
     @overload
     @typing_extensions.deprecated(
         "Creating a typing.NamedTuple using keyword arguments is deprecated and support will be removed in Python 3.15"
     )
-    def __init__(self, typename: str, fields: None = None, /, **kwargs: Any) -> None: ...
+    def __init__(self: typing_extensions.Self, typename: str, fields: None = None, /, **kwargs: Any) -> None: ...
     @classmethod
     def _make(cls, iterable: Iterable[Any]) -> typing_extensions.Self: ...
-    def _asdict(self) -> dict[str, Any]: ...
-    def _replace(self, **kwargs: Any) -> typing_extensions.Self: ...
+    def _asdict(self: typing_extensions.Self) -> dict[str, Any]: ...
+    def _replace(self: typing_extensions.Self, **kwargs: Any) -> typing_extensions.Self: ...
     if sys.version_info >= (3, 13):
-        def __replace__(self, **kwargs: Any) -> typing_extensions.Self: ...
+        def __replace__(self: typing_extensions.Self, **kwargs: Any) -> typing_extensions.Self: ...
 
 # Non-default variations to accommodate couroutines, and `AwaitableGenerator` having a 4th type parameter.
 _S = TypeVar("_S")
```

</details>
2025-09-15 16:21:53 +02:00
Alex Waygood e8b4450125
[ty] Remove unneeded disjoint-base special casing for `builtins.tuple` (#20414) 2025-09-15 13:12:20 +01:00
Alex Waygood 8341da7f63
[ty] Allow annotation expressions to be `ast::Attribute` nodes (#20413)
Fixes https://github.com/astral-sh/ty/issues/1187
2025-09-15 12:06:48 +01:00
Takayuki Maeda 093fa72656
[`ty`] Include `NamedTupleFallback` members in `NamedTuple` instance completions (#20356)
## Summary

Fixes https://github.com/astral-sh/ty/issues/1161

Include `NamedTupleFallback` members in `NamedTuple` instance
completions.

- Augment instance attribute completions when completing on NamedTuple
instances by merging members from
`_typeshed._type_checker_internals.NamedTupleFallback`

## Test Plan

Adds a minimal completion test `namedtuple_fallback_instance_methods`

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-09-15 11:00:03 +02:00
David Peter 02c58f1beb
[ty] Remove 'materialize' from the ecosystem projects (#20412)
## Summary

This project was [recently removed from
mypy_primer](https://github.com/astral-sh/ruff/pull/20378), so we need
to remove it from `good.txt` in order for ecosystem-analyzer to work
correctly.

## Test Plan

Run mypy_primer and ecosystem-analyzer on this branch.
2025-09-15 10:42:35 +02:00
Alex Waygood 1745554809
[ty] Temporary hack to reduce false positives around `builtins.open()` (#20367)
## Summary

https://github.com/astral-sh/ruff/pull/20165 added a lot of false
positives around calls to `builtins.open()`, because our missing support
for PEP-613 type aliases means that we don't understand typeshed's
overloads for `builtins.open()` at all yet, and therefore always select
the first overload. This didn't use to matter very much, but now that we
have a much stricter implementation of protocol assignability/subtyping
it matters a lot, because most of the stdlib functions dealing with I/O
(`pickle`, `marshal`, `io`, `json`, etc.) are annotated in typeshed as
taking in protocols of some kind.

In lieu of full PEP-613 support, which is blocked on various things and
might not land in time for our next alpha release, this PR adds some
temporary special-casing for `builtins.open()` to avoid the false
positives. We just infer `Todo` for anything that isn't meant to match
typeshed's first `open()` overload. This should be easy to rip out again
once we have proper support for PEP-613 type aliases, which hopefully
should be pretty soon!

## Test Plan

Added an mdtest
2025-09-12 22:20:38 +01:00
Alex Waygood 98708976e4
[ty] Fix subtyping/assignability of function- and class-literal types to callback protocols (#20363)
## Summary

Fixes https://github.com/astral-sh/ty/issues/377.

We were treating any function as being assignable to any callback
protocol, because we were trying to figure out a type's `Callable`
supertype by looking up the `__call__` attribute on the type's
meta-type. But a function-literal's meta-type is `types.FunctionType`,
and `types.FunctionType.__call__` is `(...) -> Any`, which is not very
helpful!

While working on this PR, I also realised that assignability between
class-literals and callback protocols was somewhat broken too, so I
fixed that at the same time.

## Test Plan

Added mdtests
2025-09-12 22:20:09 +01:00
Carl Meyer 82796df9b5
[ty] add cycle handling to BoundMethodType::into_callable_type() (#20369)
## Summary

This looks like it should fix the errors that we've been seeing in sympy
in recent mypy-primer runs.

## Test Plan

I wasn't able to reproduce the sympy failures locally; it looks like
there is probably a dependency on the order in which files are checked.
So I don't have a minimal reproducible example, and wasn't able to add a
test :/ Obviously I would be happier if we could commit a regression
test here, but since the change is straightforward and clearly
desirable, I'm not sure how many hours it's worth trying to track it
down.

Mypy-primer is still failing in CI on this PR, because it fails on the
"old" ty commit already (i.e. on main). But it passes [on a no-op PR
stacked on top of this](https://github.com/astral-sh/ruff/pull/20370),
which strongly suggests this PR fixes the problem.
2025-09-12 13:39:38 -07:00
Alex Waygood 33b3d44ebd
[ty] Proper assignability/subtyping checks for protocols with method members (#20165) 2025-09-12 10:10:31 +00:00
Dhruv Manilawala bb9be263c7
[ty] Retry parameter matching for argument type expansion (#20153)
## Summary

This PR addresses an issue for a variadic argument when involved in
argument type expansion of overload call evaluation.

The issue is that the expansion of the variadic argument could result in
argument list of different arity. For example, in `*args: tuple[int] |
tuple[int, str]`, the expansion would lead to the variadic argument
being unpacked into 1 and 2 element respectively. This means that the
parameter matching that was performed initially isn't sufficient and
each expanded argument list would need to redo the parameter matching
