## Summary
Add a rule for defaultdict(default_factory=callable). Instead suggest
using defaultdict(callable).
See: https://github.com/astral-sh/ruff/issues/9509
If a user tries to bind a "non-callable" to default_factory, the rule
ignores it. Another option would be to warn that it's probably not what
you want. Because Python allows the following:
```python
from collections import defaultdict
defaultdict(default_factory=1)
```
this raises after you actually try to use it:
```python
dd = defaultdict(default_factory=1)
dd[1]
```
=>
```bash
KeyError: 1
```
Instead using callable directly in the constructor it will raise (not
being a callable):
```python
from collections import defaultdict
defaultdict(1)
```
=>
```bash
TypeError: first argument must be callable or None
```
## Test Plan
```bash
cargo test
```
## Summary
Checks for unnecessary `dict` comprehension when creating a new
dictionary from iterable. Suggest to replace with
`dict.fromkeys(iterable)`
See: https://github.com/astral-sh/ruff/issues/9592
## Test Plan
```bash
cargo test
```
## Summary
This PR introduces a new rule to sort `__slots__` and `__match_args__`
according to a [natural sort](https://en.wikipedia.org/wiki/Natural_sort_order), as was
requested in https://github.com/astral-sh/ruff/issues/1198#issuecomment-1881418365.
The implementation here generalises some of the machinery introduced in
3aae16f1bd
so that different kinds of sorts can be applied to lists of string
literals. (We use an "isort-style" sort for `__all__`, but that isn't
really appropriate for `__slots__` and `__match_args__`, where nearly
all items will be snake_case.) Several sections of code have been moved
from `sort_dunder_all.rs` to a new module, `sorting_helpers.rs`, which
`sort_dunder_all.rs` and `sort_dunder_slots.rs` both make use of.
`__match_args__` is very similar to `__all__`, in that it can only be a
tuple or a list. `__slots__` differs from the other two, however, in
that it can be any iterable of strings. If slots is a dictionary, the
values are used by the builtin `help()` function as per-attribute
docstrings that show up in the output of `help()`. (There's no
particular use-case for making `__slots__` a set, but it's perfectly
legal at runtime, so there's no reason for us not to handle it in this
rule.)
Note that we don't do an autofix for multiline `__slots__` if `__slots__` is a dictionary: that's out of scope. Everything else, we can nearly always fix, however.
## Test Plan
`cargo test` / `cargo insta review`.
I also ran this rule on CPython, and the diff looked pretty good
---
Co-authored-by: Micha Reiser <micha@reiser.io>
## Summary
Implement rule `mutable-fromkeys-value` (`RUF023`).
Autofixes
```python
dict.fromkeys(foo, [])
```
to
```python
{key: [] for key in foo}
```
The fix is marked as unsafe as it changes runtime behaviour. It also
uses `key` as the comprehension variable, which may not always be
desired.
Closes#4613.
## Test Plan
`cargo test`
## Summary
#5920 with a fix for the erroneous slice in `module_name`. Fixes#9547.
## Test Plan
Added `import bbb.ccc._ddd as eee` to the test fixture to ensure it no
longer panics.
`cargo test`
## Summary
This implements the rule proposed in #1198 (though it doesn't close the
issue, as there are some open questions about configuration that might
merit some further discussion).
## Test Plan
`cargo test` / `cargo insta review`. I also ran this PR branch on the CPython
codebase with `--fix --select=RUF022 --preview `, and the results looked
pretty good to me.
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
Co-authored-by: Andrew Gallant <andrew@astral.sh>
Implements SIM113 from #998
Added tests
Limitations
- No fix yet
- Only flag cases where index variable immediately precede `for` loop
@charliermarsh please review and let me know any improvements
---------
Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>
## Summary
We haven't found time to flip this on, so feels like it's best to remove
it for now -- can always restore from source when we get back to it.
## Summary
Closes#9319, implements the [`SIM911` rule from
`flake8-simplify`](https://github.com/MartinThoma/flake8-simplify/pull/183).
#### Note
I wasn't sure whether or not to include
```rs
if checker.settings.preview.is_disabled() {
return;
}
```
at the beginning of the function with violation logic if the rule's
already declared as part of `RuleGroup::Preview`.
I've seen both variants, so I'd appreciate some feedback on that :)
Fixes#8721
## Summary
This implements the rule proposed in #8721, as RUF021. `and` always
binds more tightly than `or` when chaining the two together.
(This should definitely be autofixable, but I'm leaving that to a
followup PR for now.)
## Test Plan
`cargo test` / `cargo insta review`
## Summary
This PR implements Y058 from flake8-pyi -- this is a new flake8-pyi rule
that was released as part of `flake8-pyi 23.11.0`. I've followed the
Python implementation as closely as possible (see
858c0918a8),
except that for the Ruff version, the rule also applies to `.py` files
as well as for `.pyi` files. (For `.py` files, we only emit the
diagnostic in very specific situations, however, as there's a much
higher likelihood of emitting false positives when applying this rule to
a `.py` file.)
## Test Plan
`cargo test`/`cargo insta review`
## Summary
Part of #970.
This adds Pylint's [R0244
empty_comment](https://pylint.pycqa.org/en/latest/user_guide/messages/refactor/empty-comment.html)
lint as well as an always-safe fix.
