Commit Graph

221 Commits

Author SHA1 Message Date
Matthew Mckee c60b4d7f30
[ty] Add subtyping between Callable types and class literals with `__init__` (#17638)
## Summary

Allow classes with `__init__` to be subtypes of `Callable`

Fixes https://github.com/astral-sh/ty/issues/358

## Test Plan

Update is_subtype_of.md

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-05-28 13:43:07 -07:00
Douglas Creager 452f992fbc
[ty] Simplify signature types, use them in `CallableType` (#18344)
There were many fields in `Signature` and friends that really had more
to do with how a signature was being _used_ — how it was looked up,
details about an individual call site, etc. Those fields more properly
belong in `Bindings` and friends.

This is a pure refactoring, and should not affect any tests or ecosystem
projects.

I started on this journey in support of
https://github.com/astral-sh/ty/issues/462. It seemed worth pulling out
as a separate PR.

One major concrete benefit of this refactoring is that we can now use
`CallableSignature` directly in `CallableType`. (We can't use
`CallableSignature` directly in that `Type` variant because signatures
are not currently interned.)
2025-05-28 13:11:45 -04:00
Alex Waygood a5ebb3f3a2
[ty] Support ephemeral uv virtual environments (#18335) 2025-05-28 14:54:59 +00:00
David Peter bbcd7e0196
[ty] Synthetic function-like callables (#18242)
## Summary

We create `Callable` types for synthesized functions like the `__init__`
method of a dataclass. These generated functions are real functions
though, with descriptor-like behavior. That is, they can bind `self`
when accessed on an instance. This was modeled incorrectly so far.

## Test Plan

Updated tests
2025-05-28 10:00:56 +02:00
Carl Meyer 3eada01153
put similar dunder-call tests next to each other (#18343)
Follow-up from post-land review on
https://github.com/astral-sh/ruff/pull/18260
2025-05-27 12:16:41 -07:00
Alex Waygood 3e811fc369
[ty] Derive `PartialOrd, Ord` for `KnownInstanceType` (#18340) 2025-05-27 19:37:01 +01:00
Alex Waygood 743764d384
[ty] Simplify `Type::try_bool()` (#18342)
## Summary

I don't think we're ever going to add any `KnownInstanceType` variants
that evaluate to `False` in a boolean context; the
`KnownInstanceType::bool()` method just seems like unnecessary
complexity.

## Test Plan

`cargo test -p ty_python_semantic`
2025-05-27 19:32:17 +01:00
Alex Waygood e03e05d2b3
[ty] Simplify `Type::normalized` slightly (#18339) 2025-05-27 18:08:59 +00:00
Alex Waygood 9ec4a178a4
[ty] Move arviz off the list of selected primer projects (#18336) 2025-05-27 17:51:19 +01:00
Alex Waygood 6453ac9ea1
[ty] Tell the user why we inferred a certain Python version when reporting version-specific syntax errors (#18295) 2025-05-26 20:44:43 +00:00
Alex Waygood 0a11baf29c
[ty] Implement implicit inheritance from `Generic[]` for PEP-695 generic classes (#18283) 2025-05-26 20:40:16 +01:00
lipefree 1d20cf9570
[ty] Add hint if async context manager is used in non-async with statement (#18299)
# Summary

Adds a subdiagnostic hint in the following scenario where a
synchronous `with` is used with an async context manager:
```py
class Manager:
    async def __aenter__(self): ...
    async def __aexit__(self, *args): ...

# error: [invalid-context-manager] "Object of type `Manager` cannot be used with `with` because it does not implement `__enter__` and `__exit__`"
# note: Objects of type `Manager` *can* be used as async context managers
# note: Consider using `async with` here
with Manager():
    ...
```

closes https://github.com/astral-sh/ty/issues/508

## Test Plan

New MD snapshot tests

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-05-26 21:34:47 +02:00
David Peter 4e68dd96a6
[ty] Infer types for ty_extensions.Intersection[A, B] tuple expressions (#18321)
## Summary

fixes astral-sh/ty#366

## Test Plan

* Added panic corpus regression tests
* I also wrote a hover regression test (see below), but decided not to
include it. The corpus tests are much more "effective" at finding these
types of errors, since they exhaustively check all expressions for
types.

<details>

```rs
#[test]
fn hover_regression_test_366() {
    let test = cursor_test(
        r#"
    from ty_extensions import Intersection

    class A: ...
    class B: ...

    def _(x: Intersection[A,<CURSOR> B]):
        pass
    "#,
    );

    assert_snapshot!(test.hover(), @r"
    A & B
    ---------------------------------------------
    ```text
    A & B
    ```
    ---------------------------------------------
    info[hover]: Hovered content is
     --> main.py:7:31
      |
    5 |         class B: ...
    6 |
    7 |         def _(x: Intersection[A, B]):
      |                               ^^-^
      |                               | |
      |                               | Cursor offset
      |                               source
    8 |             pass
      |
    ");
}
```

</details>
2025-05-26 17:08:52 +02:00
David Peter e1b662bf5d
[ty] Always pass `NO_INSTANCE_FALLBACK` in `try_call_dunder_with_policy` (#18315)
## Summary

The previous `try_call_dunder_with_policy` API was a bit of a footgun
since you needed to pass `NO_INSTANCE_FALLBACK` in *addition* to other
policies that you wanted for the member lookup. Implicit calls to dunder
methods never access instance members though, so we can do this
implicitly in `try_call_dunder_with_policy`.