again.

This is currently done by redoing the parameter matching directly,
maintaining the state of argument forms (and the conflicting forms), and
updating the `Bindings` values if it changes.

Closes: astral-sh/ty#735

## Test Plan

Update existing mdtest.
2025-09-12 08:40:07 +00:00
Douglas Creager 1cd8ab3f26
[ty] Remove the `Constraints` trait (#20355)
This PR removes the `Constraints` trait. We removed the `bool`
implementation several weeks back, and are using `ConstraintSet`
everywhere. There have been discussions about trying to include the
reason for an assignability failure as part of the result, but that
there are no concrete plans to do so soon, and it's not clear that we'll
need the `Constraints` trait to do that. (We can ideally just update the
`ConstraintSet` type directly.)

In the meantime, this just complicates the code for no good reason.

This PR is a pure refactoring, and contains no behavioral changes.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-09-11 20:55:28 -04:00
Ibraheem Ahmed 36888198a6
[ty] Integrate type context for bidirectional inference (#20337)
## Summary

Adds the infrastructure necessary to perform bidirectional type
inference (https://github.com/astral-sh/ty/issues/168) without any
typing changes.
2025-09-11 15:19:12 -04:00
Carl Meyer c4cd5c00fd
[ty] guard against recursion in determining completion kind (#20354)
## Summary

Fixes https://github.com/astral-sh/ty/issues/1158

## Test Plan

Added test.
2025-09-11 11:25:06 -07:00
Douglas Creager abb705aa4e
[ty] Add dedicated variant for `NominalInstance(object)` (#20340)
Previously, `Type::object` would find the definition of the `object`
class in typeshed, load that in (to produce a `ClassLiteral` and
`ClassType`), and then create a `NominalInstance` of that class.

It's possible that we are using a typeshed that doesn't define `object`.
We will not be able to do much useful work with that kind of typeshed,
but it's still a possibility that we have to support at least without
panicking. Previously, we would handle this situation by falling back on
`Unknown`.

In most cases, that's a perfectly fine fallback! But `object` is also
our top type — the type of all values. `Unknown` is _not_ an acceptable
stand-in for the top type.

This PR adds a new `NominalInstance` variant for "instances of
`object`". Unlike other nominal instances, we do not need to load in
`object`'s `ClassType` to instantiate this variant. We will use this new
variant even when the current typeshed does not define an `object`
class, ensuring that we have a fully static representation of our top
type at all times.

There are several operations that need access to a nominal instance's
class, and for this new `object` variant we load it lazily only when
it's needed. That means this operation is now fallible, since this is
where the "typeshed doesn't define `object`" failure shows up.

This new approach also has the benefit of avoiding some salsa cycles
that were cropping up while I was debugging #20093, since the new
constraint set representation was trying to instantiate `Type::object`
while in the middle of processing its definition in typeshed. Cycle
handling was kicking in correctly and returning the `Unknown` fallback
mentioned above. But the constraint set implementation depends on
`Type::object` being a distinct and fully static type, highlighting that
this is a correctness fix, not just an optimization fix.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-09-11 13:02:58 -04:00
Alex Waygood 0e3697a643
[ty] Minor fixes to `Protocol` tests (#20347) 2025-09-11 14:42:13 +00:00
Carl Meyer ffd4340dce
[ty] use Type::Divergent to avoid panic in infinitely-nested-tuple implicit attribute (#20333)
## Summary

Use `Type::Divergent` to avoid "too many iterations" panic on an
infinitely-nested tuple in an implicit instance attribute.

The regression here is from checking all tuple elements to see if they
contain a Divergent type. It's 5% on one project, 1% on another, and
zero on the rest. I spent some time looking into eliminating this
regression by tracking a flag on inference results to note if they could
possibly contain any Divergent type, but this doesn't really work --
there are too many different ways a type containing a Divergent type
could enter an inference result. Still thinking about whether there are
other ways to reduce this. One option is if we see certain kinds of
non-atomic types that are commonly expensive to check for Divergent, we
could make `has_divergent_type` a Salsa query on those types.

## Test Plan

Added mdtest.

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-09-11 06:51:22 -07:00
Alex Waygood 89f17467ef
[ty] Require that implementors of `Constraints` also implement `Debug` (#20348)
The debug representation isn't as useful as calling `.display(db)`, but
it's still kind-of annoying when `dbg!()` calls don't compile locally
due to the compiler not being able to guarantee that an object of type
`impl Constraints` implements `Debug`
2025-09-11 14:34:40 +01:00
David Peter 59c8fda3f8
[ty] Fix CallableTypeOf[…] for classmethods (#20345)
## Summary

See https://github.com/astral-sh/ruff/pull/20338#discussion_r2337731998

## Test Plan

Regression test.
2025-09-11 10:14:38 +02:00
Carl Meyer c6b92b918e
[ty] split up `types/infer.rs` (#20342) 2025-09-10 19:25:07 -07:00
David Peter cde5e4e343
[ty] Fix `CallableTypeOf[…]` for bound methods (#20338)
## Summary

`CallableTypeOf[bound_method]` would previously bind `self` to the
bound method type itself, instead of binding it to the instance type
stored inside the bound method type.

## Test Plan

Added regression test
2025-09-10 21:13:23 +02:00
Alex Waygood 8a0edf0da8
[ty] Ensure various special-cased builtin functions are understood as assignable to `Callable` (#20331) 2025-09-10 19:03:33 +00:00
Alex Waygood d23cae870e
[ty] Ensure various special-cased bound methods are understood as assignable to `Callable` (#20330) 2025-09-10 19:58:54 +01:00
Douglas Creager 2ac4147435
[ty] Add mdtests that exercise constraint sets (#20319)
