## 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.
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
## 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.
## 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
## 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
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.
## 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.
## 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
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.
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
## 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
## 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
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.)
## 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`.
## 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
## 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
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>
* [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
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>
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>
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.
## 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
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)
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>
## 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>
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>
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.
## 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`.
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`.
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.]_
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
## 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`.
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.
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:

---------
Co-authored-by: UnboundVariable <unbound@gmail.com>
Co-authored-by: Micha Reiser <micha@reiser.io>
## 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
This makes use of the new `Type` field on `Completion` to figure out the
"kind" of a `Completion`.
The mapping here is perhaps a little suspect for some cases.
Closesastral-sh/ty#775
Since we generally need (so far) to get the type information of each
suggestion to figure out its boundness anyway, we might as well expose
it here. Completions want to use this information to enhance the
metadata on each suggestion for a more pleasant user experience.
For the most part, this was pretty straight-forward. The most exciting
part was in computing the types for instance attributes. I'm not 100%
sure it's correct or is the best way to do it.
This commit doesn't change any behavior, but makes it so `all_members`
returns a `Vec<Member>` instead of `Vec<Name>`, where a `Member`
contains a `Name`. This gives us an expansion point to include other
data (such as the type of the `Name`).
## Summary
Change `ClassLiteral.into_callable` to also look for `__init__` functions
of type `Type::Callable` (such as synthesized `__init__` functions of
dataclasses).
Fixes https://github.com/astral-sh/ty/issues/760
## Test Plan
Add subtype test
---------
Co-authored-by: David Peter <mail@david-peter.de>
## Summary
Emit a diagnostic when a `Final`-qualified symbol is modified. This
first iteration only works for name targets. Tests with TODO comments
were added for attribute assignments as well.
related ticket: https://github.com/astral-sh/ty/issues/158
## Ecosystem impact
Correctly identified [modification of a `Final`
symbol](7b4164a5f2/sphinx/__init__.py (L44))
(behind a `# type: ignore`):
```diff
- warning[unused-ignore-comment] sphinx/__init__.py:44:56: Unused blanket `type: ignore` directive
```
And the same
[here](5471a37e82/src/trio/_core/_run.py (L128)):
```diff
- warning[unused-ignore-comment] src/trio/_core/_run.py:128:45: Unused blanket `type: ignore` directive
```
## Test Plan
New Markdown tests
## Summary
Fixes a bug where conditionally defined dataclass fields were previously
ignored.
Thanks to @lipefree for reporting this.
## Test Plan
New Markdown tests
## Summary
This PR addresses some additional feedback on #19053:
- Renaming the `syntax_error` methods to `invalid_syntax` to match the
lint id
- Moving the standalone `diagnostic_from_violation` function to
`Violation::into_diagnostic`
- Removing the `Ord` and `PartialOrd` implementations from `Diagnostic`
in favor of `Diagnostic::start_ordering`
## Test Plan
Existing tests
## Additional Follow-ups
Besides these, I also put the following comments on my todo list, but
they seemed like they might be big enough to have their own PRs:
- [Use `LintId::IOError` for IO
errors](https://github.com/astral-sh/ruff/pull/19053#discussion_r2189425922)
- [Move `Fix` and
`Edit`](https://github.com/astral-sh/ruff/pull/19053#discussion_r2189448647)
- [Avoid so many
unwraps](https://github.com/astral-sh/ruff/pull/19053#discussion_r2189465980)
## Summary
Related:
- https://github.com/astral-sh/ty/issues/111
- https://github.com/astral-sh/ruff/pull/17974#discussion_r2108527106
Previously, when validating an attribute assignment, a `__setattr__`
call check was only done if the attribute wasn't found as either a class
member or instance member
This PR changes the `__setattr__` call check to be attempted first,
prior to the "[normal
mechanism](https://docs.python.org/3/reference/datamodel.html#object.__setattr__)",
as a defined `__setattr__` should take precedence over setting an
attribute on the instance dictionary directly.
if the return type of `__setattr__` is `Never`, an `invalid-assignment`
diagnostic is emitted
Once this is merged, a subsequent PR will synthesize a `__setattr__`
method with a `Never` return type for frozen dataclasses.
## Test Plan
Existing tests + mypy_primer
---------
Co-authored-by: David Peter <mail@david-peter.de>
This PR implements a basic semantic token provider for ty's language
server. This allows for more accurate semantic highlighting / coloring
within editors that support this LSP functionality.
Here are screen shots that show how code appears in VS Code using the
"rainbow" theme both before and after this change.


The token types and modifier tags in this implementation largely mirror
those used in Microsoft's default language server for Python.
