Commit Graph

738 Commits

Author SHA1 Message Date
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)
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) 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)
`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
Alex Waygood 6de84ed56e
Add `else`-branch narrowing for `if type(a) is A` when `A` is `@final` (#19925) 2025-08-15 14:52:30 +01:00
github-actions[bot] bd4506aac5
[ty] Sync vendored typeshed stubs (#19923)
Close and reopen this PR to trigger CI

---------

Co-authored-by: typeshedbot <>
Co-authored-by: Carl Meyer <carl@astral.sh>
2025-08-14 18:09:35 -07:00
Shunsuke Shibayama 0e5577ab56
[ty] fix lazy snapshot sweeping in nested scopes (#19908)
## Summary

This PR closes astral-sh/ty#955.

## Test Plan

New test cases in `narrowing/conditionals/nested.md`.
2025-08-14 17:52:52 -07:00
Andrii Turov 957320c0f1
[ty] Add diagnostics for invalid `await` expressions (#19711)
## Summary

This PR adds a new lint, `invalid-await`, for all sorts of reasons why
an object may not be `await`able, as discussed in astral-sh/ty#919.
Precisely, `__await__` is guarded against being missing, possibly
unbound, or improperly defined (expects additional arguments or doesn't
return an iterator).

Of course, diagnostics need to be fine-tuned. If `__await__` cannot be
called with no extra arguments, it indicates an error (or a quirk?) in
the method signature, not at the call site. Without any doubt, such an
object is not `Awaitable`, but I feel like talking about arguments for
an *implicit* call is a bit leaky.
I didn't reference any actual diagnostic messages in the lint
definition, because I want to hear feedback first.

Also, there's no mention of the actual required method signature for
`__await__` anywhere in the docs. The only reference I had is the
`typing` stub. I basically ended up linking `[Awaitable]` to ["must
implement
`__await__`"](https://docs.python.org/3/library/collections.abc.html#collections.abc.Awaitable),
which is insufficient on its own.

## Test Plan

The following code was tested:
```python
import asyncio
import typing


class Awaitable:
    def __await__(self) -> typing.Generator[typing.Any, None, int]:
        yield None
        return 5


class NoDunderMethod:
    pass


class InvalidAwaitArgs:
    def __await__(self, value: int) -> int:
        return value


class InvalidAwaitReturn:
    def __await__(self) -> int:
        return 5


class InvalidAwaitReturnImplicit:
    def __await__(self):
        pass


async def main() -> None:
    result = await Awaitable()  # valid
    result = await NoDunderMethod()  # `__await__` is missing
    result = await InvalidAwaitReturn()  # `__await__` returns `int`, which is not a valid iterator 
    result = await InvalidAwaitArgs()  # `__await__` expects additional arguments and cannot be called implicitly
    result = await InvalidAwaitReturnImplicit()  # `__await__` returns `Unknown`, which is not a valid iterator


asyncio.run(main())
```

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-08-14 14:38:33 -07:00
Alex Waygood f6093452ed
[ty] Synthesize read-only properties for all declared members on `NamedTuple` classes (#19899) 2025-08-14 21:25:45 +00:00
Alex Waygood 82350a398e
[ty] Remove use of `ClassBase::try_from_type` from `super()` machinery (#19902) 2025-08-14 22:14:31 +01:00
justin dc2e8ab377
[ty] support `kw_only=True` for `dataclass()` and `field()` (#19677)
## Summary
https://github.com/astral-sh/ty/issues/111

adds support for `@dataclass(kw_only=True)`
(https://docs.python.org/3/library/dataclasses.html)

## Test Plan
- new mdtests
- triaged conformance diffs (notes here:
https://diffswarm.dev/d-01k2gknwyq82f6x17zqf3apjxc)
- `mypy_primer` no-op
2025-08-14 08:02:55 -07:00
Alex Waygood 3288ac2dfb
[ty] Add caching to `CodeGeneratorKind::matches()` (#19912) 2025-08-14 11:54:11 +01:00
Carl Meyer 5a570c8e6d
[ty] fix deferred name loading in PEP695 generic classes/functions (#19888)
## Summary

For PEP 695 generic functions and classes, there is an extra "type
params scope" (a child of the outer scope, and wrapping the body scope)
in which the type parameters are defined; class bases and function
parameter/return annotations are resolved in that type-params scope.

This PR fixes some longstanding bugs in how we resolve name loads from
inside these PEP 695 type parameter scopes, and also defers type
inference of PEP 695 typevar bounds/constraints/default, so we can
handle cycles without panicking.

We were previously treating these type-param scopes as lazy nested
scopes, which is wrong. In fact they are eager nested scopes; the class
`C` here inherits `int`, not `str`, and previously we got that wrong:

```py
Base = int

class C[T](Base): ...

Base = str
```

But certain syntactic positions within type param scopes (typevar
bounds/constraints/defaults) are lazy at runtime, and we should use
deferred name resolution for them. This also means they can have cycles;
in order to handle that without panicking in type inference, we need to
actually defer their type inference until after we have constructed the
`TypeVarInstance`.

PEP 695 does specify that typevar bounds and constraints cannot be
generic, and that typevar defaults can only reference prior typevars,
not later ones. This reduces the scope of (valid from the type-system
perspective) cycles somewhat, although cycles are still possible (e.g.
`class C[T: list[C]]`). And this is a type-system-only restriction; from
the runtime perspective an "invalid" case like `class C[T: T]` actually
works fine.

I debated whether to implement the PEP 695 restrictions as a way to
avoid some cycles up-front, but I ended up deciding against that; I'd
rather model the runtime name-resolution semantics accurately, and
implement the PEP 695 restrictions as a separate diagnostic on top.
(This PR doesn't yet implement those diagnostics, thus some `# TODO:
error` in the added tests.)

Introducing the possibility of cyclic typevars made typevar display
potentially stack overflow. For now I've handled this by simply removing
typevar details (bounds/constraints/default) from typevar display. This
impacts display of two kinds of types. If you `reveal_type(T)` on an
unbound `T` you now get just `typing.TypeVar` instead of
`typing.TypeVar("T", ...)` where `...` is the bound/constraints/default.
This matches pyright and mypy; pyrefly uses `type[TypeVar[T]]` which
seems a bit confusing, but does include the name. (We could easily
include the name without cycle issues, if there's a syntax we like for
that.)

It also means that displaying a generic function type like `def f[T:
int](x: T) -> T: ...` now displays as `f[T](x: T) -> T` instead of `f[T:
int](x: T) -> T`. This matches pyright and pyrefly; mypy does include
bound/constraints/defaults of typevars in function/callable type
display. If we wanted to add this, we would either need to thread a
visitor through all the type display code, or add a `decycle` type
transformation that replaced recursive reoccurrence of a type with a
marker.

## Test Plan

Added mdtests and modified existing tests to improve their correctness.

After this PR, there's only a single remaining py-fuzzer seed in the
0-500 range that panics! (Before this PR, there were 10; the fuzzer
likes to generate cyclic PEP 695 syntax.)

## Ecosystem report

It's all just the changes to `TypeVar` display.
2025-08-13 15:51:59 -07:00
Douglas Creager baadb5a78d
[ty] Add some additional type safety to `CycleDetector` (#19903)
This PR adds a type tag to the `CycleDetector` visitor (and its
aliases).

There are some places where we implement e.g. an equivalence check by
making a disjointness check. Both `is_equivalent_to` and
`is_disjoint_from` use a `PairVisitor` to handle cycles, but they should
not use the same visitor. I was finding it tedious to remember when it
was appropriate to pass on a visitor and when not to. This adds a
`PhantomData` type tag to ensure that we can't pass on one method's
visitor to a different method.

For `has_relation` and `apply_type_mapping`, we have an existing type
that we can use as the tag. For the other methods, I've added empty
structs (`Normalized`, `IsDisjointFrom`, `IsEquivalentTo`) to use as
tags.
2025-08-13 17:32:35 -04:00
Aria Desires f0b03c3e86
[ty] resolve docstrings for modules (#19898)
This also reintroduces the `ResolvedDefinition::Module` variant because
reverse-engineering it in several places is a bit confusing. In an ideal
world we wouldn't have `ResolvedDefinition::FileWithRange` as it kinda
kills the ability to do richer analysis, so I want to chip away at its
scope wherever I can (currently it's used to point at asname parts of
import statements when doing `ImportAliasResolution::PreserveAliases`,
and also keyword arguments).

This also makes a kind of odd change to allow a hover to *only* produce
a docstring. This works around an oddity where hovering over a module
name in an import fails to resolve to a `ty` even though hovering over
uses of that imported name *does*.

The two fixed tests reflect the two interesting cases here.
2025-08-13 12:24:01 -04:00
Alex Waygood 9f6146a13d
[ty] Add precise inference for indexing, slicing and unpacking `NamedTuple` instances (#19560)
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
2025-08-13 15:19:44 +00:00
Carl Meyer e12747a903
[ty] simplify return type of place_from_declarations (#19884)
## Summary

A [passing
comment](https://github.com/astral-sh/ruff/pull/19711#issuecomment-3169312014)
led me to explore why we didn't report a class attribute as possibly
unbound if it was a method and defined in two different conditional
branches.

I found that the reason was because of our handling of "conflicting
declarations" in `place_from_declarations`. It returned a `Result` which
would be `Err` in case of conflicting declarations.

But we only actually care about conflicting declarations when we are
actually doing type inference on that scope and might emit a diagnostic
about it. And in all cases (including that one), we want to otherwise
proceed with the union of the declared types, as if there was no
conflict.

In several cases we were failing to handle the union of declared types
in the same way as a normal declared type if there was a declared-types
conflict. The `Result` return type made this mistake really easy to
make, as we'd match on e.g. `Ok(Place::Type(...))` and do one thing,
then match on `Err(...)` and do another, even though really both of
those cases should be handled the same.

This PR refactors `place_from_declarations` to instead return a struct
which always represents the declared type we should use in the same way,
as well as carrying the conflicting declared types, if any. This struct
has a method to allow us to explicitly ignore the declared-types
conflict (which is what we want in most cases), as well as a method to
get the declared type and the conflict information, in the case where we
want to emit a diagnostic on the conflict.

## Test Plan

Existing CI; added a test showing that we now understand a
multiply-conditionally-defined method as possibly-unbound.

This does trigger issues on a couple new fuzzer seeds, but the issues
are just new instances of an already-known (and rarely occurring)
problem which I already plan to address in a future PR, so I think it's
OK to land as-is.

I happened to build this initially on top of
https://github.com/astral-sh/ruff/pull/19711, which adds invalid-await
diagnostics, so I also updated some invalid-syntax tests to not await on
an invalid type, since the purpose of those tests is to check the
syntactic location of the `await`, not the validity of the awaited type.
2025-08-13 14:17:08 +00:00
Alex Waygood 5725c4b17f
[ty] Various minor cleanups to tuple internals (#19891) 2025-08-13 13:46:22 +00:00
Alex Waygood 2f3c7ad1fc
[ty] Improve `sys.version_info` special casing (#19894) 2025-08-13 14:39:13 +01:00
Carl Meyer 13bdba5d28
[ty] support recursive type aliases (#19805)
## Summary

Support recursive type aliases by adding a `Type::TypeAlias` type
variant, which allows referring to a type alias directly as a type
without eagerly unpacking it to its value.

We still unpack type aliases when they are added to intersections and
unions, so that we can simplify the intersection/union appropriately
based on the unpacked value of the type alias.

This introduces new possible recursive types, and so also requires
expanding our usage of recursion-detecting visitors in Type methods. The
use of these visitors is still not fully comprehensive in this PR, and
will require further expansion to support recursion in more kinds of
types (I already have further work on this locally), but I think it may
be better to do this incrementally in multiple PRs.

## Test Plan

Added some recursive type-alias tests and made them pass.
2025-08-12 09:03:10 -07:00
Alex Waygood d76fd103ae
[ty] Remove unsafe `salsa::Update` implementations in `tuple.rs` (#19880) 2025-08-12 15:53:34 +01:00
Matthew Mckee ad28b80f96
[ty] Function argument inlay hints (#19269) 2025-08-12 13:56:54 +00:00
Alex Waygood 3458f365da
[ty] Remove Salsa interning for `TypedDictType` (#19879) 2025-08-12 14:35:26 +01:00
Alex Waygood 498a04804d
[ty] Reduce memory usage of `TupleSpec` and `TupleType` (#19872) 2025-08-12 12:51:16 +01:00
Ibraheem Ahmed f34b65b7a0
[ty] Track heap usage of salsa structs (#19790)
Co-authored-by: Micha Reiser <micha@reiser.io>
2025-08-12 13:28:44 +02:00
Carl Meyer 28820db1cd
[ty] simplify CycleDetector::visit signature (#19873)
## Summary

After https://github.com/astral-sh/ruff/pull/19871, I realized that now
that we are passing around shared references to `CycleDetector`
visitors, we can now also simplify the `visit` callback signature; we
don't need to smuggle a single visitor reference through it anymore.
This is a pretty minor simplification, and it doesn't really make
anything shorter since I typically used a very short name (`v`) for the
smuggled reference, but I think it reduces cognitive overhead in reading
these `visit` usages; the extra variable would likely be confusing
otherwise for a reader.

## Test Plan

Existing CI.
2025-08-11 17:12:26 -07:00
Carl Meyer ea1aa9ebfe
[ty] use interior mutability in type visitors (#19871)
## Summary

Type visitors are conceptually immutable, they just internally track the
types they've seen (and some maintain a cache of results.) Passing
around mutable visitors everywhere can get us into borrow-checker
trouble in some cases, where we need to recursively pass along the
visitor inside more than one closure with non-disjoint lifetime.

Use interior mutability (via `RefCell` and `Cell`) inside the visitors
instead, to allow us to pass around shared references.

## Test Plan

Existing tests.
2025-08-11 15:42:53 -07:00
Alex Waygood d2fbf2af8f
[ty] Remove `Type::Tuple` (#19669) 2025-08-11 22:03:32 +01:00
Micha Reiser 2abd683376
[ty] Short circuit `ReachabilityConstraints::analyze_single` for dynamic types (#19867) 2025-08-11 21:58:34 +02:00
Douglas Creager dc84645c36
[ty] Use separate Rust types for bound and unbound type variables (#19796)
This PR creates separate Rust types for bound and unbound type
variables, as proposed in https://github.com/astral-sh/ty/issues/926.

Closes https://github.com/astral-sh/ty/issues/926

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-08-11 15:29:58 -04:00
Alex Waygood 5a116e48c3
[ty] Add Salsa caching to `TupleType::to_class_type` (#19840) 2025-08-09 09:29:26 +01:00
Douglas Creager 3a542a80f6
[ty] Handle cycles when finding implicit attributes (#19833)
The [minimal
reproduction](https://gist.github.com/dcreager/fc53c59b30d7ce71d478dcb2c1c56444)
of https://github.com/astral-sh/ty/issues/948 is an example of a class
with implicit attributes whose types end up depending on themselves. Our
existing cycle detection for `infer_expression_types` is usually enough
to handle this situation correctly, but when there are very many of
these implicit attributes, we get a combinatorial explosion of running
time and memory usage.

Adding a separate cycle handler for `ClassLiteral::implicit_attribute`
lets us catch and recover from this situation earlier.

Closes https://github.com/astral-sh/ty/issues/948
2025-08-08 17:01:17 -04:00
Aria Desires 7cc3f1ebe9
[ty] Implement stdlib stub mapping (#19529)
by using essentially the same logic for system site-packages, on the
assumption that system site-packages are always a subdir of the stdlib
we were looking for.
2025-08-08 15:52:15 -04:00
Eric Jolibois 0095ff4c1a
[ty] Implement module-level `__getattr__` support (#19791)
fix https://github.com/astral-sh/ty/issues/943

## Summary

Add module-level `__getattr__` support for ty's type checker, fixing
issue https://github.com/astral-sh/ty/issues/943.
Module-level `__getattr__` functions ([PEP
562](https://peps.python.org/pep-0562/)) are now respected when
resolving dynamic attributes, matching the behavior of mypy and pyright.

