## Summary
Fixes https://github.com/astral-sh/ty/issues/1409
This PR allows `Final` instance attributes to be initialized in
`__init__` methods, as mandated by the Python typing specification (PEP
591). Previously, ty incorrectly prevented this initialization, causing
false positive errors.
The fix checks if we're inside an `__init__` method before rejecting
Final attribute assignments, allowing assignments during
instance initialization while still preventing reassignment elsewhere.
## Test Plan
- Added new test coverage in `final.md` for the reported issue with
`Self` annotations
- Updated existing tests that were incorrectly expecting errors
- All 278 mdtest tests pass
- Manually tested with real-world code examples
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
Fixes https://github.com/astral-sh/ty/issues/1487
This one is a true extension of non-standard semantics, and is therefore
a certified Hot Take we might conclude is simply a Bad Take (let's see
what ecosystem tests say...).
By resolving `.` and the LHS of the from import during semantic
indexing, we can check if the LHS is a submodule of `.`, and handle
`from whatever.thispackage.x.y import z` exactly like we do `from .x.y
import z`.
Fixes https://github.com/astral-sh/ty/issues/1484
This manifested as an error when inferring the type of a PEP-695 generic
class via its constructor parameters:
```py
class D[T, U]:
@overload
def __init__(self: "D[str, U]", u: U) -> None: ...
@overload
def __init__(self, t: T, u: U) -> None: ...
def __init__(self, *args) -> None: ...
# revealed: D[Unknown, str]
# SHOULD BE: D[str, str]
reveal_type(D("string"))
```
This manifested because `D` is inferred to be bivariant in both `T` and
`U`. We weren't seeing this in the equivalent example for legacy
typevars, since those default to invariant. (This issue also showed up
for _covariant_ typevars, so this issue was not limited to bivariance.)
The underlying cause was because of a heuristic that we have in our
current constraint solver, which attempts to handle situations like
this:
```py
def f[T](t: T | None): ...
f(None)
```
Here, the `None` argument matches the non-typevar union element, so this
argument should not add any constraints on what `T` can specialize to.
Our previous heuristic would check for this by seeing if the argument
type is a subtype of the parameter annotation as a whole — even if it
isn't a union! That would cause us to erroneously ignore the `self`
parameter in our constructor call, since bivariant classes are
equivalent to each other, regardless of their specializations.
The quick fix is to move this heuristic "down a level", so that we only
apply it when the parameter annotation is a union. This heuristic should
go away completely 🤞 with the new constraint solver.
This loses any ability to have "per-function" implicit submodule
imports, to avoid the "ok but now we need per-scope imports" and "ok but
this should actually introduce a global that only exists during this
function" problems. A simple and clean implementation with no weird
corners.
Fixes https://github.com/astral-sh/ty/issues/1482
This rips out the previous implementation in favour of a new
implementation with 3 rules:
- **froms are locals**: a `from..import` can only define locals, it does
not have global
side-effects. Specifically any submodule attribute `a` that's implicitly
introduced by either
`from .a import b` or `from . import a as b` (in an `__init__.py(i)`) is
a local and not a
global. If you do such an import at the top of a file you won't notice
this. However if you do
such an import in a function, that means it will only be function-scoped
(so you'll need to do
it in every function that wants to access it, making your code less
sensitive to execution
order).
- **first from first serve**: only the *first* `from..import` in an
`__init__.py(i)` that imports a
particular direct submodule of the current package introduces that
submodule as a local.
Subsequent imports of the submodule will not introduce that local. This
reflects the fact that
in actual python only the first import of a submodule (in the entire
execution of the program)
introduces it as an attribute of the package. By "first" we mean "the
first time in this scope
(or any parent scope)". This pairs well with the fact that we are
specifically introducing a
local (as long as you don't accidentally shadow or overwrite the local).
- **dot re-exports**: `from . import a` in an `__init__.pyi` is
considered a re-export of `a`
(equivalent to `from . import a as a`). This is required to properly
handle many stubs in the
wild. Currently it must be *exactly* `from . import ...`.
This implementation is intentionally limited/conservative (notably,
often requiring a from import to be relative). I'm going to file a ton
of followups for improvements so that their impact can be evaluated
separately.
Fixes https://github.com/astral-sh/ty/issues/133
## Summary
Fixed RUF065 (`logging-eager-conversion`) to only flag `str()` calls
when they perform a simple conversion that can be safely removed. The
rule now ignores `str()` calls with no arguments, multiple arguments,
starred arguments, or keyword unpacking, preventing false positives.
Fixes#21315
## Problem Analysis
The RUF065 rule was incorrectly flagging all `str()` calls in logging
statements, even when `str()` was performing actual conversion work
beyond simple type coercion. Specifically, the rule flagged:
- `str()` with no arguments - which returns an empty string
- `str(b"data", "utf-8")` with multiple arguments - which performs
encoding conversion
- `str(*args)` with starred arguments - which unpacks arguments
- `str(**kwargs)` with keyword unpacking - which passes keyword
arguments
These cases cannot be safely removed because `str()` is doing meaningful
work (encoding conversion, argument unpacking, etc.), not just redundant
type conversion.
The root cause was that the rule only checked if the function was
`str()` without validating the call signature. It didn't distinguish
between simple `str(value)` conversions (which can be removed) and more
complex `str()` calls that perform actual work.
## Approach
The fix adds validation to the `str()` detection logic in
`logging_eager_conversion.rs`:
1. **Check argument count**: Only flag `str()` calls with exactly one
positional argument (`str_call_args.args.len() == 1`)
2. **Check for starred arguments**: Ensure the single argument is not
starred (`!str_call_args.args[0].is_starred_expr()`)
3. **Check for keyword arguments**: Ensure there are no keyword
arguments (`str_call_args.keywords.is_empty()`)
This ensures the rule only flags cases like `str(value)` where `str()`
is truly redundant and can be removed, while ignoring cases where
`str()` performs actual conversion work.
The fix maintains backward compatibility - all existing valid test cases
continue to be flagged correctly, while the new edge cases are properly
ignored.
---------
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
It's everyone's favourite language corner case!
Also having kicked the tires on it, I'm pretty happy to call this (in
conjunction with #21367):
Fixes https://github.com/astral-sh/ty/issues/494
There's cases where you can make noisy Literal hints appear, so we can
always iterate on it, but this handles like, 98% of the cases in the
wild, which is great.
