## Summary
This PR fixes a bug in the lexer specifically around line continuation
character at end of file.
The reason this was occurring is because the lexer wouldn't check for
EOL _after_ consuming the escaped newline but only if the EOL was right
after the line continuation character.
fixes: #17398
## Test Plan
Add tests for the scenarios where this should occur mainly (a) when the
state is `AfterNewline` and (b) when the state is `Other`.
Summary
--
This PR implements detecting the use of `await` expressions outside of
async functions. This is a reimplementation of
[await-outside-async
(PLE1142)](https://docs.astral.sh/ruff/rules/await-outside-async/) as a
semantic syntax error.
Despite the rule name, PLE1142 also applies to `async for` and `async
with`, so these are covered here too.
Test Plan
--
Existing PLE1142 tests.
I also deleted more code from the `SemanticSyntaxCheckerVisitor` to
avoid changes in other parser tests.
Summary
--
This PR reimplements [yield-outside-function
(F704)](https://docs.astral.sh/ruff/rules/yield-outside-function/) as a
semantic syntax error. Despite the name, this rule covers `yield from`
and `await` in addition to `yield`.
Test Plan
--
New linter tests, along with the existing F704 test.
---------
Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
## Summary
Based on the discussion in
https://github.com/astral-sh/ruff/pull/17298#discussion_r2033975460, we
decided to move the scope handling out of the `SemanticSyntaxChecker`
and into the `SemanticSyntaxContext` trait. This PR implements that
refactor by:
- Reverting all of the `Checkpoint` and `in_async_context` code in the
`SemanticSyntaxChecker`
- Adding four new methods to the `SemanticSyntaxContext` trait
- `in_async_context`: matches `SemanticModel::in_async_context` and only
detects the nearest enclosing function
- `in_sync_comprehension`: uses the new `is_async` tracking on
`Generator` scopes to detect any enclosing sync comprehension
- `in_module_scope`: reports whether we're at the top-level scope
- `in_notebook`: reports whether we're in a Jupyter notebook
- In-lining the `TestContext` directly into the
`SemanticSyntaxCheckerVisitor`
- This allows modifying the context as the visitor traverses the AST,
which wasn't possible before
One potential question here is "why not add a single method returning a
`Scope` or `Scopes` to the context?" The main reason is that the `Scope`
type is defined in the `ruff_python_semantic` crate, which is not
currently a dependency of the parser. It also doesn't appear to be used
in red-knot. So it seemed best to use these more granular methods
instead of trying to access `Scope` in `ruff_python_parser` (and
red-knot).
## Test Plan
Existing parser and linter tests.
Summary
--
This PR extends the documentation of the `LoadBeforeGlobalDeclaration`
check to specify the behavior on versions of Python before 3.13. Namely,
on Python 3.12, the `else` clause of a `try` statement is visited before
the `except` handlers:
```pycon
Python 3.12.9 (main, Feb 12 2025, 14:50:50) [Clang 19.1.6 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> a = 10
>>> def g():
... try:
... 1 / 0
... except:
... a = 1
... else:
... global a
...
>>> def f():
... try:
... pass
... except:
... global a
... else:
... print(a)
...
File "<stdin>", line 5
SyntaxError: name 'a' is used prior to global declaration
```
The order is swapped on 3.13 (see
[CPython#111123](https://github.com/python/cpython/issues/111123)):
```pycon
Python 3.13.2 (main, Feb 5 2025, 08:05:21) [GCC 14.2.1 20250128] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> a = 10
... def g():
... try:
... 1 / 0
... except:
... a = 1
... else:
... global a
...
File "<python-input-0>", line 8
global a
^^^^^^^^
SyntaxError: name 'a' is assigned to before global declaration
>>> def f():
... try:
... pass
... except:
... global a
... else:
... print(a)
...
>>>
```
The current implementation of PLE0118 is correct for 3.13 but not 3.12:
[playground](https://play.ruff.rs/d7467ea6-f546-4a76-828f-8e6b800694c9)
(it flags the first case regardless of Python version).