## Implementation

Thanks @sharkdp for the guidance in
https://github.com/astral-sh/ty/issues/943#issuecomment-3157566579
- Adds module-specific `__getattr__` resolution in
`ModuleLiteral.static_member()`
- Maintains proper attribute precedence: explicit attributes >
submodules > `__getattr__`

## Test Plan
- New mdtest covering basic functionality, type annotations, attribute
precedence, and edge cases
(run ```cargo nextest run -p ty_python_semantic
mdtest__import_module_getattr```)
- All new tests pass, verifying `__getattr__` is called correctly and
returns proper types
  - Existing test suite passes, ensuring no regressions introduced
2025-08-08 10:39:37 -07:00
Alex Waygood 8489816edc
[ty] Improve ability to solve TypeVars when they appear in unions (#19829) 2025-08-08 17:50:37 +01:00
Micha Reiser fd35435281
[ty] Improve performance of subtyping and assignability checks for protocols (#19824) 2025-08-08 13:05:12 +02:00
Jack O'Connor 827456f977 [ty] more cases for the class body global fallback 2025-08-07 17:30:27 -07:00
Shunsuke Shibayama 462adfd0e6
[ty] fix incorrect member narrowing (#19802)
## Summary

Reported in:
https://github.com/astral-sh/ruff/pull/19795#issuecomment-3161981945

If a root expression is reassigned, narrowing on the member should be
invalidated, but there was an oversight in the current implementation.

This PR fixes that, and also removes some unnecessary handling.

## Test Plan

New tests cases in `narrow/conditionals/nested.md`.
2025-08-07 16:04:07 -07:00
Andrew Gallant d5e1b7983e
[ty] Fix static assertion size check (#19814)
A `Segment` has a `Box` in it, which has a platform dependent size.
Restrict the check to only 64-bit targets.
2025-08-07 13:38:16 -05:00
Micha Reiser 7dfde3b929
Update Rust toolchain to 1.89 (#19807) 2025-08-07 18:21:50 +02:00
Alex Waygood c401a6d86e
[ty] Add failing tests for tuple subclasses (#19803) 2025-08-07 13:11:15 +00:00
UnboundVariable b005cdb7ff
[ty] Implemented support for "rename" language server feature (#19551)
This PR adds support for the "rename" language server feature. It builds
upon existing functionality used for "go to references".

The "rename" feature involves two language server requests. The first is
a "prepare rename" request that determines whether renaming should be
possible for the identifier at the current offset. The second is a
"rename" request that returns a list of file ranges where the rename
should be applied.

Care must be taken when attempting to rename symbols that span files,
especially if the symbols are defined in files that are not part of the
project. We don't want to modify code in the user's Python environment
or in the vendored stub files.

I found a few bugs in the "go to references" feature when implementing
"rename", and those bug fixes are included in this PR.

---------

Co-authored-by: UnboundVariable <unbound@gmail.com>
2025-08-07 15:58:18 +05:30
Micha Reiser b96aa4605b
[ty] Reduce size of member table (#19572) 2025-08-07 11:16:04 +02:00
Matthew Mckee ef1802b94f
[ty] Repurpose `FunctionType.into_bound_method_type` to return `BoundMethodType` (#19793)
## Summary

As per our naming scheme (at least for callable types) this should
return a `BoundMethodType`, or be renamed, but it makes more sense to
change the return type.

I also ensure `ClassType.into_callable` returns a `Type::Callable` in
the changed branch.

Ideally we could return a `CallableType` from these `into_callable`
functions (and rename to `into_callable_type` but because of unions we
cannot do this.
2025-08-06 15:24:59 -07:00
David Peter 98df62db79
[ty] Validate writes to `TypedDict` keys (#19782)
## Summary

Validates writes to `TypedDict` keys, for example:

```py
class Person(TypedDict):
    name: str
    age: int | None


def f(person: Person):
    person["naem"] = "Alice"  # error: [invalid-key]

    person["age"] = "42"  # error: [invalid-assignment]
```

The new specialized `invalid-assignment` diagnostic looks like this:

<img width="1160" height="279" alt="image"
src="https://github.com/user-attachments/assets/51259455-3501-4829-a84e-df26ff90bd89"
/>

## Ecosystem analysis

As far as I can tell, all true positives!

There are some extremely long diagnostic messages. We should truncate
our display of overload sets somehow.

## Test Plan

New Markdown tests
2025-08-06 15:19:13 -07:00
Douglas Creager 585ce12ace
[ty] `typing.Self` is bound by the method, not the class (#19784)
This fixes our logic for binding a legacy typevar with its binding
context. (To recap, a legacy typevar starts out "unbound" when it is
first created, and each time it's used in a generic class or function,
we "bind" it with the corresponding `Definition`.)

We treat `typing.Self` the same as a legacy typevar, and so we apply
this binding logic to it too. Before, we were using the enclosing class
as its binding context. But that's not correct — it's the method where
`typing.Self` is used that binds the typevar. (Each invocation of the
method will find a new specialization of `Self` based on the specific
instance type containing the invoked method.)

This required plumbing through some additional state to the
`in_type_expression` method.

This also revealed that we weren't handling `Self`-typed instance
attributes correctly (but were coincidentally not getting the expected
false positive diagnostics).
2025-08-06 17:26:17 -04:00
Ibraheem Ahmed 21ac16db85
[ty] Avoid overcounting shared memory usage (#19773)
## Summary

Use a global tracker to avoid double counting `Arc` instances.
2025-08-06 15:32:02 -04:00
David Peter b96929ee19
[ty] Disallow `typing.TypedDict` in type expressions (#19777)
## Summary

Disallow `typing.TypedDict` in type expressions.

Related reference: https://github.com/python/mypy/issues/11030

## Test Plan

New Markdown tests, checked ecosystem and conformance test impact.
2025-08-06 15:58:35 +02:00
Alex Waygood 529d81daca
[ty] Improve subscript narrowing for "safe mutable classes" (#19781)
## Summary

This PR improves the `is_safe_mutable_class` function in `infer.rs` in
several ways:
- It uses `KnownClass::to_instance()` for all "safe mutable classes".
Previously, we were using `SpecialFormType::instance_fallback()` for
some variants -- I'm not totally sure why. Switching to
`KnownClass::to_instance()` for all "safe mutable classes" fixes a
number of TODOs in the `assignment.md` mdtest suite
- Rather than eagerly calling `.to_instance(db)` on all "safe mutable
classes" every time `is_safe_mutable_class` is called, we now only call
it lazily on each element, allowing us to short-circuit more
effectively.
- I removed the entry entirely for `TypedDict` from the list of "safe
mutable classes", as it's not correct.
`SpecialFormType::TypedDict.instance_fallback(db)` just returns an
instance type representing "any instance of `typing._SpecialForm`",
which I don't think was the intent of this code. No tests fail as a
result of removing this entry, as we already check separately whether an
object is an inhabitant of a `TypedDict` type (and consider that object
safe-mutable if so!).

## Test Plan

mdtests updated
2025-08-06 12:26:25 +01:00
David Peter 4887bdf205
[ty] Infer types for key-based access on TypedDicts (#19763)
## Summary

This PR adds type inference for key-based access on `TypedDict`s and a
new diagnostic for invalid subscript accesses:

```py
class Person(TypedDict):
    name: str
    age: int | None

alice = Person(name="Alice", age=25)

reveal_type(alice["name"])  # revealed: str
reveal_type(alice["age"])  # revealed: int | None

alice["naem"]  # Unknown key "naem" - did you mean "name"?
```

## Test Plan

Updated Markdown tests
2025-08-06 09:36:33 +02:00
Matthew Mckee 18ad2848e3
Display generic function signature properly (#19544)
## Summary

Resolves https://github.com/astral-sh/ty/issues/817

## Test Plan

Update mdtest

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-08-05 16:35:08 -07:00
Alex Waygood 4090297a11
[ty] Fix more false positives related to `Generic` or `Protocol` being subscripted with a `ParamSpec` or `TypeVarTuple` (#19764) 2025-08-05 15:45:56 +01:00
Simon Lamon 934fd37d2b
[ty] Diagnostics for async context managers (#19704)
## Summary

Implements diagnostics for async context managers. Fixes
https://github.com/astral-sh/ty/issues/918.

## Test Plan

Mdtests have been added.
2025-08-05 07:41:37 -07:00
Alex Waygood 7dccb6a98c
[ty] Improve effectiveness of `KnownClass` fast paths in `instance.rs` (#19762) 2025-08-05 13:26:14 +01:00
David Peter 948f3f856c
[ty] Fix attribute access on `TypedDict`s (#19758)
## Summary

This PR fixes a few inaccuracies in attribute access on `TypedDict`s. It
also changes the return type of `type(person)` to `type[dict[str,
object]]` if `person: Person` is an inhabitant of a `TypedDict`
`Person`. We still use `type[Person]` as the *meta type* of Person,
however (see reasoning
[here](https://github.com/astral-sh/ruff/pull/19733#discussion_r2253297926)).

## Test Plan

Updated Markdown tests.
2025-08-05 13:59:10 +02:00
Alex Waygood 3af0b31de3
[ty] Speedup the `known_class_doesnt_fallback_to_unknown_unexpectedly_on_low_python_version` test (#19760) 2025-08-05 11:55:11 +00:00
David Peter 7df7be5c7d
[ty] Keep track of type qualifiers in stub declarations without right-hand side (#19756)
## Summary

closes https://github.com/astral-sh/ty/issues/937

## Test Plan

Regression test
2025-08-05 12:07:05 +02:00
David Peter 14fbc2b167
[ty] New `Type` variant for `TypedDict` (#19733)
## Summary

This PR adds a new `Type::TypedDict` variant. Before this PR, we treated
`TypedDict`-based types as dynamic Todo-types, and I originally planned
to make this change a no-op. And we do in fact still treat that new
variant similar to a dynamic type when it comes to type properties such
as assignability and subtyping. But then I somehow tricked myself into
implementing some of the things correctly, so here we are. The two main
behavioral changes are: (1) we now also detect generic `TypedDict`s,
which removes a few false positives in the ecosystem, and (2) we now
support *attribute* access (not key-based indexing!) on these types,
i.e. we infer proper types for something like
`MyTypedDict.__required_keys__`. Nothing exciting yet, but gets the
infrastructure into place.

Note that with this PR, the type of (the type) `MyTypedDict` itself is
still represented as a `Type::ClassLiteral` or `Type::GenericAlias` (in
case `MyTypedDict` is generic). Only inhabitants of `MyTypedDict`
(instances of `dict` at runtime) are represented by `Type::TypedDict`.
We may want to revisit this decision in the future, if this turns out to
be too error-prone. Right now, we need to use `.is_typed_dict(db)` in
all the right places to distinguish between actual (generic) classes and
`TypedDict`s. But so far, it seemed unnecessary to add additional `Type`
variants for these as well.

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

## Ecosystem impact

The new diagnostics on `cloud-init` look like true positives to me.

## Test Plan

Updated and new Markdown tests
2025-08-05 11:19:49 +02:00
Shunsuke Shibayama 351121c5c5
[ty] fix incorrect lazy scope narrowing (#19744)
## Summary

This is a follow-up to #19321.

Narrowing constraints introduced in a class scope were not applied even
when they can be applied in lazy nested scopes. This PR fixes so that
they are now applied.
Conversely, there were cases where narrowing constraints were being
applied in places where they should not, so it is also fixed.

## Test Plan

Some TODOs in `narrow/conditionals/nested.md` are now work correctly.
2025-08-04 20:32:08 -07:00
Shunsuke Shibayama 64bcc8db2f
[ty] fix lookup order of class variables before they are defined (#19743)
## Summary

This is a follow-up to #19321.

If we try to access a class variable before it is defined, the variable
is looked up in the global scope, rather than in any enclosing scopes.

Closes https://github.com/astral-sh/ty/issues/875.

## Test Plan

New tests in `narrow/conditionals/nested.md`.
2025-08-04 20:21:28 -07:00
Alex Waygood 3a9341f7be
[ty] Remove false positives when subscripting `Generic` or `Protocol` with a `ParamSpec` or `TypeVarTuple` (#19749) 2025-08-04 21:42:46 +01:00
David Peter 739c94f95a
[ty] Support as-patterns in reachability analysis (#19728)
## Summary

Support `as` patterns in reachability analysis:

```py
from typing import assert_never


def f(subject: str | int):
    match subject:
        case int() as x:
            pass
        case str():
            pass
        case _:
            assert_never(subject)  # would previously emit an error
```

Note that we still don't support inferring correct types for the bound
name (`x`).

Closes https://github.com/astral-sh/ty/issues/928

## Test Plan

New Markdown tests
2025-08-04 20:13:50 +02:00
Alex Waygood 41207ec901
[ty] Infer `type[tuple[int, str]]` as the meta-type of `tuple[int, str]` (#19741) 2025-08-04 13:10:47 +00:00
Alex Waygood bc6e8b58ce
[ty] Return `Option<TupleType>` from `infer_tuple_type_expression` (#19735)
## Summary

This PR reduces the virality of some of the `Todo` types in
`infer_tuple_type_expression`. Rather than inferring `Todo`, we instead
infer `tuple[Todo, ...]`. This reflects the fact that whatever the
contents of the slice in a `tuple[]` type expression, we would always
infer some kind of tuple type as the result of the type expression. Any
tuple type should be assignable to `tuple[Todo, ...]`, so this shouldn't
introduce any new false positives; this can be seen in the ecosystem
report.

As a result of the change, we are now able to enforce in the signature
of `Type::infer_tuple_type_expression` that it returns an
`Option<TupleType<'db>>`, which is more strongly typed and expresses
clearly the invariant that a tuple type expression should always be
inferred as a `tuple` type. To enable this, it was necessary to refactor
several `TupleType` constructors in `tuple.rs` so that they return
`Option<TupleType>` rather than `Type`; this means that callers of these
constructor functions are now free to either propagate the
`Option<TupleType<'db>>` or convert it to a `Type<'db>`.

## Test Plan

Mdtests updated.
2025-08-04 13:48:19 +01:00
Douglas Creager d37911685f
[ty] Correctly instantiate generic class that inherits `__init__` from generic base class (#19693)
This is subtle, and the root cause became more apparent with #19604,
since we now have many more cases of superclasses and subclasses using
different typevars. The issue is easiest to see in the following:

```py
class C[T]:
    def __init__(self, t: T) -> None: ...

class D[U](C[T]):
    pass

reveal_type(C(1))  # revealed: C[int]
reveal_type(D(1))  # should be: D[int]
```

When instantiating a generic class, the `__init__` method inherits the
generic context of that class. This lets our call binding machinery
infer a specialization for that context.

Prior to this PR, the instantiation of `C` worked just fine. Its
`__init__` method would inherit the `[T]` generic context, and we would
infer `{T = int}` as the specialization based on the argument
parameters.

It didn't work for `D`. The issue is that the `__init__` method was
inheriting the generic context of the class where `__init__` was defined
(here, `C` and `[T]`). At the call site, we would then infer `{T = int}`
as the specialization — but that wouldn't help us specialize `D[U]`,
since `D` does not have `T` in its generic context!

Instead, the `__init__` method should inherit the generic context of the
class that we are performing the lookup on (here, `D` and `[U]`). That
lets us correctly infer `{U = int}` as the specialization, which we can
successfully apply to `D[U]`.

(Note that `__init__` refers to `C`'s typevars in its signature, but
that's okay; our member lookup logic already applies the `T = U`
specialization when returning a member of `C` while performing a lookup
on `D`, transforming its signature from `(Self, T) -> None` to `(Self,
U) -> None`.)

Closes https://github.com/astral-sh/ty/issues/588
2025-08-01 15:29:18 -04:00
Douglas Creager 06cd249a9b
[ty] Track different uses of legacy typevars, including context when rendering typevars (#19604)
This PR introduces a few related changes:

- We now keep track of each time a legacy typevar is bound in a
different generic context (e.g. class, function), and internally create
a new `TypeVarInstance` for each usage. This means the rest of the code
can now assume that salsa-equivalent `TypeVarInstance`s refer to the
same typevar, even taking into account that legacy typevars can be used
more than once.

- We also go ahead and track the binding context of PEP 695 typevars.
That's _much_ easier to track since we have the binding context right
there during type inference.

- With that in place, we can now include the name of the binding context
when rendering typevars (e.g. `T@f` instead of `T`)
2025-08-01 12:20:32 -04:00
David Peter 48d5bd13fa
[ty] Initial test suite for `TypedDict` (#19686)
## Summary

Adds an initial set of tests based on the highest-priority items in
https://github.com/astral-sh/ty/issues/154. This is certainly not yet
exhaustive (required/non-required, `total`, and other things are
missing), but will be useful to measure progress on this feature.

