## 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 PR stabilizes the preview behavior introduced in
https://github.com/astral-sh/ruff/pull/15719 to recognize all symbols
named `TYPE_CHECKING` as type-checking
checks in `if TYPE_CHECKING` conditions. This ensures compatibility with
mypy and pyright.
This PR also stabilizes the new behavior that removes `if 0:` and `if
False` to be no longer considered type checking blocks.
Since then, this syntax has been removed from the typing spec and was
only used for Python modules that don't have a `typing` module
([comment](https://github.com/astral-sh/ruff/pull/15719#issuecomment-2612787793)).
The preview behavior was first released with Ruff 0.9.5 (6th of
February), which was about a month ago. There are no open issues or PRs
for the changed behavior
## Test Plan
The snapshots for `SIM108` change because `SIM108` ignored type checking
blocks but it can no
simplify `if 0` or `if False` blocks again because they're no longer
considered type checking blocks.
The changes in the `TC005` snapshot or only due to that `if 0` and `if
False` are no longer recognized as type checking blocks
<!-- How was it tested? -->
Closes#15681
## Summary
This changes `analyze::typing::is_type_checking_block` to recognize all
symbols named "TYPE_CHECKING".
This matches the current behavior of mypy and pyright as well as
`flake8-type-checking`.
It also drops support for detecting `if False:` and `if 0:` as type
checking blocks. This used to be an option for
providing backwards compatibility with Python versions that did not have
a `typing` module, but has since
been removed from the typing spec and is no longer supported by any of
the mainstream type checkers.
## Test Plan
`cargo nextest run`
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
Closes#14000
## Summary
For typing context bindings we know that they won't be available at
runtime. We shouldn't recommend a fix, that will result in name errors
at runtime.
## Test Plan
`cargo nextest run`
## Summary
- Check if `hashlib` and `crypt` imports have been seen for `FURB181`
and `S324`
- Mark the fix for `FURB181` as safe: I think it was accidentally marked
as unsafe in the first place. The rule does not support user-defined
classes as the "fix safety" section suggests.
- Removed `hashlib._Hash`, as it's not part of the `hashlib` module.
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
Updated the test snapshots
## Summary
This came up as part of #12927 when implementing
`SemanticModel::simulate_runtime_load`.
Should be fairly self-explanatory, if the scope returns a binding with
`BindingKind::Annotation` the bottom part of the loop gets skipped, so
there's no chance for `seen_function` to have been updated. So unless
there's something subtle going on here, like function scopes never
containing bindings with `BindingKind::Annotation`, this seems like a
bug.
## Test Plan
`cargo nextest run`
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Related to #970. Implement [`shallow-copy-environ /
W1507`](https://pylint.readthedocs.io/en/stable/user_guide/messages/warning/shallow-copy-environ.html).
## Test Plan
<!-- How was it tested? -->
Unit test
---------
Co-authored-by: Simon Brugman <sbrugman@users.noreply.github.com>
Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>
Remove unnecessary uses of `.as_ref()`, `.iter()`, `&**` and similar, mostly in situations when iterating over variables. Many of these changes are only possible following #13826, when we bumped our MSRV to 1.80: several useful implementations on `&Box<[T]>` were only stabilised in Rust 1.80. Some of these changes we could have done earlier, however.
## Summary
Update the name of `ASYNC109` to match
[upstream](https://flake8-async.readthedocs.io/en/latest/rules.html).
Also update to the functionality to match upstream by supporting
additional context managers from `asyncio` and `anyio`. This doesn't
change any of the detection functionality, but recommends additional
context managers from `asyncio` and `anyio` depending on context.
Part of https://github.com/astral-sh/ruff/issues/12039.
## Test Plan
Added fixture for asyncio recommendation
## Summary
Implement mutable-contextvar-default (B039) which was added to
flake8-bugbear in https://github.com/PyCQA/flake8-bugbear/pull/476.
This rule is similar to [mutable-argument-default
(B006)](https://docs.astral.sh/ruff/rules/mutable-argument-default) and
[function-call-in-default-argument
(B008)](https://docs.astral.sh/ruff/rules/function-call-in-default-argument),
except that it checks the `default` keyword argument to
`contextvars.ContextVar`.
