Commit Graph

92 Commits

Author SHA1 Message Date
Micha Reiser 515de2d062
Move `Token`, `TokenKind` and `Tokens` to `ruff-python-ast` (#21760) 2025-12-02 20:10:46 +01:00
Dan Parizher 474b00568a
[`parser`] Fix panic when parsing IPython escape command expressions (#21480)
## Summary

Fixes a panic when parsing IPython escape commands with `Help` kind
(`?`) in expression contexts. The parser now reports an error instead of
panicking.

Fixes #21465.

## Problem

The parser panicked with `unreachable!()` in
`parse_ipython_escape_command_expression` when encountering escape
commands with `Help` kind (`?`) in expression contexts, where only
`Magic` (`%`) and `Shell` (`!`) are allowed.

## Approach

Replaced the `unreachable!()` panic with error handling that adds a
`ParseErrorType::OtherError` and continues parsing, returning a valid
AST node with the error attached.

## Test Plan

Added `test_ipython_escape_command_in_with_statement` and
`test_ipython_help_escape_command_as_expression` to verify the fix.

---------

Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
2025-11-24 05:40:27 +00:00
Brent Westbrook 38c074e67d
Catch syntax errors in nested interpolations before Python 3.12 (#20949)
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
2025-10-20 09:03:13 -04:00
Brent Westbrook 8b9ab48ac6
Fix syntax error false positives for escapes and quotes in f-strings (#20867)
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/
2025-10-15 09:23:16 -04:00
Micha Reiser 4fc7dd300c
Improved error recovery for unclosed strings (including f- and t-strings) (#20848) 2025-10-15 09:50:56 +02:00
Brent Westbrook 71f8389f61
Fix syntax error false positives on parenthesized context managers (#20846)
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.
2025-10-13 14:13:27 -04:00
Ibraheem Ahmed 7abc41727b
[ty] Shrink size of `AstNodeRef` (#20028)
## 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.
2025-08-22 17:03:22 -04:00
Micha Reiser 7dfde3b929
Update Rust toolchain to 1.89 (#19807) 2025-08-07 18:21:50 +02:00
Dylan 008bbfdf5a
Disallow implicit concatenation of t-strings and other string types (#19485)
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.
2025-07-27 12:41:03 +00:00
Dylan 53fc0614da
Fix `unreachable` panic in parser (#19183)
Parsing the (invalid) expression `f"{\t"i}"` caused a panic because the
`TStringMiddle` character was "unreachable" due the way the parser
recovered from the line continuation (it ate the t-string start).

The cause of the issue is as follows: 

The parser begins parsing the f-string and expects to see a list of
objects, essentially alternating between _interpolated elements_ and
ordinary strings. It is happy to see the first left brace, but then
there is a lexical error caused by the line-continuation character. So
instead of the parser seeing a list of elements with just one member, it
sees a list that starts like this:

- Interpolated element with an invalid token, stored as a `Name`
- Something else built from tokens beginning with `TStringStart` and
`TStringMiddle`

When it sees the `TStringStart` error recovery says "that's a list
element I don't know what to do with, let's skip it". When it sees
`TStringMiddle` it says "oh, that looks like the middle of _some
interpolated string_ so let's try to parse it as one of the literal
elements of my `FString`". Unfortunately, the function being used to
parse individual list elements thinks (arguably correctly) that it's not
possible to have a `TStringMiddle` sitting in your `FString`, and hits
`unreachable`.

Two potential ways (among many) to solve this issue are:

1. Allow a `TStringMiddle` as a valid "literal" part of an f-string
during parsing (with the hope/understanding that this would only occur
in an invalid context)
2. Skip the `TStringMiddle` as an "unexpected/invalid list item" in the
same way that we skipped `TStringStart`.

I have opted for the second approach since it seems somehow more morally
correct, even though it loses more information. To implement this, the
recovery context needs to know whether we are in an f-string or t-string
- hence the changes to that enum. As a bonus we get slightly more
specific error messages in some cases.

