To enable ruff_dev to automatically generate the rule Markdown tables in
the README the ruff library contained the following function:
Linter::codes() -> Vec<RuleSelector>
which was slightly changed to `fn prefixes(&self) -> Prefixes` in
9dc66b5a65 to enable ruff_dev to split
up the Markdown tables for linters that have multiple prefixes
(pycodestyle has E & W, Pylint has PLC, PLE, PLR & PLW).
The definition of this method was however largely redundant with the
#[prefix] macro attributes in the Linter enum, which are used to
derive the Linter::parse_code function, used by the --explain command.
This commit removes the redundant Linter::prefixes by introducing a
same-named method with a different signature to the RuleNamespace trait:
fn prefixes(&self) -> &'static [&'static str];
As well as implementing IntoIterator<Rule> for &Linter. We extend the
extisting RuleNamespace proc macro to automatically derive both
implementations from the Linter enum definition.
To support the previously mentioned Markdown table splitting we
introduce a very simple hand-written method to the Linter impl:
fn categories(&self) -> Option<&'static [LinterCategory]>;
ParseCode was a fitting name since the trait only contained a single
parse_code method ... since we now however want to introduce an
additional `prefixes` method RuleNamespace is more fitting.
543865c96b introduced
RuleCode::origin() -> RuleOrigin generation via a macro, while that
signature now has been renamed to Rule::origin() -> Linter we actually
want to get rid of it since rules and linters shouldn't be this tightly
coupled (since one rule can exist in multiple linters).
Another disadvantage of the previous approach was that the prefixes
had to be defined in ruff_macros/src/prefixes.rs, which was easy to
miss when defining new linters in src/*, case in point
INP001 => violations::ImplicitNamespacePackage has in the meantime been
added without ruff_macros/src/prefixes.rs being updated accordingly
which resulted in `ruff --explain INP001` mistakenly reporting that the
rule belongs to isort (since INP001 starts with the isort prefix "I").
The derive proc macro introduced in this commit requires every variant
to have at least one #[prefix = "..."], eliminating such mistakes.
More accurate since the enum also encompasses:
* ALL (which isn't a prefix at all)
* fully-qualified rule codes (which aren't prefixes unless you say
they're a prefix to the empty string but that's not intuitive)
"origin" was accurate since ruff rules are currently always modeled
after one origin (except the Ruff-specific rules).
Since we however want to introduce a many-to-many mapping between codes
and rules, the term "origin" no longer makes much sense. Rules usually
don't have multiple origins but one linter implements a rule first and
then others implement it later (often inspired from another linter).
But we don't actually care much about where a rule originates from when
mapping multiple rule codes to one rule implementation, so renaming
RuleOrigin to Linter is less confusing with the many-to-many system.
Previous output for `ruff --explain E711`:
E711 (pycodestyle): Comparison to `None` should be `cond is None`
New output:
none-comparison
Code: E711 (pycodestyle)
Autofix is always available.
Message formats:
* Comparison to `None` should be `cond is None`
* Comparison to `None` should be `cond is not None`
This commit fixes a bug accidentally introduced in
6cf770a692,
which resulted every `ruff --explain <code>` invocation to fail with:
thread 'main' panicked at 'Mismatch between definition and access of `explain`.
Could not downcast to ruff::registry::Rule, need to downcast to &ruff::registry::Rule',
ruff_cli/src/cli.rs:184:18
We also add an integration test for --explain to prevent such bugs from
going by unnoticed in the future.
The idea is nice and simple we replace:
fn placeholder() -> Self;
with
fn message_formats() -> &'static [&'static str];
So e.g. if a Violation implementation defines:
fn message(&self) -> String {
format!("Local variable `{name}` is assigned to but never used")
}
it would also have to define:
fn message_formats() -> &'static [&'static str] {
&["Local variable `{name}` is assigned to but never used"]
}
Since we however obviously do not want to duplicate all of our format
strings we simply introduce a new procedural macro attribute
#[derive_message_formats] that can be added to the message method
declaration in order to automatically derive the message_formats
implementation.
This commit implements the macro. The following and final commit
updates violations.rs to use the macro. (The changes have been separated
because the next commit is autogenerated via a Python script.)
While ruff displays the string returned by Violation::message in its
output for detected violations the messages displayed in the README
and in the `--explain <code>` output previously used the
DiagnosticKind::summary() function which for some verbose messages
provided shorter descriptions.
This commit removes DiagnosticKind::summary, and moves the more
extensive documentation into doc comments ... these are not displayed
yet to the user but doing that is very much planned.
Fixes: #1953
@charliermarsh thank you for the tips in the issue.
I'm not very familiar with Rust, so please excuse if my string formatting syntax is messy.
In terms of testing, I compared output of `flake8 --format=pylint ` and `cargo run --format=pylint` on the same code and the output syntax seems to check out.
# This commit was automatically generated by running the following
# script (followed by `cargo +nightly fmt`):
import glob
import re
from typing import NamedTuple
class Rule(NamedTuple):
code: str
name: str
path: str
def rules() -> list[Rule]:
"""Returns all the rules defined in `src/registry.rs`."""
file = open('src/registry.rs')
rules = []
while next(file) != 'ruff_macros::define_rule_mapping!(\n':
continue
while (line := next(file)) != ');\n':
line = line.strip().rstrip(',')
if line.startswith('//'):
continue
code, path = line.split(' => ')
name = path.rsplit('::')[-1]
rules.append(Rule(code, name, path))
return rules
code2name = {r.code: r.name for r in rules()}
for pattern in ('src/**/*.rs', 'ruff_cli/**/*.rs', 'ruff_dev/**/*.rs', 'scripts/add_*.py'):
for name in glob.glob(pattern, recursive=True):
with open(name) as f:
text = f.read()
text = re.sub('Rule(?:Code)?::([A-Z]\w+)', lambda m: 'Rule::' + code2name[m.group(1)], text)
text = re.sub(r'(?<!"<FilePattern>:<)RuleCode\b', 'Rule', text)
text = re.sub('(use crate::registry::{.*, Rule), Rule(.*)', r'\1\2', text) # fix duplicate import
with open(name, 'w') as f:
f.write(text)
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)
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).
This makes it easier to see which rules you're enabling when selecting
one of the pylint codes (like `PLC`). This also makes it clearer what
those abbreviations stand for. When I first saw the pylint section, I
was very confused by that, so other might be as well.
See it rendered here:
https://github.com/thomkeh/ruff/blob/patch-1/README.md#pylint-plc-ple-plr-plw
Charlie Marsh
Martin Fischer
Damien Allen
messense
Thomas MK