We decided to maintain this incorrect diagnostic for Python versions
before 3.13 because the pre-3.13 behavior is very unintuitive and
confirmed to be a bug, although the bug fix was not backported to
earlier versions. This can lead to false positives and false negatives
for pre-3.13 code, but we also expect that to be very rare, as
demonstrated by the ecosystem check (before the version-dependent check
was reverted here).
Test Plan
--
N/a
Summary
--
Detect async comprehensions nested in sync comprehensions in async
functions before Python 3.11, when this was [changed].
The actual logic of this rule is very straightforward, but properly
tracking the async scopes took a bit of work. An alternative to the
current approach is to offload the `in_async_context` check into the
`SemanticSyntaxContext` trait, but that actually required much more
extensive changes to the `TestContext` and also to ruff's semantic
model, as you can see in the changes up to
31554b473507034735bd410760fde6341d54a050. This version has the benefit
of mostly centralizing the state tracking in `SemanticSyntaxChecker`,
although there was some subtlety around deferred function body traversal
that made the changes to `Checker` more intrusive too (hence the new
linter test).
The `Checkpoint` struct/system is obviously overkill for now since it's
only tracking a single `bool`, but I thought it might be more useful
later.
[changed]: https://github.com/python/cpython/issues/77527
Test Plan
--
New inline tests and a new linter integration test.
Summary
--
This PR extends the checks in #17101 and #17282 to annotated assignments
after Python 3.13.
Currently stacked on #17282 to include `await`.
Test Plan
--
New inline tests. These are simpler than the other cases because there's
no place to put generics.
Summary
--
This PR extends the changes in #17101 to include `await` in the same
positions.
I also renamed the `valid_annotation_function` test to include `_py313`
and explicitly passed a Python version to contrast it with the `_py314`
version.
Test Plan
--
New test cases added to existing files.
Summary
--
This PR fixes the issue pointed out by @JelleZijlstra in
https://github.com/astral-sh/ruff/pull/17101#issuecomment-2777480204.
Namely, I conflated two very different errors from CPython:
```pycon
>>> def m[T](x: (yield from 1)): ...
File "<python-input-310>", line 1
def m[T](x: (yield from 1)): ...
^^^^^^^^^^^^
SyntaxError: yield expression cannot be used within the definition of a generic
>>> def m(x: (yield from 1)): ...
File "<python-input-311>", line 1
def m(x: (yield from 1)): ...
^^^^^^^^^^^^
SyntaxError: 'yield from' outside function
>>> def outer():
... def m(x: (yield from 1)): ...
...
>>>
```
I thought the second error was the same as the first, but `yield` (and
`yield from`) is actually valid in this position when inside a function
scope. The same is true for base classes, as pointed out in the original
comment.
We don't currently raise an error for `yield` outside of a function, but
that should be handled separately.
On the upside, this had the benefit of removing the
`InvalidExpressionPosition::BaseClass` variant and the
`allow_named_expr` field from the visitor because they were both no
longer used.
Test Plan
--
Updated inline tests.
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.
Summary
--
Detects duplicate attributes in a `match` class pattern:
```python
match x:
case Class(x=1, x=2): ...
```
which are more analogous to the similar check for mapping patterns than
to the
multiple assignments rule.
I also realized that both this and the mapping check would only work on
top-level patterns, despite the possibility that they can be nested
inside other
patterns:
```python
match x:
case [{"x": 1, "x": 2}]: ... # false negative in the old version
```
and moved these checks into the recursive pattern visitor instead.
I also tidied up some of the names like the `multiple_case_assignment`
function
and the `MultipleCaseAssignmentVisitor`, which are now doing more than
checking
for multiple assignments.
Test Plan
--
New inline tests for both classes and mappings.
Summary
--
Fixes#17181. The cases being tested with multiple *keys* being equal
are actually a slightly different error, more like the error for
`MatchMapping` than like the other multiple assignment errors:
```pycon
>>> match x:
... case Class(x=x, x=x): ...
...
File "<python-input-249>", line 2
case Class(x=x, x=x): ...
^
SyntaxError: attribute name repeated in class pattern: x
>>> match x:
... case {"x": 1, "x": 2}: ...
...
File "<python-input-251>", line 2
case {"x": 1, "x": 2}: ...