No functional changes.
2025-05-26 13:20:27 +02:00
Felix Scherz f885cb8a2f
[ty] use `__getattribute__` to lookup unknown members on a type (#18280)
## Summary

`Type::member_lookup_with_policy` now falls back to calling
`__getattribute__` when a member cannot be found as a second fallback
after `__getattr__`.


closes https://github.com/astral-sh/ty/issues/441

## Test Plan

Added markdown tests.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: David Peter <mail@david-peter.de>
2025-05-26 12:59:45 +02:00
David Peter 4ef2c223c9
[ty] Respect `MRO_NO_OBJECT_FALLBACK` policy when looking up symbols on `type` instances (#18312)
## Summary

This should address a problem that came up while working on
https://github.com/astral-sh/ruff/pull/18280. When looking up an
attribute (typically a dunder method) with the `MRO_NO_OBJECT_FALLBACK`
policy, the attribute is first looked up on the meta type. If the meta
type happens to be `type`, we go through the following branch in
`find_name_in_mro_with_policy`:


97ff015c88/crates/ty_python_semantic/src/types.rs (L2565-L2573)

The problem is that we now look up the attribute on `object` *directly*
(instead of just having `object` in the MRO). In this case,
`MRO_NO_OBJECT_FALLBACK` has no effect in `class_member_from_mro`:


c3feb8ce27/crates/ty_python_semantic/src/types/class.rs (L1081-L1082)

So instead, we need to explicitly respect the `MRO_NO_OBJECT_FALLBACK`
policy here by returning `Symbol::Unbound`.

## Test Plan

Added new Markdown tests that explain the ecosystem changes that we
observe.
2025-05-26 12:03:29 +02:00
David Peter 7eca6f96e3
[ty] Fix attribute writes to unions/intersections including modules (#18313)
## Summary

Fix a bug that involved writes to attributes on union/intersection types
that included modules as elements.

This is a prerequisite to avoid some ecosystem false positives in
https://github.com/astral-sh/ruff/pull/18312

## Test Plan

Added regression test
2025-05-26 11:41:03 +02:00
Alex Waygood e293411679
[ty] `get_protocol_members` returns a frozenset, not a tuple (#18284) 2025-05-23 23:20:34 +00:00
lipefree 53d19f8368
[ty] Resolving Python path using `CONDA_PREFIX` variable to support Conda and Pixi (#18267) 2025-05-23 20:00:42 +02:00
InSync a1399656c9
[ty] Fix binary intersection comparison inference logic (#18266)
## Summary

Resolves https://github.com/astral-sh/ty/issues/485.

`infer_binary_intersection_type_comparison()` now checks for all
positive members before concluding that an operation is unsupported for
a given intersection type.

## Test Plan

Markdown tests.

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-05-23 12:55:17 +02:00
David Peter 93ac0934dd
[ty] Type compendium (#18263)
## Summary

This is something I wrote a few months ago, and continued to update from
time to time. It was mostly written for my own education. I found a few
bugs while writing it at the time (there are still one or two TODOs in
the test assertions that are probably bugs). Our other tests are fairly
comprehensive, but they are usually structured around a certain
functionality or operation (subtyping, assignability, narrowing). The
idea here was to focus on individual *types and their properties*.

closes #197 (added `JustFloat` and `JustComplex` to `ty_extensions`).
2025-05-23 11:41:31 +02:00
Alex Waygood d02c9ada5d
[ty] Do not carry the generic context of `Protocol` or `Generic` in the `ClassBase` enum (#17989)
## Summary

It doesn't seem to be necessary for our generics implementation to carry
the `GenericContext` in the `ClassBase` variants. Removing it simplifies
the code, fixes many TODOs about `Generic` or `Protocol` appearing
multiple times in MROs when each should only appear at most once, and
allows us to more accurately detect runtime errors that occur due to
`Generic` or `Protocol` appearing multiple times in a class's bases.

In order to remove the `GenericContext` from the `ClassBase` variant, it
turns out to be necessary to emulate
`typing._GenericAlias.__mro_entries__`, or we end up with a large number
of false-positive `inconsistent-mro` errors. This PR therefore also does
that.

Lastly, this PR fixes the inferred MROs of PEP-695 generic classes,
which implicitly inherit from `Generic` even if they have no explicit
bases.

## Test Plan

mdtests
2025-05-22 21:37:03 -04:00
Carl Meyer 0b181bc2ad
Fix instance vs callable subtyping/assignability (#18260)
## Summary

Fix some issues with subtying/assignability for instances vs callables.
We need to look up dunders on the class, not the instance, and we should
limit our logic here to delegating to the type of `__call__`, so it
doesn't get out of sync with the calls we allow.

Also, we were just entirely missing assignability handling for
`__call__` implemented as anything other than a normal bound method
(though we had it for subtyping.)

A first step towards considering what else we want to change in
https://github.com/astral-sh/ty/issues/491

## Test Plan

mdtests

---------

Co-authored-by: med <medioqrity@gmail.com>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-05-22 19:47:05 +00:00
InSync bcefa459f4
[ty] Rename `call-possibly-unbound-method` to `possibly-unbound-implicit-call` (#18017) 2025-05-22 15:25:51 +00:00
Brandt Bucher 91b7a570c2
[ty] Implement Python's floor division semantics for `Literal` `int`s (#18249)
Division works differently in Python than in Rust. If the result is
negative and there is a remainder, the division rounds down (instead of
towards zero). The remainder needs to be adjusted to compensate so that
`(lhs // rhs) * rhs + (lhs % rhs) == lhs`.