---------
Co-authored-by: David Peter <sharkdp@users.noreply.github.com>
I'm not 100% sold on this implementation, but it's a strict improvement
and it adds a ton of snapshot tests for future iteration.
Part of https://github.com/astral-sh/ty/issues/494
## Summary
Fixes FURB105 (`print-empty-string`) to detect empty f-strings in
addition to regular empty strings. Previously, the rule only flagged
`print("")` but missed `print(f"")`. This fix ensures both cases are
detected and can be automatically fixed.
Fixes#21346
## Problem Analysis
The FURB105 rule checks for unnecessary empty strings passed to
`print()` calls. The `is_empty_string` helper function was only checking
for `Expr::StringLiteral` with empty values, but did not handle
`Expr::FString` (f-strings). As a result, `print(f"")` was not being
flagged as a violation, even though it's semantically equivalent to
`print("")` and should be simplified to `print()`.
The issue occurred because the function used a `matches!` macro that
only checked for string literals:
```rust
fn is_empty_string(expr: &Expr) -> bool {
matches!(
expr,
Expr::StringLiteral(ast::ExprStringLiteral { value, .. }) if value.is_empty()
)
}
```
## Approach
1. **Import the helper function**: Added `is_empty_f_string` to the
imports from `ruff_python_ast::helpers`, which already provides logic to
detect empty f-strings.
2. **Update `is_empty_string` function**: Changed the implementation
from a `matches!` macro to a `match` expression that handles both string
literals and f-strings:
```rust
fn is_empty_string(expr: &Expr) -> bool {
match expr {
Expr::StringLiteral(ast::ExprStringLiteral { value, .. }) =>
value.is_empty(),
Expr::FString(f_string) => is_empty_f_string(f_string),
_ => false,
}
}
```
The fix leverages the existing `is_empty_f_string` helper function which
properly handles the complexity of f-strings, including nested f-strings
and interpolated expressions. This ensures the detection is accurate and
consistent with how empty strings are detected elsewhere in the
codebase.
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## Summary
Resolves https://github.com/astral-sh/ty/issues/1494
## Test Plan
Add a test showing if we are in `from <name> <name> ` we provide the
keyword completion "import"
This elides the following inlay hints:
```py
foo([x=]x)
foo([x=]y.x)
foo([x=]x[0])
foo([x=]x(...))
# composes to complex situations
foo([x=]y.x(..)[0])
```
Fixes https://github.com/astral-sh/ty/issues/1514
Summary
--
Fixes#21360 by using the union of names instead of overwriting them, as
Micha suggested originally on #21104.
This avoids overwriting the `n` name in the `Subscript` by the empty set
of names visited in the nested OR pattern before visiting the other arm
of the outer OR pattern.
Test Plan
--
A new inline test case taken from the issue
## Summary
Detect usages of implicit `self` in property getters, which allows us to
treat their signature as being generic.
closes https://github.com/astral-sh/ty/issues/1502
## Typing conformance
Two new type assertions that are succeeding.
## Ecosystem results
Mostly look good. There are a few new false positives related to a bug
with constrained typevars that is unrelated to the work here. I reported
this as https://github.com/astral-sh/ty/issues/1503.
## Test Plan
Added regression tests.
## Summary
Add support for `Optional` and `Annotated` in implicit type aliases
part of https://github.com/astral-sh/ty/issues/221
## Typing conformance changes
New expected diagnostics.
## Ecosystem
A lot of true positives, some known limitations unrelated to this PR.
## Test Plan
New Markdown tests
## Summary
This PR adds extra validation for `isinstance()` and `issubclass()`
calls that use `UnionType` instances for their second argument.
According to typeshed's annotations, any `UnionType` is accepted for the
second argument, but this isn't true at runtime: at runtime, all
elements in the `UnionType` must either be class objects or be `None` in
order for the `isinstance()` or `issubclass()` call to reliably succeed:
```pycon
% uvx python3.14
Python 3.14.0 (main, Oct 10 2025, 12:54:13) [Clang 20.1.4 ] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from typing import LiteralString
>>> import types
>>> type(LiteralString | int) is types.UnionType
True
>>> isinstance(42, LiteralString | int)
Traceback (most recent call last):
File "<python-input-5>", line 1, in <module>
isinstance(42, LiteralString | int)
~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/alexw/Library/Application Support/uv/python/cpython-3.14.0-macos-aarch64-none/lib/python3.14/typing.py", line 559, in __instancecheck__
raise TypeError(f"{self} cannot be used with isinstance()")
TypeError: typing.LiteralString cannot be used with isinstance()
```
## Test Plan
Added mdtests/snapshots
## Summary
Fixed FURB101 (`read-whole-file`) to handle annotated assignments.
Previously, the rule would detect violations in code like `contents: str
= f.read()` but fail to generate a fix. Now it correctly generates fixes
that preserve type annotations (e.g., `contents: str =
Path("file.txt").read_text(encoding="utf-8")`).
Fixes#21274
## Problem Analysis
The FURB101 rule was only checking for `Stmt::Assign` statements when
determining whether a fix could be applied. When encountering annotated
assignments (`Stmt::AnnAssign`) like `contents: str = f.read()`, the
rule would:
1. Correctly detect the violation (the diagnostic was reported)
2. Fail to generate a fix because:
- The `visit_expr` method only matched `Stmt::Assign`, not
`Stmt::AnnAssign`
- The `generate_fix` function only accepted `Stmt::Assign` in its body
validation
- The replacement code generation didn't account for type annotations
This occurred because Python's AST represents annotated assignments as a
different node type (`StmtAnnAssign`) with separate fields for the
target, annotation, and value, unlike regular assignments which use a
list of targets.
## Approach
The fix extends the rule to handle both assignment types:
1. **Updated `visit_expr` method**: Now matches both `Stmt::Assign` and
`Stmt::AnnAssign`, extracting:
- Variable name from the target expression
- Type annotation code (when present) using the code generator
2. **Updated `generate_fix` function**:
- Added `annotation: Option<String>` parameter to accept annotation code
- Updated body validation to accept both `Stmt::Assign` and
`Stmt::AnnAssign`
- Modified replacement code generation to preserve annotations: `{var}:
{annotation} = {binding}({filename_code}).{suggestion}`
3. **Added test case**: Added an annotated assignment test case to
verify the fix works correctly.
The implementation maintains backward compatibility with regular
assignments while adding support for annotated assignments, ensuring
type annotations are preserved in the generated fixes.
