Commit Graph

490 Commits

Author SHA1 Message Date
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