## Test Plan

Checked intended behavior against runtime and other type checkers.
2025-08-01 16:56:02 +02:00
Alex Waygood e7e7b7bf21
[ty] Improve debuggability of protocol types (#19662) 2025-08-01 15:16:13 +01:00
Alex Waygood 57e2e8664f
[ty] Simplify lifetime requirements for `PySlice` trait (#19687) 2025-08-01 15:13:47 +01:00
Alex Waygood 18aae21b9a
[ty] Improve `isinstance()` truthiness analysis for generic types (#19668) 2025-08-01 14:44:22 +01:00
David Peter ade6a4262a
[ty] Remove `Specialization::display` (full) (#19682)
## Summary

This seems to be unused
2025-08-01 10:44:11 +02:00
David Peter d43e6fb9c6
[ty] Remove `KnownModule::is_enum` (#19681)
## Summary

Changes the visibility of `KnownModule` and removes an unneeded
function.
2025-08-01 10:31:12 +02:00
Matthew Mckee b30d97e5e0
[ty] Support `__setitem__` and improve `__getitem__` related diagnostics (#19578)
## Summary

Adds validation to subscript assignment expressions.

```py
class Foo: ...

class Bar:
    __setattr__ = None

class Baz:
    def __setitem__(self, index: str, value: int) -> None:
        pass

# We now emit a diagnostic on these statements
Foo()[1] = 2
Bar()[1] = 2
Baz()[1] = 2

```

Also improves error messages on invalid `__getitem__` expressions

## Test Plan

Update mdtests and add more to `subscript/instance.md`

---------

Co-authored-by: David Peter <sharkdp@users.noreply.github.com>
Co-authored-by: David Peter <mail@david-peter.de>
2025-08-01 09:23:27 +02:00
Alex Waygood 2ab1502e51
[ty] Improve the `Display` for generic `type[]` types (#19667) 2025-07-31 19:45:01 +01:00
Alex Waygood a3f28baab4
[ty] Refactor `TypeInferenceBuilder::infer_subscript_expression_types` (#19658) 2025-07-31 13:38:43 +00:00
Brent Westbrook a71513bae1
Fix tests on 32-bit architectures (#19652)
Summary
--

Fixes #19640. I'm not sure these are the exact fixes we really want, but
I
reproduced the issue in a 32-bit Docker container and tracked down the
causes,
so I figured I'd open a PR.

As I commented on the issue, the `goto_references` test depends on the
iteration
order of the files in an `FxHashSet` in `Indexed`. In this case, we can
just
sort the output in test code.

Similarly, the tuple case depended on the order of overloads inserted in
an
`FxHashMap`. `FxIndexMap` seemed like a convenient drop-in replacement,
but I
don't know if that will have other detrimental effects. I did have to
change the
assertion for the tuple test, but I think it should now be stable across
architectures.

Test Plan
--

Running the tests in the aforementioned Docker container
2025-07-31 08:52:19 -04:00
Alex Waygood d2d4b115e3
[ty] Move `pandas-stubs` to bad.txt (#19659) 2025-07-31 12:33:24 +01:00
Alex Waygood 27b03a9d7b
[ty] Remove special casing for string-literal-in-tuple `__contains__` (#19642) 2025-07-31 11:28:03 +01:00
Ibraheem Ahmed 8f8c39c435
Simplify `get_size2` usage (#19643)
## Summary

These were added in the 0.5.0 release.
2025-07-30 15:31:37 -04:00
Matthew Mckee 4739bc8d14
[ty] Fix incorrect diagnostic when calling `__setitem__` (#19645)
## Summary

Resolves https://github.com/astral-sh/ty/issues/862 by not emitting a
diagnostic.

## Test Plan

Add test to show we don't emit the diagnostic
2025-07-30 20:34:52 +02:00
Alex Waygood 7b4103bcb6
[ty] Remove special casing for tuple addition (#19636) 2025-07-30 16:25:42 +00:00
Alex Waygood ec3d5ebda2
[ty] Upcast heterogeneous and mixed tuples to homogeneous tuples where it's necessary to solve a `TypeVar` (#19635)
## Summary

This PR improves our generics solver such that we are able to solve the
`TypeVar` in this snippet to `int | str` (the union of the elements in
the heterogeneous tuple) by upcasting the heterogeneous tuple to its
pure-homogeneous-tuple supertype:

```py
def f[T](x: tuple[T, ...]) -> T:
    return x[0]

def g(x: tuple[int, str]):
    reveal_type(f(x))
```

## Test Plan

Mdtests. Some TODOs remain in the mdtest regarding solving `TypeVar`s
for mixed tuples, but I think this PR on its own is a significant step
forward for our generics solver when it comes to tuple types.

---------

Co-authored-by: Douglas Creager <dcreager@dcreager.net>
2025-07-30 17:12:21 +01:00
David Peter eb02aa5676
[ty] Async for loops and async iterables (#19634)
## Summary

Add support for `async for` loops and async iterables.

part of https://github.com/astral-sh/ty/issues/151

## Ecosystem impact

```diff
- boostedblob/listing.py:445:54: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
```

This is correct. We now find a true positive in the `# type: ignore`'d
code.

All of the other ecosystem hits are of the type

```diff
trio (https://github.com/python-trio/trio)
+ src/trio/_core/_tests/test_guest_mode.py:532:24: error[not-iterable] Object of type `MemorySendChannel[int] | MemoryReceiveChannel[int]` may not be iterable
```

The message is correct, because only `MemoryReceiveChannel` has an
`__aiter__` method, but `MemorySendChannel` does not. What's not correct
is our inferred type here. It should be `MemoryReceiveChannel[int]`, not
the union of the two. This is due to missing unpacking support for tuple
subclasses, which @AlexWaygood is working on. I don't think this should
block merging this PR, because those wrong types are already there,
without this PR.

## Test Plan

New Markdown tests and snapshot tests for diagnostics.
2025-07-30 17:40:24 +02:00
Andrew Gallant d1a286226c [ty] Update module resolution diagram to account for typeshed `VERSIONS` file
This does unfortunately add a fair bit of complexity to the flow
diagram.

Ref https://github.com/astral-sh/ruff/pull/19620#issuecomment-3133684294
2025-07-30 10:34:58 -04:00
Alex Waygood feaedb1812
[ty] Synthesize precise `__getitem__` overloads for tuple subclasses (#19493) 2025-07-30 11:25:44 +00:00
David Peter 4ecf1d205a
[ty] Support `async`/`await`, `async with` and `yield from` (#19595)
## Summary

- Add support for the return types of `async` functions
- Add type inference for `await` expressions
- Add support for `async with` / async context managers
- Add support for `yield from` expressions

This PR is generally lacking proper error handling in some cases (e.g.
illegal `__await__` attributes). I'm planning to work on this in a
follow-up.

part of https://github.com/astral-sh/ty/issues/151

closes https://github.com/astral-sh/ty/issues/736

## Ecosystem

There are a lot of true positives on `prefect` which look similar to:
```diff
prefect (https://github.com/PrefectHQ/prefect)
+ src/integrations/prefect-aws/tests/workers/test_ecs_worker.py:406:12: error[unresolved-attribute] Type `str` has no attribute `status_code`
```

This is due to a wrong return type annotation
[here](e926b8c4c1/src/integrations/prefect-aws/tests/workers/test_ecs_worker.py (L355-L391)).

```diff
mitmproxy (https://github.com/mitmproxy/mitmproxy)
+ test/mitmproxy/addons/test_clientplayback.py:18:1: error[invalid-argument-type] Argument to function `asynccontextmanager` is incorrect: Expected `(...) -> AsyncIterator[Unknown]`, found `def tcp_server(handle_conn, **server_args) -> Unknown | tuple[str, int]`
```


[This](a4d794c59a/test/mitmproxy/addons/test_clientplayback.py (L18-L19))
is a true positive. That function should return
`AsyncIterator[Address]`, not `Address`.

I looked through almost all of the other new diagnostics and they all
look like known problems or true positives.

## Typing conformance

The typing conformance diff looks good.

## Test Plan

New Markdown tests
2025-07-30 11:51:21 +02:00
Andrew Gallant 88a679945c [ty] Add flow diagram for import resolution
The diagram is written in the Dot language, which can
be converted to SVG (or any other image) by GraphViz.

I thought it was a good idea to write this down in
preparation for adding routines that list modules.
Code reuse is likely to be difficult and I wanted to
be sure I understood how it worked.
2025-07-29 14:49:20 -04:00
Andrew Gallant 941be52358 [ty] Add comments to some core resolver functions
Some of the contracts were a little tricky to discover from just the
parameter types, so I added some docs (and fixed what I believe was one
typo).
2025-07-29 14:49:20 -04:00
Andrew Gallant 13624ce17f [ty] Add missing ticks and use consistent quoting
This irked me while I was reading the code, so I just tried to fix what
I could see.
2025-07-29 14:49:20 -04:00
Andrew Gallant edb2f8e997 [ty] Reflow some long lines
I mostly just did this because the long string literals were annoying
me. And these can make rustfmt give up on formatting.

I also re-flowed some long comment lines while I was here.
2025-07-29 14:49:20 -04:00
Andrew Gallant 5e6ad849ff [ty] Unexport helper function
I'm not sure if this used to be used elsewhere, but it no longer is.
And it looks like an internal-only helper function, so just un-export
it.

And note that `ModuleNameIngredient` is also un-exported, so this
function isn't really usable outside of its defining module anyway.
2025-07-29 14:49:20 -04:00
हिमांशु f7c6a6b2d0
[ty] fix a typo (#19621)
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-07-29 17:53:44 +00:00
justin 656273bf3d
[ty] synthesize `__replace__` for dataclasses (>=3.13) (#19545)
## Summary
https://github.com/astral-sh/ty/issues/111

adds support for the new `copy.replace` and `__replace__` protocol
[added in 3.13](https://docs.python.org/3/whatsnew/3.13.html#copy)

- docs: https://docs.python.org/3/library/copy.html#object.__replace__
- some discussion on pyright/mypy implementations:
https://discuss.python.org/t/dataclass-transform-and-replace/69067



### Burndown
- [x] add tests
- [x] implement `__replace__`
- [ ]
[collections.namedtuple()](https://docs.python.org/3/library/collections.html#collections.namedtuple)
- [x]
[dataclasses.dataclass](https://docs.python.org/3/library/dataclasses.html#dataclasses.dataclass)

## Test Plan
new mdtests

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-07-29 17:32:01 +02:00
Alex Waygood 81867ea7ce
[ty] Discard `Definition`s when normalizing `Signature`s (#19615) 2025-07-29 14:37:47 +01:00
github-actions[bot] c6a123290d
[ty] Sync vendored typeshed stubs (#19607)
Co-authored-by: typeshedbot <>
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-07-28 22:06:33 +00:00
Douglas Creager 130d4e1135
[ty] Don't panic with argument that doesn't actually implement Iterable (#19602)
This eliminates the panic reported in
https://github.com/astral-sh/ty/issues/909, though it doesn't address
the underlying cause, which is that we aren't yet checking the types of
the fields of a protocol when checking whether a class implements the
protocol. And in particular, if a class explictly opts out of iteration
via

```py
class NotIterable:
    __iter__ = None
```

we currently treat that as "having an `__iter__`" member, and therefore
implementing `Iterable`.

Note that the assumption that was in the comment before is still
correct: call binding will have already checked that the argument
satisfies `Iterable`, and so it shouldn't be an error to iterate over
said argument. But arguably, the new logic in this PR is a better way to
discharge that assumption — instead of panicking if we happen to be
wrong, fall back on an unknown iteration result.
2025-07-28 12:09:54 -04:00
David Peter 2680f2ed81
[ty] Minor: test isolation (#19597)
## Summary

Split the "Generator functions" tests into two parts. The first part
(synchronous) refers to a function called `i` from a function `i2`. But
`i` is later redeclared in the asynchronous part, which was probably not
intended.
2025-07-28 15:52:59 +02:00
Dylan 008bbfdf5a
Disallow implicit concatenation of t-strings and other string types (#19485)
As of [this cpython PR](https://github.com/python/cpython/pull/135996),
it is not allowed to concatenate t-strings with non-t-strings,
implicitly or explicitly. Expressions such as `"foo" t"{bar}"` are now
syntax errors.

This PR updates some AST nodes and parsing to reflect this change.

The structural change is that `TStringPart` is no longer needed, since,
as in the case of `BytesStringLiteral`, the only possibilities are that
we have a single `TString` or a vector of such (representing an implicit
concatenation of t-strings). This removes a level of nesting from many
AST expressions (which is what all the snapshot changes reflect), and
simplifies some logic in the implementation of visitors, for example.

The other change of note is in the parser. When we meet an implicit
concatenation of string-like literals, we now count the number of
t-string literals. If these do not exhaust the total number of
implicitly concatenated pieces, then we emit a syntax error. To recover
from this syntax error, we encode any t-string pieces as _invalid_
string literals (which means we flag them as invalid, record their
range, and record the value as `""`). Note that if at least one of the
pieces is an f-string we prefer to parse the entire string as an
f-string; otherwise we parse it as a string.

This logic is exactly the same as how we currently treat
`BytesStringLiteral` parsing and error recovery - and carries with it
the same pros and cons.

Finally, note that I have not implemented any changes in the
implementation of the formatter. As far as I can tell, none are needed.
I did change a few of the fixtures so that we are always concatenating
t-strings with t-strings.
2025-07-27 12:41:03 +00:00
Alex Waygood df5eba7583
[ty] Mark `all_type_assignable_to_iterable_are_iterable` as flaky (#19574) 2025-07-27 11:04:13 +00:00
Douglas Creager e867830848
[ty] Don't include already-bound legacy typevars in function generic context (#19558)
We now correctly exclude legacy typevars from enclosing scopes when
constructing the generic context for a generic function.

more detail:

A function is generic if it refers to legacy typevars in its signature:

```py
from typing import TypeVar

T = TypeVar("T")

def f(t: T) -> T:
    return t
```

Generic functions are allowed to appear inside of other generic
contexts. When they do, they can refer to the typevars of those
enclosing generic contexts, and that should not rebind the typevar:

```py
from typing import TypeVar, Generic

T = TypeVar("T")
U = TypeVar("U")

class C(Generic[T]):
    @staticmethod
    def method(t: T, u: U) -> None: ...

# revealed: def method(t: int, u: U) -> None
reveal_type(C[int].method)
```

This substitution was already being performed correctly, but we were
also still including the enclosing legacy typevars in the method's own
generic context, which can be seen via `ty_extensions.generic_context`
(which has been updated to work on generic functions and methods):

```py
from ty_extensions import generic_context

# before: tuple[T, U]
# after: tuple[U]
reveal_type(generic_context(C[int].method))
```

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-07-25 18:14:19 -04:00
Alex Waygood 859262bd49
[ty] Move `zope.interface` to `good.txt` for primer runs (#19208) 2025-07-25 14:12:17 +01:00
David Peter c0768dfd96
[ty] Attribute access on intersections with negative parts (#19524)
## Summary

We currently infer a `@Todo` type whenever we access an attribute on an
intersection type with negative components. This can happen very
naturally. Consequently, this `@Todo` type is rather pervasive and hides
a lot of true positives that ty could otherwise detect:

```py
class Foo:
    attr: int = 1

def _(f: Foo | None):
    if f:
        reveal_type(f)  # Foo & ~AlwaysFalsy

        reveal_type(f.attr)  # now: int, previously: @Todo
```

The changeset here proposes to handle member access on these
intersection types by simply ignoring all negative contributions. This
is not always ideal: a negative contribution like `~<Protocol with
members 'attr'>` could be a hint that `.attr` should not be accessible
on the full intersection type. The behavior can certainly be improved in
the future, but this seems like a reasonable initial step to get rid of
this unnecessary `@Todo` type.

## Ecosystem analysis

There are quite a few changes here. I spot-checked them and found one
bug where attribute access on pure negation types (`~P == object & ~P`)
would not allow attributes on `object` to be accessed. After that was
fixed, I only see true positives and known problems. The fact that a lot
of `unused-ignore-comment` diagnostics go away are also evidence for the
fact that this touches a sensitive area, where static analysis clashes
with dynamically adding attributes to objects:
```py
… # type: ignore # Runtime attribute access
```

## Test Plan

Updated tests.
2025-07-25 14:56:14 +02:00
David Peter d4eb4277ad
[ty] Add basic support for `dataclasses.field` (#19553)
## Summary

Add basic support for `dataclasses.field`:
* remove fields with `init=False` from the signature of the synthesized
`__init__` method
* infer correct default value types from `default` or `default_factory`
arguments

```py
from dataclasses import dataclass, field

def default_roles() -> list[str]:
    return ["user"]

@dataclass
class Member:
    name: str
    roles: list[str] = field(default_factory=default_roles)
    tag: str | None = field(default=None, init=False)

# revealed: (self: Member, name: str, roles: list[str] = list[str]) -> None
reveal_type(Member.__init__)
```

Support for `kw_only` has **not** been added.

part of https://github.com/astral-sh/ty/issues/111

## Test Plan

New Markdown tests
2025-07-25 14:56:04 +02:00
Micha Reiser b033fb6bfd
[ty] Split `ScopedPlaceId` into `ScopedSymbolId` and `ScopedMemberId` (#19497) 2025-07-25 13:54:33 +02:00
Alex Waygood f722bfa9e6
[ty] Do not consider a type `T` to satisfy a method member on a protocol unless the method is available on the meta-type of `T` (#19187) 2025-07-25 11:16:04 +01:00
Shunsuke Shibayama b124e182ca
[ty] improve lazy scope place lookup (#19321)
Co-authored-by: David Peter <sharkdp@users.noreply.github.com>
Co-authored-by: Carl Meyer <carl@oddbird.net>
Co-authored-by: Micha Reiser <micha@reiser.io>
2025-07-25 07:11:11 +00:00
Carl Meyer ae9d450b5f
[ty] Fallback to Unknown if no type is stored for an expression (#19517)
## Summary

See discussion at
https://github.com/astral-sh/ruff/pull/19478/files#r2223870292

Fixes https://github.com/astral-sh/ty/issues/865

## Test Plan

Added one mdtest for invalid Callable annotation; removed `pull-types:
skip` from that test file.