The implementation supports two LSP interfaces. The first provides
semantic tokens for an entire document, and the second returns semantic
tokens for a requested range within a document.
The PR includes unit tests. It also includes comments that document
known limitations and areas for future improvements.
---------
Co-authored-by: UnboundVariable <unbound@gmail.com>
## Summary
It was recently clarified in the [typing
spec](https://typing.python.org/en/latest/spec/class-compat.html#classvar)
that bare `ClassVar` annotations are allowed. For annotated assignments
with a right hand side value, the spec requires type checkers to infer
the type as something "to which [the] value is assignable". For a value
of `2`, the spec suggests `int`, `Literal[2]`, or `Any` as examples.
Here, we choose `Unknown | Literal[2]` instead, conforming with out
usual treatment of attribute types.
closes https://github.com/astral-sh/ty/issues/211
## Summary
This PR implements the following pieces of `Protocol` semantics:
1. A protocol with a method member that does not have a fully static
signature should not be considered fully static. I.e., this protocol is
not fully static because `Foo.x` has no return type; we previously
incorrectly considered that it was:
```py
class Foo(Protocol):
def f(self): ...
```
2. Two protocols `P1` and `P2`, both with method members `x`, should be
considered equivalent if the signature of `P1.x` is equivalent to the
signature of `P2.x`. Currently we do not recognize this.
Implementing these semantics requires distinguishing between method
members and non-method members. The stored type of a method member must
be eagerly upcast to a `Callable` type when collecting the protocol's
interface: doing otherwise would mean that it would be hard to implement
equivalence of protocols even in the face of differently ordered unions,
since the two equivalent protocols would have different Salsa IDs even
when normalized.
The semantics implemented by this PR are that we consider something a
method member if:
1. It is accessible on the class itself; and
2. It is a function-like callable: a callable type that also has a
`__get__` method, meaning it can be used as a method when accessed on
instances.
Note that the spec has complicated things to say about classmethod
members and staticmethod members. These semantics are not implemented by
this PR; they are all deferred for now.
The infrastructure added in this PR fixes bugs in its own right, but
also lays the groundwork for implementing subtyping and assignability
rules for method members of protocols. A (currently failing) test is
added to verify this.
## Test Plan
mdtests
## Summary
Infer the type of symbols with a `Final` qualifier as their
right-hand-side inferred type:
```py
x: Final = 1
y: Final[int] = 1
def _():
reveal_type(x) # previously: Unknown, now: Literal[1]
reveal_type(y) # int, same as before
```
Part of https://github.com/astral-sh/ty/issues/158
## Ecosystem analysis
### aiohttp
```diff
aiohttp (https://github.com/aio-libs/aiohttp)
+ error[invalid-argument-type] aiohttp/compression_utils.py:131:54: Argument to bound method `__init__` is incorrect: Expected `ZLibBackendProtocol`, found `<module 'zlib'>`
```
This code [creates a
protocol](a83597fa88/aiohttp/compression_utils.py (L52-L77))
that looks like
```pyi
class ZLibBackendProtocol(Protocol):
Z_FULL_FLUSH: int
Z_SYNC_FLUSH: int
# more fields…
```
It then [tries to
assign](a83597fa88/aiohttp/compression_utils.py (L131))
the module literal `zlib` to that protocol. Howefer, in typeshed, these
`zlib` members are annotated like this:
```pyi
Z_FULL_FLUSH: Final = 3
Z_SYNC_FLUSH: Final = 2
```
With the proposed change here, we now infer these as `Literal[3]` /
`Literal[2]`. Since protocol members have to be assignable both ways
(invariance), we do not consider `zlib` assignable to this protocol
anymore.
That seems rather unfortunate. Not sure who is to blame here? That
`ZLibBackendProtocol` protocol should probably not annotate the members
with `int`, given that `typeshed` doesn't use an explicit annotation
here either? But what should they do instead? Annotate those fields with
`Any`?
Or is it another case where we should consider literal-widening?
FYI @AlexWaygood
### cloud-init
```diff
cloud-init (https://github.com/canonical/cloud-init)
+ error[invalid-argument-type] tests/unittests/sources/test_smartos.py:575:32: Argument to function `oct` is incorrect: Expected `SupportsIndex`, found `int | float`
+ error[invalid-argument-type] tests/unittests/sources/test_smartos.py:593:32: Argument to function `oct` is incorrect: Expected `SupportsIndex`, found `int | float`
+ error[invalid-argument-type] tests/unittests/sources/test_smartos.py:647:35: Argument to function `oct` is incorrect: Expected `SupportsIndex`, found `int | float`
```
New false positives on expressions like
`oct(os.stat(legacy_script_f)[stat.ST_MODE])`. We now correctly infer
`stat.ST_MODE` as `Literal[1]`, because in typeshed, it is annotated as
`ST_MODE: Final = 0`. `os.stat` returns a `stat_result` which is a tuple
subclass. Accessing it at index 0 should return an `int`, but we
currently return `int | float`, presumably due to missing support for
tuple subclasses (FYI @AlexWaygood):
```pyi
class stat_result(structseq[float], tuple[int, int, int, int, int, int, int, float, float, float]):
```
In terms of `typing.Final`, things are working as expected here.
