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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
This PR fixes#20811 , current approach reverses the order in `BtreeSet`
however as pointed in
https://github.com/astral-sh/ruff/issues/20811#issuecomment-3398958832
here we cannot use I`IndexSet` to preserve config order since Settings
derives `CacheKey` which isn't implemented for `IndexSet`, another
approach to preserve the original order might be to use `Vec` however
lookup time complexity might get affected as a result.
<!-- How was it tested? -->
I have tested it locally its working as expected ,
<img width="2200" height="1071" alt="image"
src="https://github.com/user-attachments/assets/7d97b488-1552-4a42-9d90-92acf55ec493"
/>
---------
Signed-off-by: Bhuminjay <bhuminjaysoni@gmail.com>
## Summary
- Adds an alternative example to the PT017 (`pytest-assert-in-except`)
rule documentation showing pytest's `check` parameter for validating
exceptions, available since pytest 8.4.0
Closes#22529
## Test plan
Documentation-only change. Verified with `uvx prek run -a`.
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Part of #18972
This PR makes [invalid-suppression-comment
(RUF103)](https://docs.astral.sh/ruff/rules/invalid-suppression-comment/#invalid-suppression-comment-ruf103)'s
example error out-of-the-box.
[Old example](https://play.ruff.rs/3ff757f3-04ae-4d27-986d-49972338fa24)
```py
ruff: disable # missing codes
```
[New example](https://play.ruff.rs/4a9970c4-3b33-4533-8ffa-f15d481b1e6f)
```py
# ruff: disable # missing codes
```
## Test Plan
<!-- How was it tested? -->
N/A, no functionality/tests affected
This fixes issue #2470 where recursive type aliases like `type
RecursiveT = int | tuple[RecursiveT, ...]` caused a stack overflow when
used in return type checking with constructors like `list()`.
The fix moves all type mapping processing for `UniqueSpecialization`
(and other non-EagerExpansion mappings) inside the `visitor.visit()`
closure. This ensures that if we encounter the same TypeAlias
recursively during type mapping, the cycle detector will properly detect
it and return the fallback value instead of recursing infinitely.
The key insight is that the previous code called
`apply_function_specialization` followed by another
`apply_type_mapping_impl` AFTER the visitor closure returned. At that
point, the TypeAlias was no longer in the visitor's `seen` set, so
recursive references would not be detected as cycles.
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## Summary
The test I've added illustrates the fix. Copying it here too:
```python
from contextlib import contextmanager
from typing import Iterator
from typing_extensions import Self
class Base:
@classmethod
@contextmanager
def create(cls) -> Iterator[Self]:
yield cls()
class Child(Base): ...
with Base.create() as base:
reveal_type(base) # revealed: Base (after the fix, None before)
with Child.create() as child:
reveal_type(child) # revealed: Child (after the fix, None before)
```
Full disclosure: I've used LLMs for this PR, but the result is
thoroughly reviewed by me before submitting. I'm excited about my first
Rust contribution to Astral tools and will address feedback quickly.
Related to https://github.com/astral-sh/ty/issues/2030, I am working on
a fix for the TypeVar case also reported in that issue (by me)
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
<!-- How was it tested? -->
Updated mdtests
---------
Co-authored-by: Douglas Creager <dcreager@dcreager.net>
## Summary
I didn't want to make the "dynamic" `type(...)` PR any larger, but it
probably makes sense to rename these now that we have `Dynamic`
variants.
Fixes https://github.com/astral-sh/ty/issues/2467
When calling a method on an instance of a generic class with bounded
type parameters (e.g., `C[T: K]` where `K` is a NewType), ty was
incorrectly reporting: "Argument type `C[K]` does not satisfy upper
bound `C[T@C]` of type variable `Self`"
The issue was introduced by PR #22105, which moved the catch-all case
for NewType assignments that falls back to the concrete base type. This
case was moved before the TypeVar handling cases, so when checking `K <:
T@C` (where K is a NewType and T@C is a TypeVar with upper bound K):
1. The NewType fallback matched first
2. It delegated to `int` (K's concrete base type)
3. Then checked `int <: T@C`, which checks if `int` satisfies bound `K`
4. But `int` is not assignable to `K` (NewTypes are distinct from their
bases)
The fix moves the NewType fallback case after the TypeVar cases, so
TypeVar handling takes precedence. Now when checking `K <: T@C`, we use
the TypeVar case at line 828 which returns `false` for non-inferable
typevars - but this is correct because the *other* direction (`T@C <:
K`) passes, and for the overall specialization comparison both
directions are checked.
## Summary
This PR adds support for dynamic classes created via `type()`. The core
of the change is that `ClassLiteral` is now an enum:
```rust
pub enum ClassLiteral<'db> {
/// A class defined via a `class` statement.
Stmt(StmtClassLiteral<'db>),
/// A class created via the functional form `type(name, bases, dict)`.
Functional(FunctionalClassLiteral<'db>),
}
```
And, in turn, various methods on `ClassLiteral` like `body_scope` now
return `Option` or similar (and callers must adjust to that change in
signature).
Over time, we can expand the enum to include functional namedtuples,
etc. (I already have this working in a separate branch, and I believe it
slots in well.)
(I'd love help with the names -- I think `StmtClassLiteral` is kind of
lame. Maybe `DeclarativeClassLiteral`?)