This PR adds a new `ty_extensions.ConstraintSet` class, which is used to
expose constraint sets to our mdtest framework. This lets us write a
large collection of unit tests that exercise the invariants and rewrite
rules of our constraint set implementation.

As part of this, `is_assignable_to` and friends are updated to return a
`ConstraintSet` instead of a `bool`, and we implement
`ConstraintSet.__bool__` to return when a constraint set is always
satisfied. That lets us still use
`static_assert(is_assignable_to(...))`, since the assertion will coerce
the constraint set to a bool, and also lets us
`reveal_type(is_assignable_to(...))` to see more detail about
whether/when the two types are assignable. That lets us get rid of
`reveal_when_assignable_to` and friends, since they are now redundant
with the expanded capabilities of `is_assignable_to`.
2025-09-10 13:22:19 -04:00
Alex Waygood ffead90410
[ty] Add more tests for special-cased builtin functions and methods (#20329) 2025-09-10 18:08:32 +01:00
Shunsuke Shibayama 8770b95509
[ty] introduce `DivergentType` (#20312)
## Summary

From #17371

In #17371, `DivergentType` was introduced to prevent type inference for
recursive functions from diverging and causing panics. This turned out
to be useful for other divergent type inferences
(https://github.com/astral-sh/ruff/pull/17371#discussion_r2329337965),
so I extracted the introduction part of `DivergentType` into this PR so
that we can use it without waiting for the merge of #17371.

Note that this PR only introduces `DivergentType` and does not actually
address divergent type inference yet. Please refer to
https://github.com/astral-sh/ruff/pull/17371/files#diff-20b910c6e20faa962bb1642e111db1cbad8e66ace089bdd966ac9d7f9fa99ff2R542-R622
etc. when implementing handling of divergence suppression using this
type.

## Test Plan

---------

Co-authored-by: Carl Meyer <carl@oddbird.net>
2025-09-10 08:32:26 -07:00
David Peter 65982a1e14
[ty] Use 'unknown' specialization for upper bound on Self (#20325)
## Summary

closes https://github.com/astral-sh/ty/issues/1156

## Test Plan

Added a regression test
2025-09-10 17:00:28 +02:00
David Peter 57d1f7132d
[ty] Simplify unions of enum literals and subtypes thereof (#20324)
## Summary

When adding an enum literal `E = Literal[Color.RED]` to a union which
already contained a subtype of that enum literal(!), we were previously
not simplifying the union correctly. My assumption is that our property
tests didn't catch that earlier, because the only possible non-trivial
subytpe of an enum literal that I can think of is `Any & E`. And in
order for that to be detected by the property tests, it would have to
randomly generate `Any & E | E` and then also compare that with `E` on
the other side (in an equivalence test, or the subtyping-antisymmetry
test).

closes https://github.com/astral-sh/ty/issues/1155

## Test Plan

* Added a regression test.
* I also ran the property tests for a while, but probably not for two
months worth of daily CI runs.
2025-09-10 15:54:06 +02:00
David Peter 2b51ec6531
[ty] Improve specialization-error diagnostics (#20326)
## Summary

Add information about the upper bound or the constraints of the type
variable to the `SpecializationError` diagnostics.
2025-09-10 14:01:23 +02:00
Alex Waygood b85c995927
[ty] `"foo".startswith` is not an instance of `types.MethodWrapperType` (#20317) 2025-09-10 11:14:26 +00:00
Alex Waygood fd7eb1e22f
[ty] Allow protocols to participate in nominal subtyping as well as structural subtyping (#20314) 2025-09-10 11:05:50 +00:00
Alex Waygood 4de7d653bd
[ty] Treat `Hashable`, and similar protocols, equivalently to `object` for subtyping/assignability (#20284) 2025-09-10 11:38:58 +01:00
Douglas Creager ed06fb5ce2
[ty] Use partial-order-friendly representation of typevar constraints (#20306)
The constraint representation that we added in #19997 was subtly wrong,
in that it didn't correctly model that type assignability is a _partial_
order — it's possible for two types to be incomparable, with neither a
subtype of the other. That means the negation of a constraint like `T ≤
t` (typevar `T` must be a subtype of `t`) is **_not_** `t < T`, but
rather `t < T ∨ T ≁ t` (using ≁ to mean "not comparable to").

That means we need to update our constraint representation to be an
enum, so that we can track both _range_ constraints (upper/lower bound
on the typevar), and these new _incomparable_ constraints.

Since we need an enum now, that also lets us simplify how we were
modeling range constraints. Before, we let the lower/upper bounds be
either open (<) or closed (≤). Now, range constraints are always closed,
and we add a third kind of constraint for _not equivalent_ (≠). We can
translate an open upper bound `T < t` into `T ≤ t ∧ T ≠ t`.

We already had the logic for doing adding _clauses_ to a _set_ by doing
a pairwise simplification. We copy that over to where we add
_constraints_ to a _clause_. To calculate the intersection or union of
two constraints, the new enum representation makes it easy to break down
all of the possibilities into a small number of cases: intersect range
with range, intersect range with not-equivalent, etc. I've done the math
[here](https://dcreager.net/theory/constraints/) to show that the
simplifications for each of these cases is correct.
2025-09-09 15:54:47 -04:00
Alex Waygood bf66178959
[ty] Add tests for protocols with generic method members (#20316) 2025-09-09 16:44:00 +00:00
Renkai Ge 61f906d8e7
[ty] equality narrowing on enums that don't override `__eq__` or `__ne__` (#20285)
Add equality narrowing for enums, if they don't override `__eq__` or `__ne__` in an unsafe way.

Follow-up to PR https://github.com/astral-sh/ruff/pull/20164

Fixes https://github.com/astral-sh/ty/issues/939
2025-09-08 16:56:28 -07:00
Shunsuke Shibayama 08a561fc05
[ty] more precise lazy scope place lookup (#19932)
## Summary

This is a follow-up to https://github.com/astral-sh/ruff/pull/19321.

Now lazy snapshots are updated to take into account new bindings on
every symbol reassignment.