^^^^^^^^^^^^^^^^
SyntaxError: mapping pattern checks duplicate key ('x')
>>> match x:
... case [x, x]: ...
...
File "<python-input-252>", line 2
case [x, x]: ...
^
SyntaxError: multiple assignments to name 'x' in pattern
```
This PR just stops the false positive reported in the issue, but I will
quickly follow it up with a new rule (or possibly combined with the
mapping rule) catching the repeated attributes separately.
Test Plan
--
New inline `test_ok` and updating the `test_err` cases to have duplicate
values instead of keys.
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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
--
Detects duplicate literals in `match` mapping keys.
This PR also adds a `source` method to `SemanticSyntaxContext` to
display the duplicated key in the error message by slicing out its
range.
Test Plan
--
New inline tests.
Summary
--
This PR reimplements
[load-before-global-declaration
(PLE0118)](https://docs.astral.sh/ruff/rules/load-before-global-declaration/)
as a semantic syntax error.
I added a `global` method to the `SemanticSyntaxContext` trait to make
this very easy, at least in ruff. Does red-knot have something similar?
If this approach will also work in red-knot, I think some of the other
PLE rules are also compile-time errors in CPython, PLE0117 in
particular. 0115 and 0116 also mention `SyntaxError`s in their docs, but
I haven't confirmed them in the REPL yet.
Test Plan
--
Existing linter tests for PLE0118. I think this actually can't be tested
very easily in an inline test because the `TestContext` doesn't have a
real way to track globals.
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
Summary
--
Fixes https://github.com/astral-sh/ruff/issues/16520 by flagging single,
starred expressions in `return`, `yield`, and
`for` statements.
I thought `yield from` would also be included here, but that error is
emitted by
the CPython parser:
```pycon
>>> ast.parse("def f(): yield from *x")
Traceback (most recent call last):
File "<python-input-214>", line 1, in <module>
ast.parse("def f(): yield from *x")
~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.13/ast.py", line 54, in parse
return compile(source, filename, mode, flags,
_feature_version=feature_version, optimize=optimize)
File "<unknown>", line 1
def f(): yield from *x
^
SyntaxError: invalid syntax
```
And we also already catch it in our parser.
Test Plan
--
New inline tests and updates to existing tests.
## Summary
Implement basic *Goto type definition* support for Red Knot's LSP.
This PR also builds the foundation for other LSP operations. E.g., Goto
definition, hover, etc., should be able to reuse some, if not most,
logic introduced in this PR.
The basic steps of resolving the type definitions are:
1. Find the closest token for the cursor offset. This is a bit more
subtle than I first anticipated because the cursor could be positioned
right between the callee and the `(` in `call(test)`, in which case we
want to resolve the type for `call`.
2. Find the node with the minimal range that fully encloses the token
found in 1. I somewhat suspect that 1 and 2 could be done at the same
time but it complicated things because we also need to compute the spine
(ancestor chain) for the node and there's no guarantee that the found
nodes have the same ancestors
3. Reduce the node found in 2. to a node that is a valid goto target.
This may require traversing upwards to e.g. find the closest expression.
4. Resolve the type for the goto target
5. Resolve the location for the type, return it to the LSP
## Design decisions
The current implementation navigates to the inferred type. I think this
is what we want because it means that it correctly accounts for
narrowing (in which case we want to go to the narrowed type because
that's the value's type at the given position). However, it does have
the downside that Goto type definition doesn't work whenever we infer `T
& Unknown` because intersection types aren't supported. I'm not sure
what to do about this specific case, other than maybe ignoring `Unkown`
in Goto type definition if the type is an intersection?
## Known limitations
* Types defined in the vendored typeshed aren't supported because the
client can't open files from the red knot binary (we can either
implement our own file protocol and handler OR extract the typeshed
files and point there). See
https://github.com/astral-sh/ruff/issues/17041
* Red Knot only exposes an API to get types for expressions and
definitions. However, there are many other nodes with identifiers that
can have a type (e.g. go to type of a globals statement, match patterns,
...). We can add support for those in separate PRs (after we figure out
how to query the types from the semantic model). See
https://github.com/astral-sh/ruff/issues/17113
* We should have a higher-level API for the LSP that doesn't directly
call semantic queries. I intentionally decided not to design that API
just yet.