Fixes astral-sh/ty#481.
2025-05-22 10:42:29 -04:00
justin 01eeb2f0d6
[ty] Support frozen dataclasses (#17974)
## Summary
https://github.com/astral-sh/ty/issues/111

This PR adds support for `frozen` dataclasses. It will emit a diagnostic
with a similar message to mypy

Note: This does not include emitting a diagnostic if `__setattr__` or
`__delattr__` are defined on the object as per the
[spec](https://docs.python.org/3/library/dataclasses.html#module-contents)

## Test Plan
mdtest

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
2025-05-22 00:20:34 -04:00
Alex Waygood cb04343b3b
[ty] Split `invalid-base` error code into two error codes (#18245) 2025-05-21 18:02:39 -04:00
Alex Waygood 02394b8049
[ty] Improve `invalid-type-form` diagnostic where a module-literal type is used in a type expression and the module has a member which would be valid in a type expression (#18244) 2025-05-21 15:38:56 -04:00
Alex Waygood 41463396cf
[ty] Add a subdiagnostic if `invalid-return-type` is emitted on a method with an empty body on a non-protocol subclass of a protocol class (#18243) 2025-05-21 17:38:07 +00:00
David Peter da4be789ef
[ty] Ignore `ClassVar` declarations when resolving instance members (#18241)
## Summary

Make sure that the following definitions all lead to the same outcome
(bug originally noticed by @AlexWaygood)

```py
from typing import ClassVar

class Descriptor:
    def __get__(self, instance, owner) -> int:
        return 42

class C:
    a: ClassVar[Descriptor]
    b: Descriptor = Descriptor()
    c: ClassVar[Descriptor] = Descriptor()

reveal_type(C().a)  # revealed: int  (previously: int | Descriptor)
reveal_type(C().b)  # revealed: int
reveal_type(C().c)  # revealed: int
```

## Test Plan

New Markdown tests
2025-05-21 19:23:35 +02:00
Max Mynter 02fd48132c
[ty] Don't warn `yield` not in function when `yield` is in function (#18008) 2025-05-21 18:16:25 +02:00
Alex Waygood d37592175f
[ty] Tell the user why we inferred the Python version we inferred (#18082) 2025-05-21 11:06:27 -04:00
Micha Reiser 76ab77fe01
[ty] Support `import <namespace>` and `from <namespace> import module` (#18137) 2025-05-21 07:28:33 +00:00
Carl Meyer d098118e37
[ty] disable division-by-zero by default (#18220)
## Summary

I think `division-by-zero` is a low-value diagnostic in general; most
real division-by-zero errors (especially those that are less obvious to
the human eye) will occur on values typed as `int`, in which case we
don't issue the diagnostic anyway. Mypy and pyright do not emit this
diagnostic.

Currently the diagnostic is prone to false positives because a) we do
not silence it in unreachable code, and b) we do not implement narrowing
of literals from inequality checks. We will probably fix (a) regardless,
but (b) is low priority apart from division-by-zero.

I think we have many more important things to do and should not allow
false positives on a low-value diagnostic to be a distraction. Not
opposed to re-enabling this diagnostic in future when we can prioritize
reducing its false positives.

References https://github.com/astral-sh/ty/issues/443

## Test Plan

Existing tests.
2025-05-20 14:47:56 -04:00
Ramil Aleskerov 7917269d9a
[ty] Add support for PyPy virtual environments (#18203)
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-05-20 14:46:50 -04:00
Alex Waygood e8d4f6d891
[ty] Ensure that a function-literal type is always equivalent to itself (#18227) 2025-05-20 14:11:03 -04:00
Alex Waygood 60b486abce
[ty] Deeply normalize many types (#18222) 2025-05-20 11:41:26 -04:00
InSync 76ab3425d3
[ty] Integer indexing into `bytes` returns `int` (#18218)
## Summary

Resolves [#461](https://github.com/astral-sh/ty/issues/461).

ty was hardcoded to infer `BytesLiteral` types for integer indexing into
`BytesLiteral`. It will now infer `IntLiteral` types instead.

## Test Plan

Markdown tests.
2025-05-20 16:44:12 +02:00
Micha Reiser 3b56c7ca3d
Update salsa (#18212) 2025-05-20 09:19:34 +02:00
Adam Aaronson 8729cb208f
[ty] Raise `invalid-exception-caught` even when exception is not captured (#18202)
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
2025-05-19 18:13:34 -04:00
Emily B. Zhang a2c87c2bc1
[ty] Add note to `unresolved-import` hinting to users to configure their Python environment (#18207)
Closes https://github.com/astral-sh/ty/issues/453.

## Summary

Add an additional info diagnostic to `unresolved-import` check to hint
to users that they should make sure their Python environment is properly
configured for ty, linking them to the corresponding doc. This
diagnostic is only shown when an import is not relative, e.g., `import
maturin` not `import .maturin`.

## Test Plan

Updated snapshots with new info message and reran tests.
2025-05-19 17:24:25 -04:00
Douglas Creager ce43dbab58
[ty] Promote literals when inferring class specializations from constructors (#18102)
This implements the stopgap approach described in
https://github.com/astral-sh/ty/issues/336#issuecomment-2880532213 for
handling literal types in generic class specializations.

