## 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
<!-- How was it tested? -->
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
<!-- What's the purpose of the change? What does it do, and why? -->
This PR refactors semantic error tests in each seperate file
## Test Plan
<!-- How was it tested? -->
## 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.
## Summary
implement pylint rule stop-iteration-return / R1708
## Test Plan
<!-- How was it tested? -->
---------
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
* Extend `airflow.models.Param` to include `airflow.models.param.Param`
case and include both `airflow.models.param.ParamDict` and
`airflow.models.param.DagParam` and their `airflow.models.` counter part
## Test Plan
<!-- How was it tested? -->
update the text fixture accordingly and reorganize them in the third
commit
Summary
--
Inspired by #20859, this PR adds the version a rule was added, and the
file and line where it was defined, to `ViolationMetadata`. The file and
line just use the standard `file!` and `line!` macros, while the more
interesting version field uses a new `violation_metadata` attribute
parsed by our `ViolationMetadata` derive macro.
I moved the commit modifying all of the rule files to the end, so it
should be a lot easier to review by omitting that one.
As a curiosity and a bit of a sanity check, I also plotted the rule
numbers over time:
<img width="640" height="480" alt="image"
src="https://github.com/user-attachments/assets/75b0b5cc-3521-4d40-a395-8807e6f4925f"
/>
I think this looks pretty reasonable and avoids some of the artifacts
the earlier versions of the script ran into, such as the `rule`
sub-command not being available or `--explain` requiring a file
argument.
<details><summary>Script and summary data</summary>
```shell
gawk --csv '
NR > 1 {
split($2, a, ".")
major = a[1]; minor = a[2]; micro = a[3]
# sum the number of rules added per minor version
versions[minor] += 1
}
END {
tot = 0
for (i = 0; i <= 14; i++) {
tot += versions[i]
print i, tot
}
}
' ruff_rules_metadata.csv > summary.dat
```
```
0 696
1 768
2 778
3 803
4 822
5 848
6 855
7 865
8 893
9 915
10 916
11 924
12 929
13 932
14 933
```
</details>
Test Plan
--
I built and viewed the documentation locally, and it looks pretty good!
<img width="1466" height="676" alt="image"
src="https://github.com/user-attachments/assets/5e227df4-7294-4d12-bdaa-31cac4e9ad5c"
/>
The spacing seems a bit awkward following the `h1` at the top, so I'm
wondering if this might look nicer as a footer in Ruff. The links work
well too:
- [v0.0.271](https://github.com/astral-sh/ruff/releases/tag/v0.0.271)
- [Related
issues](https://github.com/astral-sh/ruff/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20airflow-variable-name-task-id-mismatch)
- [View
source](https://github.com/astral-sh/ruff/blob/main/crates%2Fruff_linter%2Fsrc%2Frules%2Fairflow%2Frules%2Ftask_variable_name.rs#L34)
The last one even works on `main` now since it points to the
`derive(ViolationMetadata)` line.
In terms of binary size, this branch is a bit bigger than main with
38,654,520 bytes compared to 38,635,728 (+20 KB). I guess that's not
_too_ much of an increase, but I wanted to check since we're generating
a lot more code with macros.
---------
Co-authored-by: GiGaGon <107241144+MeGaGiGaGon@users.noreply.github.com>
## Summary
Infer a type of `Self` for unannotated `self` parameters in methods of
classes.