Closes https://github.com/astral-sh/ty/issues/740.
---------
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
## Summary
The type inference system already correctly special-cases `__file__` to
return `str` for the current module (since the code is executing from an
existing file). However, the completion system was bypassing this logic
and pulling `__file__: str | None` directly from `types.ModuleType` in
typeshed.
This PR adds implicit module globals (like `__file__`, `__name__`, etc.)
with their correctly-typed values to completions, reusing the existing
`module_type_implicit_global_symbol` function that already handles the
special-casing.
Closes https://github.com/astral-sh/ty/issues/2445.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
Like `ProtocolInstance`, we now use `left.cmp(right)` by deriving
`PartialOrd` and `Ord`. IIUC, this uses Salsa ID for Salsa-interned
types, but avoids `None.cmp(None)` for synthesized variants.
Closes https://github.com/astral-sh/ty/issues/2451.
## Summary
Correctly handle upper bounds for contravariant type variables during
specialization inference. Previously, the type checker incorrectly
applied covariant subtyping rules, requiring the actual type to directly
satisfy the bound rather than checking for a valid intersection.
In contravariant positions, subtyping relationships are inverted. The
bug caused valid code like `f(x: Contra[str])` where `f` expects
`Contra[T: int]` to be incorrectly rejected, when it should solve `T` to
`Never` (the intersection of `int` and `str`).
Closes https://github.com/astral-sh/ty/issues/2427
## Details
- Added `is_contravariant()` helper to `TypeVarVariance` in
`variance.rs`
- Updated `SpecializationBuilder::infer_map_impl` in `generics.rs` to
treat bounds and constraints differently based on variance:
* Skip immediate `ty <: bound` check for contravariant upper bounds
* Flip constraint check to `constraint <: ty` for contravariant
positions
- Added test case for bounded contravariant type variables in
`variance.md`
- All 308 mdtest cases pass & 150 ty_python_semantic unit tests pass
---------
Co-authored-by: Douglas Creager <dcreager@dcreager.net>
## Summary
prek allows you to set priorities, and can run tasks of the same
priority concurrently (e.g., we can run Ruff's Python formatting and
`cargo fmt` at the same time). On my machine, this takes `uvx prek run
-a` from 19.4s to 5.0s (~a 4x speed-up).
This PR adjusts the logic for skipping formatting so that a `fmt: skip`
can affect multiple statements if they lie on the same line.
Specifically, a `fmt: skip` comment will now suppress all the statements
in the suite in which it appears whose range intersects the line
containing the skip directive. For example:
```python
x=[
'1'
];x=2 # fmt: skip
```
remains unchanged after formatting.
(Note that compound statements are somewhat special and were handled in
a previous PR - see #20633).
Closes#17331 and #11430.
Simplest to review commit by commit - the key diffs of interest are the
commit introducing the core logic, and the diff between the snapshots
introduced in the last commit (compared to the second commit).
# Implementation
On `main` we format a suite of statements by iterating through them. If
we meet a statement with a leading or trailing (own-line)`fmt: off`
comment, then we suppress formatting until we meet a `fmt: on` comment.
Otherwise we format the statement using its own formatting rule.
How are `fmt: skip` comments handled then? They are handled internally
to the formatting of each statement. Specifically, calling `.fmt` on a
statement node will first check to see if there is a trailing,
end-of-line `fmt: skip` (or `fmt: off`/`yapf: off`), and if so then
write the node with suppressed formatting.
In this PR we move the responsibility for handling `fmt: skip` into the
formatting logic of the suite itself. This is done as follows:
- Before beginning to format the suite, we do a pass through the
statements and collect the data of ranges with skipped formatting. More
specifically, we create a map with key given by the _first_ skipped
statement in a block and value a pair consisting of the _last_ skipped
statement and the _range_ to write verbatim.
- We iterate as before, but if we meet a statement that is a key in the
map constructed above, we pause to write the associated range verbatim.
We then advance the iterator to the last statement in the block and
proceed as before.
## Addendum on range formatting
We also had to make some changes to range formatting in order to support
this new behavior. For example, we want to make sure that
```python
<RANGE_START>x=1<RANGE_END>;x=2 # fmt: skip
```
formats verbatim, rather than becoming
```python
x = 1;x=2 # fmt: skip
```
Recall that range formatting proceeds in two steps:
1. Find the smallest enclosing node containing the range AND that has
enough info to format the range (so it may be larger than you think,
e.g. a docstring has enclosing node given by the suite, not the string
itself.)
2. Carve out the formatted range from the result of formatting that
enclosing node.
We had to modify (1), since the suite knows how to format skipped nodes,
but nodes may not "know" they are skipped. To do this we altered the
`visit_body` bethod of the `FindEnclosingNode` visitor: now we iterate
through the statements and check for skipped ranges intersecting the
format range. If we find them, we return without descending. The result
is to consider the statement containing the suite as the enclosing node
in this case.
## Summary
If parent violates LSP against grandparent, and child has the same
violation (but matches parent), we no longer flag the LSP violation on
child, since it can't be fixed without violating parent.
If parent violates LSP against grandparent, and child violates LSP
against both parent and grandparent, we emit two diagnostics (one for
each violation).
If parent violates LSP against grandparent, and child violates LSP
against parent (but not grandparent), we flag it.
Closes https://github.com/astral-sh/ty/issues/2000.