With this approach, we will promote any literal to its instance type,
but _only_ when inferring a generic class specialization from a
constructor call:

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

reveal_type(C("string"))  # revealed: C[str]
```

If you specialize the class explicitly, we still use whatever type you
provide, even if it's a literal:

```py
from typing import Literal

reveal_type(C[Literal[5]](5))  # revealed: C[Literal[5]]
```

And this doesn't apply at all to generic functions:

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

reveal_type(f(5))  # revealed: Literal[5]
```

---

As part of making this happen, we also generalize the `TypeMapping`
machinery. This provides a way to apply a function to type, returning a
new type. Complicating matters is that for function literals, we have to
apply the mapping lazily, since the function's signature is not created
until (and if) someone calls its `signature` method. That means we have
to stash away the mappings that we want to apply to the signatures
parameter/return annotations once we do create it. This requires some
minor `Cow` shenanigans to continue working for partial specializations.
2025-05-19 15:42:54 -04:00
Felix Scherz fb589730ef
[ty]: Consider a class with a dynamic element in its MRO assignable to any subtype of `type` (#18205) 2025-05-19 19:30:30 +00:00
Douglas Creager 4fad15805b
[ty] Use first matching constructor overload when inferring specializations (#18204)
This is a follow-on to #18155. For the example raised in
https://github.com/astral-sh/ty/issues/370:

```py
import tempfile

with tempfile.TemporaryDirectory() as tmp: ...
```

the new logic would notice that both overloads of `TemporaryDirectory`
match, and combine their specializations, resulting in an inferred type
of `str | bytes`.

This PR updates the logic to match our other handling of other calls,
where we only keep the _first_ matching overload. The result for this
example then becomes `str`, matching the runtime behavior. (We still do
not implement the full [overload resolution
algorithm](https://typing.python.org/en/latest/spec/overload.html#overload-call-evaluation)
from the spec.)
2025-05-19 15:12:28 -04:00
David Peter 0ede831a3f
[ty] Add hint that PEP 604 union syntax is only available in 3.10+ (#18192)
## Summary

Add a new diagnostic hint if you try to use PEP 604 `X | Y` union syntax
in a non-type-expression before 3.10.

closes https://github.com/astral-sh/ty/issues/437

## Test Plan

New snapshot test
2025-05-19 19:47:31 +02:00
Douglas Creager 97058e8093
[ty] Infer function call typevars in both directions (#18155)
This primarily comes up with annotated `self` parameters in
constructors:

```py
class C[T]:
    def __init__(self: C[int]): ...
```

Here, we want infer a specialization of `{T = int}` for a call that hits
this overload.

Normally when inferring a specialization of a function call, typevars
appear in the parameter annotations, and not in the argument types. In
this case, this is reversed: we need to verify that the `self` argument
(`C[T]`, as we have not yet completed specialization inference) is
assignable to the parameter type `C[int]`.

To do this, we simply look for a typevar/type in both directions when
performing inference, and apply the inferred specialization to argument
types as well as parameter types before verifying assignability.

As a wrinkle, this exposed that we were not checking
subtyping/assignability for function literals correctly. Our function
literal representation includes an optional specialization that should
be applied to the signature. Before, function literals were considered
subtypes of (assignable to) each other only if they were identical Salsa
objects. Two function literals with different specializations should
still be considered subtypes of (assignable to) each other if those
specializations result in the same function signature (typically because
the function doesn't use the typevars in the specialization).

Closes https://github.com/astral-sh/ty/issues/370
Closes https://github.com/astral-sh/ty/issues/100
Closes https://github.com/astral-sh/ty/issues/258

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-05-19 11:45:40 -04:00
David Peter 4c889d5251
[ty] Support `typing.TypeAliasType` (#18156)
## Summary

Support direct uses of `typing.TypeAliasType`, as in:

```py
from typing import TypeAliasType

IntOrStr = TypeAliasType("IntOrStr", int | str)

def f(x: IntOrStr) -> None:
    reveal_type(x)  # revealed: int | str
```

closes https://github.com/astral-sh/ty/issues/392

## Ecosystem

The new false positive here:
```diff
+ error[invalid-type-form] altair/utils/core.py:49:53: The first argument to `Callable` must be either a list of types, ParamSpec, Concatenate, or `...`
```
comes from the fact that we infer the second argument as a type
expression now. We silence false positives for PEP695 `ParamSpec`s, but
not for `P = ParamSpec("P")` inside `Callable[P, ...]`.

## Test Plan

New Markdown tests
2025-05-19 16:36:49 +02:00
Alex Waygood dd04ca7f58
[ty] Add regression test for fixed `pyvenv.cfg` parsing bug (#18157) 2025-05-17 21:10:15 +00:00
Carl Meyer 2abcd86c57
Revert "[ty] Better control flow for boolean expressions that are inside if (#18010)" (#18150)
This reverts commit 9910ec700c.

## Summary

This change introduced a serious performance regression. Revert it while
we investigate.