## Test plan
https://github.com/user-attachments/assets/fa077297-a42d-4ec8-b71f-90c0802b4edb
Goto type definition on a union
<img width="1215" alt="Screenshot 2025-04-01 at 13 02 55"
src="https://github.com/user-attachments/assets/689cabcc-4a86-4a18-b14a-c56f56868085"
/>
Note: I recorded this using a custom typeshed path so that navigating to
builtins works.
Summary
--
Detects starred assignment targets outside of tuples and lists like `*a
= (1,)`.
This PR only considers assignment statements. I also checked annotated
assigment statements, but these give a separate error that we already
catch, so I think they're okay not to consider:
```pycon
>>> *a: list[int] = []
File "<python-input-72>", line 1
*a: list[int] = []
^
SyntaxError: invalid syntax
```
Fixes#13759
Test Plan
--
New inline tests, plus a new `SemanticSyntaxError` for an existing
parser test. I also removed a now-invalid case from an otherwise-valid
test fixture.
The new semantic error leads to two errors for the case below:
```python
*foo() = 42
```
but this matches [pyright] too.
[pyright]: https://pyright-play.net/?code=FQMw9mAUCUAEC8sAsAmAUEA
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.
Summary
--
This PR detects multiple assignments to the same name in `case` patterns
by recursively visiting each pattern.
Test Plan
--
New inline tests.
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.
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
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.
## Summary
This PR implements the "greeter" approach for checking the AST for
syntax errors emitted by the CPython compiler. It introduces two main
infrastructural changes to support all of the compile-time errors:
1. Adds a new `semantic_errors` module to the parser crate with public
`SemanticSyntaxChecker` and `SemanticSyntaxError` types
2. Embeds a `SemanticSyntaxChecker` in the `ruff_linter::Checker` for
checking these errors in ruff
As a proof of concept, it also implements detection of two syntax
errors:
1. A reimplementation of
[`late-future-import`](https://docs.astral.sh/ruff/rules/late-future-import/)
(`F404`)
2. Detection of rebound comprehension iteration variables
(https://github.com/astral-sh/ruff/issues/14395)
## Test plan
Existing F404 tests, new inline tests in the `ruff_python_parser` crate,
and a linter CLI test showing an example of the `Message` output.
I also tested in VS Code, where `preview = false` and turning off syntax
errors both disable the new errors:
And on the playground, where `preview = false` also disables the errors:
Fixes#14395
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
## 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.
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.
## 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
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.
## 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.
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.
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.
## 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
--
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
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
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.
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
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.
Summary
--
This is a follow up addressing the comments on #16425. As @dhruvmanila
pointed out, the naming is a bit tricky. I went with `has_no_errors` to
try to differentiate it from `is_valid`. It actually ends up negated in
most uses, so it would be more convenient to have `has_any_errors` or
`has_errors`, but I thought it would sound too much like the opposite of
`is_valid` in that case. I'm definitely open to suggestions here.
Test Plan
--
Existing tests.
## 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.
## 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>
## 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:
---------
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
## 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.
## Summary
This PR makes the following changes:
- It adjusts various callsites to use the new
`ast::StringLiteral::contents_range()` method that was introduced in
https://github.com/astral-sh/ruff/pull/16183. This is less verbose and
more type-safe than using the `ast::str::raw_contents()` helper
function.
- It adds a new `ast::ExprStringLiteral::as_unconcatenated_literal()`
helper method, and adjusts various callsites to use it. This addresses
@MichaReiser's review comment at
https://github.com/astral-sh/ruff/pull/16183#discussion_r1957334365.
There is no functional change here, but it helps readability to make it
clearer that we're differentiating between implicitly concatenated
strings and unconcatenated strings at various points.
- It renames the `StringLiteralValue::flags()` method to
`StringLiteralFlags::first_literal_flags()`. If you're dealing with an
implicitly concatenated string `string_node`,
`string_node.value.flags().closer_len()` could give an incorrect result;
this renaming makes it clearer that the `StringLiteralFlags` instance
returned by the method is only guaranteed to give accurate information
for the first `StringLiteral` contained in the `ExprStringLiteral` node.