---------
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
We have lots of `TypeVisitor`s that end up having very similar
`visit_type` implementations. This PR consolidates some of the code for
these so that there's less repetition and duplication.
When checking whether a constraint set is satisfied, if a typevar has a
non-fully-static upper bound or constraint, we are free to choose any
materialization that makes the check succeed.
In non-inferable positions, we have to show that the constraint set is
satisfied for all valid specializations, so it's best to choose the most
restrictive materialization, since that minimizes the set of valid
specializations that have to pass.
In inferable positions, we only have to show that the constraint set is
satisfied for _some_ valid specializations, so it's best to choose the
most permissive materialization, since that maximizes our chances of
finding a specialization that passes.
Summary
--
These rules are themselves in preview, so we don't need the additional
preview checks on the fixes or the separate preview tests. This has
confused me in a couple of reviews of changes to the fixes.
Test Plan
--
Existing tests, with the fixes previously only shown in the preview
tests now in the "non-preview" tests.
## Summary
Add support for `Literal` types in implicit type aliases.
part of https://github.com/astral-sh/ty/issues/221
## Ecosystem analysis
This looks good to me, true positives and known problems.
## Test Plan
New Markdown tests.
## Summary
This PR adds support for understanding the legacy definition and PEP 695
definition for `ParamSpec`.
This is still very initial and doesn't really implement any of the
semantics.
Part of https://github.com/astral-sh/ty/issues/157
## Test Plan
Add mdtest cases.
## Ecosystem analysis
Most of the diagnostics in `starlette` are due to the fact that ty now
understands `ParamSpec` is not a `Todo` type, so the assignability check
fails. The code looks something like:
```py
class _MiddlewareFactory(Protocol[P]):
def __call__(self, app: ASGIApp, /, *args: P.args, **kwargs: P.kwargs) -> ASGIApp: ... # pragma: no cover
class Middleware:
def __init__(
self,
cls: _MiddlewareFactory[P],
*args: P.args,
**kwargs: P.kwargs,
) -> None:
self.cls = cls
self.args = args
self.kwargs = kwargs
# ty complains that `ServerErrorMiddleware` is not assignable to `_MiddlewareFactory[P]`
Middleware(ServerErrorMiddleware, handler=error_handler, debug=debug)
```
There are multiple diagnostics where there's an attribute access on the
`Wrapped` object of `functools` which Pyright also raises:
```py
from functools import wraps
def my_decorator(f):
@wraps(f)
def wrapper(*args, **kwds):
return f(*args, **kwds)
# Pyright: Cannot access attribute "__signature__" for class "_Wrapped[..., Unknown, ..., Unknown]"
Attribute "__signature__" is unknown [reportAttributeAccessIssue]
# ty: Object of type `_Wrapped[Unknown, Unknown, Unknown, Unknown]` has no attribute `__signature__` [unresolved-attribute]
wrapper.__signature__
return wrapper
```
There are additional diagnostics that is due to the assignability checks
failing because ty now infers the `ParamSpec` instead of using the
`Todo` type which would always succeed. This results in a few
`no-matching-overload` diagnostics because the assignability checks
fail.
There are a few diagnostics related to
https://github.com/astral-sh/ty/issues/491 where there's a variable
which is either a bound method or a variable that's annotated with
`Callable` that doesn't contain the instance as the first parameter.
Another set of (valid) diagnostics are where the code hasn't provided
all the type variables. ty is now raising diagnostics for these because
we include `ParamSpec` type variable in the signature. For example,
`staticmethod[Any]` which contains two type variables.
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Closes https://github.com/astral-sh/ty/issues/989
There are various situations where users expect the Python packages
installed in the same environment as ty itself to be considered during
type checking. A minimal example would look like:
```
uv venv my-env
uv pip install my-env ty httpx
echo "import httpx" > foo.py
./my-env/bin/ty check foo.py
```
or
```
uv tool install ty --with httpx
echo "import httpx" > foo.py
ty check foo.py
```
While these are a bit contrived, there are real-world situations where a
user would expect a similar behavior to work. Notably, all of the other
type checkers consider their own environment when determining search
paths (though I'll admit that I have not verified when they choose not
to do this).
One common situation where users are encountering this today is with
`uvx --with-requirements script.py ty check script.py` — which is
currently our "best" recommendation for type checking a PEP 723 script,
but it doesn't work.
Of the options discussed in
https://github.com/astral-sh/ty/issues/989#issuecomment-3307417985, I've
chosen (2) as our criteria for including ty's environment in the search
paths.
- If no virtual environment is discovered, we will always include ty's
environment.
- If a `.venv` is discovered in the working directory, we will _prepend_
ty's environment to the search paths. The dependencies in ty's
environment (e.g., from `uvx --with`) will take precedence.
- If a virtual environment is active, e.g., `VIRTUAL_ENV` (i.e.,
including conda prefixes) is set, we will not include ty's environment.
The reason we need to special case the `.venv` case is that we both
1. Recommend `uvx ty` today as a way to check your project
2. Want to enable `uvx --with <...> ty`
And I don't want (2) to break when you _happen_ to be in a project
(i.e., if we only included ty's environment when _no_ environment is
found) and don't want to remove support for (1).
I think long-term, I want to make `uvx <cmd>` layer the environment on
_top_ of the project environment (in uv), which would obviate the need
for this change when you're using uv. However, that change is breaking
and I think users will expect this behavior in contexts where they're
not using uv, so I think we should handle it in ty regardless.
I've opted not to include the environment if it's non-virtual (i.e., a
system environment) for now. It seems better to start by being more
restrictive. I left a comment in the code.
## Test Plan
I did some manual testing with the initial commit, then subsequently
added some unit tests.
```
❯ echo "import httpx" > example.py
❯ uvx --with httpx ty check example.py
Installed 8 packages in 19ms
error[unresolved-import]: Cannot resolve imported module `httpx`
--> foo/example.py:1:8
|
1 | import httpx
| ^^^^^
|
info: Searched in the following paths during module resolution:
info: 1. /Users/zb/workspace/ty/python (first-party code)
info: 2. /Users/zb/workspace/ty (first-party code)
info: 3. vendored://stdlib (stdlib typeshed stubs vendored by ty)
info: make sure your Python environment is properly configured: https://docs.astral.sh/ty/modules/#python-environment
info: rule `unresolved-import` is enabled by default
Found 1 diagnostic
❯ uvx --from . --with httpx ty check example.py
All checks passed!