part of https://github.com/astral-sh/ty/issues/159
closes https://github.com/astral-sh/ty/issues/1081
## Conformance tests changes
```diff
+enums_member_values.py:85:9: error[invalid-assignment] Object of type `int` is not assignable to attribute `_value_` of type `str`
```
A true positive ✔️
```diff
-generics_self_advanced.py:35:9: error[type-assertion-failure] Argument does not have asserted type `Self@method2`
-generics_self_basic.py:14:9: error[type-assertion-failure] Argument does not have asserted type `Self@set_scale
```
Two false positives going away ✔️
```diff
+generics_syntax_infer_variance.py:82:9: error[invalid-assignment] Cannot assign to final attribute `x` on type `Self@__init__`
```
This looks like a true positive to me, even if it's not marked with `#
E` ✔️
```diff
+protocols_explicit.py:56:9: error[invalid-assignment] Object of type `tuple[int, int, str]` is not assignable to attribute `rgb` of type `tuple[int, int, int]`
```
True positive ✔️
```
+protocols_explicit.py:85:9: error[invalid-attribute-access] Cannot assign to ClassVar `cm1` from an instance of type `Self@__init__`
```
This looks like a true positive to me, even if it's not marked with `#
E`. But this is consistent with our understanding of `ClassVar`, I
think. ✔️
```py
+qualifiers_final_annotation.py:52:9: error[invalid-assignment] Cannot assign to final attribute `ID4` on type `Self@__init__`
+qualifiers_final_annotation.py:65:9: error[invalid-assignment] Cannot assign to final attribute `ID7` on type `Self@method1`
```
New true positives ✔️
```py
+qualifiers_final_annotation.py:52:9: error[invalid-assignment] Cannot assign to final attribute `ID4` on type `Self@__init__`
+qualifiers_final_annotation.py:57:13: error[invalid-assignment] Cannot assign to final attribute `ID6` on type `Self@__init__`
+qualifiers_final_annotation.py:59:13: error[invalid-assignment] Cannot assign to final attribute `ID6` on type `Self@__init__`
```
This is a new false positive, but that's a pre-existing issue on main
(if you annotate with `Self`):
https://play.ty.dev/3ee1c56d-7e13-43bb-811a-7a81e236e6ab❌ => reported
as https://github.com/astral-sh/ty/issues/1409
## Ecosystem
* There are 5931 new `unresolved-attribute` and 3292 new
`possibly-missing-attribute` attribute errors, way too many to look at
all of them. I randomly sampled 15 of these errors and found:
* 13 instances where there was simply no such attribute that we could
plausibly see. Sometimes [I didn't find it
anywhere](8644d886c6/openlibrary/plugins/openlibrary/tests/test_listapi.py (L33)).
Sometimes it was set externally on the object. Sometimes there was some
[`setattr` dynamicness going
on](a49f6b927d/setuptools/wheel.py (L88-L94)).
I would consider all of them to be true positives.
* 1 instance where [attribute was set on `obj` in
`__new__`](9e87b44fd4/sympy/tensor/array/array_comprehension.py (L45C1-L45C36)),
which we don't support yet
* 1 instance [where the attribute was defined via `__slots__`
](e250ec0fc8/lib/spack/spack/vendor/pyrsistent/_pdeque.py (L48C5-L48C14))
* I see 44 instances [of the false positive
above](https://github.com/astral-sh/ty/issues/1409) with `Final`
instance attributes being set in `__init__`. I don't think this should
block this PR.
## Test Plan
New Markdown tests.
---------
Co-authored-by: Shaygan Hooshyari <sh.hooshyari@gmail.com>
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Fixes#21017
Taught UP032’s parenthesize check to ignore underscores when inspecting
decimal integer literals so the converter emits `f"{(1_2).real}"`
instead of invalid syntax.
## Test Plan
Added test cases to UP032_2.py.
<!-- How was it tested? -->
This PR adds another useful simplification when rendering constraint
sets: `T = int` instead of `T = int ∧ T ≠ str`. (The "smaller"
constraint `T = int` implies the "larger" constraint `T ≠ str`.
Constraint set clauses are intersections, and if one constraint in a
clause implies another, we can throw away the "larger" constraint.)
While we're here, we also normalize the bounds of a constraint, so that
we equate e.g. `T ≤ int | str` with `T ≤ str | int`, and change the
ordering of BDD variables so that all constraints with the same typevar
are ordered adjacent to each other.
Lastly, we also add a new `display_graph` helper method that prints out
the full graph structure of a BDD.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
Fall back to `C[Divergent]` if we are trying to specialize `C[T]` with a
type that itself already contains deeply nested specialized generic
classes. This is a way to prevent infinite recursion for cases like
`self.x = [self.x]` where type inference for the implicit instance
attribute would not converge.
closes https://github.com/astral-sh/ty/issues/1383
closes https://github.com/astral-sh/ty/issues/837
## Test Plan
Regression tests.
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Fixes#18778
Prevent SIM911 from triggering when zip() is called on .keys()/.values()
that take any positional or keyword arguments, so Ruff
never suggests the lossy rewrite.
## Test Plan
<!-- How was it tested? -->
Added a test case to SIM911.py.
## Summary
I spun this out from #21005 because I thought it might be helpful
separately. It just renders a nice `Diagnostic` for syntax errors
pointing to the source of the error. This seemed a bit more helpful to
me than just the byte offset when working on #21005, and we had most of
the code around after #20443 anyway.