Fixes https://github.com/astral-sh/ty/issues/431

## Test Plan

Timing on the snippet in https://github.com/astral-sh/ty/issues/431
again shows times similar to before the regression.
2025-05-17 08:27:32 -04:00
Matthew Mckee c6e55f673c
Remove pyvenv.cfg validation check for lines with multiple `=` (#18144) 2025-05-17 08:42:39 +02:00
Micha Reiser 3d55a16c91
[ty] Migrate the namespace package module resolver tests to mdtests (#18133)
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-05-16 19:56:33 +02:00
Alex Waygood 0adbb3d600
[ty] Fix assignability checks for invariant generics parameterized by gradual types (#18138) 2025-05-16 13:37:07 -04:00
Alex Waygood 28fb802467
[ty] Merge `SemanticIndexBuilder` impl blocks (#18135)
## Summary

just a minor nit followup to
https://github.com/astral-sh/ruff/pull/18010 -- put all the
non-`Visitor` methods of `SemanticIndexBuilder` in the same impl block
rather than having multiple impl blocks

## Test Plan

`cargo build`
2025-05-16 11:05:02 -04:00
Micha Reiser 1ba56b4bc6
[ty] Fix relative imports in stub packages (#18132) 2025-05-16 15:30:10 +02:00
TomerBin 9910ec700c
[ty] Better control flow for boolean expressions that are inside if (#18010)
## Summary
With this PR we now detect that x is always defined in `use`:
```py
if flag and (x := number):
    use(x)
```

When outside if, it's still detected as possibly not defined
```py
flag and (x := number)
# error: [possibly-unresolved-reference]
use(x)
```
In order to achieve that, I had to find a way to get access to the
flow-snapshots of the boolean expression when analyzing the flow of the
if statement. I did it by special casing the visitor of boolean
expression to return flow control information, exporting two snapshots -
`maybe_short_circuit` and `no_short_circuit`. When indexing
boolean expression itself we must assume all possible flows, but when
it's inside if statement, we can be smarter than that.

## Test Plan
Fixed existing and added new mdtests.
I went through some of mypy primer results and they look fine

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-05-16 11:59:21 +00:00
Micha Reiser 9ae698fe30
Switch to Rust 2024 edition (#18129) 2025-05-16 13:25:28 +02:00
David Peter e67b35743a
[ty] NamedTuple 'fallback' attributes (#18127)
## Summary

Add various attributes to `NamedTuple` classes/instances that are
available at runtime.

closes https://github.com/astral-sh/ty/issues/417

## Test Plan

New Markdown tests
2025-05-16 12:56:43 +02:00
David Peter 8644c9da43
[ty] Regression test for relative import in stubs package (#18123)
## Summary

Regression test for https://github.com/astral-sh/ty/issues/408
2025-05-16 12:49:35 +02:00
Micha Reiser 196e4befba
Update MSRV to 1.85 and toolchain to 1.87 (#18126) 2025-05-16 09:19:55 +02:00
David Peter 6e39250015
[ty] Allow unions including `Any`/`Unknown` as bases (#18094)
## Summary

Alternative fix for https://github.com/astral-sh/ty/issues/312

## Test Plan

New Markdown test
2025-05-16 06:57:26 +02:00
Felix Scherz d3a7cb3fe4
[ty] support accessing `__builtins__` global (#18118)
## Summary

The PR adds an explicit check for `"__builtins__"` during name lookup,
similar to how `"__file__"` is implemented. The inferred type is
`Any`.

closes https://github.com/astral-sh/ty/issues/393

## Test Plan

Added a markdown test for `__builtins__`.

---------

Co-authored-by: David Peter <sharkdp@users.noreply.github.com>
2025-05-15 22:01:38 +02:00
Andrew Gallant 69393b2e6e
[ty] Improve invalid method calls for unmatched overloads (#18122)
This makes an easy tweak to allow our diagnostics for unmatched
overloads to apply to method calls. Previously, they only worked for
function calls.

There is at least one other case worth addressing too, namely, class
literals. e.g., `type()`. We had a diagnostic snapshot test case to
track it.

Closes astral-sh/ty#274
2025-05-15 11:39:14 -04:00
David Peter c066bf0127
[ty] `type[…]` is always assignable to `type` (#18121)
## Summary

Model that `type[C]` is always assignable to `type`, even if `C` is not
fully static.

closes https://github.com/astral-sh/ty/issues/312

## Test Plan

* New Markdown tests
* Property tests
2025-05-15 17:13:47 +02:00
David Peter 279dac1c0e
[ty] Make dataclass instances adhere to DataclassInstance (#18115)
## Summary

Make dataclass instances adhere to the `DataclassInstance` protocol.

fixes astral-sh/ty#400

## Test Plan

New Markdown tests
2025-05-15 14:27:23 +02:00
InSync 46be305ad2
[ty] Include synthesized arguments in displayed counts for `too-many-positional-arguments` (#18098)
## Summary

Resolves [#290](https://github.com/astral-sh/ty/issues/290).

All arguments, synthesized or not, are now accounted for in
`too-many-positional-arguments`'s error message.