Closes #18860
2025-07-20 22:04:14 +00:00
Dylan c5b58187da
Add syntax error when conversion flag does not immediately follow exclamation mark (#18706)
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
```
2025-06-16 11:44:42 -05:00
Dylan 1889a5e6eb
[syntax-errors] Raise unsupported syntax error for template strings prior to Python 3.14 (#18664)
Closes #18662

One question is whether we would like the range to exclude the quotes?
2025-06-13 14:04:37 -05:00
Ibraheem Ahmed c9dff5c7d5
[ty] AST garbage collection (#18482)
## 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.
2025-06-13 08:40:11 -04:00
Dylan 9bbf4987e8
Implement template strings (#17851)
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.
2025-05-30 15:00:56 -05:00
Micha Reiser 9ae698fe30
Switch to Rust 2024 edition (#18129) 2025-05-16 13:25:28 +02:00
Abhijeet Prasad Bodas f5096f2050
[parser] Flag single unparenthesized generator expr with trailing comma in arguments. (#17893)
Fixes #17867

## Summary

The CPython parser does not allow generator expressions which are the
sole arguments in an argument list to have a trailing comma.
With this change, we start flagging such instances.

## Test Plan

Added new inline tests.
2025-05-07 14:11:35 -04:00
Abhijeet Prasad Bodas 0eeb02c0c1
[syntax-errors] Detect single starred expression assignment `x = *y` (#17624)
## Summary

Part of #17412

Starred expressions cannot be used as values in assignment expressions.
Add a new semantic syntax error to catch such instances.
Note that we already have
`ParseErrorType::InvalidStarredExpressionUsage` to catch some starred
expression errors during parsing, but that does not cover top level
assignment expressions.

## Test Plan

- Added new inline tests for the new rule
- Found some examples marked as "valid" in existing tests (`_ = *data`),
which are not really valid (per this new rule) and updated them
- There was an existing inline test - `assign_stmt_invalid_value_expr`
which had instances of `*` expression which would be deemed invalid by
this new rule. Converted these to tuples, so that they do not trigger
this new rule.
2025-04-30 15:04:00 -04:00
Dylan 3c460a7b9a
Make syntax error for unparenthesized except tuples version specific to before 3.14 (#17660)
What it says on the tin 😄
2025-04-29 07:55:30 -05:00
Abhijeet Prasad Bodas cf59cee928
[syntax-errors] `nonlocal` declaration at module level (#17559)
## Summary

Part of #17412

Add a new compile-time syntax error for detecting `nonlocal`
declarations at a module level.

## Test Plan

- Added new inline tests for the syntax error
- Updated existing tests for `nonlocal` statement parsing to be inside a
function scope

Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
2025-04-24 16:11:46 -04:00
Brent Westbrook d5410ef9fe
[syntax-errors] Make duplicate parameter names a semantic error (#17131)
Status
--

This is a pretty minor change, but it was breaking a red-knot mdtest
until #17463 landed. Now this should close #11934 as the last syntax
error being tracked there!

Summary
--

Moves `Parser::validate_parameters` to
`SemanticSyntaxChecker::duplicate_parameter_name`.

Test Plan
--

Existing tests, with `## Errors` replaced with `## Semantic Syntax
Errors`.
2025-04-23 15:45:51 -04:00
Brent Westbrook c2b2e42ad3
[syntax-errors] Invalid syntax in annotations (#17101)
Summary
--

This PR detects the use of invalid syntax in annotation scopes,
including
`yield` and `yield from` expressions and named expressions. I combined a
few
different types of CPython errors here, but I think the resulting error
messages
still make sense and are even preferable to what CPython gives. For
example, we
report `yield expression cannot be used in a type annotation` for both
of these:

```pycon
>>> def f[T](x: (yield 1)): ...
  File "<python-input-26>", line 1
    def f[T](x: (yield 1)): ...
                 ^^^^^^^
SyntaxError: yield expression cannot be used within the definition of a generic
>>> def foo() -> (yield x): ...
  File "<python-input-28>", line 1
    def foo() -> (yield x): ...
                  ^^^^^^^
SyntaxError: 'yield' outside function
```

Fixes https://github.com/astral-sh/ruff/issues/11118.

Test Plan
--

New inline tests, along with some updates to existing tests.
2025-04-03 17:56:55 -04:00
Micha Reiser 8a4158c5f8
Upgrade to Rust 1.86 and bump MSRV to 1.84 (#17171)
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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>
2025-04-03 15:59:44 +00:00
Brent Westbrook a0819f0c51
[syntax-errors] Store to or delete `__debug__` (#16984)
Summary
--

Detect setting or deleting `__debug__`. Assigning to `__debug__` was a
`SyntaxError` on the earliest version I tested (3.8). Deleting
`__debug__` was made a `SyntaxError` in [BPO 45000], which said it was
resolved in Python 3.10. However, `del __debug__` was also a runtime
error (`NameError`) when I tested in Python 3.9.6, so I thought it was
worth including 3.9 in this check.

I don't think it was ever a *good* idea to try `del __debug__`, so I
think there's also an argument for not making this version-dependent at
all. That would only simplify the implementation very slightly, though.

[BPO 45000]: https://github.com/python/cpython/issues/89163

Test Plan
--

New inline tests. This also required adding a `PythonVersion` field to
the `TestContext` that could be taken from the inline `ParseOptions` and
making the version field on the options accessible.
2025-03-29 12:07:20 -04:00
Brent Westbrook 5697d21fca
[syntax-errors] Irrefutable case pattern before final case (#16905)
Summary
--

Detects irrefutable `match` cases before the final case using a modified
version
of the existing `Pattern::is_irrefutable` method from the AST crate. The
modified method helps to retrieve a more precise diagnostic range to
match what
Python 3.13 shows in the REPL.

Test Plan
--

New inline tests, as well as some updates to existing tests that had
irrefutable
patterns before the last block.
2025-03-26 12:27:16 -04:00
Brent Westbrook 2711e08eb8
[syntax-errors] Fix false positive for parenthesized tuple index (#16948)
Summary
--

Fixes #16943 by checking if the tuple is not parenthesized before
emitting an error.

Test Plan
--

New inline test based on the initial report
2025-03-24 10:34:38 -04:00
Brent Westbrook e4f5fe8cf7
[syntax-errors] Duplicate type parameter names (#16858)
Summary
--

Detects duplicate type parameter names in function definitions, class
definitions, and type alias statements.

I also boxed the `type_params` field on `StmtTypeAlias` to make it
easier to
`match` with functions and classes. (That's the reason for the red-knot
code
owner review requests, sorry!)

Test Plan
--

New `ruff_python_syntax_errors` unit tests.

Fixes #11119.
2025-03-21 15:06:22 -04:00
Junhson Jean-Baptiste 2a4d835132
Use the common `OperatorPrecedence` for the parser (#16747)
## Summary

This change continues to resolve #16071 (and continues the work started
in #16162). Specifically, this PR changes the code in the parser so that
it uses the `OperatorPrecedence` struct from `ruff_python_ast` instead
of its own version. This is part of an effort to get rid of the
redundant definitions of `OperatorPrecedence` throughout the codebase.

Note that this PR only makes this change for `ruff_python_parser` -- we
still want to make a similar change for the formatter (namely the
`OperatorPrecedence` defined in the expression part of the formatter,
the pattern one is different). I separated the work to keep the PRs
small and easily reviewable.

## Test Plan

Because this is an internal change, I didn't add any additional tests.
Existing tests do pass.
2025-03-21 09:40:37 +05:30
Brent Westbrook 42cbce538b
[syntax-errors] Fix star annotation before Python 3.11 (#16878)
Summary
--

Fixes #16874. I previously emitted a syntax error when starred
annotations were _allowed_ rather than when they were actually used.
This caused false positives for any starred parameter name because these
are allowed to have starred annotations but not required to. The fix is
to check if the annotation is actually starred after parsing it.

Test Plan
--

New inline parser tests derived from the initial report and more
examples from the comments, although I think the first case should cover
them all.
2025-03-20 17:44:52 -04:00
Brent Westbrook dcf31c9348
[syntax-errors] PEP 701 f-strings before Python 3.12 (#16543)
## 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
2025-03-18 11:12:15 -04:00
Brent Westbrook 75a562d313
[syntax-errors] Parenthesized context managers before Python 3.9 (#16523)
Summary
--

I thought this was very complicated based on the comment here:
https://github.com/astral-sh/ruff/pull/16106#issuecomment-2653505671 and
on some of the discussion in the CPython issue here:
https://github.com/python/cpython/issues/56991. However, after a little
bit of experimentation, I think it boils down to this example:

```python
with (x as y): ...
```

The issue is parentheses around a `with` item with an `optional_var`, as
we (and
[Python](https://docs.python.org/3/library/ast.html#ast.withitem)) call
the trailing variable name (`y` in this case). It's not actually about
line breaks after all, except that line breaks are allowed in
parenthesized expressions, which explains the validity of cases like


```pycon
>>> with (
...     x,
...     y
... ) as foo:
...     pass
... 
```

even on Python 3.8.

I followed [pyright]'s example again here on the diagnostic range (just
the opening paren) and the wording of the error.


Test Plan
--
Inline tests

[pyright]:
https://pyright-play.net/?pythonVersion=3.7&strict=true&code=FAdwlgLgFgBAFAewA4FMB2cBEAzBCB0EAHhJgJQwCGAzjLgmQFwz6tA
2025-03-17 08:54:55 -04:00
Alex Waygood 38bfda94ce
[syntax-errors] Improve error message and range for pre-PEP-614 decorator syntax errors (#16581)
## Summary

A small followup to https://github.com/astral-sh/ruff/pull/16386. We now
tell the user exactly what it was about their decorator that constituted
invalid syntax on Python <3.9, and the range now highlights the specific
sub-expression that is invalid rather than highlighting the whole
decorator

## Test Plan

Inline snapshots are updated, and new ones are added.
2025-03-17 11:17:27 +00:00
Brent Westbrook 3a32e56445
[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)
## Summary
This PR detects unparenthesized assignment expressions used in set
literals and comprehensions and in sequence indexes. The link to the
release notes in https://github.com/astral-sh/ruff/issues/6591 just has
this entry:
> * Assignment expressions can now be used unparenthesized within set
literals and set comprehensions, as well as in sequence indexes (but not
slices).

with no other information, so hopefully the test cases I came up with
cover all of the changes. I also tested these out in the Python REPL and
they actually worked in Python 3.9 too. I'm guessing this may be another
case that was "formally made part of the language spec in Python 3.10,
but usable -- and commonly used -- in Python >=3.9" as @AlexWaygood
added to the body of #6591 for context managers. So we may want to
change the version cutoff, but I've gone along with the release notes
for now.

## Test Plan

New inline parser tests and linter CLI tests.
2025-03-14 15:06:42 -04:00
Brent Westbrook 6311412373
[syntax-errors] Star annotations before Python 3.11 (#16545)
Summary
--

This is closely related to (and stacked on)
https://github.com/astral-sh/ruff/pull/16544 and detects star
annotations in function definitions.

I initially called the variant `StarExpressionInAnnotation` to mirror
`StarExpressionInIndex`, but I realized it's not really a "star
expression" in this position and renamed it. `StarAnnotation` seems in
line with the PEP.

Test Plan
--

Two new inline tests. It looked like there was pretty good existing
coverage of this syntax, so I just added simple examples to test the
version cutoff.
2025-03-14 15:20:44 +00:00
Brent Westbrook 4f2851982d
[syntax-errors] Star expression in index before Python 3.11 (#16544)
Summary
--

This PR detects tuple unpacking expressions in index/subscript
expressions before Python 3.11.

Test Plan
--

New inline tests
2025-03-14 14:51:34 +00:00
Brent Westbrook 2382fe1f25
[syntax-errors] Tuple unpacking in `for` statement iterator clause before Python 3.9 (#16558)
Summary
--

This PR reuses a slightly modified version of the
`check_tuple_unpacking` method added for detecting unpacking in `return`
and `yield` statements to detect the same issue in the iterator clause
of `for` loops.

I ran into the same issue with a bare `for x in *rest: ...` example
(invalid even on Python 3.13) and added it as a comment on
https://github.com/astral-sh/ruff/issues/16520.

I considered just making this an additional `StarTupleKind` variant as
well, but this change was in a different version of Python, so I kept it
separate.

Test Plan
--

New inline tests.
2025-03-13 15:55:17 -04:00
Brent Westbrook b3c884f4f3
[syntax-errors] Parenthesized keyword argument names after Python 3.8 (#16482)
Summary
--

Unlike the other syntax errors detected so far, parenthesized keyword
arguments are only allowed *before* 3.8. It sounds like they were only
accidentally allowed before that [^1].

As an aside, you get a pretty confusing error from Python for this, so
it's nice that we can catch it:

```pycon
>>> def f(**kwargs): ...
... f((a)=1)
...
  File "<python-input-0>", line 2
    f((a)=1)
       ^^^
SyntaxError: expression cannot contain assignment, perhaps you meant "=="?
>>>
```
Test Plan
--
Inline tests.

[^1]: https://github.com/python/cpython/issues/78822
2025-03-06 12:18:13 -05:00
Brent Westbrook 6c14225c66
[syntax-errors] Tuple unpacking in `return` and `yield` before Python 3.8 (#16485)
Summary
--

Checks for tuple unpacking in `return` and `yield` statements before
Python 3.8, as described [here].

Test Plan
--
Inline tests.

[here]: https://github.com/python/cpython/issues/76298
2025-03-06 11:57:20 -05:00
Brent Westbrook 318f503714
[syntax-errors] Named expressions in decorators before Python 3.9 (#16386)
Summary
--

This PR detects the relaxed grammar for decorators proposed in [PEP
614](https://peps.python.org/pep-0614/) on Python 3.8 and lower.

The 3.8 grammar for decorators is
[here](https://docs.python.org/3.8/reference/compound_stmts.html#grammar-token-decorators):

```
decorators                ::=  decorator+
decorator                 ::=  "@" dotted_name ["(" [argument_list [","]] ")"] NEWLINE
dotted_name               ::=  identifier ("." identifier)*
```

in contrast to the current grammar
[here](https://docs.python.org/3/reference/compound_stmts.html#grammar-token-python-grammar-decorators)

```
decorators                ::= decorator+
decorator                 ::= "@" assignment_expression NEWLINE
assignment_expression ::= [identifier ":="] expression
```

Test Plan
--

New inline parser tests.
2025-03-05 17:08:18 +00:00
Brent Westbrook d0623888b3
[syntax-errors] Positional-only parameters before Python 3.8 (#16481)
Summary
--

Detect positional-only parameters before Python 3.8, as marked by the
`/` separator in a parameter list.

Test Plan
--
Inline tests.
2025-03-05 13:46:43 +00:00
Brent Westbrook 81bcdcebd3
[syntax-errors] Type parameter lists before Python 3.12 (#16479)
Summary
--

Another simple one, just detect type parameter lists in functions
and classes. Like pyright, we don't emit a second diagnostic for
`type` alias statements, which were also introduced in 3.12.

Test Plan
--
Inline tests.
2025-03-05 13:19:09 +00:00
Brent Westbrook 32c66ec4b7
[syntax-errors] `type` alias statements before Python 3.12 (#16478)
Summary
--
Another simple one, just detect standalone `type` statements. I limited
the diagnostic to `type` itself like [pyright]. That probably makes the
most sense for more complicated examples.

Test Plan
--
Inline tests.

[pyright]:
https://pyright-play.net/?pythonVersion=3.8&strict=true&code=C4TwDgpgBAHlC8UCWA7YQ
2025-03-04 17:20:10 +00:00
Brent Westbrook e7b93f93ef
[syntax-errors] Type parameter defaults before Python 3.13 (#16447)
Summary
--

Detects the presence of a [PEP 696] type parameter default before Python
3.13.

Test Plan
--

New inline parser tests for type aliases, generic functions and generic
classes.

[PEP 696]: https://peps.python.org/pep-0696/#grammar-changes
2025-03-04 16:53:38 +00:00
Brent Westbrook c8a06a9be8
[syntax-errors] Limit `except*` range to `*` (#16473)
Summary
--
This is a follow-up to #16446 to fix the diagnostic range to point to
the `*` like `pyright` does
(https://github.com/astral-sh/ruff/pull/16446#discussion_r1976900643).

Storing the range in the `ExceptClauseKind::Star` variant feels slightly
awkward, but we don't store the star itself anywhere on the
`ExceptHandler`. And we can't just take `ExceptHandler.start() +
"except".text_len()` because this code appears to be valid:

```python
try: ...
except    *    Error: ...
```

Test Plan
--
Existing tests.
2025-03-04 16:50:09 +00:00
Brent Westbrook e924ecbdac
[syntax-errors] `except*` before Python 3.11 (#16446)
Summary
--

One of the simpler ones, just detect the use of `except*` before 3.11.

Test Plan
--

New inline tests.
2025-03-02 18:20:18 +00:00
Brent Westbrook 4431978262
[syntax-errors] Assignment expressions before Python 3.8 (#16383)
## Summary
This PR is the first in a series derived from
https://github.com/astral-sh/ruff/pull/16308, each of which add support
for detecting one version-related syntax error from
https://github.com/astral-sh/ruff/issues/6591. This one should be
the largest because it also includes the addition of the 
`Parser::add_unsupported_syntax_error` method

Otherwise I think the general structure will be the same for each syntax
error:
* Detecting the error in the parser
* Inline parser tests for the new error
* New ruff CLI tests for the new error

## Test Plan
As noted above, there are new inline parser tests, as well as new ruff
CLI
tests. Once https://github.com/astral-sh/ruff/pull/16379 is resolved,
there should also be new mdtests for red-knot,
but this PR does not currently include those.
2025-02-28 17:13:46 -05:00
Brent Westbrook 764aa0e6a1
Allow passing `ParseOptions` to inline tests (#16357)
## Summary

This PR adds support for a pragma-style header for inline parser tests
containing JSON-serialized `ParseOptions`. For example,

```python
# parse_options: { "target-version": "3.9" }
match 2:
    case 1:
        pass
```

The line must start with `# parse_options: ` and then the rest of the
(trimmed) line is deserialized into `ParseOptions` used for parsing the
the test.

## Test Plan

Existing inline tests, plus two new inline tests for
`match-before-py310`.

---------

Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-02-27 10:23:15 -05:00
Brent Westbrook 78806361fd
Start detecting version-related syntax errors in the parser (#16090)
## Summary

This PR builds on the changes in #16220 to pass a target Python version
to the parser. It also adds the `Parser::unsupported_syntax_errors` field, which
collects version-related syntax errors while parsing. These syntax
errors are then turned into `Message`s in ruff (in preview mode).

This PR only detects one syntax error (`match` statement before Python
3.10), but it has been pretty quick to extend to several other simple
errors (see #16308 for example).

## Test Plan

The current tests are CLI tests in the linter crate, but these could be
supplemented with inline parser tests after #16357.

I also tested the display of these syntax errors in VS Code:


![image](https://github.com/user-attachments/assets/062b4441-740e-46c3-887c-a954049ef26e)

![image](https://github.com/user-attachments/assets/101f55b8-146c-4d59-b6b0-922f19bcd0fa)

---------

Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-02-25 23:03:48 -05:00
Brent Westbrook 97d0659ce3
Pass `ParserOptions` to the parser (#16220)
## 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.
2025-02-19 10:50:50 -05:00
Alex Waygood cb71393332
Simplify the `StringFlags` trait (#15944) 2025-02-04 18:14:28 +00:00
Shaygan Hooshyari cf4ab7cba1
Parse triple quoted string annotations as if parenthesized (#15387)
## Summary

Resolves #9467 

Parse quoted annotations as if the string content is inside parenthesis.
With this logic `x` and `y` in this example are equal:

```python
y: """
   int |
   str
"""

z: """(
    int |
    str
)
"""
```

Also this rule only applies to triple
quotes([link](https://github.com/python/typing-council/issues/9#issuecomment-1890808610)).

This PR is based on the
[comments](https://github.com/astral-sh/ruff/issues/9467#issuecomment-2579180991)
on the issue.

I did one extra change, since we don't want any indentation tokens I am
setting the `State::Other` as the initial state of the Lexer.

Remaining work:

- [x] Add a test case for red-knot.
- [x] Add more tests.

## Test Plan

Added a test which previously failed because quoted annotation contained
indentation.
Added an mdtest for red-knot.
Updated previous test.

Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
Co-authored-by: Micha Reiser <micha@reiser.io>
2025-01-16 11:38:15 +05:30