## Test Plan
This doesn't actually affect any passing tests, but here's an example of
the additional output I got when I broke the spacing after the `in`
token:
```
error[internal-error]: Expected 'in', found name
--> /home/brent/astral/ruff/crates/ruff_python_formatter/resources/test/fixtures/black/cases/cantfit.py:50:79
|
48 | need_more_to_make_the_line_long_enough,
49 | )
50 | del ([], name_1, name_2), [(), [], name_4, name_3], name_1[[name_2 for name_1 inname_0]]
| ^^^^^^^^
51 | del ()
|
```
I just appended this to the other existing output for now.
This is an alternative to #21012 that more narrowly handles this logic
in the stub-mapping machinery rather than pervasively allowing us to
identify cached files as typeshed stubs. Much of the logic is the same
(pulling the logic out of ty_server so it can be reused).
I don't have a good sense for if one approach is "better" or "worse" in
terms of like, semantics and Weird Bugs that this can cause. This one is
just "less spooky in its broad consequences" and "less muddying of
separation of concerns" and puts the extra logic on a much colder path.
I won't be surprised if one day the previous implementation needs to be
revisited for its more sweeping effects but for now this is good.
Fixes https://github.com/astral-sh/ty/issues/1054
## Summary
We currently panic in the seemingly rare case where the type of a
default value of a parameter depends on the callable itself:
```py
class C:
def f(self: C):
self.x = lambda a=self.x: a
```
Types of default values are only used for display reasons, and it's
unclear if we even want to track them (or if we should rather track the
actual value). So it didn't seem to me that we should spend a lot of
effort (and runtime) trying to achieve a theoretically correct type here
(which would be infinite).
Instead, we simply replace *nested* default types with `Unknown`, i.e.
only if the type of the default value is a callable itself.
closes https://github.com/astral-sh/ty/issues/1402
## Test Plan
Regression tests
## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
This PR implements a new semantic syntax error where name is parameter &
global.
## Test Plan
<!-- How was it tested? -->
I have written inline test as directed in #17412
---------
Signed-off-by: 11happy <soni5happy@gmail.com>
Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
## Summary
Only run the "pull types" test after performing the "actual" mdtest. We
observed that the order matters. There is currently one mdtest which
panics when checked in the CLI or the playground. With this change, it
also panics in the mdtest suite.
reopens https://github.com/astral-sh/ty/issues/837?
## Summary
Implement handling of ellipsis (`...`) defaults in the `FAST002` autofix
to correctly differentiate between required and optional parameters in
FastAPI route definitions.
Previously, the autofix did not properly handle cases where parameters
used `...` as a default value (to indicate required parameters). This
could lead to incorrect transformations when applying the autofix.
This change updates the `FAST002` autofix logic to:
- Correctly recognize `...` as a valid FastAPI required default.
- Preserve the semantics of required parameters while still applying
other autofix improvements.
- Avoid incorrectly substituting or removing ellipsis defaults.
Fixes https://github.com/astral-sh/ruff/issues/20800
## Test Plan
Added a new test fixture at:
```crates/ruff_linter/resources/test/fixtures/fastapi/FAST002_2.py```
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Fixes#20941
Skip autofix for keyword and __debug__ path params
## Test Plan
<!-- How was it tested? -->
I added two test cases to
crates/ruff_linter/resources/test/fixtures/fastapi/FAST003.py.
Closes#20997
This will _decrease_ the number of diagnostics emitted for
[zip-without-explicit-strict
(B905)](https://docs.astral.sh/ruff/rules/zip-without-explicit-strict/#zip-without-explicit-strict-b905),
since previously it triggered on any `zip` call no matter the number of
arguments. It may _increase_ the number of diagnostics for
[map-without-explicit-strict
(B912)](https://docs.astral.sh/ruff/rules/map-without-explicit-strict/#map-without-explicit-strict-b912)
since it will now trigger on a single starred argument where before it
would not. However, the latter rule is in `preview` so this is
acceptable.
Note - we do not need to make any changes to
[batched-without-explicit-strict
(B911)](https://docs.astral.sh/ruff/rules/batched-without-explicit-strict/#batched-without-explicit-strict-b911)
since that just takes a single iterable.
I am doing this in one PR rather than two because we should keep the
behavior of these rules consistent with one another.
For review: apologies for the unreadability of the snapshot for `B905`.
Unfortunately I saw no way of keeping a small diff and a correct fixture
(the fixture labeled a whole block as `# Error` whereas now several in
the block became `# Ok`).Probably simplest to just view the actual
snapshot - it's relatively small.