Co-authored-by: lipefree <willy.ngo.2000@gmail.com>
2025-07-25 02:05:32 +00:00
David Peter d77b7312b0
[ty] Minor: fix incomplete docstring (#19534) 2025-07-24 21:01:15 +02:00
David Peter dc6be457b5
[ty] Support `dataclasses.InitVar` (#19527)
## Summary

I saw that this creates a lot of false positives in the ecosystem, and
it seemed to be relatively easy to add basic support for this.

Some preliminary work on this was done by @InSyncWithFoo — thank you.

part of https://github.com/astral-sh/ty/issues/111

## Ecosystem analysis

The results look good.

## Test Plan

New Markdown tests

---------

Co-authored-by: InSync <insyncwithfoo@gmail.com>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-07-24 16:33:33 +02:00
David Peter 9461d3076f
[ty] Rename type_api => ty_extensions (#19523) 2025-07-24 08:24:26 +00:00
Douglas Creager e0149cd9f3
[ty] Return a tuple spec from the iterator protocol (#19496)
This PR updates our iterator protocol machinery to return a tuple spec
describing the elements that are returned, instead of a type. That
allows us to track heterogeneous iterators more precisely, and
consolidates the logic in unpacking and splatting, which are the two
places where we can take advantage of that more precise information.
(Other iterator consumers, like `for` loops, have to collapse the
iterated elements down to a single type regardless, and we provide a new
helper method on `TupleSpec` to perform that summarization.)
2025-07-23 17:11:44 -04:00
David Peter 2a00eca66b
[ty] Exhaustiveness checking & reachability for `match` statements (#19508)
## Summary

Implements proper reachability analysis and — in effect — exhaustiveness
checking for `match` statements. This allows us to check the following
code without any errors (leads to *"can implicitly return `None`"* on
`main`):

```py
from enum import Enum, auto

class Color(Enum):
    RED = auto()
    GREEN = auto()
    BLUE = auto()

def hex(color: Color) -> str:
    match color:
        case Color.RED:
            return "#ff0000"
        case Color.GREEN:
            return "#00ff00"
        case Color.BLUE:
            return "#0000ff"
```

Note that code like this already worked fine if there was a
`assert_never(color)` statement in a catch-all case, because we would
then consider that `assert_never` call terminal. But now this also works
without the wildcard case. Adding a member to the enum would still lead
to an error here, if that case would not be handled in `hex`.

What needed to happen to support this is a new way of evaluating match
pattern constraints. Previously, we would simply compare the type of the
subject expression against the patterns. For the last case here, the
subject type would still be `Color` and the value type would be
`Literal[Color.BLUE]`, so we would infer an ambiguous truthiness.

Now, before we compare the subject type against the pattern, we first
generate a union type that corresponds to the set of all values that
would have *definitely been matched* by previous patterns. Then, we
build a "narrowed" subject type by computing `subject_type &
~already_matched_type`, and compare *that* against the pattern type. For
the example here, `already_matched_type = Literal[Color.RED] |
Literal[Color.GREEN]`, and so we have a narrowed subject type of `Color
& ~(Literal[Color.RED] | Literal[Color.GREEN]) = Literal[Color.BLUE]`,
which allows us to infer a reachability of `AlwaysTrue`.

<details>

<summary>A note on negated reachability constraints</summary>

It might seem that we now perform duplicate work, because we also record
*negated* reachability constraints. But that is still important for
cases like the following (and possibly also for more realistic
scenarios):

```py
from typing import Literal

def _(x: int | str):
    match x:
        case None:
            pass # never reachable
        case _:
            y = 1

    y
```

</details>

closes https://github.com/astral-sh/ty/issues/99

## Test Plan

* I verified that this solves all examples from the linked ticket (the
first example needs a PEP 695 type alias, because we don't support
legacy type aliases yet)
* Verified that the ecosystem changes are all because of removed false
positives
* Updated tests
2025-07-23 22:45:45 +02:00
David Peter 3d17897c02
[ty] Fix narrowing and reachability of class patterns with arguments (#19512)
## Summary

I noticed that our type narrowing and reachability analysis was
incorrect for class patterns that are not irrefutable. The test cases
below compare the old and the new behavior:

```py
from dataclasses import dataclass

@dataclass
class Point:
    x: int
    y: int

class Other: ...

def _(target: Point):
    y = 1

    match target:
        case Point(0, 0):
            y = 2
        case Point(x=0, y=1):
            y = 3
        case Point(x=1, y=0):
            y = 4
    
    reveal_type(y)  # revealed: Literal[1, 2, 3, 4]    (previously: Literal[2])


def _(target: Point | Other):
    match target:
        case Point(0, 0):
            reveal_type(target)  # revealed: Point
        case Point(x=0, y=1):
            reveal_type(target)  # revealed: Point    (previously: Never)
        case Point(x=1, y=0):
            reveal_type(target)  # revealed: Point    (previously: Never)
        case Other():
            reveal_type(target)  # revealed: Other    (previously: Other & ~Point)
```

## Test Plan

New Markdown test
2025-07-23 18:45:03 +02:00
Jack O'Connor 88bd82938f
[ty] highlight the argument in `static_assert` error messages (#19426)
Closes https://github.com/astral-sh/ty/issues/209.

Before:
```
error[static-assert-error]: Static assertion error: custom message
 --> test.py:2:1
  |
1 | from ty_extensions import static_assert
2 | static_assert(3 > 4, "custom message")
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
```

After:
```
error[static-assert-error]: Static assertion error: custom message
 --> test.py:2:1
  |
1 | from ty_extensions import static_assert
2 | static_assert(3 > 4, "custom message")
  | ^^^^^^^^^^^^^^-----^^^^^^^^^^^^^^^^^^^
  |               |
  |               Inferred type of argument is `Literal[False]`
  |
```
2025-07-23 08:24:12 -07:00
David Peter 5a55bab3f3
[ty] Infer single-valuedness for enums based on `int`/`str` (#19510)
## Summary

We previously didn't recognize `Literal[Color.RED]` as single-valued, if
the enum also derived from `str` or `int`:
```py
from enum import Enum

class Color(str, Enum):
    RED = "red"
    GREEN = "green"
    BLUE = "blue"

def _(color: Color):
    if color == Color.RED:
        reveal_type(color)  # previously: Color, now: Literal[Color.RED]
```

The reason for that was that `int` and `str` have "custom" `__eq__` and
`__ne__` implementations that return `bool`. We do not treat enum
literals from classes with custom `__eq__` and `__ne__` implementations
as single-valued, but of course we know that `int.__eq__` and
`str.__eq__` are well-behaved.

## Test Plan

New Markdown tests.
2025-07-23 15:55:42 +02:00
Andrew Gallant cc5885e564 [ty] Restructure submodule query around `File` dependency
This makes caching of submodules independent of whether `Module`
is itself a Salsa ingredient. In fact, this makes the work done in
the prior commit superfluous. But we're possibly keeping it as an
ingredient for now since it's a bit of a tedious change and we might
need it in the near future.

Ref https://github.com/astral-sh/ruff/pull/19495#pullrequestreview-3045736715
2025-07-23 09:46:40 -04:00
Andrew Gallant 4573a0f6a0 [ty] Make `Module` a Salsa ingredient
We want to write queries that depend on `Module` for caching. While it
seems it can be done without making `Module` an ingredient, it seems it
is best practice to do so.

[best practice to do so]: https://github.com/astral-sh/ruff/pull/19408#discussion_r2215867301
2025-07-23 09:46:40 -04:00
David Peter 905b9d7f51
[ty] Reachability analysis for `isinstance(…)` branches (#19503)
## Summary

Add more precise type inference for a limited set of `isinstance(…)`
calls, i.e. return `Literal[True]` if we can be sure that this is the
correct result. This improves exhaustiveness checking / reachability
analysis for if-elif-else chains with `isinstance` checks. For example:

```py
def is_number(x: int | str) -> bool:  # no "can implicitly return `None` error here anymore
    if isinstance(x, int):
        return True
    elif isinstance(x, str):
        return False

    # code here is now detected as being unreachable
```

This PR also adds a new test suite for exhaustiveness checking.

## Test Plan

New Markdown tests

### Ecosystem analysis

The removed diagnostics look good. There's [one
case](f52c4f1afd/torchvision/io/video_reader.py (L125-L143))
where a "true positive" is removed in unreachable code. `src` is
annotated as being of type `str`, but there is an `elif isinstance(src,
bytes)` branch, which we now detect as unreachable. And so the
diagnostic inside that branch is silenced. I don't think this is a
problem, especially once we have a "graying out" feature, or a lint that
warns about unreachable code.
2025-07-23 13:06:30 +02:00
David Peter b605c3e232
[ty] Normalize single-member enums to their instance type (#19502)
## Summary

Fixes https://github.com/astral-sh/ty/issues/874

Labeling this as `internal`, since we haven't released the
enum-expansion feature.

## Test Plan

New Markdown tests
2025-07-23 10:14:20 +02:00
David Peter 385d6fa608
[ty] Detect enums if metaclass is a subtype of EnumType/EnumMeta (#19481)
## Summary

This PR implements the following section from the [typing spec on
enums](https://typing.python.org/en/latest/spec/enums.html#enum-definition):

> Enum classes can also be defined using a subclass of `enum.Enum` **or
any class that uses `enum.EnumType` (or a subclass thereof) as a
metaclass**. Note that `enum.EnumType` was named `enum.EnumMeta` prior
to Python 3.11.

part of https://github.com/astral-sh/ty/issues/183

## Test Plan

New Markdown tests
2025-07-23 08:46:51 +02:00
Jack O'Connor ba070bb6d5
[ty] perform type narrowing for places marked `global` too (#19381)
Fixes https://github.com/astral-sh/ty/issues/311.
2025-07-22 16:42:10 -07:00
Micha Reiser dc10ab81bd
[ty] Use `ThinVec` for sub segments in `PlaceExpr` (#19470) 2025-07-22 20:39:39 +02:00
Douglas Creager 7673d46b71
[ty] Splat variadic arguments into parameter list (#18996)
This PR updates our call binding logic to handle splatted arguments.

Complicating matters is that we have separated call bind analysis into
two phases: parameter matching and type checking. Parameter matching
looks at the arity of the function signature and call site, and assigns
arguments to parameters. Importantly, we don't yet know the type of each
argument! This is needed so that we can decide whether to infer the type
of each argument as a type form or value form, depending on the
requirements of the parameter that the argument was matched to.

This is an issue when splatting an argument, since we need to know how
many elements the splatted argument contains to know how many positional
parameters to match it against. And to know how many elements the
splatted argument has, we need to know its type.

To get around this, we now make the assumption that splatted arguments
can only be used with value-form parameters. (If you end up splatting an
argument into a type-form parameter, we will silently pass in its
value-form type instead.) That allows us to preemptively infer the
(value-form) type of any splatted argument, so that we have its arity
available during parameter matching. We defer inference of non-splatted
arguments until after parameter matching has finished, as before.

We reuse a lot of the new tuple machinery to make this happen — in
particular resizing the tuple spec representing the number of arguments
passed in with the tuple length representing the number of parameters
the splat was matched with.

This work also shows that we might need to change how we are performing
argument expansion during overload resolution. At the moment, when we
expand parameters, we assume that each argument will still be matched to
the same parameters as before, and only retry the type-checking phase.
With splatted arguments, this is no longer the case, since the inferred
arity of each union element might be different than the arity of the
union as a whole, which can affect how many parameters the splatted
argument is matched to. See the regression test case in
`mdtest/call/function.md` for more details.
2025-07-22 14:33:08 -04:00
David Peter 64e5780037
[ty] Consistent use of American english (in rules) (#19488)
## Summary

Just noticed this as a minor inconsistency in our rules, and had Claude
do a few more automated replacements.
2025-07-22 16:10:38 +02:00
David Peter da8aa6a631
[ty] Support iterating over enums (#19486)
## Summary

Infer the correct type in a scenario like this:

```py
class Color(Enum):
    RED = 1
    GREEN = 2
    BLUE = 3

for color in Color:
    reveal_type(color)  # revealed: Color
```

We should eventually support this out-of-the-box when
https://github.com/astral-sh/ty/issues/501 is implemented. For this
reason, @AlexWaygood would prefer to keep things as they are (we
currently infer `Unknown`, so false positives seem unlikely). But it
seemed relatively easy to support, so I'm opening this for discussion.

part of https://github.com/astral-sh/ty/issues/183

## Test Plan

Adapted existing test.

## Ecosystem analysis

```diff
- warning[unused-ignore-comment] rotkehlchen/chain/aggregator.py:591:82: Unused blanket `type: ignore` directive
```

This `unused-ignore-comment` goes away due to a new true positive.
2025-07-22 16:09:28 +02:00
David Peter ee69d38000
Fix panic for illegal `Literal[…]` annotations with inner subscript expressions (#19489)
## Summary

Fixes pull-types panics for illegal annotations like
`Literal[object[index]]`.

Originally reported by @AlexWaygood

## Test Plan

* Verified that this caused panics in the playground, when typing (and
potentially hovering over) `x: Literal[obj[0]]`.
* Added a regression test
2025-07-22 14:07:20 +00:00
Brent Westbrook fd335eb8b7
Move fix suggestion to subdiagnostic (#19464)
Summary
--

This PR tweaks Ruff's internal usage of the new diagnostic model to more
closely
match the intended use, as I understand it. Specifically, it moves the
fix/help
suggestion from the primary annotation's message to a subdiagnostic. In
turn, it
adds the secondary/noqa code as the new primary annotation message. As
shown in
the new `ruff_db` tests, this more closely mirrors Ruff's current
diagnostic
output.

I also added `Severity::Help` to render the fix suggestion with a
`help:` prefix
instead of `info:`.

These changes don't have any external impact now but should help a bit
with #19415.

Test Plan
--

New full output format tests in `ruff_db`

Rendered Diagnostics
--

Full diagnostic output from `annotate-snippets` in this PR:

``` 
error[unused-import]: `os` imported but unused
  --> fib.py:1:8
   |
 1 | import os
   |        ^^
   |
 help: Remove unused import: `os`
```

Current Ruff output for the same code:

```
fib.py:1:8: F401 [*] `os` imported but unused
  |
1 | import os
  |        ^^ F401
  |
  = help: Remove unused import: `os`
```

Proposed final output after #19415:

``` 
F401 [*] `os` imported but unused
  --> fib.py:1:8
   |
 1 | import os
   |        ^^
   |
 help: Remove unused import: `os`
```

These are slightly updated from
https://github.com/astral-sh/ruff/pull/19464#issuecomment-3097377634
below to remove the extra noqa codes in the primary annotation messages
for the first and third cases.
2025-07-22 10:03:58 -04:00
Aria Desires c82fa94e0a
[ty] Implement non-stdlib stub mapping for classes and functions (#19471)
This implements mapping of definitions in stubs to definitions in the
"real" implementation using the approach described in
https://github.com/astral-sh/ty/issues/788#issuecomment-3097000287

I've tested this with goto-definition in vscode with code that uses
`colorama` and `types-colorama`.

Notably this implementation does not add support for stub-mapping stdlib
modules, which can be done as an essentially orthogonal followup in the
implementation of `resolve_real_module`.

Part of https://github.com/astral-sh/ty/issues/788
2025-07-22 12:42:55 +00:00
David Peter 6d4687c9af
[ty] Disallow illegal uses of `ClassVar` (#19483)
## Summary

It was faster to implement this then to write the ticket: Disallow
`ClassVar` annotations almost everywhere outside of class body scopes.

## Test Plan

New Markdown tests
2025-07-22 14:21:29 +02:00
David Peter 9180cd094d
[ty] Disallow `Final` in function parameter/return-type annotations (#19480)
## Summary

Disallow `Final` in function parameter- and return-type annotations.