For example, consider this example:

```python
class C:
	def foo(self): ...

C().foo(1)  # !!!
```

Previously, ty would say:

> Too many positional arguments to bound method foo: expected 0, got 1

After this change, it will say:

> Too many positional arguments to bound method foo: expected 1, got 2

This is what Python itself does too:

```text
Traceback (most recent call last):
  File "<python-input-0>", line 3, in <module>
    C().foo()
    ~~~~~~~^^
TypeError: C.foo() takes 0 positional arguments but 1 was given
```

## Test Plan

Markdown tests.
2025-05-14 22:51:23 -04:00
Alex Waygood c3a4992ae9
[ty] Fix normalization of unions containing instances parameterized with unions (#18112) 2025-05-14 22:48:33 -04:00
Alex Waygood 9aa6330bb1
[ty] Fix `redundant-cast` false positives when casting to `Unknown` (#18111) 2025-05-14 22:38:53 -04:00
github-actions[bot] b600ff106a
Sync vendored typeshed stubs (#18110)
Close and reopen this PR to trigger CI

---------

Co-authored-by: typeshedbot <>
Co-authored-by: Carl Meyer <carl@astral.sh>
2025-05-14 22:14:52 -04:00
David Peter 6800a9f6f3
[ty] Add type-expression syntax link to invalid-type-expression (#18104)
## Summary

Add a link to [this
page](https://typing.python.org/en/latest/spec/annotations.html#type-and-annotation-expressions)
when emitting `invalid-type-expression` diagnostics.
2025-05-14 18:56:44 +00:00
Alex Waygood 0590b38214
[ty] Fix more generics-related TODOs (#18062) 2025-05-14 12:26:52 -04:00
Andrew Gallant faf54c0181 ty_python_semantic: improve failed overloaded function call
The diagnostic now includes a pointer to the implementation definition
along with each possible overload.

This doesn't include information about *why* each overload failed. But
given the emphasis on concise output (since there can be *many*
unmatched overloads), it's not totally clear how to include that
additional information.

Fixes #274
2025-05-14 11:13:41 -04:00
Andrew Gallant 451c5db7a3 ty_python_semantic: move some routines to `FunctionType`
These are, after all, specific to function types. The methods on `Type`
are more like conveniences that return something when the type *happens*
to be a function. But defining them on `FunctionType` itself makes it
easy to call them when you have a `FunctionType` instead of a `Type`.
2025-05-14 11:13:41 -04:00
Andrew Gallant bd5b7f415f ty_python_semantic: rejigger handling of overload error conditions
I found the previous code somewhat harder to read. Namely, a `for`
loop was being used to encode "execute zero or one times, but not
more." Which is sometimes okay, but it seemed clearer to me to use
more explicit case analysis here.

This should have no behavioral changes.
2025-05-14 11:13:41 -04:00
Andrew Gallant 0230cbac2c ty_python_semantic: update "no matching overload" diagnostic test
It looks like support for `@overload` has been added since this test was
created, so we remove the TODO and add a snippet (from #274).
2025-05-14 11:13:41 -04:00
David Peter 97d7b46936
[ty] Do not look up `__init__` on instances (#18092)
## Summary

Dunder methods are never looked up on instances. We do this implicitly
in `try_call_dunder`, but the corresponding flag was missing in the
instance-construction code where we use `member_lookup_with_policy`
directly.

fixes https://github.com/astral-sh/ty/issues/322

## Test Plan

Added regression test.
2025-05-14 15:33:42 +02:00
Micha Reiser e7f97a3e4b
[ty] Reduce log level of 'symbol .. (via star import) not found' log message (#18087) 2025-05-14 09:20:23 +02:00
Chandra Kiran G d17557f0ae
[ty] Fix Inconsistent casing in diagnostic (#18084) 2025-05-14 08:26:48 +02:00
Dhruv Manilawala 8cbd433a31
[ty] Add cycle handling for unpacking targets (#18078)
## Summary

This PR adds cycle handling for `infer_unpack_types` based on the
analysis in astral-sh/ty#364.

Fixes: astral-sh/ty#364

## Test Plan

Add a cycle handling test for unpacking in `cycle.md`
2025-05-13 21:27:48 +00:00
Alex Waygood 65e48cb439
[ty] Check assignments to implicit global symbols are assignable to the types declared on `types.ModuleType` (#18077) 2025-05-13 16:37:20 -04:00
Douglas Creager fe653de3dd
[ty] Infer parameter specializations of explicitly implemented generic protocols (#18054)
Follows on from (and depends on)
https://github.com/astral-sh/ruff/pull/18021.

This updates our function specialization inference to infer type
mappings from parameters that are generic protocols.

For now, this only works when the argument _explicitly_ implements the
protocol by listing it as a base class. (We end up using exactly the
same logic as for generic classes in #18021.) For this to work with
classes that _implicitly_ implement the protocol, we will have to check
the types of the protocol members (which we are not currently doing), so
that we can infer the specialization of the protocol that the class
implements.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-05-13 13:13:00 -04:00
InSync a9f7521944
[ty] Shorten snapshot names (#18039)
Co-authored-by: Micha Reiser <micha@reiser.io>
2025-05-13 18:43:19 +02:00
Carl Meyer f8890b70c3
[ty] __file__ is always a string inside a Python module (#18071)
## Summary

Understand that `__file__` is always set and a `str` when looked up as
an implicit global from a Python file we are type checking.