## Summary
Make rules `INT001`, `INT002`, and `INT003` also
* trigger on qualified names when we're sure the calls are calls to the
`gettext` module. For example
```python
from gettext import gettext as foo
foo(f"{'bar'}") # very certain that this is a call to a real `gettext`
function => worth linting
```
* trigger on `builtins` bindings
```python
from builtins, gettext
gettext.install("...") # binds `gettext.gettext` to `builtins._`
builtins.__dict__["_"] = ... # also a common pattern
_(f"{'bar'}") # should therefore also be linted
```
Fixes: https://github.com/astral-sh/ruff/issues/19028
## Test Plan
Tests have been added to all three rules.
---------
Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
Summary
--
This PR fixes the issue I added in #20867 and noticed in #20930. Cases
like this
cause an error on any Python version:
```py
f"{1:""}"
```
which gave me a false sense of security before. Cases like this are
still
invalid only before 3.12 and weren't flagged after the changes in
#20867:
```py
f'{1: abcd "{'aa'}" }'
# ^ reused quote
f'{1: abcd "{"\n"}" }'
# ^ backslash
```
I didn't recognize these as nested interpolations that also need to be
checked
for invalid expressions, so filtering out the whole format spec wasn't
quite
right. And `elements.interpolations()` only iterates over the outermost
interpolations, not the nested ones.
There's basically no code change in this PR, I just moved the existing
check
from `parse_interpolated_string`, which parses the entire string, to
`parse_interpolated_element`. This kind of seems more natural anyway and
avoids
having to try to recursively visit nested elements after the fact in
`parse_interpolated_string`. So viewing the diff with something like
```
git diff --color-moved --ignore-space-change --color-moved-ws=allow-indentation-change main
```
should make this more clear.
Test Plan
--
New tests
## Summary
- Type checkers (and type-checker authors) think in terms of types, but
I think most Python users think in terms of values. Rather than saying
that a _type_ `X` "has no attribute `foo`" (which I think sounds strange
to many users), say that "an object of type `X` has no attribute `foo`"
- Special-case certain types so that the diagnostic messages read more
like normal English: rather than saying "Type `<class 'Foo'>` has no
attribute `bar`" or "Object of type `<class 'Foo'>` has no attribute
`bar`", just say "Class `Foo` has no attribute `bar`"
## Test Plan
Mdtests and snapshots updated
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
This PR implements semantic syntax error where alternative patterns bind
different names
## Test Plan
<!-- How was it tested? -->
I have written inline tests as directed in #17412
---------
Signed-off-by: 11happy <soni5happy@gmail.com>
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
## Summary
Derived from #20900
Implement `VarianceInferable` for `KnownInstanceType` (especially for
`KnownInstanceType::TypeAliasType`).
The variance of a type alias matches its value type. In normal usage,
type aliases are expanded to value types, so the variance of a type
alias can be obtained without implementing this. However, for example,
if we want to display the variance when hovering over a type alias, we
need to be able to obtain the variance of the type alias itself (cf.
#20900).
## Test Plan
I couldn't come up with a way to test this in mdtest, so I'm testing it
in a test submodule at the end of `types.rs`.
I also added a test to `mdtest/generics/pep695/variance.md`, but it
passes without the changes in this PR.
## Summary
Fixes#20774 by tracking whether an `InterpolatedStringState` element is
nested inside of another interpolated element. This feels like kind of a
naive fix, so I'm welcome to other ideas. But it resolves the problem in
the issue and clears up the syntax error in the black compatibility
test, without affecting many other cases.
The other affected case is actually interesting too because the
[input](96b156303b/crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/fstring.py (L707))
is invalid, but the previous quote selection fixed the invalid syntax:
```pycon
Python 3.11.13 (main, Sep 2 2025, 14:20:25) [Clang 20.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> f'{1: abcd "{'aa'}" }' # input
File "<stdin>", line 1
f'{1: abcd "{'aa'}" }'
^^
SyntaxError: f-string: expecting '}'
>>> f'{1: abcd "{"aa"}" }' # old output
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: Invalid format specifier ' abcd "aa" ' for object of type 'int'
>>> f'{1: abcd "{'aa'}" }' # new output
File "<stdin>", line 1
f'{1: abcd "{'aa'}" }'
^^
SyntaxError: f-string: expecting '}'
```
We now preserve the invalid syntax in the input.
