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
--
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
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
## 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.
## 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
--
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/
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.
This PR resolves the issue noticed in
https://github.com/astral-sh/ruff/pull/20777#discussion_r2417233227.
Namely, cases like this were being flagged as syntax errors despite
being perfectly valid on Python 3.8:
```pycon
Python 3.8.20 (default, Oct 2 2024, 16:34:12)
[Clang 18.1.8 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> with (open("foo.txt", "w")): ...
...
Ellipsis
>>> with (open("foo.txt", "w")) as f: print(f)
...
<_io.TextIOWrapper name='foo.txt' mode='w' encoding='UTF-8'>
```
The second of these was already allowed but not the first:
```shell
> ruff check --target-version py38 --ignore ALL - <<EOF
with (open("foo.txt", "w")): ...
with (open("foo.txt", "w")) as f: print(f)
EOF
invalid-syntax: Cannot use parentheses within a `with` statement on Python 3.8 (syntax was added in Python 3.9)
--> -:1:6
|
1 | with (open("foo.txt", "w")): ...
| ^
2 | with (open("foo.txt", "w")) as f: print(f)
|
Found 1 error.
```
There was some discussion of related cases in
https://github.com/astral-sh/ruff/pull/16523#discussion_r1984657793, but
it seems I overlooked the single-element case when flagging tuples. As
suggested in the other thread, we can just check if there's more than
one element or a trailing comma, which will cause the tuple parsing on
<=3.8 and avoid the false positives.
## Summary
Based on the suggestion in
https://github.com/astral-sh/ruff/issues/20774#issuecomment-3383153511,
I added rendering of unsupported syntax errors in our `format` test.
In support of this, I added a `DummyFileResolver` type to `ruff_db` to
pass to `DisplayDiagnostics::new` (first commit). Another option would
obviously be implementing this directly in the fixtures, but we'd have
to import a `NotebookIndex` somehow; either by depending directly on
`ruff_notebook` or re-exporting it from `ruff_db`. I thought it might be
convenient elsewhere to have a dummy resolver, for example in the
parser, where we currently have a separate rendering pipeline
[copied](https://github.com/astral-sh/ruff/blob/main/crates/ruff_python_parser/tests/fixtures.rs#L321)
from our old rendering code in `ruff_linter`. I also briefly tried
implementing a `TestDb` in the formatter since I noticed the
`ruff_python_formatter::db` module, but that was turning into a lot more
code than the dummy resolver.
We could also push this a bit further if we wanted. I didn't add the new
snapshots to the black compatibility tests or to the preview snapshots,
for example. I thought it was kind of noisy enough (and helpful enough)
already, though. We could also use a shorter diagnostic format, but the
full output seems most useful once we accept this initial large batch of
changes.
## Test Plan
I went through the baseline snapshots pretty quickly, but they all
looked reasonable to me, with one exception I noted below. I also tested
that the case from #20774 produces a new unsupported syntax error.
Summary
--
Closes#19467 and also removes the warning about using Python 3.14
without
preview enabled.
I also bumped `PythonVersion::default` to 3.9 because it reaches EOL
this month,
but we could also defer that for now if we wanted.
The first three commits are related to the `latest` bump to 3.14; the
fourth commit
bumps the default to 3.10.
Note that this PR also bumps the default Python version for ty to 3.10
because
there was a test asserting that it stays in sync with
`ast::PythonVersion`.
Test Plan
--
Existing tests
I spot-checked the ecosystem report, and I believe these are all
expected. Inbits doesn't specify a target Python version, so I guess
we're applying the default. UP007, UP035, and UP045 all use the new
default value to emit new diagnostics.
Resolves a crash when attempting to format code like:
```
from x import (a as # whatever
b)
```
Reworks the way comments are associated with nodes when parsing modules,
so that all possible comment positions can be retained and reproduced during
formatting.
Overall follows Black's formatting style for multi-line import statements.
Fixes issue #19138
This adds a new `backend: internal | uv` option to the LSP
`FormatOptions` allowing users to perform document and range formatting
operations though uv. The idea here is to prototype a solution for users
to transition to a `uv format` command without encountering version
mismatches (and consequently, formatting differences) between the LSP's
version of `ruff` and uv's version of `ruff`.
The primarily alternative to this would be to use uv to discover the
`ruff` version used to start the LSP in the first place. However, this
would increase the scope of a minimal `uv format` command beyond "run a
formatter", and raise larger questions about how uv should be used to
coordinate toolchain discovery. I think those are good things to
explore, but I'm hesitant to let them block a `uv format`
implementation. Another downside of using uv to discover `ruff`, is that
it needs to be implemented _outside_ the LSP; e.g., we'd need to change
the instructions on how to run the LSP and implement it in each editor
integration, like the VS Code plugin.
---------
Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
## Summary
Removes the `module_ptr` field from `AstNodeRef` in release mode, and
change `NodeIndex` to a `NonZeroU32` to reduce the size of
`Option<AstNodeRef<_>>` fields.