```python
def outer(x: A | None):
    if x is None:
        x = A()

    reveal_type(x)  # revealed: A

    def inner() -> None:
        # lazy snapshot: {x: A}
        reveal_type(x)  # revealed: A
    inner()

def outer() -> None:
    x = None

    x = 1

    def inner() -> None:
        # lazy snapshot: {x: Literal[1]} -> {x: Literal[1, 2]}
        reveal_type(x)  # revealed: Literal[1, 2]
    inner()

    x = 2
```

Closes astral-sh/ty#559.

## Test Plan

Some TODOs in `public_types.md` now work properly.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-09-08 21:08:35 +00:00
Ibraheem Ahmed aa5d665d52
[ty] Add support for generic PEP695 type aliases (#20219)
## Summary

Adds support for generic PEP695 type aliases, e.g.,
```python
type A[T] = T
reveal_type(A[int]) # A[int]
```

Resolves https://github.com/astral-sh/ty/issues/677.
2025-09-08 13:26:21 -07:00
David Peter d55edb3d74
[ty] Support "legacy" `typing.Self` in combination with PEP 695 generic contexts (#20304)
## Summary

Support cases like the following, where we need the generic context to
include both `Self` and `T` (not just `T`):

```py
from typing import Self

class C:
    def method[T](self: Self, arg: T): ...