## Test Plan

mdtests
2025-05-13 08:20:43 -07:00
David Peter 142c1bc760
[ty] Recognize submodules in self-referential imports (#18005)
## Summary

Fix the lookup of `submodule`s in cases where the `parent` module has a
self-referential import like `from parent import submodule`. This allows
us to infer proper types for many symbols where we previously inferred
`Never`. This leads to many new false (and true) positives across the
ecosystem because the fact that we previously inferred `Never` shadowed
a lot of problems. For example, we inferred `Never` for `os.path`, which
is why we now see a lot of new diagnostics related to `os.path.abspath`
and similar.

```py
import os

reveal_type(os.path)  # previously: Never, now: <module 'os.path'>
```

closes https://github.com/astral-sh/ty/issues/261
closes https://github.com/astral-sh/ty/issues/307

## Ecosystem analysis

```
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━━━┳━━━━━━━┳━━━━━━━━━━━━┓
┃ Diagnostic ID                 ┃ Severity ┃ Removed ┃ Added ┃ Net Change ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━╇━━━━━━━━━╇━━━━━━━╇━━━━━━━━━━━━┩
│ call-non-callable             │ error    │       1 │     5 │         +4 │
│ call-possibly-unbound-method  │ warning  │       6 │    26 │        +20 │
│ invalid-argument-type         │ error    │      26 │    94 │        +68 │
│ invalid-assignment            │ error    │      18 │    46 │        +28 │
│ invalid-context-manager       │ error    │       9 │     4 │         -5 │
│ invalid-raise                 │ error    │       1 │     1 │          0 │
│ invalid-return-type           │ error    │       3 │    20 │        +17 │
│ invalid-super-argument        │ error    │       4 │     0 │         -4 │
│ invalid-type-form             │ error    │     573 │     0 │       -573 │
│ missing-argument              │ error    │       2 │    10 │         +8 │
│ no-matching-overload          │ error    │       0 │   715 │       +715 │
│ non-subscriptable             │ error    │       0 │    35 │        +35 │
│ not-iterable                  │ error    │       6 │     7 │         +1 │
│ possibly-unbound-attribute    │ warning  │      14 │    31 │        +17 │
│ possibly-unbound-import       │ warning  │      13 │     0 │        -13 │
│ possibly-unresolved-reference │ warning  │       0 │     8 │         +8 │
│ redundant-cast                │ warning  │       1 │     0 │         -1 │
│ too-many-positional-arguments │ error    │       2 │     0 │         -2 │
│ unknown-argument              │ error    │       2 │     0 │         -2 │
│ unresolved-attribute          │ error    │     583 │   304 │       -279 │
│ unresolved-import             │ error    │       0 │    96 │        +96 │
│ unsupported-operator          │ error    │       0 │    17 │        +17 │
│ unused-ignore-comment         │ warning  │      29 │     2 │        -27 │
├───────────────────────────────┼──────────┼─────────┼───────┼────────────┤
│ TOTAL                         │          │    1293 │  1421 │       +128 │
└───────────────────────────────┴──────────┴─────────┴───────┴────────────┘

Analysis complete. Found 23 unique diagnostic IDs.
Total diagnostics removed: 1293
Total diagnostics added: 1421
Net change: +128
```

* We see a lot of new errors (`no-matching-overload`) related to
`os.path.dirname` and other `os.path` operations because we infer `str |
None` for `__file__`, but many projects use something like
`os.path.dirname(__file__)`.
* We also see many new `unresolved-attribute` errors related to the fact
that we now infer proper module types for some imports (e.g. `import
kornia.augmentation as K`), but we don't allow implicit imports (e.g.
accessing `K.auto.operations` without also importing `K.auto`). See
https://github.com/astral-sh/ty/issues/133.
* Many false positive `invalid-type-form` are removed because we now
infer the correct type for some type expression instead of `Never`,
which is not valid in a type annotation/expression context.

## Test Plan

Added new Markdown tests
2025-05-13 16:59:11 +02:00
Alex Waygood c0f22928bd
[ty] Add a note to the diagnostic if a new builtin is used on an old Python version (#18068)
## Summary

If the user tries to use a new builtin on an old Python version, tell
them what Python version the builtin was added on, what our inferred
Python version is for their project, and what configuration settings
they can tweak to fix the error.

## Test Plan

Snapshots and screenshots:


![image](https://github.com/user-attachments/assets/767d570e-7af1-4e1f-98cf-50e4311db511)
2025-05-13 10:08:04 -04:00
Alex Waygood 5bf5f3682a
[ty] Add tests for `else` branches of `hasattr()` narrowing (#18067)
## Summary

This addresses @sharkdp's post-merge review in
https://github.com/astral-sh/ruff/pull/18053#discussion_r2086190617

## Test Plan

`cargo test -p ty_python_semantic`
2025-05-13 09:57:53 -04:00
Alex Waygood 5913997c72
[ty] Improve diagnostics for `assert_type` and `assert_never` (#18050) 2025-05-13 13:00:20 +00:00
Abhijeet Prasad Bodas 68b0386007
[ty] Implement `DataClassInstance` protocol for dataclasses. (#18018)
Fixes: https://github.com/astral-sh/ty/issues/92

## Summary

We currently get a `invalid-argument-type` error when using
`dataclass.fields` on a dataclass, because we do not synthesize the
`__dataclass_fields__` member.

This PR fixes this diagnostic.

Note that we do not yet model the `Field` type correctly. After that is
done, we can assign a more precise `tuple[Field, ...]` type to this new
member.