```
```
❯ uv init --script foo.py
Initialized script at `foo.py`
❯ uv add --script foo.py httpx
warning: The Python request from `.python-version` resolved to Python 3.13.8, which is incompatible with the script's Python requirement: `>=3.14`
Updated `foo.py`
❯ echo "import httpx" >> foo.py
❯ uvx --with-requirements foo.py ty check foo.py
error[unresolved-import]: Cannot resolve imported module `httpx`
--> foo.py:15:8
|
13 | if __name__ == "__main__":
14 | main()
15 | import httpx
| ^^^^^
|
info: Searched in the following paths during module resolution:
info: 1. /Users/zb/workspace/ty/python (first-party code)
info: 2. /Users/zb/workspace/ty (first-party code)
info: 3. vendored://stdlib (stdlib typeshed stubs vendored by ty)
info: make sure your Python environment is properly configured: https://docs.astral.sh/ty/modules/#python-environment
info: rule `unresolved-import` is enabled by default
Found 1 diagnostic
❯ uvx --from . --with-requirements foo.py ty check foo.py
All checks passed!
```
Notice we do not include ty's environment if `VIRTUAL_ENV` is set
```
❯ VIRTUAL_ENV=.venv uvx --with httpx ty check foo/example.py
error[unresolved-import]: Cannot resolve imported module `httpx`
--> foo/example.py:1:8
|
1 | import httpx
| ^^^^^
|
info: Searched in the following paths during module resolution:
info: 1. /Users/zb/workspace/ty/python (first-party code)
info: 2. /Users/zb/workspace/ty (first-party code)
info: 3. vendored://stdlib (stdlib typeshed stubs vendored by ty)
info: 4. /Users/zb/workspace/ty/.venv/lib/python3.13/site-packages (site-packages)
info: make sure your Python environment is properly configured: https://docs.astral.sh/ty/modules/#python-environment
info: rule `unresolved-import` is enabled by default
Found 1 diagnostic
```
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## Summary
Raised by @AlexWaygood.
We previously did not favour imported symbols, when we probably
should've
## Test Plan
Add test showing that we favour imported symbol even if it is
alphabetically after other symbols that are builtin.
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
This PR ports PLE0117 as a semantic syntax error.
## Test Plan
<!-- How was it tested? -->
Tests previously written
---------
Signed-off-by: 11happy <soni5happy@gmail.com>
Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
This PR carries over some of the `has_relation_to` logic for comparing a
typevar with itself. A typevar will specialize to the same type if it's
mentioned multiple times, so it is always assignable to and a subtype of
itself. (Note that typevars can only specialize to fully static types.)
This is also true when the typevar appears in a union on the right-hand
side, or in an intersection on the left-hand side. Similarly, a typevar
is always disjoint from its negation, so when a negated typevar appears
on the left-hand side, the constraint set is never satisfiable.
(Eventually this will allow us to remove the corresponding clauses from
`has_relation_to`, but that can't happen until more of #20093 lands.)
## Summary
Splitting this one out from https://github.com/astral-sh/ruff/pull/21210. This is also something that should be made obselete by the new constraint solver, but is easy enough to fix now.
## Summary
Fixes FURB157 false negative where `Decimal("_-1")` was not flagged as
verbose when underscores precede the sign character. This fixes#21186.
## Problem Analysis
The `verbose-decimal-constructor` (FURB157) rule failed to detect
verbose `Decimal` constructors when the sign character (`+` or `-`) was
preceded by underscores. For example, `Decimal("_-1")` was not flagged,
even though it can be simplified to `Decimal(-1)`.
The bug occurred because the rule checked for the sign character at the
start of the string before stripping leading underscores. According to
Python's `Decimal` parser behavior (as documented in CPython's
`_pydecimal.py`), underscores are removed before parsing the sign. The
rule's logic didn't match this behavior, causing a false negative for
cases like `"_-1"` where the underscore came before the sign.
This was a regression introduced in version 0.14.3, as these cases were
correctly flagged in version 0.14.2.
## Approach
The fix updates the sign extraction logic to:
1. Strip leading underscores first (matching Python's Decimal parser
behavior)
2. Extract the sign from the underscore-stripped string
3. Preserve the string after the sign for normalization purposes
This ensures that cases like `Decimal("_-1")`, `Decimal("_+1")`, and
`Decimal("_-1_000")` are correctly detected and flagged. The
normalization logic was also updated to use the string after the sign
(without underscores) to avoid double signs in the replacement output.
## Summary
Allow values of type `None` in type expressions. The [typing
spec](https://typing.python.org/en/latest/spec/annotations.html#type-and-annotation-expressions)
could be more explicit on whether this is actually allowed or not, but
it seems relatively harmless and does help in some use cases like:
```py
try:
from module import MyClass
except ImportError:
MyClass = None # ty: ignore
def f(m: MyClass):
pass
```
## Test Plan
Updated tests, ecosystem check.
Summary
--
This PR fixes#17796 by taking the approach mentioned in
https://github.com/astral-sh/ruff/issues/17796#issuecomment-2847943862
of simply recursing into the `MatchAs` patterns when checking if we need
parentheses. This allows us to reuse the parentheses in the inner
pattern before also breaking the `MatchAs` pattern itself:
```diff
match class_pattern:
case Class(xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) as capture:
pass
- case (
- Class(xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) as capture
- ):
+ case Class(
+ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+ ) as capture:
pass
- case (
- Class(
- xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
- ) as capture
- ):
+ case Class(
+ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+ ) as capture:
pass
case (
Class(
@@ -685,13 +683,11 @@
match sequence_pattern_brackets:
case [xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx] as capture:
pass
- case (
- [xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx] as capture
- ):
+ case [
+ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+ ] as capture:
pass
- case (
- [
- xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
- ] as capture
- ):
+ case [
+ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+ ] as capture:
pass
```
I haven't really resolved the question of whether or not it's okay
always to recurse, but I'm hoping the ecosystem check on this PR might
shed some light on that.
Test Plan
--
New tests based on the issue and then reviewing the ecosystem check here
## Summary
A lot of the bidirectional inference work relies on `dict` not being
assignable to `TypedDict`, so I think it makes sense to add this before
fully implementing https://github.com/astral-sh/ty/issues/1387.
## Summary
Add support for implicit type aliases that use PEP 604 unions:
```py
IntOrStr = int | str
reveal_type(IntOrStr) # UnionType
def _(int_or_str: IntOrStr):
reveal_type(int_or_str) # int | str
```
## Typing conformance
The changes are either removed false positives, or new diagnostics due
to known limitations unrelated to this PR.