- It deletes the unused `BytesLiteralValue::flags()` method. This seems
prone to misuse in the same way as `StringLiteralValue::flags()`: if
it's an implicitly concatenated bytestring, the `BytesLiteralFlags`
instance returned by the method would only give accurate information for
the first `BytesLiteral` in the bytestring.
## Test Plan
`cargo test`
## Summary
Resolves#13294, follow-up to #13882.
At #13882, it was concluded that a fix should not be offered for raw
strings. This change implements that. The five rules in question are now
no longer always fixable.
## Test Plan
`cargo nextest run` and `cargo insta test`.
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
## Summary
This is a follow-up to #15726, #15778, and #15794 to preserve the triple
quote and prefix flags in plain strings, bytestrings, and f-strings.
I also added a `StringLiteralFlags::without_triple_quotes` method to
avoid passing along triple quotes in rules like SIM905 where it might
not make sense, as discussed
[here](https://github.com/astral-sh/ruff/pull/15726#discussion_r1930532426).
## Test Plan
Existing tests, plus many new cases in the `generator::tests::quote`
test that should cover all combinations of quotes and prefixes, at least
for simple string bodies.
Closes#7799 when combined with #15694, #15726, #15778, and #15794.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
This is a first step toward fixing #7799 by using the quoting style
stored in the `flags` field on `ast::StringLiteral`s to select a quoting
style. This PR does not include support for f-strings or byte strings.
Several rules also needed small updates to pass along existing quoting
styles instead of using `StringLiteralFlags::default()`. The remaining
snapshot changes are intentional and should preserve the quotes from the
input strings.
## Test Plan
Existing tests with some accepted updates, plus a few new RUF055 tests
for raw strings.
---------
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
## 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>
This update includes some missing `^` in the diagnostic annotations.
This update also includes some shifting of "syntax error" annotations to
the end of the preceding line. I believe this is technically a
regression, but fixing them has proven quite difficult. I *think* the
best way to do that might be to tweak the spans generated by the Python
parser errors, but I didn't want to dig into that. (Another approach
would be to change the `annotate-snippets` rendering, but when I tried
that and managed to fix these regressions, I ended up causing a bunch of
other regressions.)
Ref 77d454525e (r1915458616)
We do this because `...` is valid Python, which makes it pretty likely
that some line trimming will lead to ambiguous output. So we add support
for overriding the cut indicator. This also requires changing some of
the alignment math, which was previously tightly coupled to `...`.
For Ruff, we go with `…` (`U+2026 HORIZONTAL ELLIPSIS`) for our cut
indicator.
For more details, see the patch sent to upstream:
https://github.com/rust-lang/annotate-snippets-rs/pull/172
This looks like a bug fix that occurs when the annotation is a
zero-width span immediately following a line terminator. Previously, the
caret seems to be rendered on the next line, but it should be rendered
at the end of the line the span corresponds to.
I admit that this one is kinda weird. I would somewhat expect that our
spans here are actually incorrect, and that to obtain this sort of
rendering, we should identify a span just immediately _before_ the line
terminator and not after it. But I don't want to dive into that rabbit
hole for now (and given how `annotate-snippets` now renders these
spans, perhaps there is more to it than I see), and this does seem like
a clear improvement given the spans we feed to `annotate-snippets`.
The previous rendering just seems wrong in that a `^` is omitted. The
new version of `annotate-snippets` seems to get this right. I checked a
pseudo random sample of these, and it seems to only happen when the
position pointed at a line terminator.
These updates center around the addition of annotations in the
diagnostic rendering. Previously, the annotation was just not rendered
at all. With the `annotate-snippets` upgrade, it is now rendered. I
examined a pseudo random sample of these, and they all look correct.
As will be true in future batches, some of these snapshots also have
changes to whitespace in them as well.
These snapshot changes should *all* only be a result of changes to
trailing whitespace in the output. I checked a psuedo random sample of
these, and the whitespace found in the previous snapshots seems to be an
artifact of the rendering and _not_ of the source data. So this seems
like a strict bug fix to me.
