## Summary
fixes: #13813
This PR fixes a bug in the formatting assignment statement when the
value is an f-string.
This is resolved by using custom best fit layouts if the f-string is (a)
not already a flat f-string (thus, cannot be multiline) and (b) is not a
multiline string (thus, cannot be flattened). So, it is used in cases
like the following:
```py
aaaaaaaaaaaaaaaaaa = f"testeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee{
expression}moreeeeeeeeeeeeeeeee"
```
Which is (a) `FStringLayout::Multiline` and (b) not a multiline.
There are various other examples in the PR diff along with additional
explanation and context as code comments.
## Test Plan
Add multiple test cases for various scenarios.
## Summary
This PR implements new rule discussed
[here](https://github.com/astral-sh/ruff/discussions/14449).
In short, it searches for assert messages which were unintentionally
used as a expression to be matched against.
## Test Plan
`cargo test` and review of `ruff-ecosystem`
Fix#14558
## Summary
- Add `typing.NoReturn` and `typing.Never` to known instances and infer
them as `Type::Never`
- Add `is_assignable_to` cases for `Type::Never`
I skipped emitting diagnostic for when a function is annotated as
`NoReturn` but it actually returns.
## Test Plan
Added tests from
https://github.com/python/typing/blob/main/conformance/tests/specialtypes_never.py
except from generics and checking if the return value of the function
and the annotations match.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
Closes#14588
```py
x: Literal[42, "hello"] = 42 if bool_instance() else "hello"
reveal_type(x) # revealed: Literal[42] | Literal["hello"]
_ = ... if isinstance(x, str) else ...
# The `isinstance` test incorrectly narrows the type of `x`.
# As a result, `x` is revealed as Literal["hello"], but it should remain Literal[42, "hello"].
reveal_type(x) # revealed: Literal["hello"]
```
## Test Plan
mdtest included!
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
This is just a small refactor to remove the `FormatFStringPart` as it's
only used in the case when the f-string is not implicitly concatenated
in which case the only part is going to be `FString`. In implicitly
concatenated f-strings, we use `StringLike` instead.
## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Fix#14525
## Test Plan
<!-- How was it tested? -->
New test cases
---------
Signed-off-by: harupy <hkawamura0130@gmail.com>
## Summary
Resolves#14289
The documentation for B028 no_explicit_stacklevel is updated to be more
clear.
---------
Co-authored-by: dylwil3 <dylwil3@gmail.com>
This PR adds a sometimes-available, safe autofix for [unraw-re-pattern
(RUF039)](https://docs.astral.sh/ruff/rules/unraw-re-pattern/#unraw-re-pattern-ruf039),
which prepends an `r` prefix. It is used only when the string in
question has no backslahses (and also does not have a `u` prefix, since
that causes a syntax error.)
Closes#14527
Notes:
- Test fixture unchanged, but snapshot changed to include fix messages.
- This fix is automatically only available in preview since the rule
itself is in preview
## Summary
This fix addresses panics related to invalid syntax like the following
where a `break` statement is used in a nested definition inside a
loop:
```py
while True:
def b():
x: int
break
```
closes#14342
## Test Plan
* New corpus regression tests.
* New unit test to make sure we handle nested while loops correctly.
This test is passing on `main`, but can easily fail if the
`is_inside_loop` state isn't properly saved/restored.
## Summary
Add support for (non-generic) type aliases. The main motivation behind
this was to get rid of panics involving expressions in (generic) type
aliases. But it turned out the best way to fix it was to implement
(partial) support for type aliases.
```py
type IntOrStr = int | str
reveal_type(IntOrStr) # revealed: typing.TypeAliasType
reveal_type(IntOrStr.__name__) # revealed: Literal["IntOrStr"]
x: IntOrStr = 1
reveal_type(x) # revealed: Literal[1]
def f() -> None:
reveal_type(x) # revealed: int | str
```
## Test Plan
- Updated corpus test allow list to reflect that we don't panic anymore.
- Added Markdown-based test for type aliases (`type_alias.md`)
## Summary
Fixes a panic related to sub-expressions of `typing.Union` where we fail
to store a type for the `int, str` tuple-expression in code like this:
```
x: Union[int, str] = 1
```
relates to [my
comment](https://github.com/astral-sh/ruff/pull/14499#discussion_r1851794467)
on #14499.
## Test Plan
New corpus test