## Ecosystem impact
Spot checked, a mix of true positives and known limitations.
## Test Plan
New Markdown tests.
Fixes https://github.com/astral-sh/ty/issues/1053
## Summary
Other type checkers prioritize a submodule over a package `__getattr__`
in `from mod import sub`, even though the runtime precedence is the
other direction. In effect, this is making an implicit assumption that a
module `__getattr__` will not handle (that is, will raise
`AttributeError`) for names that are also actual submodules, rather than
shadowing them. In practice this seems like a realistic assumption in
the ecosystem? Or at least the ecosystem has adapted to it, and we need
to adapt this precedence also, for ecosystem compatibility.
The implementation is a bit ugly, precisely because it departs from the
runtime semantics, and our implementation is oriented toward modeling
runtime semantics accurately. That is, `__getattr__` is modeled within
the member-lookup code, so it's hard to split "member lookup result from
module `__getattr__`" apart from other member lookup results. I did this
via a synthetic `TypeQualifier::FROM_MODULE_GETATTR` that we attach to a
type resulting from a member lookup, which isn't beautiful but it works
well and doesn't introduce inefficiency (e.g. redundant member lookups).
## Test Plan
Updated mdtests.
Also added a related mdtest formalizing our support for a module
`__getattr__` that is explicitly annotated to accept a limited set of
names. In principle this could be an alternative (more explicit) way to
handle the precedence problem without departing from runtime semantics,
if the ecosystem would adopt it.
### Ecosystem analysis
Lots of removed diagnostics which are an improvement because we now
infer the expected submodule.
Added diagnostics are mostly unrelated issues surfaced now because we
previously had an earlier attribute error resulting in `Unknown`; now we
correctly resolve the module so that earlier attribute error goes away,
we get an actual type instead of `Unknown`, and that triggers a new
error.
In scipy and sklearn, the module `__getattr__` which we were respecting
previously is un-annotated so returned a forgiving `Unknown`; now we
correctly see the actual module, which reveals some cases of
https://github.com/astral-sh/ty/issues/133 that were previously hidden
(`scipy/optimize/__init__.py` [imports `from
._tnc`](eff82ca575/scipy/optimize/__init__.py (L429)).)
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
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## Summary
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* extend AIR301 to include deprecated argument `concurrency` in
`airflow....DAG`
## Test Plan
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update the existing test fixture in the first commit and then reorganize
in the second one
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## Summary
Resolves https://github.com/astral-sh/ty/issues/1464
We sort the completions before we add the unimported ones, meaning that
imported completions show up before unimported ones.
This is also spoken about in
https://github.com/astral-sh/ty/issues/1274, and this is probably a
duplicate of that.
@AlexWaygood mentions this
[here](https://github.com/astral-sh/ty/issues/1274#issuecomment-3345942698)
too.
## Test Plan
Add a test showing even if an unimported completion "should"
(alphabetically before) come first, we favor the imported one.
Summary
--
This code has been unused since #14233 but not detected by clippy I
guess. This should help to remove the temptation to use the set
comparison again like I suggested in #21144. And we shouldn't do the set
comparison because of #13802, which #14233 fixed.
Test Plan
--
Existing tests
Fixes https://github.com/astral-sh/ty/issues/1368
## Summary
Add support for patterns like this, where a type alias to a literal type
(or union of literal types) is used to subscript `typing.Literal`:
```py
type MyAlias = Literal[1]
def _(x: Literal[MyAlias]): ...
```
This shows up in the ecosystem report for PEP 613 type alias support.
One interesting case is an alias to `bool` or an enum type. `bool` is an
equivalent type to `Literal[True, False]`, which is a union of literal
types. Similarly an enum type `E` is also equivalent to a union of its
member literal types. Since (for explicit type aliases) we infer the RHS
directly as a type expression, this makes it difficult for us to
distinguish between `bool` and `Literal[True, False]`, so we allow
either one to (or an alias to either one) to appear inside `Literal`,
where other type checkers allow only the latter.
I think for implicit type aliases it may be simpler to support only
types derived from actually subscripting `typing.Literal`, though, so I
didn't make a TODO-comment commitment here.
## Test Plan
Added mdtests, including TODO-filled tests for PEP 613 and implicit type
aliases.
### Conformance suite
All changes here are positive -- we now emit errors on lines that should
be errors. This is a side effect of the new implementation, not the
primary purpose of this PR, but it's still a positive change.
### Ecosystem
Eliminates one ecosystem false positive, where a PEP 695 type alias for
a union of literal types is used to subscript `typing.Literal`.
## Summary
Adds type inference for list/dict/set comprehensions, including
bidirectional inference:
```py
reveal_type({k: v for k, v in [("a", 1), ("b", 2)]}) # dict[Unknown | str, Unknown | int]
squares: list[int | None] = [x for x in range(10)]
reveal_type(squares) # list[int | None]
```
## Ecosystem impact
I did spot check the changes and most of them seem like known
limitations or true positives. Without proper bidirectional inference,
we saw a lot of false positives.
## Test Plan
New Markdown tests
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## Summary
@BurntSushi provided some feedback in #21146 so i address it here.
Summary
--
This is a first step toward fixing #9745. After reviewing our open
issues and several Black issues and PRs, I personally found the function
case the most compelling, especially with very long argument lists:
```py
def func(
self,
arg1: int,
arg2: bool,
arg3: bool,
arg4: float,
arg5: bool,
) -> tuple[...]:
if arg2 and arg3:
raise ValueError
```
or many annotations:
```py
def function(
self, data: torch.Tensor | tuple[torch.Tensor, ...], other_argument: int
) -> torch.Tensor | tuple[torch.Tensor, ...]:
do_something(data)
return something
```
I think docstrings help the situation substantially both because syntax
highlighting will usually give a very clear separation between the
annotations and the docstring and because we already allow a blank line
_after_ the docstring:
```py
def function(
self, data: torch.Tensor | tuple[torch.Tensor, ...], other_argument: int
) -> torch.Tensor | tuple[torch.Tensor, ...]:
"""
A function doing something.
And a longer description of the things it does.