I believe CI runs in debug mode, so this won't show up in the memory
report, but this reduces memory by ~2% in release mode.
As of [this cpython PR](https://github.com/python/cpython/pull/135996),
it is not allowed to concatenate t-strings with non-t-strings,
implicitly or explicitly. Expressions such as `"foo" t"{bar}"` are now
syntax errors.
This PR updates some AST nodes and parsing to reflect this change.
The structural change is that `TStringPart` is no longer needed, since,
as in the case of `BytesStringLiteral`, the only possibilities are that
we have a single `TString` or a vector of such (representing an implicit
concatenation of t-strings). This removes a level of nesting from many
AST expressions (which is what all the snapshot changes reflect), and
simplifies some logic in the implementation of visitors, for example.
The other change of note is in the parser. When we meet an implicit
concatenation of string-like literals, we now count the number of
t-string literals. If these do not exhaust the total number of
implicitly concatenated pieces, then we emit a syntax error. To recover
from this syntax error, we encode any t-string pieces as _invalid_
string literals (which means we flag them as invalid, record their
range, and record the value as `""`). Note that if at least one of the
pieces is an f-string we prefer to parse the entire string as an
f-string; otherwise we parse it as a string.
This logic is exactly the same as how we currently treat
`BytesStringLiteral` parsing and error recovery - and carries with it
the same pros and cons.
Finally, note that I have not implemented any changes in the
implementation of the formatter. As far as I can tell, none are needed.
I did change a few of the fixtures so that we are always concatenating
t-strings with t-strings.
Closes#18671
Note that while this has, I believe, always been invalid syntax, it was
reported as a different syntax error until Python 3.12:
Python 3.11:
```pycon
>>> x = 1
>>> f"{x! s}"
File "<stdin>", line 1
f"{x! s}"
^
SyntaxError: f-string: invalid conversion character: expected 's', 'r', or 'a'
```
Python 3.12:
```pycon
>>> x = 1
>>> f"{x! s}"
File "<stdin>", line 1
f"{x! s}"
^^^
SyntaxError: f-string: conversion type must come right after the exclamanation mark
```
## Summary
Garbage collect ASTs once we are done checking a given file. Queries
with a cross-file dependency on the AST will reparse the file on demand.
This reduces ty's peak memory usage by ~20-30%.
The primary change of this PR is adding a `node_index` field to every
AST node, that is assigned by the parser. `ParsedModule` can use this to
create a flat index of AST nodes any time the file is parsed (or
reparsed). This allows `AstNodeRef` to simply index into the current
instance of the `ParsedModule`, instead of storing a pointer directly.
The indices are somewhat hackily (using an atomic integer) assigned by
the `parsed_module` query instead of by the parser directly. Assigning
the indices in source-order in the (recursive) parser turns out to be
difficult, and collecting the nodes during semantic indexing is
impossible as `SemanticIndex` does not hold onto a specific
`ParsedModuleRef`, which the pointers in the flat AST are tied to. This
means that we have to do an extra AST traversal to assign and collect
the nodes into a flat index, but the small performance impact (~3% on
cold runs) seems worth it for the memory savings.
Part of https://github.com/astral-sh/ty/issues/214.
## Summary
https://github.com/astral-sh/ty/issues/214 will require a couple
invasive changes that I would like to get merged even before garbage
collection is fully implemented (to avoid rebasing):
- `ParsedModule` can no longer be dereferenced directly. Instead you
need to load a `ParsedModuleRef` to access the AST, which requires a
reference to the salsa database (as it may require re-parsing the AST if
it was collected).
- `AstNodeRef` can only be dereferenced with the `node` method, which
takes a reference to the `ParsedModuleRef`. This allows us to encode the
fact that ASTs do not live as long as the database and may be collected
as soon a given instance of a `ParsedModuleRef` is dropped. There are a
number of places where we currently merge the `'db` and `'ast`
lifetimes, so this requires giving some types/functions two separate
lifetime parameters.
This PR implements template strings (t-strings) in the parser and
formatter for Ruff.
Minimal changes necessary to compile were made in other parts of the code (e.g. ty, the linter, etc.). These will be covered properly in follow-up PRs.
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## Summary
I decided to disable the new
[`needless_continue`](https://rust-lang.github.io/rust-clippy/master/index.html#needless_continue)
rule because I often found the explicit `continue` more readable over an
empty block or having to invert the condition of an other branch.
## Test Plan
`cargo test`
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
I don't remember exactly when we made `Identifier` a node but it is now
considered a node (it implements `AnyNodeRef`, it has a range). However,
we never updated
the `SourceOrderVisitor` to visit identifiers because we never had a use
case for it and visiting new nodes can change how the formatter
associates comments (breaking change!).
This PR updates the `SourceOrderVisitor` to visit identifiers and
changes the formatter comment visitor to skip identifiers (updating the
visitor might be desired because it could help simplifying some comment
placement logic but this is out of scope for this PR).