## Test Plan
The included snapshot verifies the following:
- A line containing only a non-empty comment is not changed
- A line containing leading whitespace before a non-empty comment is not
changed
- A line containing only an empty comment has its content deleted
- A line containing only leading whitespace before an empty comment has
its content deleted
- A line containing only leading and trailing whitespace on an empty
comment has its content deleted
- A line containing trailing whitespace after a non-empty comment is not
changed
- A line containing only a single newline character (i.e. a blank line)
is not changed
- A line containing code followed by a non-empty comment is not changed
- A line containing code followed by an empty comment has its content
deleted after the last non-whitespace character
- Lines containing code and no comments are not changed
- Empty comment lines within block comments are ignored
- Empty comments within triple-quoted sections are ignored
## Comparison to Pylint
Running Ruff and Pylint 3.0.3 with Python 3.12.0 against the
`empty_comment.py` file added in this PR, we see the following:
* Identical behavior:
* empty_comment.py:3:0: R2044: Line with empty comment (empty-comment)
* empty_comment.py:4:0: R2044: Line with empty comment (empty-comment)
* empty_comment.py:5:0: R2044: Line with empty comment (empty-comment)
* empty_comment.py:18:0: R2044: Line with empty comment (empty-comment)
* Differing behavior:
* Pylint doesn't ignore empty comments in block comments commonly used
for visual spacing; I decided these were fine in this implementation
since many projects use these and likely do not want them removed.
* empty_comment.py:28:0: R2044: Line with empty comment (empty-comment)
* Pylint detects "empty comments" within the triple-quoted section at
the bottom of the file, which is arguably a bug in the Pylint
implementation since these are not truly comments. These are ignored by
this implementation.
* empty_comment.py:37:0: R2044: Line with empty comment (empty-comment)
* empty_comment.py:38:0: R2044: Line with empty comment (empty-comment)
* empty_comment.py:39:0: R2044: Line with empty comment (empty-comment)
## Summary
Adds a rule to detect unions that include `typing.NoReturn` or
`typing.Never`. In such cases, the use of the bottom type is redundant.
Closes https://github.com/astral-sh/ruff/issues/9113.
## Test Plan
`cargo test`
## Summary
A common mistake is to add quotes around one member in an `X | Y`-style
type union, as in:
```python
contract_versions_list: list[ContractVersion] | 'QuerySet[ContractVersion]' | None = None
```
However, doing so will lead to a runtime error if the annotation is
runtime-evaluated. This PR lints against such patterns.
Closes https://github.com/astral-sh/ruff/issues/9139.
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## Summary
Adds the Pylint rule E1132 to check for repeated keyword arguments in a
function call.
## Test Plan
Tested via the included unit tests and manual spot checking.
## Summary
Implements
[FURB136](https://github.com/dosisod/refurb/blob/master/docs/checks.md#furb136-use-min-max)
that checks for `if` expressions that can be replaced with `min()` or
`max()` calls. See issue #1348 for more information.
This implementation diverges from Refurb's original implementation by
retaining the order of equal values. For example, Refurb suggest that
the following expressions:
```python
highest_score1 = score1 if score1 > score2 else score2
highest_score2 = score1 if score1 >= score2 else score2
```
should be to rewritten as:
```python
highest_score1 = max(score1, score2)
highest_score2 = max(score1, score2)
```
whereas this implementation provides more correct alternatives:
```python
highest_score1 = max(score2, score1)
highest_score2 = max(score1, score2)
```
## Test Plan
Unit test checks all eight possibilities.
When using the autofixer for `Q000` it does not remove the backslashes
from quotes that no longer need escaping.
This new rule checks for such backslashes (regardless whether they come
from the autofixer or not) and can remove them.
fixes#8617
## Summary
This PR extends `unnecessary-pass` (`PIE790`) to flag unnecessary
ellipsis expressions in addition to `pass` statements. A `pass` is
equivalent to a standalone `...`, so it feels correct to me that a
single rule should cover both cases.
When we look to v0.2.0, we should also consider deprecating `PYI013`,
which flags ellipses only for classes.
Closes https://github.com/astral-sh/ruff/issues/8602.
## Summary
PIE807 will rewrite `lambda: []` to `list` -- AFAICT though, the same
rationale also applies to dicts, so I've modified the code to also
rewrite `lambda: {}` to `dict`.
Two things I'm not sure about:
* Should this go to a new rule? This no longer actually matches the
behavior of flake8-pie, and while I think thematically it makes sense to
be part of the same rule, we could make it a standalone rule (but if so,
where should I put it and what error code should I use)?
* If we want a single rule, are there backwards compatibility concerns
with the rule name change (from `reimplemented_list_builtin` to
`reimplemented_container_builtin`?
## Test Plan
Added snapshot tests of the functionality.
## Summary
Implement
[`no-is-type-none`](https://github.com/dosisod/refurb/blob/master/refurb/checks/builtin/no_is_type_none.py)
as `type-none-comparison` (`FURB169`).
Auto-fixes comparisons that use `type` to compare the type of an object
to `type(None)` to a `None` identity check. For example,
```python
type(foo) is type(None)
```
becomes
```python
foo is None
```
Related to #1348.
## Test Plan
`cargo test`
## Summary
Adds `TRIO105` from the [flake8-trio
plugin](https://github.com/Zac-HD/flake8-trio). The `MethodName` logic
mirrors that of `TRIO100` to stay consistent within the plugin.
It is at 95% parity with the exception of upstream also checking for a
slightly more complex scenario where a call to `start()` on a
`trio.Nursery` context should also be immediately awaited. Upstream
plugin appears to just check for anything named `nursery` judging from
[the relevant issue](https://github.com/Zac-HD/flake8-trio/issues/56).
Unsure if we want to do so something similar or, alternatively, if there
is some capability in ruff to check for calls made on this context some
other way
## Test Plan
Added a new fixture, based on [the one from upstream
plugin](https://github.com/Zac-HD/flake8-trio/blob/main/tests/eval_files/trio105.py)
## Issue link
Refers: https://github.com/astral-sh/ruff/issues/8451