Unfortunately, this also seems to be another edge case I didn't consider
in https://github.com/astral-sh/ruff/pull/20867 because we don't flag
this as a syntax error after 0.14.1:
<details><summary>Shell output</summary>
<p>
```
> uvx ruff@0.14.0 check --ignore ALL --target-version py311 - <<EOF
f'{1: abcd "{'aa'}" }'
EOF
invalid-syntax: Cannot reuse outer quote character in f-strings on Python 3.11 (syntax was added in Python 3.12)
--> -:1:14
|
1 | f'{1: abcd "{'aa'}" }'
| ^
|
Found 1 error.
> uvx ruff@0.14.1 check --ignore ALL --target-version py311 - <<EOF
f'{1: abcd "{'aa'}" }'
EOF
All checks passed!
> uvx python@3.11 -m ast <<EOF
f'{1: abcd "{'aa'}" }'
EOF
Traceback (most recent call last):
File "<frozen runpy>", line 198, in _run_module_as_main
File "<frozen runpy>", line 88, in _run_code
File "/home/brent/.local/share/uv/python/cpython-3.11.13-linux-x86_64-gnu/lib/python3.11/ast.py", line 1752, in <module>
main()
File "/home/brent/.local/share/uv/python/cpython-3.11.13-linux-x86_64-gnu/lib/python3.11/ast.py", line 1748, in main
tree = parse(source, args.infile.name, args.mode, type_comments=args.no_type_comments)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/brent/.local/share/uv/python/cpython-3.11.13-linux-x86_64-gnu/lib/python3.11/ast.py", line 50, in parse
return compile(source, filename, mode, flags,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "<stdin>", line 1
f'{1: abcd "{'aa'}" }'
^^
SyntaxError: f-string: expecting '}'
```
</p>
</details>
I assumed that was the same `ParseError` as the one caused by
`f"{1:""}"`, but this is a nested interpolation inside of the format
spec.
## Test Plan
New test copied from the black compatibility test. I guess this is a
duplicate now, I started working on this branch before the new black
tests were imported, so I could delete the separate test in our fixtures
if that's preferable.
## Summary
Support `dataclass_transform` when used on a (base) class.
## Typing conformance
* The changes in `dataclasses_transform_class.py` look good, just a few
mistakes due to missing `alias` support.
* I didn't look closely at the changes in
`dataclasses_transform_converter.py` since we don't support `converter`
yet.
## Ecosystem impact
The impact looks huge, but it's concentrated on a single project (ibis).
Their setup looks more or less like this:
* the real `Annotatable`:
d7083c2c96/ibis/common/grounds.py (L100-L101)
* the real `DataType`:
d7083c2c96/ibis/expr/datatypes/core.py (L161-L179)
* the real `Array`:
d7083c2c96/ibis/expr/datatypes/core.py (L1003-L1006)
```py
from typing import dataclass_transform
@dataclass_transform()
class Annotatable:
pass
class DataType(Annotatable):
nullable: bool = True
class Array[T](DataType):
value_type: T
```
They expect something like `Array([1, 2])` to work, but ty, pyright,
mypy, and pyrefly would all expect there to be a first argument for the
`nullable` field on `DataType`. I don't really understand on what
grounds they expect the `nullable` field to be excluded from the
signature, but this seems to be the main reason for the new diagnostics
here. Not sure if related, but it looks like their typing setup is not
really complete
(https://github.com/ibis-project/ibis/issues/6844#issuecomment-1868274770,
this thread also mentions `dataclass_transform`).
## Test Plan
Update pre-existing tests.
Detect legacy namespace packages and treat them like namespace packages
when looking them up as the *parent* of the module we're interested in.
In all other cases treat them like a regular package.
(This PR is coauthored by @MichaReiser in a shared coding session)
Fixes https://github.com/astral-sh/ty/issues/838
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
## Summary
Prefer the declared type for collection literals, e.g.,
```py
x: list[Any] = [1, "2", (3,)]
reveal_type(x) # list[Any]
```
This solves a large part of https://github.com/astral-sh/ty/issues/136
for invariant generics, where respecting the declared type is a lot more
important. It also means that annotated dict literals with `dict[_,
Any]` is a way out of https://github.com/astral-sh/ty/issues/1248.
We have to track whether a typevar appears in a position where it's
inferable or not. In a non-inferable position (in the body of the
generic class or function that binds it), assignability must hold for
every possible specialization of the typevar. In an inferable position,
it only needs to hold for _some_ specialization.
https://github.com/astral-sh/ruff/pull/20093 is working on using
constraint sets to model assignability of typevars, and the constraint
sets that we produce will be the same for inferable vs non-inferable
typevars; what changes is what we _compare_ that constraint set to. (For
a non-inferable typevar, the constraint set must equal the set of valid
specializations; for an inferable typevar, it must not be `never`.)