There are other snapshots with whitespace changes, but they also have
other changes that we split out into separate commits. Basically, we're
going to do approximately one commit per category of change.
This represents, by far, the biggest chunk of changes to snapshots as a
result of the `annotate-snippets` upgrade.
This is pretty much just moving to the new API and taking care to use
byte offsets. This is *almost* enough. The next commit will fix a bug
involving the handling of unprintable characters as a result of
switching to byte offsets.
When confronted with `raise from exc` the parser will now create a
`StmtRaise` that has `None` for the exception and `exc` for the cause.
Before, the parser created a `StmtRaise` with `from` for the exception,
no cause, and a spurious expression `exc` afterwards.
This PR adds a syntax error if the parser encounters a `TryStmt` that
has except clauses both with and without a star.
The displayed error points to each except clause that contradicts the
original except clause kind. So, for example,
```python
try:
....
except: #<-- we assume this is the desired except kind
....
except*: #<--- error will point here
....
except*: #<--- and here
....
```
Closes#14860
## Summary
This PR gets rid of the `requirements.in` and `requirements.txt` files
in the `scripts/fuzz-parser` directory, and replaces them with
`pyproject.toml` and `uv.lock` files. The script is renamed from
`fuzz-parser` to `py-fuzzer` (since it can now also be used to fuzz
red-knot as well as the parser, following
https://github.com/astral-sh/ruff/pull/14566), and moved from the
`scripts/` directory to the `python/` directory, since it's now a
(uv)-pip-installable project in its own right.
I've been resisting this for a while, because conceptually this script
just doesn't feel "complicated" enough to me for it to be a full-blown
package. However, I think it's time to do this. Making it a proper
package has several advantages:
- It means we can run it from the project root using `uv run` without
having to activate a virtual environment and ensure that all required
dependencies are installed into that environment
- Using a `pyproject.toml` file means that we can express that the
project requires Python 3.12+ to run properly; this wasn't possible
before
- I've been running mypy on the project locally when I've been working
on it or reviewing other people's PRs; now I can put the mypy config for
the project in the `pyproject.toml` file
## Test Plan
I manually tested that all the commands detailed in
`python/py-fuzzer/README.md` work for me locally.
---------
Co-authored-by: David Peter <sharkdp@users.noreply.github.com>
## Summary
This PR fixes a bug to raise a syntax error when an unparenthesized
generator expression is used as an argument to a call when there are
more than one argument.
For reference, the grammar is:
```
primary:
| ...
| primary genexp
| primary '(' [arguments] ')'
| ...
genexp:
| '(' ( assignment_expression | expression !':=') for_if_clauses ')'
```
The `genexp` requires the parenthesis as mentioned in the grammar. So,
the grammar for a call expression is either a name followed by a
generator expression or a name followed by a list of argument. In the
former case, the parenthesis are excluded because the generator
expression provides them while in the later case, the parenthesis are
explicitly provided for a list of arguments which means that the
generator expression requires it's own parenthesis.
This was discovered in https://github.com/astral-sh/ruff/issues/12420.
## Test Plan
Add test cases for valid and invalid syntax.
Make sure that the parser from CPython also raises this at the parsing
step:
```console
$ python3.13 -m ast parser/_.py
File "parser/_.py", line 1
total(1, 2, x for x in range(5), 6)
^^^^^^^^^^^^^^^^^^^
SyntaxError: Generator expression must be parenthesized
$ python3.13 -m ast parser/_.py
File "parser/_.py", line 1
sum(x for x in range(10), 10)
^^^^^^^^^^^^^^^^^^^^
SyntaxError: Generator expression must be parenthesized
```
## Summary
This PR updates the linter, specifically the token-based rules, to work
on the tokens that come after a syntax error.
For context, the token-based rules only diagnose the tokens up to the
first lexical error. This PR builds up an error resilience by
introducing a `TokenIterWithContext` which updates the `nesting` level
and tries to reflect it with what the lexer is seeing. This isn't 100%
accurate because if the parser recovered from an unclosed parenthesis in
the middle of the line, the context won't reduce the nesting level until
it sees the newline token at the end of the line.
resolves: #11915
## Test Plan
* Add test cases for a bunch of rules that are affected by this change.