## Test Plan
Tests, updated snapshot tests
## Summary
We renamed the `PreorderVisitor` to `SourceOrderVisitor` a long time ago
but it seems that we missed to rename the `visit_preorder` functions to
`visit_source_order`.
This PR renames `visit_preorder` to `visit_source_order`
## Test Plan
`cargo test`
## Summary
This PR detects the use of PEP 701 f-strings before 3.12. This one
sounded difficult and ended up being pretty easy, so I think there's a
good chance I've over-simplified things. However, from experimenting in
the Python REPL and checking with [pyright], I think this is correct.
pyright actually doesn't even flag the comment case, but Python does.
I also checked pyright's implementation for
[quotes](98dc4469cc/packages/pyright-internal/src/analyzer/checker.ts (L1379-L1398))
and
[escapes](98dc4469cc/packages/pyright-internal/src/analyzer/checker.ts (L1365-L1377))
and think I've approximated how they do it.
Python's error messages also point to the simple approach of these
characters simply not being allowed:
```pycon
Python 3.11.11 (main, Feb 12 2025, 14:51:05) [Clang 19.1.6 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> f'''multiline {
... expression # comment
... }'''
File "<stdin>", line 3
}'''
^
SyntaxError: f-string expression part cannot include '#'
>>> f'''{not a line \
... continuation}'''
File "<stdin>", line 2
continuation}'''
^
SyntaxError: f-string expression part cannot include a backslash
>>> f'hello {'world'}'
File "<stdin>", line 1
f'hello {'world'}'
^^^^^
SyntaxError: f-string: expecting '}'
```
And since escapes aren't allowed, I don't think there are any tricky
cases where nested quotes or comments can sneak in.
It's also slightly annoying that the error is repeated for every nested
quote character, but that also mirrors pyright, although they highlight
the whole nested string, which is a little nicer. However, their check
is in the analysis phase, so I don't think we have such easy access to
the quoted range, at least without adding another mini visitor.
## Test Plan
New inline tests
[pyright]:
https://pyright-play.net/?pythonVersion=3.11&strict=true&code=EYQw5gBAvBAmCWBjALgCgO4gHaygRgEoAoEaCAIgBpyiiBiCLAUwGdknYIBHAVwHt2LIgDMA5AFlwSCJhwAuCAG8IoMAG1Rs2KIC6EAL6iIxosbPmLlq5foRWiEAAcmERAAsQAJxAomnltY2wuSKogA6WKIAdABWfPBYqCAE%2BuSBVqbpWVm2iHwAtvlMWMgB2ekiolUAgq4FjgA2TAAeEMieSADWCsoV5qoaqrrGDJ5MiDz%2B8ABuLqosAIREhlXlaybrmyYMXsDw7V4AnoysyAmQ5SIhwYo3d9cheADUeKlv5O%2BpQA
## Summary
This PR stabilizies the fix for
https://github.com/astral-sh/ruff/issues/14001
We try to only make breaking formatting changes once a year. However,
the plan was to release this fix as part of Ruff 0.9 but I somehow
missed it when promoting all other formatter changes.
I think it's worth making an exception here considering that this is a
bug fix, it improves readability, and it should be rare
(very few files in a single project). Our version policy explicitly
allows breaking formatter changes in any minor release and the idea of
only making breaking formatter changes once a year is mainly to avoid
multiple releases throughout the year that introduce large formatter
changes
Closes https://github.com/astral-sh/ruff/issues/14001
## Test Plan
Updated snapshot
## Summary
This should give us better coverage for the unsupported syntax error
features and
increases our confidence that the formatter doesn't accidentially
introduce new unsupported
syntax errors.
A feature like this would have been very useful when working on f-string
formatting
where it took a lot of iteration to find all Python 3.11 or older
incompatibilities.
## Test Plan
I applied my changes on top of
https://github.com/astral-sh/ruff/pull/16523 and
removed the target version check in the with-statement formatting code.
As expected,
the integration tests now failed
## Summary
This is part of the preparation for detecting syntax errors in the
parser from https://github.com/astral-sh/ruff/pull/16090/. As suggested
in [this
comment](https://github.com/astral-sh/ruff/pull/16090/#discussion_r1953084509),
I started working on a `ParseOptions` struct that could be stored in the
parser. For this initial refactor, I only made it hold the existing
`Mode` option, but for syntax errors, we will also need it to have a
`PythonVersion`. For that use case, I'm picturing something like a
`ParseOptions::with_python_version` method, so you can extend the
current calls to something like
```rust
ParseOptions::from(mode).with_python_version(settings.target_version)
```
But I thought it was worth adding `ParseOptions` alone without changing
any other behavior first.
Most of the diff is just updating call sites taking `Mode` to take
`ParseOptions::from(Mode)` or those taking `PySourceType`s to take
`ParseOptions::from(PySourceType)`. The interesting changes are in the
new `parser/options.rs` file and smaller parts of `parser/mod.rs` and
`ruff_python_parser/src/lib.rs`.
## Test Plan
Existing tests, this should not change any behavior.