When I first added support for tracking inferable vs non-inferable
typevars, it seemed like it would be easiest to have separate `Type`
variants for each. The alternative (which lines up with the Δ set in
[POPL15](https://doi.org/10.1145/2676726.2676991)) would be to
explicitly plumb through a list of inferable typevars through our type
property methods. That seemed cumbersome.
In retrospect, that was the wrong decision. We've had to jump through
hoops to translate types between the inferable and non-inferable
variants, which has been quite brittle. Combined with the original point
above, that much of the assignability logic will become more identical
between inferable and non-inferable, there is less justification for the
two `Type` variants. And plumbing an extra `inferable` parameter through
all of these methods turns out to not be as bad as I anticipated.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
Use the declared type of variables as type context for the RHS of assignment expressions, e.g.,
```py
x: list[int | str]
x = [1]
reveal_type(x) # revealed: list[int | str]
```
## Summary
Ignore the type context when specializing a generic call if it leads to
an unnecessarily wide return type. For example, [the example mentioned
here](https://github.com/astral-sh/ruff/pull/20796#issuecomment-3403319536)
works as expected after this change:
```py
def id[T](x: T) -> T:
return x
def _(i: int):
x: int | None = id(i)
y: int | None = i
reveal_type(x) # revealed: int
reveal_type(y) # revealed: int
```
I also added extended our usage of `filter_disjoint_elements` to tuple
and typed-dict inference, which resolves
https://github.com/astral-sh/ty/issues/1266.
## Summary
Add support for the `field_specifiers` parameter on
`dataclass_transform` decorator calls.
closes https://github.com/astral-sh/ty/issues/1068
## Conformance test results
All true positives ✔️
## Ecosystem analysis
* `trio`: this is the kind of change that I would expect from this PR.
The code makes use of a dataclass `Outcome` with a `_unwrapped: bool =
attr.ib(default=False, eq=False, init=False)` field that is excluded
from the `__init__` signature, so we now see a bunch of
constructor-call-related errors going away.
* `home-assistant/core`: They have a `domain: str = attr.ib(init=False,
repr=False)` field and then use
```py
@domain.default
def _domain_default(self) -> str:
# …
```
This accesses the `default` attribute on `dataclasses.Field[…]` with a
type of `default: _T | Literal[_MISSING_TYPE.MISSING]`, so we get those
"Object of type `_MISSING_TYPE` is not callable" errors. I don't really
understand how that is supposed to work. Even if `_MISSING_TYPE` would
be absent from that union, what does this try to call? pyright also
issues an error and it doesn't seem to work at runtime? So this looks
like a true positive?
* `attrs`: Similar here. There are some new diagnostics on code that
tries to access `.validator` on a field. This *does* work at runtime,
but I'm not sure how that is supposed to type-check (without a [custom
plugin](2c6c395935/mypy/plugins/attrs.py (L575-L602))).
pyright errors on this as well.
* A handful of new false positives because we don't support `alias` yet
## Test Plan
Updated tests.
Summary
--
This PR unifies the two different ways Ruff and ty construct syntax
errors. Ruff has been storing the primary message in the diagnostic
itself, while ty attached the message to the primary annotation:
```
> ruff check try.py
invalid-syntax: name capture `x` makes remaining patterns unreachable
--> try.py:2:10
|
1 | match 42:
2 | case x: ...
| ^
3 | case y: ...
|
Found 1 error.
> uvx ty check try.py
WARN ty is pre-release software and not ready for production use. Expect to encounter bugs, missing features, and fatal errors.
Checking ------------------------------------------------------------ 1/1 files
error[invalid-syntax]
--> try.py:2:10
|
1 | match 42:
2 | case x: ...
| ^ name capture `x` makes remaining patterns unreachable
3 | case y: ...
|
Found 1 diagnostic
```
I think there are benefits to both approaches, and I do like ty's
version, but I feel like we should pick one (and it might help with
#20901 eventually). I slightly prefer Ruff's version, so I went with
that. Hopefully this isn't too controversial, but I'm happy to close
this if it is.
Note that this shouldn't change any other diagnostic formats in ty
because
[`Diagnostic::primary_message`](98d27c4128/crates/ruff_db/src/diagnostic/mod.rs (L177))
was already falling back to the primary annotation message if the
diagnostic message was empty. As a result, I think this change will
partially resolve the FIXME therein.