* Run the fuzzer for a long time, making sure to fix any other bugs.
## Summary
This PR splits the re-lexing logic into two parts:
1. `TokenSource`: The token source will be responsible to find the
position the lexer needs to be moved to
2. `Lexer`: The lexer will be responsible to reduce the nesting level
and move itself to the new position if recovered from a parenthesized
context
This split makes it easy to find the new lexer position without needing
to implement the backwards lexing logic again which would need to handle
cases involving:
* Different kinds of newlines
* Line continuation character(s)
* Comments
* Whitespaces
### F-strings
This change did reveal one thing about re-lexing f-strings. Consider the
following example:
```py
f'{'
# ^
f'foo'
```
Here, the quote as highlighted by the caret (`^`) is the start of a
string inside an f-string expression. This is unterminated string which
means the token emitted is actually `Unknown`. The parser tries to
recover from it but there's no newline token in the vector so the new
logic doesn't recover from it. The previous logic does recover because
it's looking at the raw characters instead.
The parser would be at `FStringStart` (the one for the second line) when
it calls into the re-lexing logic to recover from an unterminated
f-string on the first line. So, moving backwards the first character
encountered is a newline character but the first token encountered is an
`Unknown` token.
This is improved with #12067fixes: #12046fixes: #12036
## Test Plan
Update the snapshot and validate the changes.
## Summary
This PR fixes the lexer logic to **not** consume the newline character
for an unterminated string literal.
Currently, the lexer would consume it to be part of the string itself
but that would be bad for recovery because then the lexer wouldn't emit
the newline token ever. This PR fixes that to avoid consuming the
newline character in that case.
This was discovered during https://github.com/astral-sh/ruff/pull/12060.
## Test Plan
Update the snapshots and validate them.
## Summary
This PR fixes a bug introduced in
https://github.com/astral-sh/ruff/pull/12008 which didn't consider the
two character newline after the line continuation character.
For example, consider the following code highlighted with whitespaces:
```py
call(foo # comment \\r\n
\r\n
def bar():\r\n
....pass\r\n
```
The lexer is at `def` when it's running the re-lexing logic and trying
to move back to a newline character. It encounters `\n` and it's being
escaped (incorrect) but `\r` is being escaped, so it moves the lexer to
`\n` character. This creates an overlap in token ranges which causes the
panic.
```
Name 0..4
Lpar 4..5
Name 5..8
Comment 9..20
NonLogicalNewline 20..22 <-- overlap between
Newline 21..22 <-- these two tokens
NonLogicalNewline 22..23
Def 23..26
...
```
fixes: #12028
## Test Plan
Add a test case with line continuation and windows style newline
character.
## Summary
(I'm pretty sure I added this in the parser re-write but must've got
lost in the rebase?)
This PR raises a syntax error if the type parameter list is empty.
As per the grammar, there should be at least one type parameter:
```
type_params:
| invalid_type_params
| '[' type_param_seq ']'
type_param_seq: ','.type_param+ [',']
```
Verified via the builtin `ast` module as well:
```console
$ python3.13 -m ast parser/_.py
Traceback (most recent call last):
[..]
File "parser/_.py", line 1
def foo[]():
^
SyntaxError: Type parameter list cannot be empty
```
## Test Plan
Add inline test cases and update the snapshots.
## Summary
This PR updates the parser test infrastructure to validate the token
ranges.
From the code documentation:
```
/// Verifies that:
/// * the ranges are strictly increasing when loop the tokens in insertion order
/// * all ranges are within the length of the source code
```
Follow-up from #12016 and #12017resolves: #11938
## Test Plan
Make sure that there are no failures.
## Summary
This PR updates the unterminated string error range to not include the
final newline character.
This is a follow-up to #12016 and required for #12019
This is not done for when the unterminated string goes till the end of
file (not a newline character). The unterminated f-string range is
correct.