C().method(1)
```

closes https://github.com/astral-sh/ty/issues/1131

## Test Plan

Added regression test
2025-09-08 16:57:09 +02:00
Alex Waygood deb3d3d150
[ty] Fall back to `object` for attribute access on synthesized protocols (#20286) 2025-09-08 13:04:37 +01:00
justin 08fcf7e106
[ty] initial support for `slots=True` in dataclasses (#20278) 2025-09-07 18:25:35 +01:00
Carl Meyer 2467c4352e
[ty] propagate visitors and constraints through has_relation_in_invariant_position (#20259)
## Summary

The sub-checks for assignability and subtyping of materializations
performed in `has_relation_in_invariant_position` and
`is_subtype_in_invariant_position` need to propagate the
`HasRelationToVisitor`, or we can stack overflow.

A side effect of this change is that we also propagate the
`ConstraintSet` through, rather than using `C::from_bool`, which I think
may also become important for correctness in cases involving type
variables (though it isn't testable yet, since we aren't yet actually
creating constraints other than always-true and always-false.)

## Test Plan

Added mdtest (derived from code found in pydantic) which
stack-overflowed before this PR.

With this change incorporated, pydantic now checks successfully on my
draft PR for PEP 613 TypeAlias support.
2025-09-06 00:17:17 +00:00
Alex Waygood 5d52902e18
[ty] Implement the legacy PEP-484 convention for indicating positional-only parameters (#20248)
Co-authored-by: Carl Meyer <carl@astral.sh>
2025-09-05 17:56:06 +01:00
Eric Mark Martin eb6154f792
[ty] add doc-comments for some variance stuff (#20189) 2025-09-05 15:03:10 +01:00
David Peter fdfb51b595
[ty] Update mypy_primer, add egglog-python project (#20078)
Now that https://github.com/astral-sh/ruff/pull/20263 is merged, we can
update mypy_primer and add the new `egglog-python` project to
`good.txt`. The ecosystem-analyzer run shows that we now add 1,356
diagnostics (where we had over 5,000 previously, due to the unsupported
project layout).
2025-09-05 14:17:07 +02:00
David Peter 8ade6c4eaf
[ty] Add backreferences to TypedDict items in diagnostics (#20262)
## Summary

Add backreferences to the original item declaration in TypedDict
diagnostics.

Thanks to @AlexWaygood for the suggestion.

## Test Plan

Updated snapshots
2025-09-05 12:38:37 +02:00
David Peter 9e45bfa9fd
[ty] Cover full range of annotated assignments (#20261)
## Summary

An annotated assignment `name: annotation` without a right-hand side was
previously not covered by the range returned from
`DefinitionKind::full_range`, because we did expand the range to include
the right-hand side (if there was one), but failed to include the
annotation.

## Test Plan

Updated snapshot tests
2025-09-05 10:12:40 +02:00
David Peter 7509d376eb
[ty] Minor: 'can not' => cannot (#20260) 2025-09-05 09:19:14 +02:00
David Peter a24a4b55ee
[ty] TypedDict: Add support for `typing.ReadOnly` (#20241)
## Summary

Add support for `typing.ReadOnly` as a type qualifier to mark
`TypedDict` fields as being read-only. If you try to mutate them, you
get a new diagnostic:

<img width="787" height="234" alt="image"
src="https://github.com/user-attachments/assets/f62fddf9-4961-4bcd-ad1c-747043ebe5ff"
/>


## Test Plan

* New Markdown tests
* The typing conformance changes are all correct. There are some false
negatives, but those are related to the missing support for the
functional form of `TypedDict`, or to overriding of fields via
inheritance. Both of these topics are tracked in
https://github.com/astral-sh/ty/issues/154
2025-09-04 15:37:42 -07:00
Alex Waygood 888a22e849
[ty] Reduce false positives for `ParamSpec`s and `TypeVarTuple`s (#20239) 2025-09-04 23:34:37 +01:00
Jelle Zijlstra 08c1d3660c
[ty] Narrow specialized generics using isinstance() (#20256)
Closes astral-sh/ty#456. Part of astral-sh/ty#994.

After all the foundational work, this is only a small change, but let's
see if it exposes any unresolved issues.
2025-09-04 15:28:33 -07:00
Jelle Zijlstra de63f408b9
[ty] Attribute access on top/bottom materializations (#20221)
## Summary

Part of astral-sh/ty#994. The goal of this PR was to add correct
behavior for attribute access on the top and bottom materializations.
This is necessary for the end goal of using the top materialization for
narrowing generics (`isinstance(x, list)`): we want methods like
`x.append` to work correctly in that case.

It turned out to be convenient to represent materialization as a
TypeMapping, so it can be stashed in the `type_mappings` list of a
function object. This also allowed me to remove most concrete
`materialize` methods, since they usually just delegate to the subparts
of the type, the same as other type mappings. That is why the net effect
of this PR is to remove a few hundred lines.

## Test Plan

I added a few more tests. Much of this PR is refactoring and covered by
existing tests.

## Followups

Assigning to attributes of top materializations is not yet covered. This
seems less important so I'd like to defer it.

I noticed that the `materialize` implementation of `Parameters` was
wrong; it did the same for the top and bottom materializations. This PR
makes the bottom materialization slightly more reasonable, but
implementing this correctly will require extending the struct.
2025-09-04 12:01:44 -07:00
Alex Waygood 555b9f78d6
[ty] Minor cleanups (#20240)
## Summary

Two minor cleanups:
- Return `Option<ClassType>` rather than `Option<ClassLiteral>` from
`TypeInferenceBuilder::class_context_of_current_method`. Now that
`ClassType::is_protocol` exists as a method as well as
`ClassLiteral::is_protocol`, this simplifies most of the call-sites of
the `class_context_of_current_method()` method.
- Make more use of the `MethodDecorator::try_from_fn_type` method in
`class.rs`. Under the hood, this method uses the new methods
`FunctionType::is_classmethod()` and `FunctionType::is_staticmethod()`
that @sharkdp recently added, so it gets the semantics more precisely
correct than the code it's replacing in `infer.rs` (by accounting for
implicit staticmethods/classmethods as well as explicit ones). By using
these methods we can delete some code elsewhere (the
`FunctionDecorators::from_decorator_types()` constructor)

## Test Plan

Existing tests
2025-09-04 10:25:49 -07:00
David Peter 1aaa0847ab
[ty] More tests for TypedDict (#20205)
## Summary

A small set of additional tests for `TypedDict` that I wrote while going
through the spec. Note that this certainly doesn't make the test suite
exhaustive (see remaining open points in the updated list here:
https://github.com/astral-sh/ty/issues/154).
2025-09-04 15:55:42 +00:00
Samuel Rigaud 1e34f3f20a
[ty] Fix small test typo (#20220)
Small typo in the comment of a test

Co-authored-by: Samuel Rigaud <rigaud@gmail.com>
2025-09-03 15:24:17 -07:00
Douglas Creager 77b2cee223
[ty] Add functions for revealing assignability/subtyping constraints (#20217)
This PR adds two new `ty_extensions` functions,
`reveal_when_assignable_to` and `reveal_when_subtype_of`. These are
closely related to the existing `is_assignable_to` and `is_subtype_of`,
but instead of returning when the property (always) holds, it produces a
diagnostic that describes _when_ the property holds. (This will let us
construct mdtests that print out constraints that are not always true or
always false — though we don't currently have any instances of those.)

I did not replace _every_ occurrence of the `is_property` variants in
the mdtest suite, instead focusing on the generics-related tests where
it will be important to see the full detail of the constraint sets.

As part of this, I also updated the mdtest harness to accept the shorter
`# revealed:` assertion format for more than just `reveal_type`, and
updated the existing uses of `reveal_protocol_interface` to take
advantage of this.
2025-09-03 16:44:35 -04:00
David Peter 0d4f7dde99
[ty] Treat `__new__` as a static method (#20212)
## Summary

Pull this out of https://github.com/astral-sh/ruff/pull/18473 as an
isolated change to make sure it has no adverse effects.

The wrong behavior is observable on `main` for something like
```py
class C:
    def __new__(cls) -> "C":
        cls.x = 1