## Test Plan
New mdtest.

---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-05-13 10:31:26 +02:00
Douglas Creager 0fb94c052e
[ty] Infer parameter specializations of generic aliases (#18021)
This updates our function specialization inference to infer type
mappings from parameters that are generic aliases, e.g.:

```py
def f[T](x: list[T]) -> T: ...

reveal_type(f(["a", "b"]))  # revealed: str
```

Though note that we're still inferring the type of list literals as
`list[Unknown]`, so for now we actually need something like the
following in our tests:

```py
def _(x: list[str]):
    reveal_type(f(x))  # revealed: str
```
2025-05-12 22:12:44 -04:00
Alex Waygood 55df9271ba
[ty] Understand homogeneous tuple annotations (#17998) 2025-05-12 22:02:25 -04:00
Douglas Creager f301931159
[ty] Induct into instances and subclasses when finding and applying generics (#18052)
We were not inducting into instance types and subclass-of types when
looking for legacy typevars, nor when apply specializations.

This addresses
https://github.com/astral-sh/ruff/pull/17832#discussion_r2081502056

```py
from __future__ import annotations
from typing import TypeVar, Any, reveal_type

S = TypeVar("S")

class Foo[T]:
    def method(self, other: Foo[S]) -> Foo[T | S]: ...  # type: ignore[invalid-return-type]

def f(x: Foo[Any], y: Foo[Any]):
    reveal_type(x.method(y))  # revealed: `Foo[Any | S]`, but should be `Foo[Any]`
```

We were not detecting that `S` made `method` generic, since we were not
finding it when searching the function signature for legacy typevars.
2025-05-12 21:53:11 -04:00
Alex Waygood 7e9b0df18a
[ty] Allow classes to inherit from `type[Any]` or `type[Unknown]` (#18060) 2025-05-12 20:30:21 -04:00
Alex Waygood 41fa082414
[ty] Allow a class to inherit from an intersection if the intersection contains a dynamic type and the intersection is not disjoint from `type` (#18055) 2025-05-12 23:07:11 +00:00
Alex Waygood c7b6108cb8
[ty] Narrowing for `hasattr()` (#18053) 2025-05-12 18:58:14 -04:00
Zanie Blue 6b64630635
Update `--python` to accept paths to executables in virtual environments (#17954)
## Summary

Updates the `--python` flag to accept Python executables in virtual
environments. Notably, we do not query the executable and it _must_ be
in a canonical location in a virtual environment. This is pretty naive,
but solves for the trivial case of `ty check --python .venv/bin/python3`
which will be a common mistake (and `ty check --python $(which python)`)

I explored this while trying to understand Python discovery in ty in
service of https://github.com/astral-sh/ty/issues/272, I'm not attached
to it, but figure it's worth sharing.

As an alternative, we can add more variants to the
`SearchPathValidationError` and just improve the _error_ message, i.e.,
by hinting that this looks like a virtual environment and suggesting the
concrete alternative path they should provide. We'll probably want to do
that for some other cases anyway (e.g., `3.13` as described in the
linked issue)

This functionality is also briefly mentioned in
https://github.com/astral-sh/ty/issues/193

Closes https://github.com/astral-sh/ty/issues/318

## Test Plan

e.g.,

```
uv run ty check --python .venv/bin/python3
```

needs test coverage still
2025-05-12 15:39:04 -05:00
Douglas Creager bdccb37b4a
[ty] Apply function specialization to all overloads (#18020)
Function literals have an optional specialization, which is applied to
the parameter/return type annotations lazily when the function's
signature is requested. We were previously only applying this
specialization to the final overload of an overloaded function.

This manifested most visibly for `list.__add__`, which has an overloaded
definition in the typeshed:


b398b83631/crates/ty_vendored/vendor/typeshed/stdlib/builtins.pyi (L1069-L1072)

Closes https://github.com/astral-sh/ty/issues/314
2025-05-12 13:48:54 -04:00
Shunsuke Shibayama 6f8f7506b4
[ty] fix infinite recursion bug in `is_disjoint_from` (#18043)
## Summary

I found this bug while working on #18041. The following code leads to
infinite recursion.

```python
from ty_extensions import is_disjoint_from, static_assert, TypeOf

class C:
    @property
    def prop(self) -> int:
        return 1

static_assert(not is_disjoint_from(int, TypeOf[C.prop]))
```

The cause is a trivial missing binding in `is_disjoint_from`. This PR
fixes the bug and adds a test case (this is a simple fix and may not
require a new test case?).

## Test Plan

A new test case is added to
`mdtest/type_properties/is_disjoint_from.md`.
2025-05-12 09:44:00 -04:00
Micha Reiser fcd858e0c8
[ty] Refine message for why a rule is enabled (#18038) 2025-05-12 13:31:42 +02:00
Alex Waygood 669855d2b5
[ty] Remove unused variants from various `Known*` enums (#18015)
## Summary

`KnownClass::Range`, `KnownInstanceType::Any` and `ClassBase::any()` are
no longer used or useful: all our tests pass with them removed.
`KnownModule::Abc` _is_ now used outside of tests, however, so I removed
the `#[allow(dead_code)]` branch above that variant.

## Test Plan

`cargo test -p ty_python_semantic`
2025-05-11 11:18:55 +01:00
Alex Waygood ff7ebecf89
[ty] Remove generic types from the daily property test run (for now) (#18004) 2025-05-11 09:27:27 +00:00
Zanie Blue 0bb8cbdf07
[ty] Do not allow invalid virtual environments from discovered `.venv` or `VIRTUAL_ENV` (#18003)
Follow-up to https://github.com/astral-sh/ruff/pull/17991 ensuring we do
not allow detection of system environments when the origin is
`VIRTUAL_ENV` or a discovered `.venv` directory — i.e., those always
require a `pyvenv.cfg` file.
2025-05-10 20:36:12 +00:00