[Typing
spec](https://typing.python.org/en/latest/spec/qualifiers.html#uppercase-final):

> `Final` may only be used in assignments or variable annotations. Using
it in any other position is an error. In particular, `Final` can’t be
used in annotations for function arguments

## Test Plan

Updated MD test
2025-07-22 13:15:19 +02:00
David Peter 9d98a66f65
[ty] Extend `Final` test suite (#19476)
## Summary

Restructures and cleans up the `typing.Final` test suite. Also adds a
few more tests with TODOs based on the [typing spec for
`typing.Final`](https://typing.python.org/en/latest/spec/qualifiers.html#uppercase-final).
2025-07-22 12:06:47 +02:00
David Peter cb60ecef6b
[ty] Minor change to diagnostic message for invalid Literal uses (#19482) 2025-07-22 11:42:12 +02:00
David Peter 215a1c55d4
[ty] Detect illegal non-enum attribute accesses in Literal annotation (#19477)
## Summary

Detect illegal attribute accesses in `Literal[X.Y]` annotations if `X`
is not an enum class.

## Test Plan

New Markdown test
2025-07-22 11:42:03 +02:00
Micha Reiser 5e29278aa2
[ty] Reduce size of `TypeInference` (#19435) 2025-07-22 11:36:36 +02:00
David Peter 30683e3a93 Revert "[ty] Detect illegal non-enum attribute accesses in Literal annotation"
This reverts commit cbc8c08016.
2025-07-22 09:19:44 +02:00
David Peter cbc8c08016 [ty] Detect illegal non-enum attribute accesses in Literal annotation 2025-07-22 09:18:50 +02:00
Alex Waygood cb5a9ff8dc
[ty] Make tuple subclass constructors sound (#19469) 2025-07-21 21:25:11 +00:00
David Peter fcdffe4ac9
[ty] Pass down specialization to generic dataclass bases (#19472)
## Summary

closes https://github.com/astral-sh/ty/issues/853

## Test Plan

Regression test
2025-07-21 20:51:58 +02:00
Douglas Creager 88de5727df
[ty] Garbage-collect reachability constraints (#19414)
This is a follow-on to #19410 that further reduces the memory usage of
our reachability constraints. When finishing the building of a use-def
map, we walk through all of the "final" states and mark only those
reachability constraints as "used". We then throw away the interior TDD
nodes of any reachability constraints that weren't marked as used.

(This helps because we build up quite a few intermediate TDD nodes when
constructing complex reachability constraints. These nodes can never be
accessed if they were _only_ used as an intermediate TDD node. The
marking step ensures that we keep any nodes that ended up being referred
to in some accessible use-def map state.)
2025-07-21 14:16:27 -04:00
David Peter b8dec79182
[ty] Implicit instance attributes declared `Final` (#19462)
## Summary

Adds proper type inference for implicit instance attributes that are
declared with a "bare" `Final` and adds `invalid-assignment` diagnostics
for all implicit instance attributes that are declared `Final` or
`Final[…]`.

## Test Plan

New and updated MD tests.

## Ecosystem analysis

```diff
pytest (https://github.com/pytest-dev/pytest)
+ error[invalid-return-type] src/_pytest/fixtures.py:1662:24: Return type does not match returned value: expected `Scope`, found `Scope | (Unknown & ~None & ~((...) -> object) & ~str) | (((str, Config, /) -> Unknown) & ~((...) -> object) & ~str) | (Unknown & ~str)
```

The definition of the `scope` attribute is [here](

5f99385635/src/_pytest/fixtures.py (L1020-L1028)).
Looks like this is a new false positive due to missing `TypeAlias`
support that is surfaced here because we now infer a more precise type
for `FixtureDef._scope`.
2025-07-21 20:01:07 +02:00
David Peter dc66019fbc
[ty] Expansion of enums into unions of literals (#19382)
## Summary

Implement expansion of enums into unions of enum literals (and the
reverse operation). For the enum below, this allows us to understand
that `Color = Literal[Color.RED, Color.GREEN, Color.BLUE]`, or that
`Color & ~Literal[Color.RED] = Literal[Color.GREEN, Color.BLUE]`. This
helps in exhaustiveness checking, which is why we see some removed
`assert_never` false positives. And since exhaustiveness checking also
helps with understanding terminal control flow, we also see a few
removed `invalid-return-type` and `possibly-unresolved-reference` false
positives. This PR also adds expansion of enums in overload resolution
and type narrowing constructs.

```py
from enum import Enum
from typing_extensions import Literal, assert_never
from ty_extensions import Intersection, Not, static_assert, is_equivalent_to

class Color(Enum):
    RED = 1
    GREEN = 2
    BLUE = 3

type Red = Literal[Color.RED]
type Green = Literal[Color.GREEN]
type Blue = Literal[Color.BLUE]

static_assert(is_equivalent_to(Red | Green | Blue, Color))
static_assert(is_equivalent_to(Intersection[Color, Not[Red]], Green | Blue))


def color_name(color: Color) -> str:  # no error here (we detect that this can not implicitly return None)
    if color is Color.RED:
        return "Red"
    elif color is Color.GREEN:
        return "Green"
    elif color is Color.BLUE:
        return "Blue"
    else:
        assert_never(color)  # no error here
```

## Performance

I avoided an initial regression here for large enums, but the
`UnionBuilder` and `IntersectionBuilder` parts can certainly still be
optimized. We might want to use the same technique that we also use for
unions of other literals. I didn't see any problems in our benchmarks so
far, so this is not included yet.

## Test Plan

Many new Markdown tests
2025-07-21 19:37:55 +02:00
github-actions[bot] 3785e13231
[ty] Sync vendored typeshed stubs (#19461)
Co-authored-by: typeshedbot <>
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-07-21 14:01:42 +01:00
Alex Waygood c2380fa0e2
[ty] Extend tuple `__len__` and `__bool__` special casing to also cover tuple subclasses (#19289)
Co-authored-by: Brent Westbrook
2025-07-21 12:50:46 +00:00
David Peter b6579eaf04
[ty] Disallow assignment to `Final` class attributes (#19457)
## Summary

Emit errors for the following assignments:
```py
class C:
    CLASS_LEVEL_CONSTANT: Final[int] = 1

C.CLASS_LEVEL_CONSTANT = 2
C().CLASS_LEVEL_CONSTANT = 2
```

## Test Plan

Updated and new MD tests
2025-07-21 14:27:56 +02:00
Micha Reiser 84e76f4d04
[ty] Avoid second lookup for `infer_maybe_standalone_expression` (#19439) 2025-07-20 18:22:04 +02:00
UnboundVariable 0acc273286
[ty] Implemented "go to definition" support for import statements (#19428)
This PR extends the "go to declaration" and "go to definition"
functionality to support import statements — both standard imports and
"from" import forms.

---------

Co-authored-by: UnboundVariable <unbound@gmail.com>
2025-07-19 11:22:07 -07:00
Aria Desires 06f9f52e59
[ty] Add support for `@warnings.deprecated` (#19376)
* [x] basic handling
  * [x] parse and discover `@warnings.deprecated` attributes
  * [x] associate them with function definitions
  * [x] associate them with class definitions
  * [x] add a new "deprecated" diagnostic
* [x] ensure diagnostic is styled appropriately for LSPs
(DiagnosticTag::Deprecated)

* [x] functions
  * [x] fire on calls
  * [x] fire on arbitrary references 
* [x] classes
  * [x] fire on initializers
  * [x] fire on arbitrary references
* [x] methods
  * [x] fire on calls
  * [x] fire on arbitrary references
* [ ] overloads
  * [ ] fire on calls
  * [ ] fire on arbitrary references(??? maybe not ???)
  * [ ] only fire if the actual selected overload is deprecated 

* [ ] dunder desugarring (warn on deprecated `__add__` if `+` is
invoked)
* [ ] alias supression? (don't warn on uses of variables that deprecated
items were assigned to)

* [ ] import logic
  * [x] fire on imports of deprecated items
* [ ] suppress subsequent diagnostics if the import diagnostic fired (is
this handled by alias supression?)
  * [x] fire on all qualified references (`module.mydeprecated`)
  * [x] fire on all references that depend on a `*` import
    


Fixes https://github.com/astral-sh/ty/issues/153
2025-07-18 23:50:29 +00:00
Jack O'Connor e9a64e5825
[ty] make `del x` force local resolution of `x` in the current scope (#19389)
Fixes https://github.com/astral-sh/ty/issues/769.

**Updated:** The preferred approach here is to keep the SemanticIndex
simple (`del` of any name marks that name "bound" in the current scope)
and to move complexity to type inference (free variable resolution stops
when it finds a binding, unless that binding is declared `nonlocal`). As
part of this change, free variable resolution will now union the types
it finds as it walks in enclosing scopes. This approach is still
incomplete, because it doesn't consider inner scopes or sibling scopes,
but it improves the common case.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-07-18 14:58:32 -07:00
UnboundVariable 360eb7005f
[ty] Added support for "go to definition" for attribute accesses and keyword arguments (#19417)
This PR builds upon #19371. It addresses a few additional code review
suggestions and adds support for attribute accesses (expressions of the
form `x.y`) and keyword arguments within call expressions.

---------

Co-authored-by: UnboundVariable <unbound@gmail.com>
2025-07-18 11:33:57 -07:00
Micha Reiser 630c7a3152
[ty] Reduce number of inline stored definitions per place (#19409) 2025-07-18 18:28:46 +02:00
Andrew Gallant 64f9481fd0
[ty] Add caching for submodule completion suggestions (#19408)
This change makes it so we aren't doing a directory traversal every time
we ask for completions from a module. Specifically, submodules that
aren't attributes of their parent module can only be discovered by
looking at the directory tree. But we want to avoid doing a directory
scan unless we think there are changes.

To make this work, this change does a little bit of surgery to
`FileRoot`. Previously, a `FileRoot` was only used for library search
paths. Its revision was bumped whenever a file in that tree was added,
deleted or even modified (to support the discovery of `pth` files and
changes to its contents). This generally seems fine since these are
presumably dependency paths that shouldn't change frequently.

In this change, we add a `FileRoot` for the project. But having the
`FileRoot`'s revision bumped for every change in the project makes
caching based on that `FileRoot` rather ineffective. That is, cache
invalidation will occur too aggressively. To the point that there is
little point in adding caching in the first place. To mitigate this, a
`FileRoot`'s revision is only bumped on a change to a child file's
contents when the `FileRoot` is a `LibrarySearchPath`. Otherwise, we
only bump the revision when a file is created or added.

The effect is that, at least in VS Code, when a new module is added or
removed, this change is picked up and the cache is properly invalidated.
Other LSP clients with worse support for file watching (which seems to
be the case for the CoC vim plugin that I use) don't work as well. Here,
the cache is less likely to be invalidated which might cause completions
to have stale results. Unless there's an obvious way to fix or improve
this, I propose punting on improvements here for now.
2025-07-18 11:54:27 -04:00
Dhruv Manilawala 99d0ac60b4
[ty] Track open files in the server (#19264)
## Summary

This PR updates the server to keep track of open files both system and
virtual files.

This is done by updating the project by adding the file in the open file
set in `didOpen` notification and removing it in `didClose`
notification.

This does mean that for workspace diagnostics, ty will only check open
files because the behavior of different diagnostic builder is to first
check `is_file_open` and only add diagnostics for open files. So, this
required updating the `is_file_open` model to be `should_check_file`
model which validates whether the file needs to be checked based on the
`CheckMode`. If the check mode is open files only then it will check
whether the file is open. If it's all files then it'll return `true` by
default.

Closes: astral-sh/ty#619

## Test Plan

### Before

There are two files in the project: `__init__.py` and `diagnostics.py`.

In the video, I'm demonstrating the old behavior where making changes to
the (open) `diagnostics.py` file results in re-parsing the file:


https://github.com/user-attachments/assets/c2ac0ecd-9c77-42af-a924-c3744b146045

### After

Same setup as above.

In the video, I'm demonstrating the new behavior where making changes to
the (open) `diagnostics.py` file doesn't result in re-parting the file:


https://github.com/user-attachments/assets/7b82fe92-f330-44c7-b527-c841c4545f8f
2025-07-18 19:33:35 +05:30
Andrew Gallant ba7ed3a6f9
[ty] Use `…` as the "cut" indicator in diagnostic rendering (#19420)
This makes ty match ruff's behavior. Specifically, we want to use `…`
instead of the default `...` because `...` has special significance in
Python.
2025-07-18 07:46:48 -04:00
justin 39b41838f3
[ty] synthesize __setattr__ for frozen dataclasses (#19307)
## Summary

Synthesize a `__setattr__` method with a return type of `Never` for
frozen dataclasses.

https://docs.python.org/3/library/dataclasses.html#frozen-instances

https://docs.python.org/3/library/dataclasses.html#dataclasses.FrozenInstanceError

### Related
https://github.com/astral-sh/ty/issues/111
https://github.com/astral-sh/ruff/pull/17974#discussion_r2108527106
https://github.com/astral-sh/ruff/pull/18347#discussion_r2128174665

## Test Plan

New Markdown tests

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-07-18 11:35:05 +02:00
Micha Reiser 1765014be3
[ty] Shrink reachability constraints (#19410) 2025-07-18 07:36:18 +02:00
Douglas Creager 4aee0398cb
[ty] Show the raw argument type in `reveal_type` (#19400)
This PR is changes how `reveal_type` determines what type to reveal, in
a way that should be a no-op to most callers.

Previously, we would reveal the type of the first parameter, _after_ all
of the call binding machinery had done its work. This includes inferring
the specialization of a generic function, and then applying that
specialization to all parameter and argument types, which is relevant
since the typeshed definition of `reveal_type` is generic:

```pyi
def reveal_type(obj: _T, /) -> _T: ...
```

Normally this does not matter, since we infer `_T = [arg type]` and
apply that to the parameter type, yielding `[arg type]`. But applying
that specialization also simplifies the argument type, which makes
`reveal_type` less useful as a debugging aid when we want to see the
actual, raw, unsimplified argument type.

With this patch, we now grab the original unmodified argument type and
reveal that instead.

In addition to making the debugging aid example work, this also makes
our `reveal_type` implementation more robust to custom typeshed
definitions, such as

```py
def reveal_type(obj: Any) -> Any: ...
```

(That custom definition is probably not what anyone would want, since
you wouldn't be able to depend on the return type being equivalent to
the argument type, but still)
2025-07-17 16:50:29 -04:00
UnboundVariable fae0b5c89e
[ty] Initial implementation of declaration and definition providers. (#19371)
This PR implements "go to definition" and "go to declaration"
functionality for name nodes only. Future PRs will add support for
attributes, module names in import statements, keyword argument names,
etc.

This PR:
* Registers a declaration and definition request handler for the
language server.
* Splits out the `goto_type_definition` into its own module. The `goto`
module contains functionality that is common to `goto_type_definition`,
`goto_declaration` and `goto_definition`.
* Roughs in a new module `stub_mapping` that is not yet implemented. It
will be responsible for mapping a definition in a stub file to its
corresponding definition(s) in an implementation (source) file.
* Adds a new IDE support function `definitions_for_name` that collects
all of the definitions associated with a name and resolves any imports
(recursively) to find the original definitions associated with that
name.
* Adds a new `VisibleAncestorsIter` stuct that iterates up the scope
hierarchy but skips scopes that are not visible to starting scope.

---------

Co-authored-by: UnboundVariable <unbound@gmail.com>
2025-07-16 15:07:24 -07:00
Matthew Mckee cbe94b094b
[ty] Support empty function bodies in `if TYPE_CHECKING` blocks (#19372)
## Summary

Resolves https://github.com/astral-sh/ty/issues/339

Supports having a blank function body inside `if TYPE_CHECKING` block or
in the elif or else of a `if not TYPE_CHECKING` block.

```py
if TYPE_CHECKING:
    def foo() -> int: ...

if not TYPE_CHECKING: ...
else:     
    def bar() -> int: ...
```

## Test Plan

Update `function/return_type.md`

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-07-16 14:48:04 -06:00
Jack O'Connor 64ac7d7dbf
[ty] use the name span rather than the statement span for unresolved `global` lints (#19379)
This is a follow-up to https://github.com/astral-sh/ruff/pull/19344 that
improves the error formatting slightly. For example with this program:

```py
def f():
    global foo, bar
```

Before we printed:

```
1 | def f():
2 |     global foo, bar
  |     ^^^^^^^^^^^^^^^ `foo` has no declarations or bindings in the global scope
...
1 | def f():
2 |     global foo, bar
  |     ^^^^^^^^^^^^^^^ `bar` has no declarations or bindings in the global scope
```

Now we print:

```
1 | def f():
2 |     global foo, bar
  |            ^^^ `foo` has no declarations or bindings in the global scope
...
1 | def f():
2 |     global foo, bar
  |                 ^^^ `bar` has no declarations or bindings in the global scope
```

---------

Co-authored-by: Micha Reiser <micha@reiser.io>
2025-07-16 15:34:47 +00:00
Jack O'Connor 5f2e855c29 allow reads of "free" variables to refer to a `global` declaration
Previously this worked if there was also a binding in the same scope as
the `global` declaration (probably almost always the case), but CPython
doesn't require this.