Test Plan
--
Existing tests with updated snapshots
## Summary
Implement `docstring-extraneous-parameter` (`DOC102`). This rule checks
that all parameters present in a functions docstring are also present in
its signature.
Split from #13280, per this
[comment](https://github.com/astral-sh/ruff/pull/13280#issuecomment-3280575506).
Part of #12434.
## Test Plan
Test cases added.
---------
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
This is the ultra-minimal implementation of
* https://github.com/astral-sh/ty/issues/296
that was previously discussed as a good starting point. In particular we
don't actually bother trying to figure out the exact python versions,
but we still mention "hey btw for No Reason At All... you're on python
3.10" when you try to access something that has a definition rooted in
the stdlib that we believe exists sometimes.
This is a drive-by improvement that I stumbled backwards into while
looking into
* https://github.com/astral-sh/ty/issues/296
I was writing some simple tests for "thing not in old version of stdlib"
diagnostics and checked what was added in 3.14, and saw
`compression.zstd` and to my surprise discovered that `import
compression.zstd` and `from compression import zstd` had completely
different quality diagnostics.
This is because `compression` and `compression.zstd` were *both*
introduced in 3.14, and so per VERSIONS policy only an entry for
`compression` was added, and so we don't actually have any definite info
on `compression.zstd` and give up on producing a diagnostic. However the
`from compression import zstd` form fails on looking up `compression`
and we *do* have an exact match for that, so it gets a better
diagnostic!
(aside: I have now learned about the VERSIONS format and I *really* wish
they would just enumerate all the submodules but, oh well!)
The fix is, when handling an import failure, if we fail to find an exact
match *we requery with the parent module*. In cases like
`compression.zstd` this lets us at least identify that, hey, not even
`compression` exists, and luckily that fixes the whole issue. In cases
where the parent module and submodule were introduced at different times
then we may discover that the parent module is in-range and that's fine,
we don't produce the richer stdlib diagnostic.
## Summary
`dataclasses.field` and field-specifier functions of commonly used
libraries like `pydantic`, `attrs`, and `SQLAlchemy` all return the
default type for the field (or `Any`) instead of an actual `Field`
instance, even if this is not what happens at runtime. Let's make use of
this fact and assume that *all* field specifiers return the type of the
default value of the field.
For standard dataclasses, this leads to more or less the same outcome
(see test diff for details), but this change is important for 3rd party
dataclass-transformers.
## Test Plan
Tested the consequences of this change on the field-specifiers branch as
well.
## Summary
Resolves https://github.com/astral-sh/ty/issues/1349.
Fix match statement value patterns to use equality comparison semantics
instead of incorrectly narrowing to literal types directly. Value
patterns use equality for matching, and equality can be overridden, so
we can't always narrow to the matched literal.
## Test Plan
Updated match.md with corrected expected types and an additional example
with explanation
---------
Co-authored-by: David Peter <mail@david-peter.de>
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please consider the following:
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with `[ty]` for ty pull
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
This PR implements `F702`
https://docs.astral.sh/ruff/rules/continue-outside-loop/ as semantic
syntax error.
## Test Plan
<!-- How was it tested? -->
Tests are already previously written in F702
---------
Signed-off-by: 11happy <soni5happy@gmail.com>
## Summary
Part of astral-sh/ty#1341
The following changes will be made to `Place`.
* Introduce `TypeOrigin`
* `Place::Type` -> `Place::Defined`
* `Place::Unbound` -> `Place::Undefined`
* `Boundness` -> `Definedness`
`TypeOrigin::Declared`+`Definedness::PossiblyUndefined` are patterns
that weren't considered before, but this PR doesn't address them yet,
only refactors.
## Test Plan
Refactoring
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
`airflow.datasets.DatasetEvent` has been removed in 3 but `AssetEvent`
might be added in the future
## Test Plan
<!-- How was it tested? -->
update the test fixture and reorg in the second commit
Summary
--
Fixes#20844 by refining the unsupported syntax error check for [PEP
701]
f-strings before Python 3.12 to allow backslash escapes and escaped
outer quotes
in the format spec part of f-strings. These are only disallowed within
the
f-string expression part on earlier versions. Using the examples from
the PR:
```pycon
>>> f"{1:\x64}"
'1'
>>> f"{1:\"d\"}"
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: Invalid format specifier '"d"' for object of type 'int'
```
Note that the second case is a runtime error, but this is actually
avoidable if
you override `__format__`, so despite being pretty weird, this could
actually be
a valid use case.