```
B039.py:19:26: B039 Do not use mutable data structures for ContextVar defaults
|
18 | # Bad
19 | ContextVar("cv", default=[])
| ^^ B039
20 | ContextVar("cv", default={})
21 | ContextVar("cv", default=list())
|
= help: Replace with `None`; initialize with `.set()` after checking for `None`
```
In the upstream flake8-plugin, this rule is written expressly as a
corollary to B008 and shares much of its logic. Likewise, this
implementation reuses the logic of the Ruff implementation of B008,
namely
f765d19402/crates/ruff_linter/src/rules/flake8_bugbear/rules/function_call_in_argument_default.rs (L104-L106)
and
f765d19402/crates/ruff_linter/src/rules/flake8_bugbear/rules/mutable_argument_default.rs (L106)
Thus, this rule deliberately replicates B006's and B008's heuristics.
For example, this rule assumes that all functions are mutable unless
otherwise qualified. If improvements are to be made to B039 heuristics,
they should probably be made to B006 and B008 as well (whilst trying to
match the upstream implementation).
This rule does not have an autofix as it is unknown where the ContextVar
next used (and it might not be within the same file).
Closes#12054
## Test Plan
`cargo nextest run`
## Summary
This PR ensures that if a variable is bound via `global`, and then the
`global` is read, the originating variable is also marked as read. It's
not perfect, in that it won't detect _rebindings_, like:
```python
from app import redis_connection
def func():
global redis_connection
redis_connection = 1
redis_connection()
```
So, above, `redis_connection` is still marked as unused.
But it does avoid flagging `redis_connection` as unused in:
```python
from app import redis_connection
def func():
global redis_connection
redis_connection()
```
Closes https://github.com/astral-sh/ruff/issues/11518.
## Summary
This PR adds updates the semantic model to detect attribute docstring.
Refer to [PEP 258](https://peps.python.org/pep-0258/#attribute-docstrings)
for the definition of an attribute docstring.
This PR doesn't add full support for it but only considers string
literals as attribute docstring for the following cases:
1. A string literal following an assignment statement in the **global
scope**.
2. A global class attribute
For an assignment statement, it's considered an attribute docstring only
if the target expression is a name expression (`x = 1`). So, chained
assignment, multiple assignment or unpacking, and starred expression,
which are all valid in the target position, aren't considered here.
In `__init__` method, an assignment to the `self` variable like `self.x = 1`
is also a candidate for an attribute docstring. **This PR does not
support this position.**
## Test Plan
I used the following source code along with a print statement to verify
that the attribute docstring detection is correct.
Refer to the PR description for the code snippet.
I'll add this in the follow-up PR
(https://github.com/astral-sh/ruff/pull/11302) which uses this method.
## Summary
If the user is analyzing a script (i.e., we have no module path), it
seems reasonable to use the script name when trying to identify paths to
objects defined _within_ the script.
Closes https://github.com/astral-sh/ruff/issues/10960.
## Test Plan
Ran:
```shell
check --isolated --select=B008 \
--config 'lint.flake8-bugbear.extend-immutable-calls=["test.A"]' \
test.py
```
On:
```python
class A: pass
def f(a=A()):
pass
```
## Summary
Fixes#3011.
Type checkers currently allow forward references in all contexts in stub
files, and stubs frequently make use of this capability (although it
doesn't actually seem to be specc'd anywhere --neither in PEP 484, nor
https://typing.readthedocs.io/en/latest/source/stubs.html#id6, nor the
CPython typing docs). Implementing it so that Ruff allows forward
references in _all contexts_ in stub files seems non-trivial, however
(or at least, I couldn't figure out how to do it easily), so this PR
does not do that. Perhaps it _should_; if we think this apporach isn't
principled enough, I'm happy to close it and postpone changing anything
here.
However, this does reduce the number of F821 errors Ruff emits on
typeshed down from 76 to 2, which would mean that we could enable the
rule at typeshed. The remaining 2 F821 errors can be trivially fixed at
typeshed by moving definitions around; forward references in class bases
were really the only remaining places where there was a real _use case_
for forward references in stub files that Ruff wasn't yet allowing.
## Test plan
`cargo test`. I also ran this PR branch on typeshed to check to see if
there were any new false positives caused by the changes here; there
were none.
## Summary
This PR adds a new semantic model flag to indicate that the checker is
inside an f-string replacement field. This will be used to ignore
certain checks if the target version doesn't support a specific feature
like PEP 701.
fixes: #10761
## Test Plan
Add a test case from the raised issue.
## Summary
In https://github.com/astral-sh/ruff/pull/10341, we fixed some false
positives in `.pyi` files, but introduced others. This PR effectively
reverts the change in #10341 and fixes it in a slightly different way.
Instead of changing the _bindings_ we generate in the semantic model in
`.pyi` files, we instead change how we _resolve_ them.
Closes https://github.com/astral-sh/ruff/issues/10509.