This change surfaced an error in an existing test, where a global
variable was only ever declared and bound using the `global` keyword,
and never mentioned explicitly in the global scope. @AlexWaygood
suggested we probably want to keep that requirement, so I'm adding an a
new test for that on top of fixing the failing test.
2025-07-16 08:30:42 -07:00
Jack O'Connor 3b4667ec32 respect annotation-only declarations in `infer_place_load` 2025-07-16 08:30:42 -07:00
Jack O'Connor e73a8ba571 lint on the `global` keyword if there's no explicit definition in the global scope 2025-07-15 16:56:54 -07:00
David Peter a1edb69ea5
[ty] Enum literal types (#19328)
## Summary

Add a new `Type::EnumLiteral(…)` variant and infer this type for member
accesses on enums.

**Example**: No more `@Todo` types here:
```py
from enum import Enum

class Answer(Enum):
    YES = 1
    NO = 2

    def is_yes(self) -> bool:
        return self == Answer.YES

reveal_type(Answer.YES)  # revealed: Literal[Answer.YES]
reveal_type(Answer.YES == Answer.NO)  # revealed: Literal[False]
reveal_type(Answer.YES.is_yes())  # revealed: bool
```

## Test Plan

* Many new Markdown tests for the new type variant
* Added enum literal types to property tests, ran property tests

## Ecosystem analysis

Summary:

Lots of false positives removed. All of the new diagnostics are
either new true positives (the majority) or known problems. Click for
detailed analysis</summary>

Details:

```diff
AutoSplit (https://github.com/Toufool/AutoSplit)
+ error[call-non-callable] src/capture_method/__init__.py:137:9: Method `__getitem__` of type `bound method CaptureMethodDict.__getitem__(key: Never, /) -> type[CaptureMethodBase]` is not callable on object of type `CaptureMethodDict`
+ error[call-non-callable] src/capture_method/__init__.py:147:9: Method `__getitem__` of type `bound method CaptureMethodDict.__getitem__(key: Never, /) -> type[CaptureMethodBase]` is not callable on object of type `CaptureMethodDict`
+ error[call-non-callable] src/capture_method/__init__.py:148:1: Method `__getitem__` of type `bound method CaptureMethodDict.__getitem__(key: Never, /) -> type[CaptureMethodBase]` is not callable on object of type `CaptureMethodDict`
```

New true positives. That `__getitem__` method is apparently annotated
with `Never` to prevent developers from using it.


```diff
dd-trace-py (https://github.com/DataDog/dd-trace-py)
+ error[invalid-assignment] ddtrace/vendor/psutil/_common.py:29:5: Object of type `None` is not assignable to `Literal[AddressFamily.AF_INET6]`
+ error[invalid-assignment] ddtrace/vendor/psutil/_common.py:33:5: Object of type `None` is not assignable to `Literal[AddressFamily.AF_UNIX]`
```

Arguably true positives:
e0a772c28b/ddtrace/vendor/psutil/_common.py (L29)

```diff
ignite (https://github.com/pytorch/ignite)
+ error[invalid-argument-type] tests/ignite/engine/test_custom_events.py:190:34: Argument to bound method `__call__` is incorrect: Expected `((...) -> Unknown) | None`, found `Literal["123"]`
+ error[invalid-argument-type] tests/ignite/engine/test_custom_events.py:220:37: Argument to function `default_event_filter` is incorrect: Expected `Engine`, found `None`
+ error[invalid-argument-type] tests/ignite/engine/test_custom_events.py:220:43: Argument to function `default_event_filter` is incorrect: Expected `int`, found `None`
+ error[call-non-callable] tests/ignite/engine/test_custom_events.py:561:9: Object of type `CustomEvents` is not callable
+ error[invalid-argument-type] tests/ignite/metrics/test_frequency.py:50:38: Argument to bound method `attach` is incorrect: Expected `Events`, found `CallableEventWithFilter`
```

All true positives. Some of them are inside `pytest.raises(TypeError,
…)` blocks 🙃

```diff
meson (https://github.com/mesonbuild/meson)
+ error[invalid-argument-type] unittests/internaltests.py:243:51: Argument to bound method `__init__` is incorrect: Expected `bool`, found `Literal[MachineChoice.HOST]`
+ error[invalid-argument-type] unittests/internaltests.py:271:51: Argument to bound method `__init__` is incorrect: Expected `bool`, found `Literal[MachineChoice.HOST]`
```

New true positives. Enum literals can not be assigned to `bool`, even if
their value types are `0` and `1`.

```diff
poetry (https://github.com/python-poetry/poetry)
+ error[invalid-assignment] src/poetry/console/exceptions.py:101:5: Object of type `Literal[""]` is not assignable to `InitVar[str]`
```

New false positive, missing support for `InitVar`.

```diff
prefect (https://github.com/PrefectHQ/prefect)
+ error[invalid-argument-type] src/integrations/prefect-dask/tests/test_task_runners.py:193:17: Argument is incorrect: Expected `StateType`, found `Literal[StateType.COMPLETED]`
```

This is confusing. There are two definitions
([one](74d8cd93ee/src/prefect/client/schemas/objects.py (L89-L100)),
[two](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/schemas/states.py#L40))
of the `StateType` enum. Here, we're trying to assign one to the other.
I don't think that should be allowed, so this is a true positive (?).

```diff
python-htmlgen (https://github.com/srittau/python-htmlgen)
+ error[invalid-assignment] test_htmlgen/form.py:51:9: Object of type `str` is not assignable to attribute `autocomplete` of type `Autocomplete | None`
+ error[invalid-assignment] test_htmlgen/video.py:38:9: Object of type `str` is not assignable to attribute `preload` of type `Preload | None`
```

True positives. [The stubs are
wrong](01e3b911ac/htmlgen/form.pyi (L8-L10)).
These should not contain type annotations, but rather just `OFF = ...`.

```diff
rotki (https://github.com/rotki/rotki)
+ error[invalid-argument-type] rotkehlchen/tests/unit/test_serialization.py:62:30: Argument to bound method `deserialize` is incorrect: Expected `str`, found `Literal[15]`
```

New true positive.

```diff
vision (https://github.com/pytorch/vision)
+ error[unresolved-attribute] test/test_extended_models.py:302:17: Type `type[WeightsEnum]` has no attribute `DEFAULT`
+ error[unresolved-attribute] test/test_extended_models.py:302:58: Type `type[WeightsEnum]` has no attribute `DEFAULT`
```

Also new true positives. No `DEFAULT` member exists on `WeightsEnum`.
2025-07-15 21:31:53 +02:00
github-actions[bot] a0d4e1f854
[ty] Sync vendored typeshed stubs (#19368)
Co-authored-by: typeshedbot <>
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-07-15 18:14:46 +00:00
Jack O'Connor a357a68fc9 distinguish references from definitions in `infer_nonlocal`
The initial implementation of `infer_nonlocal` landed in
https://github.com/astral-sh/ruff/pull/19112 fails to report an error
for this example:

```py
x = 1
def f():
    # This is only a usage of `x`, not a definition. It shouldn't be
    # enough to make the `nonlocal` statement below allowed.
    print(x)
    def g():
        nonlocal x
```

Fix this by continuing to walk enclosing scopes when the place we've
found isn't bound, declared, or `nonlocal`.
2025-07-15 07:55:40 -07:00
Douglas Creager f4d0273532
[ty] Combine CallArguments and CallArgumentTypes (#19337)
We previously had separate `CallArguments` and `CallArgumentTypes` types
in support of our two-phase call binding logic. `CallArguments` would
store only the arity/kind of each argument (positional, keyword,
variadic, etc). We then performed parameter matching using only this
arity/kind information, and then infered the type of each argument,
placing the result of this second phase into a new `CallArgumentTypes`.

In #18996, we will need to infer the types of splatted arguments
_before_ performing parameter matching, since we need to know the
argument type to accurately infer its length, which informs how many
parameters the splatted argument is matched against.

That makes this separation of Rust types no longer useful. This PR
merges everything back into a single `CallArguments`. In the case where
we are performing two-phase call binding, the types will be initialized
to `None`, and updated to the actual argument type during the second
`check_types` phase.

_[This is a refactoring in support of fixing the merge conflicts on
#18996. I've pulled this out into a separate PR to make it easier to
review in isolation.]_
2025-07-15 10:20:58 -04:00
Alex Waygood 002f9057db
[ty] Reduce false positives for `TypedDict` types (#19354) 2025-07-15 12:47:19 +01:00
Alex Waygood 2c9da80985
[ty] Use `Type::string_literal()` more (#19352) 2025-07-15 11:09:07 +00:00
Micha Reiser e506296cec
[ty] Make use of salsa `Lookup` when interning values (#19347) 2025-07-15 09:54:43 +02:00
github-actions[bot] 4f60f0e925
[ty] Sync vendored typeshed stubs (#19334)
Co-authored-by: typeshedbot <>
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-07-14 17:34:09 +01:00
Andrew Gallant f7973ac870 [ty] Fix handling of metaclasses in `object.<CURSOR>` completions
Basically, we weren't quite using `Type::member` in every case
correctly. Specifically, this example from @sharkdp:

```
class Meta(type):
    @property
    def meta_attr(self) -> int:
        return 0

class C(metaclass=Meta): ...

C.<CURSOR>
```

While we would return `C.meta_attr` here, we were claiming its type was
`property`. But its type should be `int`.

Ref https://github.com/astral-sh/ruff/pull/19216#discussion_r2197065241
2025-07-14 08:24:23 -04:00
Micha Reiser 3560f86450
[ty] Use an interval map for scopes by expression (#19025) 2025-07-14 13:50:58 +02:00
David Peter f22da352db
[ty] List all `enum` members (#19283)
## Summary

Adds a way to list all members of an `Enum` and implements almost all of
the mechanisms by which members are distinguished from non-members
([spec](https://typing.python.org/en/latest/spec/enums.html#defining-members)).
This has no effect on actual enums, so far.

## Test Plan

New Markdown tests using `ty_extensions.enum_members`.
2025-07-14 13:18:17 +02:00
Micha Reiser 90026047f9
[ty] Use python version and path from Python extension (#19012) 2025-07-14 09:47:27 +00:00
Jack O'Connor 78bd73f25a [ty] add support for `nonlocal` statements 2025-07-11 09:44:54 -07:00
Alex Waygood c9df4ddf6a [ty] Add completions for submodule imports
While we did previously support submodule completions via our
`all_members` API, that only works when submodules are attributes of
their parent module. For example, `os.path`. But that didn't work when
the submodule was not an attribute of its parent. For example,
`http.client`. To make the latter work, we read the directory of the
parent module to discover its submodules.
2025-07-11 10:06:35 -04:00
Andrew Gallant 948463aafa [ty] Move `SystemOrVendoredPathRef`
This moves the type and adds a few methods so that it can
be used elsewhere.
2025-07-11 10:06:35 -04:00
Alex Waygood a67630f907
[ty] Filter out private type aliases from stub files when offering autocomplete suggestions (#19282) 2025-07-11 13:20:16 +00:00
UnboundVariable b0b65c24ff
[ty] Initial implementation of signature help provider (#19194)
This PR includes:
* Implemented core signature help logic
* Added new docstring method on Definition that returns a docstring for
function and class definitions
* Modified the display code for Signature that allows a signature string
to be broken into text ranges that correspond to each parameter in the
signature
* Augmented Signature struct so it can track the Definition for a
signature when available; this allows us to find the docstring
associated with the signature
* Added utility functions for parsing parameter documentation from three
popular docstring formats (Google, NumPy and reST)
* Implemented tests for all of the above

"Signature help" is displayed by an editor when you are typing a
function call expression. It is typically triggered when you type an
open parenthesis. The language server provides information about the
target function's signature (or multiple signatures), documentation, and
parameters.

Here is how this appears:


![image](https://github.com/user-attachments/assets/40dce616-ed74-4810-be62-42a5b5e4b334)

---------

Co-authored-by: UnboundVariable <unbound@gmail.com>
Co-authored-by: Micha Reiser <micha@reiser.io>
2025-07-10 19:32:00 -07:00
Micha Reiser 87f6f08ef5
[ty] Make `check_file` a salsa query (#19255)
## Summary
We noticed that all files get reparsed when workspace diagnostics are
enabled.

I realised that this is because `check_file_impl` access the parsed
module but itself isn't a salsa query.
This pr makes `check_file_impl` a salsa query, so that we only access
the `parsed_module` when the file actually changed. I decided to remove
the salsa query from `check_types` because most functions it calls are
salsa queries itself and having both `check_types` and `check_file` as
salsa querise has the downside that we double cache the diagnostics.

## Test Plan

**Before**

```
2025-07-10 12:54:16.620766000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c0c))}: File `/Users/micha/astral/test/yaml/yaml-stubs/__init__.pyi` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.621942000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c13))}: File `/Users/micha/astral/test/ignore2 2/nested-repository/main.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.622107000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c09))}: File `/Users/micha/astral/test/notebook.ipynb` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.622357000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c04))}: File `/Users/micha/astral/test/no-trailing.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.622634000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c02))}: File `/Users/micha/astral/test/simple.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.623056000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c07))}: File `/Users/micha/astral/test/open/more.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.623254000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c11))}: File `/Users/micha/astral/test/ignore-bug/backend/src/subdir/log/some_logging_lib.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.623450000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c0f))}: File `/Users/micha/astral/test/yaml/tomllib/__init__.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.624599000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c05))}: File `/Users/micha/astral/test/create.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.624784000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c00))}: File `/Users/micha/astral/test/lib.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.624911000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c0a))}: File `/Users/micha/astral/test/sub/test.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.625032000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c12))}: File `/Users/micha/astral/test/ignore2/nested-repository/main.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.625101000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c08))}: File `/Users/micha/astral/test/open/test.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.625227000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c03))}: File `/Users/micha/astral/test/pseudocode_with_bom.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.625353000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c0b))}: File `/Users/micha/astral/test/yaml/yaml-stubs/loader.pyi` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.625543000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c01))}: File `/Users/micha/astral/test/test_trailing.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.625616000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c0d))}: File `/Users/micha/astral/test/yaml/tomllib/_re.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.625667000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c06))}: File `/Users/micha/astral/test/yaml/main.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.625779000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c10))}: File `/Users/micha/astral/test/yaml/tomllib/_types.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.627526000  WARN request{id=19 method="workspace/diagnostic"}:Project::check:check_file{file=file(Id(c0e))}: File `/Users/micha/astral/test/yaml/tomllib/_parser.py` was reparsed after being collected in the current Salsa revision
2025-07-10 12:54:16.627959000 DEBUG request{id=19 method="workspace/diagnostic"}:Project::check: Checking all files took 0.007s
```

Now, no more logs regarding reparsing
2025-07-10 18:46:56 +05:30
Alex Waygood 59114d0301
[ty] Consolidate submodule resolving code between `types.rs` and `ide_support.rs` (#19256) 2025-07-10 13:10:09 +00:00
Micha Reiser 492f5bf2aa
[ty] Remove countme from salsa-structs (#19257) 2025-07-10 11:45:09 +00:00
Alex Waygood 934aaa23f3
[ty] Improve and document equivalence for module-literal types (#19243) 2025-07-10 09:11:10 +00:00
Alex Waygood 59aa869724
[ty] Optimize protocol subtyping by removing expensive and unnecessary equivalence check from the top of `Type::has_relation_to()` (#19230) 2025-07-10 09:42:27 +01:00
Andrew Gallant 1eff0300d3 [ty] Add "kind" to completion suggestions
This makes use of the new `Type` field on `Completion` to figure out the
"kind" of a `Completion`.

The mapping here is perhaps a little suspect for some cases.

Closes astral-sh/ty#775
2025-07-09 12:03:56 -04:00
Andrew Gallant fea84e8777 [ty] Add type information to `all_members` API
Since we generally need (so far) to get the type information of each
suggestion to figure out its boundness anyway, we might as well expose
it here. Completions want to use this information to enhance the
metadata on each suggestion for a more pleasant user experience.

For the most part, this was pretty straight-forward. The most exciting
part was in computing the types for instance attributes. I'm not 100%
sure it's correct or is the best way to do it.
2025-07-09 12:03:56 -04:00
Andrew Gallant 79fe538458 [ty] Expand API of `all_members` to return a struct
This commit doesn't change any behavior, but makes it so `all_members`
returns a `Vec<Member>` instead of `Vec<Name>`, where a `Member`
contains a `Name`. This gives us an expansion point to include other
data (such as the type of the `Name`).
2025-07-09 12:03:56 -04:00
Matthew Mckee f32f7a3b48
[ty] Fix `ClassLiteral.into_callable` for dataclasses (#19192)
## Summary

Change `ClassLiteral.into_callable` to also look for `__init__` functions
of type `Type::Callable` (such as synthesized `__init__` functions of
dataclasses).