### Why is this required for #12019 ?
Because otherwise the token ranges will overlap. For example:
```py
f"{"
f"{foo!r"
```
Here, the re-lexing logic recovers from an unterminated f-string and
thus emitting a `Newline` token for the one at the end of the first
line. But, currently the `Unknown` and the `Newline` token would overlap
because the `Unknown` token (unterminated string literal) range would
include the newline character.
## Test Plan
Update and validate the snapshot.
## Summary
This PR fixes the range highlighted for the line continuation error.
Previously, it would highlight an incorrect range:
```
1 | call(a, b, \\\
| ^^ Syntax Error: unexpected character after line continuation character
2 |
3 | def bar():
|
```
And now:
```
|
1 | call(a, b, \\\
| ^ Syntax Error: unexpected character after line continuation character
2 |
3 | def bar():
|
```
This is implemented by avoiding to update the token range for the
`Unknown` token which is emitted when there's a lexical error. Instead,
the `push_error` helper method will be responsible to update the range
to the error location.
This actually becomes a requirement which can be seen in follow-up PRs.
## Test Plan
Update and validate the snapshot.
## Summary
This PR fixes a bug where the re-lexing logic didn't consider the line
continuation character being present before the newline character. This
meant that the lexer was being moved back to the newline character which
is actually ignored via `\`.
Considering the following code:
```py
f'middle {'string':\
'format spec'}
```
The old token stream is:
```
...
Colon 18..19
FStringMiddle 19..29 (flags = F_STRING)
Newline 20..21
Indent 21..29
String 29..42
Rbrace 42..43
...
```
Notice how the ranges are overlapping between the `FStringMiddle` token
and the tokens emitted after moving the lexer backwards.
After this fix, the new token stream which is without moving the lexer
backwards in this scenario:
```
FStringStart 0..2 (flags = F_STRING)
FStringMiddle 2..9 (flags = F_STRING)
Lbrace 9..10
String 10..18
Colon 18..19
FStringMiddle 19..29 (flags = F_STRING)
FStringEnd 29..30 (flags = F_STRING)
Name 30..36
Name 37..41
Unknown 41..44
Newline 44..45
```
fixes: #12004
## Test Plan
Add test cases and update the snapshots.
## Summary
I look at the token stream a lot, not specifically in the playground but
in the terminal output and it's annoying to scroll a lot to find
specific location. Most of the information is also redundant.
The final format we end up with is: `<kind> <range> (flags = ...)` e.g.,
`String 0..4 (flags = BYTE_STRING)` where the flags part is only
populated if there are any flags set.
## Summary
This PR does some housekeeping into moving certain structs into related
modules. Specifically,
1. Move `LexicalError` from `lexer.rs` to `error.rs` which also contains
the `ParseError`
2. Move `Token`, `TokenFlags` and `TokenValue` from `lexer.rs` to
`token.rs`
## Summary
This PR removes the duplication around `is_trivia` functions.
There are two of them in the codebase:
1. In `pycodestyle`, it's for newline, indent, dedent, non-logical
newline and comment
2. In the parser, it's for non-logical newline and comment
The `TokenKind::is_trivia` method used (1) but that's not correct in
that context. So, this PR introduces a new `is_non_logical_token` helper
method for the `pycodestyle` crate and updates the
`TokenKind::is_trivia` implementation with (2).
This also means we can remove `Token::is_trivia` method and the
standalone `token_source::is_trivia` function and use the one on
`TokenKind`.
## Test Plan
`cargo insta test`
## Summary
This PR avoids moving back the lexer for a triple-quoted f-string during
the re-lexing phase.
The reason this is a problem is that for a triple-quoted f-string the
newlines are part of the f-string itself, specifically they'll be part
of the `FStringMiddle` token. So, if we moved the lexer back, there
would be a `Newline` token whose range would be in between an
`FStringMiddle` token. This creates a panic in downstream usage.
fixes: #11937
## Test Plan
Add test cases and validate the snapshots.
Dhruv Manilawala
Brent Westbrook
Micha Reiser
renovate[bot]
Junhson Jean-Baptiste
Alex Waygood
Carl Meyer
InSync
Shaygan Hooshyari
Andrew Gallant
Dylan
Dimitri Papadopoulos Orfanos
Junzhuo ZHOU