C.x  # previously: Attribute `x` can only be accessed on instances
     # now:        Type `<class 'C'>` has no attribute `x`
```
where we currently treat `x` as an *instance* attribute (because we
consider `__new__` to be a normal function and `cls` to be the "self"
attribute). With this PR, we do not consider `x` to be an attribute,
neither on the class nor on instances of `C`. If this turns out to be an
important feature, we should add it intentionally, instead of
accidentally.

## Test Plan

Ecosystem checks.
2025-09-03 19:55:20 +02:00
Renkai Ge cda376afe0
[ty]eliminate definitely-impossible types from union in equality narrowing (#20164)
solves https://github.com/astral-sh/ty/issues/939

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-09-03 08:34:22 -07:00
Bhuminjay Soni 4c3e1930f6
[syntax-errors] Detect `yield from` inside async function (#20051)
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## Summary

This PR implements
https://docs.astral.sh/ruff/rules/yield-from-in-async-function/ as a
syntax semantic error

## Test Plan

<!-- How was it tested? -->
I have written a simple inline test as directed in
[https://github.com/astral-sh/ruff/issues/17412](https://github.com/astral-sh/ruff/issues/17412)

---------

Signed-off-by: 11happy <soni5happy@gmail.com>
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
2025-09-03 10:13:05 -04:00
Andrew Gallant 8e52027a88 [ty] Add naive implementation of completions for unimported symbols
This re-works the `all_symbols` based added previously to work across
all modules available, and not just what is directly in the workspace.

Note that we always pass an empty string as a query, which makes the
results always empty. We'll fix this in a subsequent commit.
2025-09-03 09:57:26 -04:00
Andrew Gallant 046893c186 [ty] Make `Module::all_submodules` return `Module` instead of `Name`
This is to facilitate recursive traversal of all modules in an
environment. This way, we can keep asking for submodules.

This also simplifies how this is used in completions, and probably makes
it faster. Namely, since we return the `Module` itself, callers don't
need to invoke the full module resolver just to get the module type.

Note that this doesn't include namespace packages. (Which were
previously not supported in `Module::all_submodules`.) Given how they
can be spread out across multiple search paths, they will likely require
special consideration here.
2025-09-03 09:57:26 -04:00
Andrew Gallant 9cea752934 [ty] Require that we can find a root when listing sub-modules
This is similar to a change made in the "list top-level modules"
implementation that had been masked by poor Salsa failure modes.
Basically, if we can't find a root here, it *must* be a bug. And if we
just silently skip over it, we risk voiding Salsa's purity contract,
leading to more difficult to debug panics.

This did cause one test to fail, but only because the test wasn't
properly setting up roots.
2025-09-03 09:57:26 -04:00
David Peter bbfcf6e111
[ty] `__class_getitem__` is a classmethod (#20192)
## Summary

`__class_getitem__` is [implicitly a
classmethod](https://docs.python.org/3/reference/datamodel.html#object.__class_getitem__).

## Test Plan

Added regression test.
2025-09-01 11:22:19 +02:00
David Peter 5518c84ab3
[ty] Support `__init_subclass__` (#20190)
## Summary

`__init_subclass__` is implicitly a classmethod.

closes https://github.com/astral-sh/ty/issues/1106

## Test Plan

Regression test
2025-09-01 10:16:28 +02:00
Carl Meyer 6f2b874d6c
[ty] improve cycle-detection coverage for apply_type_mapping (#20159)
## Summary

Thread visitors through the rest of `apply_type_mapping`: callable and
protocol types.

## Test Plan

Added mdtest that previously stack overflowed.
2025-08-29 16:20:07 -07:00
Carl Meyer 17dc2e4d80
[ty] don't assume that deferred type inference means deferred name resolution (#20160)
## Summary

We have the ability to defer type inference of some parts of
definitions, so as to allow us to create a type that may need to be
recursively referenced in those other parts of the definition.

We also have the ability to do type inference in a context where all
name resolution should be deferred (that is, names should be looked up
from all-reachable-definitions rather than from the location of use.)
This is used for all annotations in stubs, or if `from __future__ import
annotations` is active.

Previous to this PR, these two concepts were linked: deferred-inference
always implied deferred-name-resolution, though we also supported
deferred-name-resolution without deferred-inference, via
`DeferredExpressionState`.

For the upcoming `typing.TypeAlias` support, I will defer inference of
the entire RHS of the alias (so as to support cycles), but that doesn't
imply deferred name resolution; at runtime, the RHS of a name annotated
as `typing.TypeAlias` is executed eagerly.