Fixes https://github.com/astral-sh/ty/issues/760

## Test Plan

Add subtype test

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-07-09 10:04:55 +02:00
David Peter 68106dd631
[ty] `dataclasses.field` support (#19140)
## Summary

Add an initial set of tests for `dataclasses.field`.
2025-07-09 09:18:08 +02:00
David Peter ab3af924ef
[ty] Fix panic for attribute expressions with empty value (#19069)
## Summary

closes https://github.com/astral-sh/ty/issues/738

## Test Plan

Added corpus test
2025-07-09 08:46:33 +02:00
Matthew Mckee 05139a323b
[ty] Return `CallableType` from `BoundMethodType.into_callable_type` (#19193) 2025-07-08 20:33:43 +01:00
David Peter 1a099886ab
[ty] Improved diagnostic for reassignments of `Final` symbols (#19214)
## Summary

Implement [this
suggestion](https://github.com/astral-sh/ruff/pull/19178#discussion_r2192658146)
by @AlexWaygood.


![image](https://github.com/user-attachments/assets/f183d691-ef6e-43a2-b005-3a32205bc408)
2025-07-08 20:29:07 +02:00
David Peter a8f2c26143
[ty] Use full range for assignment definitions (#19211)
## Summary

Fix the `full_range` function for (annotated) assignment definition
kinds.

## Test Plan

Update snapshot tests
2025-07-08 19:51:09 +02:00
Alex Waygood 7533a0bfdb
[ty] Upgrade mypy_primer (#19207) 2025-07-08 15:56:54 +01:00
Charlie Marsh 3ee3434187
Auto-generate environment variable references for ty (#19205)
## Summary

This PR mirrors the environment variable implementation we have in uv:
efc361223c/crates/uv-static/src/env_vars.rs (L6-L7).

See: https://github.com/astral-sh/ty/issues/773.
2025-07-08 10:48:31 -04:00
David Peter 149350bf39
[ty] Enforce `typing.Final` (#19178)
## Summary

Emit a diagnostic when a `Final`-qualified symbol is modified. This
first iteration only works for name targets. Tests with TODO comments
were added for attribute assignments as well.

related ticket: https://github.com/astral-sh/ty/issues/158

## Ecosystem impact

Correctly identified [modification of a `Final`
symbol](7b4164a5f2/sphinx/__init__.py (L44))
(behind a `# type: ignore`):
```diff
- warning[unused-ignore-comment] sphinx/__init__.py:44:56: Unused blanket `type: ignore` directive
```
And the same
[here](5471a37e82/src/trio/_core/_run.py (L128)):
```diff
- warning[unused-ignore-comment] src/trio/_core/_run.py:128:45: Unused blanket `type: ignore` directive
```

## Test Plan

New Markdown tests
2025-07-08 16:26:09 +02:00
David Peter ce2bdb9357
[ty] Conditionally defined dataclass fields (#19197)
## Summary

Fixes a bug where conditionally defined dataclass fields were previously
ignored.

Thanks to @lipefree for reporting this.

## Test Plan

New Markdown tests
2025-07-08 16:16:50 +02:00
Brent Westbrook 2643dc5b7a
Rename `Diagnostic::syntax_error` methods, separate `Ord` implementation (#19179)
## Summary

This PR addresses some additional feedback on #19053:

- Renaming the `syntax_error` methods to `invalid_syntax` to match the
lint id
- Moving the standalone `diagnostic_from_violation` function to
`Violation::into_diagnostic`
- Removing the `Ord` and `PartialOrd` implementations from `Diagnostic`
in favor of `Diagnostic::start_ordering`

## Test Plan

Existing tests

## Additional Follow-ups

Besides these, I also put the following comments on my todo list, but
they seemed like they might be big enough to have their own PRs:

- [Use `LintId::IOError` for IO
errors](https://github.com/astral-sh/ruff/pull/19053#discussion_r2189425922)
- [Move `Fix` and
`Edit`](https://github.com/astral-sh/ruff/pull/19053#discussion_r2189448647)
- [Avoid so many
unwraps](https://github.com/astral-sh/ruff/pull/19053#discussion_r2189465980)
2025-07-08 09:54:19 -04:00
justin 738692baff
[ty] Fix __setattr__ call check precedence during attribute assignment (#18347)
## Summary

Related:

- https://github.com/astral-sh/ty/issues/111
- https://github.com/astral-sh/ruff/pull/17974#discussion_r2108527106

Previously, when validating an attribute assignment, a `__setattr__`
call check was only done if the attribute wasn't found as either a class
member or instance member

This PR changes the `__setattr__` call check to be attempted first,
prior to the "[normal
mechanism](https://docs.python.org/3/reference/datamodel.html#object.__setattr__)",
as a defined `__setattr__` should take precedence over setting an
attribute on the instance dictionary directly.

if the return type of `__setattr__` is `Never`, an `invalid-assignment`
diagnostic is emitted

Once this is merged, a subsequent PR will synthesize a `__setattr__`
method with a `Never` return type for frozen dataclasses.

## Test Plan

Existing tests + mypy_primer

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-07-08 15:34:34 +02:00
David Peter 9a4b85d845
[ty] Add tests for dataclass fields annotated with `Final` (#19202)
## Summary

Adds some tests for dataclass fields that are annotated with `Final`
(see comment
[here](https://github.com/astral-sh/ruff/pull/15768#issuecomment-3044737645)).
Turns out that nothing is needed here, everything already works as
expected (apart from the fact that we can assign to `Final` fields,
which is tracked in https://github.com/astral-sh/ty/issues/158

## Test Plan

New Markdown tests
2025-07-08 12:33:46 +00:00
David Peter 6d8c84bde9
[ty] Clarify diagnostic message (#19203)
This diagnostic message was missing the word "type"
2025-07-08 14:21:20 +02:00
Alex Waygood e16473d260
[ty] Add a new property test: all types assignable to `Iterable[object]` should be considered iterable (#19186) 2025-07-08 10:54:06 +01:00
Alex Waygood 220a584c11
[ty] Add an instance of an `Any` subclass to the property tests (#19180) 2025-07-08 10:53:50 +01:00
UnboundVariable 278f93022a
[ty] First cut at semantic token provider (#19108)
This PR implements a basic semantic token provider for ty's language
server. This allows for more accurate semantic highlighting / coloring
within editors that support this LSP functionality.

Here are screen shots that show how code appears in VS Code using the
"rainbow" theme both before and after this change.


![461737617-15630625-d4a9-4ec5-9886-77b00eb7a41a](https://github.com/user-attachments/assets/f963b55b-3195-41d1-ba38-ac2e7508d5f5)


![461737624-d6dcf5f0-7b9b-47de-a410-e202c63e2058](https://github.com/user-attachments/assets/111ca2c5-bb4f-4c8a-a0b5-6c1b2b6f246b)

The token types and modifier tags in this implementation largely mirror
those used in Microsoft's default language server for Python.

The implementation supports two LSP interfaces. The first provides
semantic tokens for an entire document, and the second returns semantic
tokens for a requested range within a document.

The PR includes unit tests. It also includes comments that document
known limitations and areas for future improvements.

---------

Co-authored-by: UnboundVariable <unbound@gmail.com>
2025-07-07 15:34:47 -07:00
Ibraheem Ahmed cd848986d7
[ty] Add separate CI job for memory usage stats (#19134)
## Summary

As discussed in https://github.com/astral-sh/ruff/pull/19059.
2025-07-07 12:17:02 -04:00
David Peter e7fb3684e8
[ty] Bare `ClassVar` annotations (#15768)
## Summary

It was recently clarified in the [typing
spec](https://typing.python.org/en/latest/spec/class-compat.html#classvar)
that bare `ClassVar` annotations are allowed. For annotated assignments
with a right hand side value, the spec requires type checkers to infer
the type as something "to which [the] value is assignable". For a value
of `2`, the spec suggests `int`, `Literal[2]`, or `Any` as examples.
Here, we choose `Unknown | Literal[2]` instead, conforming with out
usual treatment of attribute types.

closes https://github.com/astral-sh/ty/issues/211
2025-07-07 15:04:27 +02:00
Alex Waygood a6637964d2
[ty] Implement equivalence for protocols with method members (#18659)
## Summary

This PR implements the following pieces of `Protocol` semantics:
1. A protocol with a method member that does not have a fully static
signature should not be considered fully static. I.e., this protocol is
not fully static because `Foo.x` has no return type; we previously
incorrectly considered that it was:
  ```py
  class Foo(Protocol):
      def f(self): ...
  ```
2. Two protocols `P1` and `P2`, both with method members `x`, should be
considered equivalent if the signature of `P1.x` is equivalent to the
signature of `P2.x`. Currently we do not recognize this.

Implementing these semantics requires distinguishing between method
members and non-method members. The stored type of a method member must
be eagerly upcast to a `Callable` type when collecting the protocol's
interface: doing otherwise would mean that it would be hard to implement
equivalence of protocols even in the face of differently ordered unions,
since the two equivalent protocols would have different Salsa IDs even
when normalized.

The semantics implemented by this PR are that we consider something a
method member if:
1. It is accessible on the class itself; and
2. It is a function-like callable: a callable type that also has a
`__get__` method, meaning it can be used as a method when accessed on
instances.

Note that the spec has complicated things to say about classmethod
members and staticmethod members. These semantics are not implemented by
this PR; they are all deferred for now.

The infrastructure added in this PR fixes bugs in its own right, but
also lays the groundwork for implementing subtyping and assignability
rules for method members of protocols. A (currently failing) test is
added to verify this.

## Test Plan

mdtests
2025-07-07 12:28:32 +01:00
David Peter c15aa572ff
[ty] Use RHS inferred type for bare `Final` symbols (#19142)
## Summary

Infer the type of symbols with a `Final` qualifier as their
right-hand-side inferred type:
```py
x: Final = 1
y: Final[int] = 1

def _():
    reveal_type(x)  # previously: Unknown, now: Literal[1]
    reveal_type(y)  # int, same as before
```
Part of https://github.com/astral-sh/ty/issues/158

## Ecosystem analysis

### aiohttp

```diff
aiohttp (https://github.com/aio-libs/aiohttp)
+ error[invalid-argument-type] aiohttp/compression_utils.py:131:54: Argument to bound method `__init__` is incorrect: Expected `ZLibBackendProtocol`, found `<module 'zlib'>`
```

This code [creates a
protocol](a83597fa88/aiohttp/compression_utils.py (L52-L77))
that looks like
```pyi
class ZLibBackendProtocol(Protocol):
    Z_FULL_FLUSH: int
    Z_SYNC_FLUSH: int
    # more fields…
```

It then [tries to
assign](a83597fa88/aiohttp/compression_utils.py (L131))
the module literal `zlib` to that protocol. Howefer, in typeshed, these
`zlib` members are annotated like this:
```pyi
Z_FULL_FLUSH: Final = 3
Z_SYNC_FLUSH: Final = 2
```
With the proposed change here, we now infer these as `Literal[3]` /
`Literal[2]`. Since protocol members have to be assignable both ways
(invariance), we do not consider `zlib` assignable to this protocol
anymore.

That seems rather unfortunate. Not sure who is to blame here? That
`ZLibBackendProtocol` protocol should probably not annotate the members
with `int`, given that `typeshed` doesn't use an explicit annotation
here either? But what should they do instead? Annotate those fields with
`Any`?

Or is it another case where we should consider literal-widening?

FYI @AlexWaygood 

### cloud-init

```diff
cloud-init (https://github.com/canonical/cloud-init)
+ error[invalid-argument-type] tests/unittests/sources/test_smartos.py:575:32: Argument to function `oct` is incorrect: Expected `SupportsIndex`, found `int | float`
+ error[invalid-argument-type] tests/unittests/sources/test_smartos.py:593:32: Argument to function `oct` is incorrect: Expected `SupportsIndex`, found `int | float`
+ error[invalid-argument-type] tests/unittests/sources/test_smartos.py:647:35: Argument to function `oct` is incorrect: Expected `SupportsIndex`, found `int | float`
```

New false positives on expressions like
`oct(os.stat(legacy_script_f)[stat.ST_MODE])`. We now correctly infer
`stat.ST_MODE` as `Literal[1]`, because in typeshed, it is annotated as
`ST_MODE: Final = 0`. `os.stat` returns a `stat_result` which is a tuple
subclass. Accessing it at index 0 should return an `int`, but we
currently return `int | float`, presumably due to missing support for
tuple subclasses (FYI @AlexWaygood):
```pyi
class stat_result(structseq[float], tuple[int, int, int, int, int, int, int, float, float, float]):
```
In terms of `typing.Final`, things are working as expected here.


### pywin-32

Many new false positives similar to:

```diff
pywin32 (https://github.com/mhammond/pywin32)
+ error[invalid-argument-type] Pythonwin/pywin/docking/DockingBar.py:288:55: Argument to function `LoadCursor` is incorrect: Expected `PyResourceId`, found `Literal[32645]`
```

The line in question calls `win32api.LoadCursor(0, win32con.IDC_ARROW)`.
The `win32con.IDC_ARROW` symbol is annotated as [`IDC_ARROW: Final =
32512` in
typeshed](2408c028f4/stubs/pywin32/win32/lib/win32con.pyi (L594)),
but
[`LoadCursor`](2408c028f4/stubs/pywin32/win32/win32api.pyi (L197))
expects a
[`PyResourceId`](2408c028f4/stubs/pywin32/_win32typing.pyi (L1252)),
which is an empty class. So.. this seems like a true positive to me,
unless that typeshed annotation of `IDC_ARROW` is meant to imply that
the type should be `Unknown`/`Any`?

### streamlit

```diff
streamlit (https://github.com/streamlit/streamlit)
+ error[invalid-argument-type] lib/streamlit/string_util.py:163:37: Argument to bound method `translate` is incorrect: Expected `bytes`, found `bytearray`
```

This looks like a true positive? The code calls `inp.translate(None,
TEXTCHARS)`. `inp` is `bytes`, and `TEXTCHARS` is:
```py
TEXTCHARS: Final = bytearray(
    {7, 8, 9, 10, 12, 13, 27} | set(range(0x20, 0x100)) - {0x7F}
)
```
~~We now infer this as `bytearray`, but `bytes.translate` [expects
`bytes` for its `delete`
parameter](2408c028f4/stdlib/builtins.pyi (L710)).
This seems to work at runtime, so maybe the typeshed annotation is
wrong?~~ (Edit: this is now fixed in typeshed)
```pycon
>>> b"abc".translate(None, bytearray(b"b"))
b'ac'
```

## rotki

```diff
+ error[invalid-return-type] rotkehlchen/chain/ethereum/modules/yearn/decoder.py:412:13: Return type does not match returned value: expected `dict[Unknown, str]`, found `dict[Unknown, Literal["yearn-v1", "yearn-v2"]]`
```

The code in question looks like
```py
    def addresses_to_counterparties(self) -> dict[ChecksumEvmAddress, str]:
        return dict.fromkeys(self.vaults, CPT_BEEFY_FINANCE)
```
where `CPT_BEEFY_FINANCE: Final = 'beefy_finance'. We previously
inferred the value type of the returned `dict` as `Unknown`, and now we
infer it as `Literal["beefy_finance"]`, which does not match the
annotated return type because `dict` is invariant in the value type.

```diff
+ error[invalid-argument-type] rotkehlchen/tests/unit/decoders/test_curve.py:249:9: Argument is incorrect: Expected `int`, found `FVal`
```
There are true positives that were previously silenced through the
`Unknown`.

## Test Plan

New Markdown tests
2025-07-07 13:16:40 +02:00
Ivan Yakushev e0b7f496f2
[ty] Support declaration-only attributes (#19048)
## Summary

Following ty issue [#698](https://github.com/astral-sh/ty/issues/698)
this PR adds support for declarations.

closes #698

## Test Plan

Tested against mdtest (specifically attributes).