"""
do_something(data)
return something
```
There are still other comments on #9745, such as [this one] with 9
upvotes, where users specifically request blank lines in all block
types, or at least including conditionals and loops. I'm sympathetic to
that case as well, even if personally I don't find an [example] like
this:
```py
if blah:
# Do some stuff that is logically related
data = get_data()
# Do some different stuff that is logically related
results = calculate_results()
return results
```
to be much more readable than:
```py
if blah:
# Do some stuff that is logically related
data = get_data()
# Do some different stuff that is logically related
results = calculate_results()
return results
```
I'm probably just used to the latter from the formatters I've used, but
I do prefer it. I also think that functions are the least susceptible to
the accidental introduction of a newline after refactoring described in
Micha's [comment] on #8893.
I actually considered further restricting this change to functions with
multiline headers. I don't think very short functions like:
```py
def foo():
return 1
```
benefit nearly as much from the allowed newline, but I just went with
any function without a docstring for now. I guess a marginal case like:
```py
def foo(a_long_parameter: ALongType, b_long_parameter: BLongType) -> CLongType:
return 1
```
might be a good argument for not restricting it.
I caused a couple of syntax errors before adding special handling for
the ellipsis-only case, so I suspect that there are some other
interesting edge cases that may need to be handled better.
Test Plan
--
Existing tests, plus a few simple new ones. As noted above, I suspect
that we may need a few more for edge cases I haven't considered.
[this one]:
https://github.com/astral-sh/ruff/issues/9745#issuecomment-2876771400
[example]:
https://github.com/psf/black/issues/902#issuecomment-1562154809
[comment]:
https://github.com/astral-sh/ruff/issues/8893#issuecomment-1867259744
## Summary
Discussion with @ibraheemdev clarified that
https://github.com/astral-sh/ruff/pull/21168 was incorrect. In a case of
failed inference of a dict literal as a `TypedDict`, we should store the
context-less inferred type of the dict literal as the type of the dict
literal expression itself; the fallback to declared type should happen
at the level of the overall assignment definition.
The reason the latter isn't working yet is because currently we
(wrongly) consider a homogeneous dict type as assignable to a
`TypedDict`, so we don't actually consider the assignment itself as
failed. So the "bug" I observed (and tried to fix) will naturally be
fixed by implementing TypedDict assignability rules.
Rollback https://github.com/astral-sh/ruff/pull/21168 except for the
tests, and modify the tests to include TODOs as needed.
## Test Plan
Updated mdtests.
The parser currently uses single quotes to wrap tokens. This is
inconsistent with the rest of ruff/ty, which use backticks.
For example, see the inconsistent diagnostics produced in this simple
example: https://play.ty.dev/0a9d6eab-6599-4a1d-8e40-032091f7f50f
Consistently wrapping tokens in backticks produces uniform diagnostics.
Following the style decision of #723, in #2889 some quotes were already
switched into backticks.
This is also in line with Rust's guide on diagnostics
(https://rustc-dev-guide.rust-lang.org/diagnostics.html#diagnostic-structure):
> When code or an identifier must appear in a message or label, it
should be surrounded with backticks
## Summary
In general, when we have an invalid assignment (inferred assigned type
is not assignable to declared type), we fall back to inferring the
declared type, since the declared type is a more explicit declaration of
the programmer's intent. This also maintains the invariant that our
inferred type for a name is always assignable to the declared type for
that same name. For example:
```py
x: str = 1
reveal_type(x) # revealed: str
```
We weren't following this pattern for dictionary literals inferred (via
type context) as a typed dictionary; if the literal was not valid for
the annotated TypedDict type, we would just fall back to the normal
inferred type of the dict literal, effectively ignoring the annotation,
and resulting in inferred type not assignable to declared type.
## Test Plan
Added mdtest assertions.
## Summary
The solver is currently order-dependent, and will choose a supertype
over the exact type if it appears earlier in the list of constraints. We
could be smarter and try to choose the most precise subtype, but I
imagine this is something the new constraint solver will fix anyways,
and this fixes the issue showing up on
https://github.com/astral-sh/ruff/pull/21070.
This PR adds a new `satisfied_by_all_typevar` method, which implements
one of the final steps of actually using these dang constraint sets.
Constraint sets exist to help us check assignability and subtyping of
types in the presence of typevars. We construct a constraint set
describing the conditions under which assignability holds between the
two types. Then we check whether that constraint set is satisfied for
the valid specializations of the relevant typevars (which is this new
method).
We also add a new `ty_extensions.ConstraintSet` method so that we can
test this method's behavior in mdtests, before hooking it up to the rest
of the specialization inference machinery.
## Summary
We currently perform a subtyping check instead of the intended subclass
check (and the subtyping check is confusingly named `is_subclass_of`).
This showed up in https://github.com/astral-sh/ruff/pull/21070.
## Summary
Before this PR, we would emit diagnostics like "Invalid key access" for
a TypedDict literal with invalid key, which doesn't make sense since
there's no "access" in that case. This PR just adjusts the wording to be
more general, and adjusts the documentation of the lint rule too.
I noticed this in the playground and thought it would be a quick fix. As
usual, it turned out to be a bit more subtle than I expected, but for
now I chose to punt on the complexity. We may ultimately want to have
different rules for invalid subscript vs invalid TypedDict literal,
because an invalid key in a TypedDict literal is low severity: it's a
typo detector, but not actually a type error. But then there's another
wrinkle there: if the TypedDict is `closed=True`, then it _is_ a type
error. So would we want to separate the open and closed cases into
separate rules, too? I decided to leave this as a question for future.
If we wanted to use separate rules, or use specific wording for each
case instead of the generalized wording I chose here, that would also
involve a bit of extra work to distinguish the cases, since we use a
generic set of functions for reporting these errors.
## Test Plan
Added and updated mdtests.
This is a second take at the implicit imports approach, allowing `from .
import submodule` in an `__init__.pyi` to create the
`mypackage.submodule` attribute everyhere.
This implementation operates inside of the
available_submodule_attributes subsystem instead of as a re-export rule.
The upside of this is we are no longer purely syntactic, and absolute
from imports that happen to target submodules work (an intentional
discussed deviation from pyright which demands a relative from import).
Also we don't re-export functions or classes.
The downside(?) of this is star imports no longer see these attributes
(this may be either good or bad. I believe it's not a huge lift to make
it work with star imports but it's some non-trivial reworking).
I've also intentionally made `import mypackage.submodule` not trigger
this rule although it's trivial to change that.
I've tried to cover as many relevant cases as possible for discussion in
the new test file I've added (there are some random overlaps with
existing tests but trying to add them piecemeal felt confusing and
weird, so I just made a dedicated file for this extension to the rules).