So this PR fully de-couples the two concepts, instead explicitly setting
the `DeferredExpressionState` in those cases where we should defer name
resolution.

It also fixes a long-standing related bug, where we were deferring name
resolution of all names in class bases, if any of the class bases
contained a stringified annotation.

## Test Plan

Added test that failed before this PR.
2025-08-29 16:19:45 -07:00
Carl Meyer fe953e5c5c
[ty] skip a slow seed in fuzzer (#20161)
## Summary

Fuzzer seed 208 seems to be timing out all fuzzer runs on PRs today.
This has happened on multiple unrelated PRs, as well as on an initial
version of this PR that made a comment-only change in ty and didn't skip
any seeds, so the timeout appears to be consistent in CI, on ty main
branch, as of today, but it started happening due to some change in a
factor outside ty; not sure what.

I checked the code generated for seed 208 locally, and it takes about
30s to check on current ty main branch. This is slow for a fuzzer seed,
but shouldn't be slow enough to make it time out after 20min in CI (even
accounting for GH runners being slower than my laptop.)

I tried to bisect the slowness of checking that code locally, but I
didn't go back far enough to find the change that made it slow. In fact
it seems like it became significantly faster in the last few days (on an
older checkout I had to stop it after several minutes.) So whatever the
cause of the slowness, it's not a recent change in ty.

I don't want to rabbit-hole on this right now (fuzzer-discovered issues
are lower-priority than real-world-code issues), and need a working CI,
so skip this seed for now until we can investigate it.

## Test Plan

CI. This PR contains a no-op (comment) change in ty, so that the fuzz
test is triggered in CI and we can verify it now works (as well as
verify, on the previous commit, that the fuzzer job is timing out on
that seed, even with just a no-op change in ty.)
2025-08-29 13:59:16 -07:00
Alex Waygood 0bf5d2a204
Revert "[ty] Use `invalid-assignment` error code for invalid assignments to `ClassVar`s" (#20158)
Reverts astral-sh/ruff#20156. As @sharkdp noted in his post-merge
review, there were several issues with that PR that I didn't spot before
merging — but I'm out for four days now, and would rather not leave
things in an inconsistent state for that long. I'll revisit this on
Wednesday.
2025-08-29 19:48:45 +01:00
Carl Meyer 8eb8d25565
[ty] add six ecosystem projects to good.txt (#20157)
## Summary

These projects all check successfully now.

(Pandas still takes 9s, as the comment in `bad.txt` said, but I don't
think this is slow enough to exclude it; mypy-primer overall still runs
in 4 minutes, faster than e.g. the test suite on Windows.)

## Test Plan

mypy-primer CI.
2025-08-29 11:37:29 -07:00
Alex Waygood 9b1b58a451
[ty] Use `invalid-assignment` error code for invalid assignments to `ClassVar`s (#20156)
## Summary

This error is about assigning to attributes rather than reading
attributes, so I think `invalid-assignment` makes more sense than
`invalid-attribute-access`

## Test Plan

existing mdtests updated
2025-08-29 18:43:30 +01:00
Carl Meyer fa7798ddd9
[ty] minor TypedDict fixes (#20146)
## Summary

In `is_disjoint_from_impl`, we should unpack type aliases before we
check `TypedDict`. This change probably doesn't have any visible effect
until we have a more discriminating implementation of disjointness for
`TypedDict`, but making the change now can avoid some confusion/bugs in
future.

In `type_ordering.rs`, we should order `TypedDict` near more similar
types, and leave Union/Intersection together at the end of the list.
This is not necessary for correctness, but it's more consistent and it
could have saved me some confusion trying to figure out why I was only
getting an unreachable panic when my code example included a `TypedDict`
type.

## Test Plan

None besides existing tests.
2025-08-29 09:46:48 -07:00
Carl Meyer 8223fea062
[ty] ensure union normalization really normalizes (#20147)
## Summary

Now that we have `Type::TypeAlias`, which can wrap a union, and the
possibility of unions including non-unpacked type aliases (which is
necessary to support recursive type aliases), we can no longer assume in
`UnionType::normalized_impl` that normalizing each element of an
existing union will result in a set of elements that we can order and
then place raw into `UnionType` to create a normalized union. It's now
possible for those elements to themselves include union types (unpacked
from an alias). So instead, we need to feed those elements into the full
`UnionBuilder` (with alias-unpacking turned on) to flatten/normalize
them, and then order them.

## Test Plan

Added mdtest.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-08-29 09:02:35 -07:00
Eric Jolibois 5a608f7366
[ty] typecheck dict methods for `TypedDict` (#19874)
## Summary

Typecheck `get()`, `setdefault()`, `pop()` for `TypedDict`