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-07-07 12:55:32 +02:00
renovate[bot] 1a03b5841b
Update pre-commit dependencies (#19162)
This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[astral-sh/ruff-pre-commit](https://redirect.github.com/astral-sh/ruff-pre-commit)
| repository | patch | `v0.12.1` -> `v0.12.2` |
| [crate-ci/typos](https://redirect.github.com/crate-ci/typos) |
repository | minor | `v1.33.1` -> `v1.34.0` |
|
[python-jsonschema/check-jsonschema](https://redirect.github.com/python-jsonschema/check-jsonschema)
| repository | patch | `0.33.1` -> `0.33.2` |
|
[woodruffw/zizmor-pre-commit](https://redirect.github.com/woodruffw/zizmor-pre-commit)
| repository | minor | `v1.10.0` -> `v1.11.0` |

---

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<details>
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###
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[Compare
Source](https://redirect.github.com/astral-sh/ruff-pre-commit/compare/v0.12.1...v0.12.2)

See: https://github.com/astral-sh/ruff/releases/tag/0.12.2

</details>

<details>
<summary>crate-ci/typos (crate-ci/typos)</summary>

###
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[Compare
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#### \[1.34.0] - 2025-06-30

##### Features

- Updated the dictionary with the [June
2025](https://redirect.github.com/crate-ci/typos/issues/1309) changes

</details>

<details>
<summary>python-jsonschema/check-jsonschema
(python-jsonschema/check-jsonschema)</summary>

###
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[Compare
Source](https://redirect.github.com/python-jsonschema/check-jsonschema/compare/0.33.1...0.33.2)

- Update vendored schemas: bitbucket-pipelines, mergify, renovate
(2025-06-29)
- Fix a bug in the evaluation of the `date-time` format on non-string
data,
which incorrectly rejected values for which `string` was one of several
  valid types. Thanks :user:`katylava`! (:issue:`571`)

</details>

<details>
<summary>woodruffw/zizmor-pre-commit
(woodruffw/zizmor-pre-commit)</summary>

###
[`v1.11.0`](https://redirect.github.com/zizmorcore/zizmor-pre-commit/releases/tag/v1.11.0)

[Compare
Source](https://redirect.github.com/woodruffw/zizmor-pre-commit/compare/v1.10.0...v1.11.0)

See: https://github.com/zizmorcore/zizmor/releases/tag/v1.11.0

</details>

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---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
2025-07-07 04:07:44 +00:00
Alex Waygood 08d8819c8a
[ty] Fix descriptor lookups for most types that overlap with `None` (#19120) 2025-07-05 19:34:23 +01:00
Abhijeet Prasad Bodas f4bd74ab6a
[ty] Correctly handle calls to functions marked as returning `Never` / `NoReturn` (#18333)
## Summary

`ty` does not understand that calls to functions which have been
annotated as having a return type of `Never` / `NoReturn` are terminal.

This PR fixes that, by adding new reachability constraints when call
expressions are seen. If the call expression evaluates to `Never`, the
code following it will be considered to be unreachable. Note that, for
adding these constraints, we only consider call expressions at the
statement level, and that too only inside function scopes. This is
because otherwise, the number of such constraints becomes too high, and
evaluating them later on during type inference results in a major
performance degradation.

Fixes https://github.com/astral-sh/ty/issues/180

## Test Plan

New mdtests.

## Ecosystem changes

This PR removes the following false-positives:
- "Function can implicitly return `None`, which is not assignable to
...".
- "Name `foo` used when possibly not defind" - because the branch in
which it is not defined has a `NoReturn` call, or when `foo` was
imported in a `try`, and the except had a `NoReturn` call.

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-07-04 11:52:52 -07:00
Carl Meyer 411cccb35e
[ty] detect cycles in Type::is_disjoint_from (#19139) 2025-07-04 06:31:44 -07:00
Carl Meyer 7712c2fd15
[ty] don't allow first-party code to shadow stdlib types module (#19128) 2025-07-04 10:36:26 +00:00
David Peter 25bdb67d9a
[ty] Remove TODOs regarding legacy generics (#19141) 2025-07-04 10:45:06 +02:00
Matthew Mckee 3be83d36a5
[ty] Add into_callable method for Type (#19130)
## Summary

Was just playing around with this, there's definitely more to do with
this function, but it seems like maybe a better option than having so
many arms in has_relation_to for (_, Callable).

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
2025-07-03 19:04:03 -07:00
Alex Waygood 333191b7f7
[ty] Rewrite `Type::any_over_type` using a new generalised `TypeVisitor` trait (#19094) 2025-07-03 18:19:23 +00:00
Brent Westbrook 77a5c5ac80
Combine `OldDiagnostic` and `Diagnostic` (#19053)
## Summary

This PR is a collaboration with @AlexWaygood from our pairing session
last Friday.

The main goal here is removing `ruff_linter::message::OldDiagnostic` in
favor of
using `ruff_db::diagnostic::Diagnostic` directly. This involved a few
major steps:

- Transferring the fields
- Transferring the methods and trait implementations, where possible
- Converting some constructor methods to free functions
- Moving the `SecondaryCode` struct
- Updating the method names

I'm hoping that some of the methods, especially those in the
`expect_ruff_*`
family, won't be necessary long-term, but I avoided trying to replace
them
entirely for now to keep the already-large diff a bit smaller.

### Related refactors

Alex and I noticed a few refactoring opportunities while looking at the
code,
specifically the very similar implementations for
`create_parse_diagnostic`,
`create_unsupported_syntax_diagnostic`, and
`create_semantic_syntax_diagnostic`.
We combined these into a single generic function, which I then copied
into
`ruff_linter::message` with some small changes and a TODO to combine
them in the
future.

I also deleted the `DisplayParseErrorType` and `TruncateAtNewline` types
for
reporting parse errors. These were added in #4124, I believe to work
around the
error messages from LALRPOP. Removing these didn't affect any tests, so
I think
they were unnecessary now that we fully control the error messages from
the
parser.

On a more minor note, I factored out some calls to the
`OldDiagnostic::filename`
(now `Diagnostic::expect_ruff_filename`) function to avoid repeatedly
allocating
`String`s in some places.

### Snapshot changes

The `show_statistics_syntax_errors` integration test changed because the
`OldDiagnostic::name` method used `syntax-error` instead of
`invalid-syntax`
like in ty. I think this (`--statistics`) is one of the only places we
actually
use this name for syntax errors, so I hope this is okay. An alternative
is to
use `syntax-error` in ty too.

The other snapshot changes are from removing this code, as discussed on

[Discord](https://discord.com/channels/1039017663004942429/1228460843033821285/1388252408848847069):


34052a1185/crates/ruff_linter/src/message/mod.rs (L128-L135)

I think both of these are technically breaking changes, but they only
affect
syntax errors and are very narrow in scope, while also pretty
substantially
simplifying the refactor, so I hope they're okay to include in a patch
release.

## Test plan

Existing tests, with the adjustments mentioned above

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-07-03 13:01:09 -04:00
Zanie Blue 1c6717b149
Filter private symbols from stubs if they are internal types (#19121)
This implements filtering of private symbols from stub files based on
type information as discussed in
https://github.com/astral-sh/ruff/pull/19102. It extends the previous
implementation to apply to all stub files, instead of just the
`builtins` module, and uses type information to retain private names
that are may be relevant at runtime.
2025-07-03 10:19:21 -05:00
David Peter e212dc2e8e
[ty] Restructure/move dataclass tests (#19117)
Before I'm adding even more dataclass-related files, let's organize them
in a separate folder.
2025-07-03 10:36:14 +00:00
Matthew Mckee 352b896c89
[ty] Add subtyping between SubclassOf and CallableType (#19026)
## Summary

Part of https://github.com/astral-sh/ty/issues/129

There were previously some false positives here.

## Test Plan

Updated `is_subtype_of.md` and `is_assignable_to.md`
2025-07-02 19:22:31 -07:00
David Peter f76d3f87cf
[ty] Allow declared-only class-level attributes to be accessed on the class (#19071)
## Summary

Allow declared-only class-level attributes to be accessed on the class:
```py
class C:
    attr: int

C.attr  # this is now allowed
``` 

closes https://github.com/astral-sh/ty/issues/384
closes https://github.com/astral-sh/ty/issues/553

## Ecosystem analysis


* We see many removed `unresolved-attribute` false-positives for code
that makes use of sqlalchemy, as expected (see changes for `prefect`)
* We see many removed `call-non-callable` false-positives for uses of
`pytest.skip` and similar, as expected
* Most new diagnostics seem to be related to cases like the following,
where we previously inferred `int` for `Derived().x`, but now we infer
`int | None`. I think this should be a
conflicting-declarations/bad-override error anyway? The new behavior may
even be preferred here?
  ```py
  class Base:
      x: int | None
  
  
  class Derived(Base):
      def __init__(self):
          self.x: int = 1
  ```
2025-07-02 18:03:56 +02:00
Micha Reiser 5f426b9f8b
[ty] Remove `ScopedExpressionId` (#19019)
## Summary

The motivation of `ScopedExpressionId` was that we have an expression
identifier that's local to a scope and, therefore, unlikely to change if
a user makes changes in another scope. A local identifier like this has
the advantage that query results may remain unchanged even if other
parts of the file change, which in turn allows Salsa to short-circuit
dependent queries.

However, I noticed that we aren't using `ScopedExpressionId` in a place
where it's important that the identifier is local. It's main use is
inside `infer` which we always run for the entire file. The one
exception to this is `Unpack` but unpack runs as part of `infer`.

Edit: The above isn't entirely correct. We used ScopedExpressionId in
TypeInference which is a query result. Now using ExpressionNodeKey does
mean that a change to the AST invalidates most if not all TypeInference
results of a single file. Salsa then has to run all dependent queries to
see if they're affected by this change even if the change was local to
another scope.

If this locality proves to be important I suggest that we create two
queries on top of TypeInference: one that returns the expression map
which is mainly used in the linter and type inference and a second that
returns all remaining fields. This should give us a similar optimization
at a much lower cost

I also considered remove `ScopedUseId` but I believe that one is still
useful because using `ExpressionNodeKey` for it instead would mean that
all `UseDefMap` change when a single AST node changes. Whether this is
important is something difficult to assess. I'm simply not familiar
enough with the `UseDefMap`. If the locality doesn't matter for the
`UseDefMap`, then a similar change could be made and `bindings_by_use`
could be changed to an `FxHashMap<UseId, Bindings>` where `UseId` is a
thin wrapper around `NodeKey`.

Closes https://github.com/astral-sh/ty/issues/721
2025-07-02 17:57:32 +02:00
David Peter 93413d3631
[ty] Update docs links (#19092)
Point everything to the new documentation at https://docs.astral.sh/ty/
2025-07-02 17:34:56 +02:00
David Peter 4cf56d7ad4
[ty] Fix lint summary wording (#19091) 2025-07-02 16:32:11 +02:00
Alex Waygood 316c1b21e2
[ty] Add some missing calls to `normalized_impl` (#19074)
## Summary

I hoped this might fix the latest stack overflows on
https://github.com/astral-sh/ruff/pull/18659... it doesn't look like it
does, but these changes seem like they're probably correct anyway...?

## Test Plan

<!-- How was it tested? -->
2025-07-01 17:57:52 +01:00
David Peter dac4e356eb
[ty] Use all reachable bindings for instance attributes and deferred lookups (#18955)
## Summary

Remove a hack in control flow modeling that was treating `return`
statements at the end of function bodies in a special way (basically
considering the state *just before* the `return` statement as the
end-of-scope state). This is not needed anymore now that #18750 has been
merged.

In order to make this work, we now use *all reachable bindings* for
purposes of finding implicit instance attribute assignments as well as
for deferred lookups of symbols. Both would otherwise be affected by
this change:
```py
def C:
    def f(self):
        self.x = 1  # a reachable binding that is not visible at the end of the scope
        return
```

```py
def f():
    class X: ...  # a reachable binding that is not visible at the end of the scope
    x: "X" = X()  # deferred use of `X`
    return
```

Implicit instance attributes also required another change. We previously
kept track of possibly-unbound instance attributes in some cases, but we
now give up on that completely and always consider *implicit* instance
attributes to be bound if we see a reachable binding in a reachable
method. The previous behavior was somewhat inconsistent anyway because
we also do not consider attributes possibly-unbound in other scenarios:
we do not (and can not) keep track of whether or not methods are called
that define these attributes.

closes https://github.com/astral-sh/ty/issues/711

## Ecosystem analysis

I think this looks very positive!

* We see an unsurprising drop in `possibly-unbound-attribute`
diagnostics (599), mostly for classes that define attributes in `try …
except` blocks, `for` loops, or `if … else: raise …` constructs. There
might obviously also be true positives that got removed, but the vast
majority should be false positives.
* There is also a drop in `possibly-unresolved-reference` /
`unresolved-reference` diagnostics (279+13) from the change to deferred
lookups.
* Some `invalid-type-form` false positives got resolved (13), because we
can now properly look up the names in the annotations.
* There are some new *true* positives in `attrs`, since we understand
the `Attribute` annotation that was previously inferred as `Unknown`
because of a re-assignment after the class definition.


## Test Plan

The existing attributes.md test suite has sufficient coverage here.
2025-07-01 14:38:36 +02:00
Alex Waygood ebf59e2bef
[ty] Rework disjointness of protocol instances vs types with possibly unbound attributes (#19043) 2025-07-01 12:47:27 +01:00
Alex Waygood c6fd11fe36
[ty] Eagerly evaluate more constraints based on the raw AST (#19068) 2025-07-01 10:17:22 +00:00
David Peter 7d468ee58a
[ty] Model reachability of star import definitions for nonlocal lookups (#19066)
## Summary

Temporarily modify `UseDefMapBuilder::reachability` for star imports in
order for new definitions to pick up the right reachability. This was
already working for `UseDefMapBuilder::place_states`, but not for
`UseDefMapBuilder::reachable_definitions`.

closes https://github.com/astral-sh/ty/issues/728

## Test Plan

Regression test
2025-07-01 11:06:37 +02:00
David Peter 4016521bf6
[ty] Eagerly evaluate `TYPE_CHECKING` constraints (#19044)
## Summary

Evaluate `TYPE_CHECKING` to `ALWAYS_TRUE` and `not TYPE_CHECKING` to
`ALWAYS_FALSE` during semantic index building. This is a follow-up to
https://github.com/astral-sh/ruff/pull/18998 and is in principle just a
performance optimization. We see some (favorable) ecosystem changes
because we can eliminate definitely-unreachable branches early now and
retain narrowing constraints without solving
https://github.com/astral-sh/ty/issues/690 first.
2025-07-01 11:05:52 +02:00
Carl Meyer 2ae0bd9464
[ty] Normalize recursive types using Any (#19003)
## Summary

This just replaces one temporary solution to recursive protocols (the
`SelfReference` mechanism) with another one (track seen types when
recursively descending in `normalize` and replace recursive references
with `Any`). But this temporary solution can handle mutually-recursive
types, not just self-referential ones, and it's sufficient for the
primer ecosystem and some other projects we are testing on to no longer
stack overflow.

The follow-up here will be to properly handle these self-references
instead of replacing them with `Any`.

We will also eventually need cycle detection on more recursive-descent
type transformations and tests.

## Test Plan

Existing tests (including recursive-protocol tests) and primer.

Added mdtest for mutually-recursive protocols that stack-overflowed
before this PR.
2025-06-30 12:07:57 -07:00
David Peter db3dcd8ad6
[ty] Eagerly simplify 'True' and 'False' constraints (#18998)
## Summary

Simplifies literal `True` and `False` conditions to `ALWAYS_TRUE` /
`ALWAYS_FALSE` during semantic index building. This allows us to eagerly
evaluate more constraints, which should help with performance (looks
like there is a tiny 1% improvement in instrumented benchmarks), but
also allows us to eliminate definitely-unreachable branches in
control-flow merging. This can lead to better type inference in some
cases because it allows us to retain narrowing constraints without
solving https://github.com/astral-sh/ty/issues/690 first:
```py
def _(c: int | None):
    if c is None:
        assert False
    
    reveal_type(c)  # int, previously: int | None
```

closes https://github.com/astral-sh/ty/issues/713

## Test Plan

* Regression test for https://github.com/astral-sh/ty/issues/713
* Made sure that all ecosystem diffs trace back to removed false
positives
2025-06-30 13:11:52 +02:00
David Peter 54769ac9f9
[ty] While loop modeling cleanup (#18994)
## Summary

I found the previous code here very confusing, and it also did some
unnecessary work. Hopefully this is a bit easier to understand.
2025-06-30 11:38:25 +02:00
med1844 0ec2ad2fa5
[ty] Emit error for invalid binary operations in type expressions (#18991)
## Summary

This PR adds diagnostic for invalid binary operators in type
expressions. It should close https://github.com/astral-sh/ty/issues/706
if merged.

Please feel free to suggest better wordings for the diagnostic message.

## Test Plan

I modified `mdtest/annotations/invalid.md` and added a test for each
binary operator, and fixed tests that was broken by the new diagnostic.
2025-06-30 10:06:01 +02:00
InSync e7aadfc28b
[ty] Add special-cased inference for `__import__(name)` and `importlib.import_module(name)` (#19008) 2025-06-29 11:49:23 +01:00