Fixes https://github.com/astral-sh/ty/issues/133
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
<!-- How was it tested? -->
## Summary
Fixes https://github.com/astral-sh/ty/issues/1427
This PR fixes a regression introduced in alpha.24 where non-dataclass
children of generic dataclasses lost generic type parameter information
during `__init__` synthesis.
The issue occurred because when looking up inherited members in the MRO,
the child class's `inherited_generic_context` was correctly passed down,
but `own_synthesized_member()` (which synthesizes dataclass `__init__`
methods) didn't accept this parameter. It only used
`self.inherited_generic_context(db)`, which returned the parent's
context instead of the child's.
The fix threads the child's generic context through to the synthesis
logic, allowing proper generic type inference for inherited dataclass
constructors.
## Test Plan
- Added regression test for non-dataclass inheriting from generic
dataclass
- Verified the exact repro case from the issue now works
- All 277 mdtest tests passing
- Clippy clean
- Manually verified with Python runtime, mypy, and pyright - all accept
this code pattern
## Verification
Tested against multiple type checkers:
- ✅ Python runtime: Code works correctly
- ✅ mypy: No issues found
- ✅ pyright: 0 errors, 0 warnings
- ✅ ty alpha.23: Worked (before regression)
- ❌ ty alpha.24: Regression
- ✅ ty with this fix: Works correctly
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: David Peter <mail@david-peter.de>
It's possible for a constraint to mention two typevars. For instance, in
the body of
```py
def f[S: int, T: S](): ...
```
the baseline constraint set would be `(T ≤ S) ∧ (S ≤ int)`. That is, `S`
must specialize to some subtype of `int`, and `T` must specialize to a
subtype of the type that `S` specializes to.
This PR updates the new "constraint implication" relationship from
#21010 to work on these kinds of constraint sets. For instance, in the
example above, we should be able to see that `T ≤ int` must always hold:
```py
def f[S, T]():
constraints = ConstraintSet.range(Never, S, int) & ConstraintSet.range(Never, T, S)
static_assert(constraints.implies_subtype_of(T, int)) # now succeeds!
```
This did not require major changes to the implementation of
`implies_subtype_of`. That method already relies on how our `simplify`
and `domain` methods expand a constraint set to include the transitive
closure of the constraints that it mentions, and to mark certain
combinations of constraints as impossible. Previously, that transitive
closure logic only looked at pairs of constraints that constrain the
same typevar. (For instance, to notice that `(T ≤ bool) ∧ ¬(T ≤ int)` is
impossible.)
Now we also look at pairs of constraints that constraint different
typevars, if one of the constraints is bound by the other — that is,
pairs of the form `T ≤ S` and `S ≤ something`, or `S ≤ T` and `something
≤ S`. In those cases, transitivity lets us add a new derived constraint
that `T ≤ something` or `something ≤ T`, respectively. Having done that,
our existing `implies_subtype_of` logic finds and takes into account
that derived constraint.
Summary
--
Fixes#21121 by upgrading `RuntimeEvaluated` annotations like
`dataclasses.KW_ONLY` to `RuntimeRequired`. We already had special
handling for
`TypingOnly` annotations in this context but not `RuntimeEvaluated`.
Combining
that with the `future-annotations` setting, which allowed ignoring the
`RuntimeEvaluated` flag, led to the reported bug where we would try to
move
`KW_ONLY` into a `TYPE_CHECKING` block.
Test Plan
--
A new test based on the issue
## Summary
We weren't correctly modeling it as a `staticmethod` in all cases,
leading us to incorrectly infer that the `cls` argument would be bound
if it was accessed on an instance (rather than the class object).
## Test Plan
Added mdtests that fail on `main`. The primer output also looks good!
## Summary
Fixes#21101 by storing the child visitor's names in the parent visitor.
This makes sure that `visitor.names` on line 1818 isn't empty after we
visit a nested OR pattern.
## Test Plan
New inline test cases derived from the issue,
[playground](https://play.ruff.rs/7b6439ac-ee8f-4593-9a3e-c2aa34a595d0)
## Summary
Adds proper type narrowing and reachability analysis for matching on
non-inferable type variables bound to enums. For example:
```py
from enum import Enum
class Answer(Enum):
NO = 0
YES = 1
def is_yes(self) -> bool: # no error here!
match self:
case Answer.YES:
return True
case Answer.NO:
return False
```
closes https://github.com/astral-sh/ty/issues/1404
## Test Plan
Added regression tests
## Summary
We previously didn't understand `range` and wrote these custom
`IntIterable`/`IntIterator` classes for tests. We can now remove them
and make the tests shorter in some places.
## Summary
Infer a type of unannotated `self` parameters in decorated methods /
properties.
closes https://github.com/astral-sh/ty/issues/1448
## Test Plan
Existing tests, some new tests.
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## Summary
Fixed the incorrect import example in the "correct exmaple"
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
🤷
<!-- How was it tested? -->
Note that this doesn't change the evaluation results unfortunately.
In particular, prior to this fix, the correct result was ranked above
the redundant result. Our MRR-based evaluation doesn't care about
anything below the rank of the correct answer, and so this change isn't
reflected in our evaluation.
Fixesastral-sh/ty#1445
The status quo grew organically and didn't do well when one wanted to
mix and match different settings to generate a snapshot.
This does a small refactor to use more of a builder to generate
snapshots.
This fixes a bug where the `import module` part of a completion for
unimported candidates would be missing. This makes it especially
confusing because the user can't tell where the symbol is coming from,
and there is no hint that an `import` statement will be inserted.
Previously, we were using [`CompletionItemLabelDetails`] to render the
`import module` part of the suggestion. But this is only supported in
clients that support version 3.17 (or newer) of the LSP specification.
It turns out that this support isn't widespread yet. In particular,
Heliex doesn't seem to support "label details."
To fix this, we take a [cue from rust-analyzer][rust-analyzer-details].
We detect if the client supports "label details," and if so, use it.
Otherwise, we push the `import module` text into the completion label
itself.
Fixes https://github.com/astral-sh/ruff/pull/20439#issuecomment-3313689568
[`CompletionItemLabelDetails`]: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#completionItemLabelDetails
[rust-analyzer-details]: 5d905576d4/crates/rust-analyzer/src/lsp/to_proto.rs (L391-L404)
This PR updates the mdtests that test how our generics solver interacts
with our new constraint set implementation. Because the rendering of a
constraint set can get long, this standardizes on putting the `revealed`
assertion on a separate line. We also add a `static_assert` test for
each constraint set to verify that they are all coerced into simple
`bool`s correctly.