```py
from typing import TypedDict
from typing_extensions import NotRequired

class Employee(TypedDict):
    name: str
    department: NotRequired[str]

emp = Employee(name="Alice", department="Engineering")

emp.get("name")
emp.get("departmen", "Unknown")
emp.pop("department")
emp.pop("name")
```

<img width="838" height="529" alt="Screenshot 2025-08-12 at 11 42 12"
src="https://github.com/user-attachments/assets/77ce150a-223c-4931-b914-551095d8a3a6"
/>


part of https://github.com/astral-sh/ty/issues/154

## Test Plan

Updated Markdown tests

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-08-29 16:25:03 +02:00
Alex Waygood f77315776c
[ty] Better error message for attempting to assign to a read-only property (#20150) 2025-08-29 13:22:23 +00:00
Alex Waygood 04dc223710
[ty] Improve disambiguation of types via fully qualified names (#20141) 2025-08-29 08:44:18 +00:00
Alex Waygood 0d7ed32494
[ty] Enforce that an attribute on a class `X` must be callable in order to satisfy a member on a protocol `P` (#20142)
## Summary

Small, incremental progress towards checking the types of method
members.

## Test Plan

Added an mdtest
2025-08-29 08:31:26 +01:00
Dhruv Manilawala 4ca38b2974
[ty] Unpack variadic argument type in specialization (#20130)
## Summary

This PR fixes various TODOs around overload call when a variadic
argument is used.

The reason this bug existed is because the specialization wouldn't
account for unpacking the type of the variadic argument.

This is fixed by expanding `MatchedArgument` to contain the type of that
argument _only_ when it is a variadic argument. The reason is that
there's a split for when the argument type is inferred -- the
non-variadic arguments are inferred using `infer_argument_types` _after_
parameter matching while the variadic argument type is inferred _during_
the parameter matching. And, the `MatchedArgument` is populated _during_
parameter matching which means the unpacking would need to happen during
parameter matching.

This split seems a bit inconsistent but I don't want to spend a lot of
time on trying to merge them such that all argument type inference
happens in a single place. I might look into it while adding support for
`**kwargs`.

## Test Plan

Update existing tests by resolving the todos.

The ecosystem changes looks correct to me except for the `slice` call
but it seems that it's unrelated to this PR as we infer `slice[Any, Any,
Any]` for a `slice(1, 2, 3)` call on `main` as well
([playground](https://play.ty.dev/9eacce00-c7d5-4dd5-a932-4265cb2bb4f6)).
2025-08-29 04:27:28 +00:00
Douglas Creager a8039f80f0
[ty] Add constraint set implementation (#19997)
This PR adds an implementation of constraint sets.

An individual constraint restricts the specialization of a single
typevar to be within a particular lower and upper bound: the typevar can
only specialize to types that are a supertype of the lower bound, and a
subtype of the upper bound. (Note that lower and upper bounds are fully
static; we take the bottom and top materializations of the bounds to
remove any gradual forms if needed.) Either bound can be “closed” (where
the bound is a valid specialization), or “open” (where it is not).

You can then build up more complex constraint sets using union,
intersection, and negation operations. We use a disjunctive normal form
(DNF) representation, just like we do for types: a _constraint set_ is
the union of zero or more _clauses_, each of which is the intersection
of zero or more individual constraints. Note that the constraint set
that contains no clauses is never satisfiable (`⋃ {} = 0`); and the
constraint set that contains a single clause, which contains no
constraints, is always satisfiable (`⋃ {⋂ {}} = 1`).

One thing to note is that this PR does not change the logic of the
actual assignability checks, and in particular, we still aren't ever
trying to create an "individual constraint" that constrains a typevar.
Technically we're still operating only on `bool`s, since we only ever
instantiate `C::always_satisfiable` (i.e., `true`) and
`C::unsatisfiable` (i.e., `false`) in the `has_relation_to` methods. So
if you thought that #19838 introduced an unnecessarily complex stand-in
for `bool`, well here you go, this one is worse! (But still seemingly
not yielding a performance regression!) The next PR in this series,
#20093, is where we will actually create some non-trivial constraint
sets and use them in anger.

That said, the PR does go ahead and update the assignability checks to
use the new `ConstraintSet` type instead of `bool`. That part is fairly
straightforward since we had already updated the assignability checks to
use the `Constraints` trait; we just have to actively choose a different
impl type. (For the `is_whatever` variants, which still return a `bool`,
we have to convert the constraint set, but the explicit
`is_always_satisfiable` calls serve as nice documentation of our
intent.)

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
2025-08-28 20:04:29 -04:00
Jelle Zijlstra 3927b0c931
[ty] Simplify materialization of specialized generics (#20121)
This is a variant of #20076 that moves some complexity out of
`apply_type_mapping_impl` in `generics.rs`. The tradeoff is that now
every place that applies `TypeMapping::Specialization` must take care to
call `.materialize()` afterwards. (A previous version of this didn't
work because I had missed a spot where I had to call `.materialize()`.)

@carljm as asked in
https://github.com/astral-sh/ruff/pull/20076#discussion_r2305385298 .
2025-08-28 11:35:00 -07:00
Carl Meyer 9363eeca26
[ty] add support for cyclic legacy generic protocols (#20125)
## Summary

Just add the necessary Salsa cycle handling.

## Test Plan

Added mdtest.
2025-08-28 16:58:01 +00:00
Carl Meyer f4362b95d7
[ty] add cycle detection for find_legacy_typevars (#20124)
## Summary

Add cycle detection to the `find_legacy_typevars` type method.

## Test Plan

Added mdtest that stack overflowed without this.
2025-08-28 09:55:08 -07:00