### pywin-32
Many new false positives similar to:
```diff
pywin32 (https://github.com/mhammond/pywin32)
+ error[invalid-argument-type] Pythonwin/pywin/docking/DockingBar.py:288:55: Argument to function `LoadCursor` is incorrect: Expected `PyResourceId`, found `Literal[32645]`
```
The line in question calls `win32api.LoadCursor(0, win32con.IDC_ARROW)`.
The `win32con.IDC_ARROW` symbol is annotated as [`IDC_ARROW: Final =
32512` in
typeshed](2408c028f4/stubs/pywin32/win32/lib/win32con.pyi (L594)),
but
[`LoadCursor`](2408c028f4/stubs/pywin32/win32/win32api.pyi (L197))
expects a
[`PyResourceId`](2408c028f4/stubs/pywin32/_win32typing.pyi (L1252)),
which is an empty class. So.. this seems like a true positive to me,
unless that typeshed annotation of `IDC_ARROW` is meant to imply that
the type should be `Unknown`/`Any`?
### streamlit
```diff
streamlit (https://github.com/streamlit/streamlit)
+ error[invalid-argument-type] lib/streamlit/string_util.py:163:37: Argument to bound method `translate` is incorrect: Expected `bytes`, found `bytearray`
```
This looks like a true positive? The code calls `inp.translate(None,
TEXTCHARS)`. `inp` is `bytes`, and `TEXTCHARS` is:
```py
TEXTCHARS: Final = bytearray(
{7, 8, 9, 10, 12, 13, 27} | set(range(0x20, 0x100)) - {0x7F}
)
```
~~We now infer this as `bytearray`, but `bytes.translate` [expects
`bytes` for its `delete`
parameter](2408c028f4/stdlib/builtins.pyi (L710)).
This seems to work at runtime, so maybe the typeshed annotation is
wrong?~~ (Edit: this is now fixed in typeshed)
```pycon
>>> b"abc".translate(None, bytearray(b"b"))
b'ac'
```
## rotki
```diff
+ error[invalid-return-type] rotkehlchen/chain/ethereum/modules/yearn/decoder.py:412:13: Return type does not match returned value: expected `dict[Unknown, str]`, found `dict[Unknown, Literal["yearn-v1", "yearn-v2"]]`
```
The code in question looks like
```py
def addresses_to_counterparties(self) -> dict[ChecksumEvmAddress, str]:
return dict.fromkeys(self.vaults, CPT_BEEFY_FINANCE)
```
where `CPT_BEEFY_FINANCE: Final = 'beefy_finance'. We previously
inferred the value type of the returned `dict` as `Unknown`, and now we
infer it as `Literal["beefy_finance"]`, which does not match the
annotated return type because `dict` is invariant in the value type.
```diff
+ error[invalid-argument-type] rotkehlchen/tests/unit/decoders/test_curve.py:249:9: Argument is incorrect: Expected `int`, found `FVal`
```
There are true positives that were previously silenced through the
`Unknown`.
## Test Plan
New Markdown tests
## Summary
Following ty issue [#698](https://github.com/astral-sh/ty/issues/698)
this PR adds support for declarations.
closes#698
## Test Plan
Tested against mdtest (specifically attributes).
---------
Co-authored-by: David Peter <mail@david-peter.de>
## Summary
`ty` does not understand that calls to functions which have been
annotated as having a return type of `Never` / `NoReturn` are terminal.
This PR fixes that, by adding new reachability constraints when call
expressions are seen. If the call expression evaluates to `Never`, the
code following it will be considered to be unreachable. Note that, for
adding these constraints, we only consider call expressions at the
statement level, and that too only inside function scopes. This is
because otherwise, the number of such constraints becomes too high, and
evaluating them later on during type inference results in a major
performance degradation.
Fixes https://github.com/astral-sh/ty/issues/180
## Test Plan
New mdtests.
## Ecosystem changes
This PR removes the following false-positives:
- "Function can implicitly return `None`, which is not assignable to
...".
- "Name `foo` used when possibly not defind" - because the branch in
which it is not defined has a `NoReturn` call, or when `foo` was
imported in a `try`, and the except had a `NoReturn` call.
---------
Co-authored-by: David Peter <mail@david-peter.de>