This is a pure reformatting (not even a refactoring!) that changes no
behavior. I've pulled it out of #20093 to reduce the amount of effort
that will be required to review that PR.
We have several functions in `ty_extensions` for testing our constraint
set implementation. This PR refactors those functions so that they are
all methods of the `ConstraintSet` class, rather than being standalone
top-level functions. 🎩 to @sharkdp for pointing out that
`KnownBoundMethod` gives us what we need to implement that!
This PR adds the new **_constraint implication_** relationship between
types, aka `is_subtype_of_given`, which tests whether one type is a
subtype of another _assuming that the constraints in a particular
constraint set hold_.
For concrete types, constraint implication is exactly the same as
subtyping. (A concrete type is any fully static type that is not a
typevar. It can _contain_ a typevar, though — `list[T]` is considered
concrete.)
The interesting case is typevars. The other typing relationships (TODO:
will) all "punt" on the question when considering a typevar, by
translating the desired relationship into a constraint set. At some
point, though, we need to resolve a constraint set; at that point, we
can no longer punt on the question. Unlike with concrete types, the
answer will depend on the constraint set that we are considering.
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## Summary
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This PR refactors semantic error tests in each seperate file
## Test Plan
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## CC
- @ntBre
---------
Signed-off-by: 11happy <soni5happy@gmail.com>
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
Summary
--
Fixes#19550
This PR copies our non-watch diagnostic rendering code into
`Printer::write_continuously` in preview mode, allowing it to use
whatever output format is passed in.
I initially marked this as also fixing #19552, but I guess that's not
true currently but will be true once this is stabilized and we can
remove the warning.
Test Plan
--
Existing tests, but I don't think we have any `watch` tests, so some
manual testing as well. The default with just `ruff check --watch` is
still `concise`, adding just `--preview` still gives the `full` output,
and then specifying any other output format works, with JSON as one
example:
<img width="695" height="719" alt="Screenshot 2025-10-27 at 9 21 41 AM"
src="https://github.com/user-attachments/assets/98957911-d216-4fc4-8b6c-22c56c963b3f"
/>
When formatting clause headers for clauses that are not their own node,
like an `else` clause or `finally` clause, we begin searching for the
keyword at the end of the previous statement. However, if the previous
statement ended in a semicolon this caused a panic because we only
expected trivia between the end of the last statement and the keyword.
This PR adjusts the starting point of our search for the keyword to
begin after the optional semicolon in these cases.
Closes#21065
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## Summary
Add docstring sections which were missing from the numpy list as pointed
out here #20923. For now these are only the official sections as
documented
[here](https://numpydoc.readthedocs.io/en/latest/format.html#sections).
## Test Plan
Added a test case for DOC102
## Summary
Fixes#20973 (`docstring-extraneous-exception`) false positive when
exceptions mentioned in docstrings are caught and explicitly re-raised
using `raise e` or `raise e from None`.
## Problem Analysis
The DOC502 rule was incorrectly flagging exceptions mentioned in
docstrings as "not explicitly raised" when they were actually being
explicitly re-raised through exception variables bound in `except`
clauses.
**Root Cause**: The `BodyVisitor` in `check_docstring.rs` only checked
for direct exception references (like `raise OSError()`) but didn't
recognize when a variable bound to an exception in an `except` clause
was being re-raised.
**Example of the bug**:
```python
def f():
"""Do nothing.
Raises
------
OSError
If the OS errors.
"""
try:
pass
except OSError as e:
raise e # This was incorrectly flagged as not explicitly raising OSError
```
The issue occurred because `resolve_qualified_name(e)` couldn't resolve
the variable `e` to a qualified exception name, since `e` is just a
variable binding, not a direct reference to an exception class.
## Approach
Modified the `BodyVisitor` in
`crates/ruff_linter/src/rules/pydoclint/rules/check_docstring.rs` to:
1. **Track exception variable bindings**: Added `exception_variables`
field to map exception variable names to their exception types within
`except` clauses
2. **Enhanced raise statement detection**: Updated `visit_stmt` to check
if a `raise` statement uses a variable name that's bound to an exception
in the current `except` clause
3. **Proper scope management**: Clear exception variable mappings when
leaving `except` handlers to prevent cross-contamination
**Key changes**:
- Added `exception_variables: FxHashMap<&'a str, QualifiedName<'a>>` to
track variable-to-exception mappings
- Enhanced `visit_except_handler` to store exception variable bindings
when entering `except` clauses
- Modified `visit_stmt` to check for variable-based re-raising: `raise
e` → lookup `e` in `exception_variables`
- Clear mappings when exiting `except` handlers to maintain proper scope
---------
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
That PR title might be a bit inscrutable.
Consider the two constraints `T ≤ bool` and `T ≤ int`. Since `bool ≤
int`, by transitivity `T ≤ bool` implies `T ≤ int`. (Every type that is
a subtype of `bool` is necessarily also a subtype of `int`.) That means
that `T ≤ bool ∧ T ≰ int` is an impossible combination of constraints,
and is therefore not a valid input to any BDD. We say that that
assignment is not in the _domain_ of the BDD.
The implication `T ≤ bool → T ≤ int` can be rewritten as `T ≰ bool ∨ T ≤
int`. (That's the definition of implication.) If we construct that
constraint set in an mdtest, we should get a constraint set that is
always satisfiable. Previously, that constraint set would correctly
_display_ as `always`, but a `static_assert` on it would fail.
The underlying cause is that our `is_always_satisfied` method would only
test if the BDD was the `AlwaysTrue` terminal node. `T ≰ bool ∨ T ≤ int`
does not simplify that far, because we purposefully keep around those
constraints in the BDD structure so that it's easier to compare against
other BDDs that reference those constraints.
To fix this, we need a more nuanced definition of "always satisfied".
Instead of evaluating to `true` for _every_ input, we only need it to
evaluate to `true` for every _valid_ input — that is, every input in its
domain.
Alex Waygood
Mahmoud Saada
Aria Desires
Micha Reiser
Douglas Creager
Dan Parizher
Jack O'Connor
Ibraheem Ahmed
justin
Matthew Mckee
Brent Westbrook
David Peter
Henry Schreiner
Hugo van Kemenade
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Zanie Blue
Bhuminjay Soni
chiri
Carl Meyer
Wei Lee
Tom Kuson
Shunsuke Shibayama
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Gautham Venkataraman
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renovate[bot]
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