```pycon
>>> class C:
... def __format__(*args, **kwargs): return "<C>"
...
>>> f"{C():\"d\"}"
'<C>'
```
At first I thought narrowing the range we check to exclude the format
spec would
only work for escapes, but it turns out that cases like `f"{1:""}"` are
already
covered by an existing `ParseError`, so we can just narrow the range of
both our
escape and quote checks.
Our comment check also seems to be working correctly because it's based
on the
actual tokens. A case like
[this](https://play.ruff.rs/9f1c2ff2-cd8e-4ad7-9f40-56c0a524209f):
```python
f"""{1:# }"""
```
doesn't include a comment token, instead the `#` is part of an
`InterpolatedStringLiteralElement`.
Test Plan
--
New inline parser tests
[PEP 701]: https://peps.python.org/pep-0701/
A large part of the diff on #20677 just involves threading a new
`inferable` parameter through all of the type property methods. In the
interests of making that PR easier to review, I've pulled that bit out
into here, so that it can be reviewed in isolation. This should be a
pure refactoring, with no logic changes or behavioral changes.
## Summary
Fixed a typo. It should be "or", not "of". Both `.pop()` and `next()` on
an empty collection will raise `IndexError`, not "`[0]` of the `pop()`
function"
## Test Plan
n/a
Summary
--
This PR implements the black preview style from
https://github.com/psf/black/pull/4720. As of Python 3.14, you're
allowed to omit the parentheses around groups of exceptions, as long as
there's no `as` binding:
**3.13**
```pycon
Python 3.13.4 (main, Jun 4 2025, 17:37:06) [Clang 20.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> try: ...
... except (Exception, BaseException): ...
...
Ellipsis
>>> try: ...
... except Exception, BaseException: ...
...
File "<python-input-1>", line 2
except Exception, BaseException: ...
^^^^^^^^^^^^^^^^^^^^^^^^
SyntaxError: multiple exception types must be parenthesized
```
**3.14**
```pycon
Python 3.14.0rc2 (main, Sep 2 2025, 14:20:56) [Clang 20.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> try: ...
... except Exception, BaseException: ...
...
Ellipsis
>>> try: ...
... except (Exception, BaseException): ...
...
Ellipsis
>>> try: ...
... except Exception, BaseException as e: ...
...
File "<python-input-2>", line 2
except Exception, BaseException as e: ...
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
SyntaxError: multiple exception types must be parenthesized when using 'as'
```
I think this ended up being pretty straightforward, at least once Micha
showed me where to start :)
Test Plan
--
New tests
At first I thought we were deviating from black in how we handle
comments within the exception type tuple, but I think this applies to
how we format all tuples, not specifically with the new preview style.
Summary
--
```shell
git clone git@github.com:psf/black.git ../other/black
crates/ruff_python_formatter/resources/test/fixtures/import_black_tests.py ../other/black
```
Then ran our tests and accepted the snapshots
I had to make a small fix to our tuple normalization logic for `del`
statements
in the second commit, otherwise the tests were panicking at a changed
AST. I
think the new implementation is closer to the intention described in the
nearby
comment anyway, though.
The first commit adds the new Python, settings, and `.expect` files, the
next three commits make some small
fixes to help get the tests running, and then the fifth commit accepts
all but one of the new snapshots. The last commit includes the new
unsupported syntax error for one f-string example, tracked in #20774.
Test Plan
--
Newly imported tests. I went through all of the new snapshots and added
review comments below. I think they're all expected, except a few cases
I wasn't 100% sure about.
## Summary
If a function is decorated with a decorator that returns a union of
`Callable`s, also treat it as a union of function-like `Callable`s.
Labeling as `internal`, since the previous change has not been released
yet.
## Test Plan
New regression test.
chiri
Ibraheem Ahmed
Micha Reiser
Dan Parizher
David Peter
Brent Westbrook
Carl Meyer
Wei Lee
Tom Kuson
Shunsuke Shibayama
Alex Waygood
Matthew Mckee
github-actions[bot]
Gautham Venkataraman
Luca Chiodini
Douglas Creager
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Mahmoud Saada
Amethyst Reese
Prakhar Pratyush
Jonas Vacek
Andrew Gallant
Takayuki Maeda
renovate[bot]
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Dylan
Shahar Naveh
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wangxiaolei
decorator-factory
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Paillat