If a `try` block has multiple statements, a compound statement, or
control flow, rewriting it with `contextlib.suppress` would obfuscate
the fact that the exception still short-circuits further statements in
the block.
Fixes#1947.
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Since our binding tracking is somewhat limited, I opted to favor false negatives over false positives. So, e.g., this won't trigger SIM115:
```py
with contextlib.ExitStack():
f = exit_stack.enter_context(open("filename"))
```
(Notice that `exit_stack` is unbound.)
The alternative strategy required us to incorrectly trigger SIM115 on this:
```py
with contextlib.ExitStack() as exit_stack:
exit_stack_ = exit_stack
f = exit_stack_.enter_context(open("filename"))
```
Closes#1945.
The Settings struct previously contained the fields:
pub enabled: HashableHashSet<RuleCode>,
pub fixable: HashableHashSet<RuleCode>,
This commit merges both fields into one by introducing a new
RuleTable type, wrapping HashableHashMap<RuleCode, bool>,
which has the following benefits:
1. It makes the invalid state that a rule is
disabled but fixable unrepresentable.
2. It encapsulates the implementation details of the table.
(It currently uses an FxHashMap but that may change.)
3. It results in more readable code.
settings.rules.enabled(rule)
settings.rules.should_fix(rule)
is more readable than:
settings.enabled.contains(rule)
settings.fixable.contains(rule)
I accept any suggestion. By the way, I have a doubt, I have checked and all flake8-pie plugins can be fixed by ruff, but is it necessary that this one is also fixed automatically ?
rel #1543
The idea is to follow the Rust naming convention for lints[1]:
> the lint name should make sense when read as
> "allow lint-name" or "allow lint-name items"
Following that convention prefixing "Banned" is
redundant as it could be prefixed to any lint name.
[1]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
The caching mechanism of the CLI (ruff_cli::cache) relies on
ruff::settings::Settings implementing the Hash trait.
The ruff::settings::Settings struct previously couldn't automatically
derive the Hash implementation via the #[derive(Hash)] macro attribute
since some of its field types intentionally[1][2] don't implement Hash
(namely regex::Regex, globset::GlobMatcher and globset::GlobSet and
HashMap and HashSet from the standard library).
The code therefore previously implemented the Hash trait by hand for the
whole struct. Implementing Hash by hand for structs that are subject to
change is a bad idea since it's very easy to forget to update the Hash
implementation when adding a new field to the struct. And the Hash
implementation indeed was already incorrect by omitting several fields
from the hash.
This commit introduces wrapper types for Regex, GlobMatcher, GlobSet,
HashSet & HashMap that implement Hash so that we can still add
#[derive(Hash)] to the Settings struct, guaranteeing a correct hash
implementation.
[1]: https://github.com/rust-lang/regex/issues/364#issuecomment-301082076
[2]: The standard library doesn't impl<T: Hash + Ord> Hash for HashSet<T>
presumably since sorted() requires an allocation and Hash
implementations are generally expected to work without allocations.
We want to automatically derive Hash for the library settings, which
requires us to split off all the settings unused by the library
(since these shouldn't affect the hash used by ruff_cli::cache).
